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HEALTH CONSULTATION

Review of Dust Sampling Data for 45th Street Artists' Cooperative

SHERWIN WILLIAMS
EMERYVILLE, ALAMEDA COUNTY, CALIFORNIA


SUMMARY

The 45th Street Artists' Cooperative (Coop) is an artist-owned and managed cooperative located inEmeryville, California. It is across the street from a Sherwin-Williams coatings manufacturingfacility. In the spring of 1997, high levels of lead and arsenic contamination were found in flowerbeds adjacent to the Coop. This lead to an emergency cleanup of the flower beds during the summerof 1997. During the cleanup process, one Coop resident took samples of house dust from her unitand had them tested for lead and arsenic at a local laboratory, and asked the California Departmentof Health Services (CDHS) Environmental Health Investigations Branch (EHIB) to assist ininterpreting the results. The results showed very high levels of lead and arsenic. This raised a largerquestion of whether other units within the Coop might also have elevated levels of lead and arsenic.CDHS staff met with Coop residents to determine their level in interest in the Dust SamplingProject. As explained to the residents, the purpose of the Dust Sampling Project would be to (1)measure the levels of lead and arsenic in dust in certain Coop units, (2) to determine if those levelspose a threat to the health of the unit's occupants, (3) and to evaluate the results from these firstunits sampled to determine whether other units might also have elevated levels of lead and arsenic. As was also explained to the residents, the testing could not be used to identify a specific source ofcontamination. The residents indicated that they were interested in pursuing this project. CDHSstaff selected Health Science Associates (HSA) to conduct the sampling and analysis, and to providethe data to CDHS for its evaluation of potential adverse health effects.

Between October 1998 and October 1999, HSA personnel collected samples of house dust from 12units of the 45th Street Artists' Cooperative, and from the Common Areas of the Coop (office,community room, bathrooms, and hallways). HSA personnel also conducted a lead-based paintsurvey in these units. The lead-based paint survey consisted of an X-ray fluorescence (XRF)screening using a portable XRF unit, and analysis of paint chips to confirm the presence of lead-based paint. The dust samples were analyzed for lead and arsenic by HSA's laboratory, and theresults provided to CDHS. The Sherwin-Williams Company paid for the sampling and analysis, butdid not have any contact with the samples. Sherwin-Williams has received copies of the results, butwith all personal identifiers removed. CDHS evaluated the data to estimate the potential for adversehealth effects due to exposure to lead and arsenic in the dust. The overall results of the Dust Sampling Project are summarized as follows:

  1. No estimated blood lead levels greater than 10 micrograms per deciliter (µg/dL) are expected to occur in the current residents of any of the tested units.


  2. The estimated blood lead level for infants, toddlers, and young children might exceed 10 µg/dL in some of the tested units, but no children of those ages (up to 12 years old) live in those units at this time.


  3. Some of the units tested had wipe samples that showed very high levels of lead.


  4. Exposure to arsenic in the house dust in the tested units would not be expected to cause non-cancer adverse health effects in any of the current residents of the tested units.


  5. The screening values for infants, toddlers, and young children were exceeded in some of the tested units, but no children of those ages (up to 12 years old) live in those units.


  6. The increased lifetime cancer risk due to a lifetime exposure to arsenic in the house dust in the tested units is generally comparable to or only slightly higher than the increased lifetime cancer risk due to exposure to background levels of arsenic in the San Francisco Bay Area. This is a very low increased lifetime cancer risk (up to 9 x 10-5).


  7. There is a low increased lifetime cancer risk (just above 1 x 10-4) due to a lifetime exposure to arsenic in house dust in a few of the tested units.


  8. Evaluation of arsenic and lead concentrations in the microvacuum (microvac) samples


    1. The concentration of arsenic in the microvac samples lies, with two exceptions, within the range of non-detect to 150 milligrams per kilogram (mg/kg). These include interior units with no windows or outside access, and units that have windows on the outside of the building. Of the two exceptions, the concentration of arsenic was 320 mg/kg in one unit, and the concentration of arsenic was 950 mg/kg in the second unit. Both of these units are units that face the outside of the building. Based on the data that we evaluated, the concentration of arsenic seems to be relatively constant throughout the 45th Street Building of the Coop.


    2. The concentration of lead in the microvac samples ranges from approximately non-detect to 6,400 mg/kg. Five of the 15 locations tested (12 units, hallways, bathrooms, offices/community room) had levels of lead that exceeded 1,800 mg/kg. In general, the units with the highest levels of lead are all units that have windows on the outside of the building. The units with the lower levels of lead are mostly interior units with no windows or other outside access.


  9. The results of biological testing, conducted in 1997, showed no elevated levels of lead or arsenic. This biological testing is not discussed in detail in this document. However, the results of the 1997 biological monitoring are consistent with the conclusions of this document that current occupants of the 45th Street Artists' Cooperative are not likely to be exposed to levels of arsenic or lead that would cause adverse health effects.

BACKGROUND AND STATEMENT OF ISSUES

CDHS-EHIB has prepared this Health Consultation (HC) under a cooperative agreement with theAgency for Toxic Substances and Disease Registry (ATSDR). ATSDR, located in Atlanta, Georgia,is a federal agency within the United States Department of Health and Human Services. ATSDR isauthorized under the Comprehensive Environmental Response, Compensations, and Liability Act(CERCLA) of 1980 to conduct health assessments at hazardous waste sites on the NationalPriorities List (NPL).

The objectives of this HC are: to measure the levels of lead and arsenic in the house dust of selectedunits in the 45th Street Artists' Cooperative (Coop); determine if those levels of lead and arsenic posea threat to the health of current or future occupants of those units; and to try and assess whetherother units might have levels of lead and arsenic that are of health concern.

Site Description and History

The 45th Street Artists' Cooperative (Coop) is located at 1420 45th Street, Emeryville, AlamedaCounty, California (Figure 1). It is at the northeast corner of the 45th Street and Horton Street. It isbounded on the north by property owned by the Chiron Corporation, on the east by a Pacific Gasand Electric Corporation facility, on the south by 45th Street, and on the west by Horton Street(Figure 2). The Coop was founded in 1987 as an artist-owned and managed live/work space. Thebuilding is a former Shell Oil chemical research facility. The Horton Street Lofts are anotherlive/work project and are located across 45th Street to the south of the Coop. Adjacent to the HortonStreet Lofts and also facing Horton Street is the 45th Street Artists' Cooperative Annex. The Coophas a total of 56 units, with 32 units, the office, community/laundry room, and a common gardenarea at the 45th Street building, and 24 studios at the Coop Annex.

Directly across Horton Street to the west of the Coop is a Sherwin-Williams coatings manufacturingfacility. This facility has been in operation since the early 1900's, and during the 1920's to the1940's, it also produced lead-arsenate pesticides. In 1987, the plant was converted frommanufacturing oil-based products to water-based products. During this conversion, contaminationwas discovered on the Sherwin-Williams property. Both soil and groundwater were contaminated,and the contaminants included volatile organic compounds, semi-volatile organic compounds,petroleum products, and metals, primarily lead and arsenic. Lead and arsenic contamination wasalso discovered on other nearby properties, including flower beds adjacent to the Coop along HortonStreet in March 1997.

The discovery of the contamination in the flower beds prompted several actions. First, theEmeryville City Council requested biological testing for interested Coop residents. Approximately25 individuals took advantage of this testing, which was paid for by Sherwin-Williams. CDHSreviewed the results of this biological testing, and found no elevated levels of lead or arsenic.

Second, the contaminated soils in the flower beds were removed and replaced with clean soil. Thisoccurred between June 1997 and September 1997. A public health assessment documenting thepotential adverse health effects due to exposure to contamination in the flower beds was written in1999 (1). The cleanup process was very difficult for the Coop residents. The process lasted forseveral months, generated a great deal of dust, noise, and vehicular traffic, and made it difficult tofor residents to access their units or pursue their work.

While the residents complained about dust generated during the cleanup, the cleanup was carried out according to an approved air monitoring plan, and the levels of ambient arsenic were below action levels (7,8). During the cleanup, one resident collected dust samples from her unit and took them to a local laboratory to be analyzed for lead and arsenic. She sent the results to CDHS in April 1998, and asked for our assistance in interpreting the results. The results showed very high levels of lead and arsenic in the dust.

Finding high levels of lead and arsenic in the house dust in this unit lead to a larger question ofwhether other units in the Coop had similarly elevated levels of lead and arsenic contamination indust. CDHS staff met with Coop residents to ascertain their interest in pursuing this question, andwhether they would be supportive of a dust sampling project. Residents were in favor of such aproject. Afterwards, CDHS staff met with representatives of two different consulting firms in theOakland/Emeryville area to discuss the costs involved for them to collect and analyze dust samplesfor lead and arsenic. CDHS chose Health Science Associates (HSA), of Emeryville, to conduct thedust sampling and to analyze the samples for lead and arsenic. Because lead-based paint is acommon source of lead contamination in older building, CDHS and HSA decided that HSA staffwould also conduct a lead-based paint survey in the units to be tested. This lead-based paint surveywould consist of an X-ray fluorescence (XRF) screening, with analysis of paint chip samples toconfirm the presence of lead-based paint identified by XRF screening. CDHS staff would receive allof the data from HSA and evaluate potential adverse health effects due to exposure to both lead andarsenic in the house dust in these units. Sherwin-Williams agreed to pay for the sample collectionand analysis. HSA personnel collected samples from a total of 12 units and the common areasbetween October 1998 and October 1999.

Site Visit

CDHS staff accompanied HSA personnel during a pre-sampling visit to the Coop and duringsampling activities at four Coop units, and observed them as the conducted sampling activities. HSA personnel were careful in following the sampling plan prepared for the Dust Sampling Project,and in following proper sample collection procedures.

Demographics

In 1999, when the public health assessment on the contamination in the flower beds was written, 42adults lived in the 45th Street building, with 34 using their units as live/work space, and eight adultsusing their units as work-only space. Three children and one teenager also lived in the 45th Streetbuilding.

Health Outcome Data

As was discussed above, approximately 25 Coop residents took advantage of the biological testing. No abnormal levels of lead or arsenic were seen in the data. The data that CDHS reviewed had nopersonal identifiers, so we were unable to determine if there was any overlap between the residentswhose units were tested and the residents who took advantage of the biological testing. Excludingthe nuisance factor of the dust generated during the cleanup of the flower beds, CDHS is not awareof any specific health complaints that have been attributed exposure to lead or arsenic.

Community Health Concerns

In the Public Health Assessment of June 1999 for the 45th Street Artists' Cooperative, severalcommunity concerns were raised (1). Chief among their concerns were potential adverse healtheffects due to the dust that was generated during the cleanup of the flower beds during the Summerof 1997, and a lack of communication concerning remediation activities at the Sherwin-Williamssite. Through the Consultative Work Group, a committee comprising representatives of groupsconcerned with the remediation activities at the site, including representatives of the Coop,communication concerns have been largely addressed.

However, Coop residents still had concerns over the dust generated during the cleanup of the flowerbeds. Therefore, as was discussed above in the Site Description and History section, CDHSpersonnel met with Coop residents to discuss their interest in testing house dust in their units for leadand arsenic. CDHS emphasized that such testing would be used only to determine the potential foradverse health effects, not to identify the source or sources of any contamination that might befound. Several Coop residents stated that they were interested in having their units tested.

Environmental Contamination

Twelve units, numbers 16, 17, 19, 22, 24, 25e, 29, 31, 33, 35, 47, and 49, and the common areas(hallways, office, community/laundry room, bathrooms) of the coop were sampled. The units thatwere sampled are shown on the floor plan of the 45th Street building (Figure 3). However, due to thesensitive nature of the results of the dust sampling, when we discuss the results of sampling, we willidentify individual units by a randomly assigned letter (A-L). One of the questions being consideredin the sampling was whether there was a pattern in the contamination that might give an indicationas to whether other units might have elevated levels of lead and arsenic in house dust. Again,however, to avoid identifying specific units, we will refer to the locations of units in general termssuch as whether a unit faces a street or whether it is in the interior of the building.

Three general areas within an individual unit were sampled. These were the floors, window sills, and "other" areas. The surface loading of the floors represents contamination not only the floors but other large, horizontal surface areas as well. The surface loading for window sills is specific to window sills only. The surface loading for "Other" areas represents the loading in remote and seldom accessed areas of a unit. These areas tend to have a greater accumulation of dust and thus represent a "historical" accumulation of dust, and of lead and arsenic contamination. Residents are not typically exposed to the dust in these areas. "Other" areas include such locations as the tops of rafters and I-beams, the tops of high shelves, and floor areas in the backs of closets, or other hard-to-access locations.

Types of Testing

Four types of sampling were conducted as a part of the project. These were (1) dust wipe sampling,(2) microvac sampling, (3) x-ray fluorescence testing, and (4) paint chip testing. The dust wipesampling and the microvac sampling are used to evaluate the potential adverse health effects due toexposure to lead and arsenic in dust. The XRF testing and the paint chip testing were used doidentify lead-based paint, which is one possible source of lead contamination in a unit.

A brief description of the types of tests and the reason for using each type of testing are describedbelow. Details regarding the sampling protocols may be found in the Sampling Plan for the Project(2).

Dust Wipe Testing

Dust wipe samples were collected as follows: the person collecting the sample marked a known areaon the surface being sampled with masking tape. He/she then put on latex gloves, and used anindividually sealed cloth pad, pre-moistened with alcohol, to wipe up as much of the dust as possiblefrom the marked area. The pad was then placed in a sealed container and marked with a samplenumber, and sent to the laboratory for analysis. The results of the dust wipe samples were reportedas micrograms of contaminant (lead or arsenic) per square foot of surface (µg/ft2, also called surfaceloading). All wipe samples were collected as individual samples. The results of the dust wipesampling gives an indication of the distribution of contamination in that unit.

Microvacuum (Microvac) Testing

Microvac samples were collected as follows: the person collecting the sample marked a known areaon the surface being sampled with masking tape. This area is the same size as for the dust wipesample and immediately adjacent to the dust sample location. A small pump was used to vacuumthe dust from the marked area, with all particulates being trapped on a pre-weighed filter. However,the filter was not changed between vacuumed locations within the same unit. The dust from alllocations in the unit was collected as a composite sample on one filter. When all areas had beenvacuumed, the filter was put in a sealed container, marked with a sample number, and sent to thelaboratory for analysis. The results of the microvac sampling were reported as a concentration oflead or arsenic in the dust (milligrams of contaminant per kilogram of dust, mg/kg, ppm), obtainedfrom the difference between the pre- and post-sampling weight of the filter, and the mass of lead orarsenic measured in the dust. Whereas the dust wipe samples give information on the distribution ofcontamination in a unit, the microvac sample gives an overall concentration of lead and arsenic inthe unit.

X-Ray Fluorescence (XRF) Testing

To conduct the XRF screening, the person conducting the test used a hand-held XRF device at anumber of locations throughout the unit. The portable XRF device measures the concentration oflead in a paint surface. The results were reported as milligrams of lead per square centimeter ofsurface (mg/cm2). Lead-based paint is defined as containing 1 mg/cm2 or more of lead, as measuredby XRF. Lead-containing paint is defined as paint containing between 0.1 and 0.9 mg/cm2, as measured by XRF. An XRF measurement of 0.0 mg/cm2 or less is considered to be leadnon-detect. This type of hand-held XRF instrument can only detect lead. It cannot be used tomeasure the concentration of arsenic.

When evaluating the potential for lead-based paint to generate lead-contaminated dust, one mustconsider the concentration of lead in the surface (see paragraph above), and the condition of thepaint surface. The condition of a paint surface is defined as either intact, fair, or poor. An intactsurface is one with no peeling or chipped paint. A large surface, such as a wall, is considered to bein fair condition if less than 2 square feet (ft2) has deteriorated. A small surface, such as a windowsill, is considered to be in fair condition if less than 10% of the surface has deteriorated. Surfacesare considered to be in poor condition if greater than 2 ft 2 (large surfaces) or greater than 10%(small surfaces) has deteriorated. A surface that is in either fair or poor condition is considered to bedeteriorated.

If a lead-based paint surface is intact, then it is not considered to be a lead hazard, because it doesnot generate lead-contaminated dust. However, such surfaces should be watched in the future toensure that they do not become deteriorated. A lead-based paint surface that has deteriorated is alead hazard. Lead-containing paint is not considered to be a lead hazard, even if deteriorated. However, it can still generate lead-contaminated dust, but not at as high a concentration as lead-based paint.

Paint Chip Testing

To confirm the presence of lead-based paint when detected by XRF, a paint chip was collected byHSA personnel and sent to the laboratory for analysis. The paint chip sample is considered to havecome from lead-based paint if the concentration of lead is 5,000 mg/kg or greater.

Quality Assurance/Quality Control Procedures

HSA used its in-house laboratory at its Los Alamitos, California branch, for the analyses of the dustwipe, microvac, and paint chip samples. This laboratory is fully accredited by the AmericanIndustrial Hygiene Association, the National Voluntary Laboratory Accreditation Program, and bythe Environmental Laboratory Accreditation Program of the California Department of HealthServices. The laboratory used inductively coupled plasma-atomic emission spectrometry to analyzethe dust wipe, microvac, and paint chip samples. All samples collected were sent to the HSAlaboratory in Los Alamitos by HSA staff using HSA chain-of-custody.

When conducting the XRF screening, HSA personnel used a portable, hand-held XRF device(Radiation Monitoring Device (RMD) model LPA-1). The device was calibrated before and afteruse, and was used only by HSA personnel who were either a CDHS Interim Certified Inspector/RiskAssessor, or a CDHS Certified Inspector/Risk Assessor, and who had completed the RMD LPA-1training class.

To provide a QA/QC check on the HSA laboratory, duplicate samples were collected in three units. The duplicate samples were sent to Forensic Analytical Laboratory in Hayward, California. HSApersonnel collected the duplicate samples, and sent them to Forensic Analytical under HSA chain-of-custody.

Details concerning these issues are found in the Sampling Plan (3).

Identification of Contaminants of Concern

Because of the nature of this project, there are only two contaminants of concern, lead and arsenic.

Pathways Analysis

For a receptor population to be exposed to environmental contamination, there must be a mechanismby which that contamination comes into direct contact with the target population. An exposurepathway is the description of this mechanism. An exposure pathway consists of five parts: a sourceof contamination, an environmental medium and transport mechanism, a point of exposure, a routeof exposure, and a receptor population.

Exposure pathways are classified as completed, potential, or eliminated. A completed exposurepathway is one in which all five elements of the pathway are present. A potential pathway is apathway in which one or more elements of the pathway are missing, but might be present later. Apathway may also be described as a potential pathway if information on one of the elements of thepathway is missing. An eliminated pathway is one in which one or more of the elements is missingand will not be complete in the future. For a population to be exposed to an environmentalcontaminant, a completed exposure pathway (all five elements) must be present. If any one or moreof these elements are missing, then there is no exposure, though the presence of contamination maystill be significant and require remediation. This is especially true if there is a possibility of anincomplete exposure pathway becoming complete in the future.

Because of the nature of this project, only one exposure pathway is evaluated, and it will beconsidered to be a completed pathway. That pathway is of the unit resident being exposed to leadand arsenic through incidental ingestion of contaminated house dust.

Toxicological Effects of Contaminants of Concern in Completed Exposure Pathway

In this section, background information and the toxicological effects of arsenic and lead arediscussed.

Lead (4)

Lead is an element that occurs naturally in the environment. It is found normally in the soils of theSan Francisco Bay Area at a concentration of about 15 mg/kg. However, concentrations of lead insoil near industrial sources of lead can reach much higher levels. Lead is commonly used in manytypes of industrial processes and products, though its use is restricted in certain products andapplications. Exposure to lead is most harmful to children six year old and younger. Exposure tolead can cause reduced growth rated, decreased IQ, and hearing loss in children. Adults can alsoexperience adverse health effects due to exposure to lead, including decreased reaction time,memory loss, joint weakness, and increased blood pressure. Very high exposures can cause brainand kidney damage in both children and adults. Lead is also considered to be a possible humancarcinogen. This is based on data from animal studies that show that lead can cause cancer inanimals, and data from human studies that are inconclusive as to whether lead causes cancer. Currently, there are no quantitative ways to evaluate the potential of lead to cause cancer in humans.

The potential for lead to cause non-cancer adverse health effects is measured by the level of lead inthe blood steam (blood lead level, BLL). Blood lead levels are measured as micrograms of lead perdeciliter of blood (µg/dL). According to Center for Disease Control and Prevention guidelines, aBLL of greater than 10 µg/dL is considered elevated for children. Adults exposed occupationally tolead are removed from the job if they have a blood lead level of 40 µg/dL

For the purpose of this study, we estimated BLLs in exposed individuals using a computer model. The model calculates a total BLL based on exposure to lead from five different routes: those routesare diet, drinking water, soil, air, and dermal. We modified this model to exclude dermal exposure(inorganic forms of lead have a very low dermal absorption rate) and to include household dust. This model is available from the Department of Toxic Substances Control - Human and EcologicalRisk Division World Wide Web site (3). Copies of the revised model are available from CDHSupon request.

Arsenic (5,6)

Arsenic is an element that occurs naturally in the environment. It is found normally in the soil of theSan Francisco Bay Area at a concentration of between 14 mg/kg and 22 mg/kg. However,concentrations of arsenic in soil near industrial sources of arsenic can reach much higher levels. Long term exposure to relatively low levels of arsenic can cause non-cancer adverse health effects inthe form of a darkening of the skin and wart-like growths on the skin. Arsenic is also known tocause skin cancer in humans.

The potential for arsenic to cause non-cancer adverse health effects is evaluated differently than lead. To evaluate arsenic, the concentration of arsenic to which a person of a particular age is exposed is compared to a screening concentration, or screening value, for that age. A screening value is the maximum concentration of arsenic to which a person of a particular age could be exposed without the expectation of adverse health effects occurring. Screening value are set using very conservative health protective assumptions regarding the amount of dust that a person of a particular age ingests in a day and the locations in a unit at which a person of a particular age might come into contact with contaminated dust. If the concentration of arsenic to which a person of a particular age is exposed is less than or equal to the screening value, then no non-cancer adverse health effects would be expected to occur. If the concentration of arsenic to which a person of a particular age is exposed exceeds the screening value, then adverse health effects do not automatically occur. Such a situation would be examined more thoroughly to determine whether adverse health effects might occur.

To evaluate the potential for arsenic to cause cancer, we calculated the increased lifetime cancer ratedue to exposure to arsenic in the house dust in units in the Coop. The increased lifetime cancer riskis the number of excess cases of cancers, over and above the background cancer rate. In the UnitedStates, the background cancer rate is between 25% and 33%, meaning that in a random populationof 1,000,000 people, between approximately 250,000 and 333,000 people will develop some formof cancer over an average 70 year lifetime. If one calculates an increased lifetime cancer risk of 1 in1,000,000 (1 x 10-6) due to exposure to a chemical, then in that same population of 1,000,000people, one would see 250,001 to 333,001 cases of cancer. For this project, to be most healthprotective, we calculated a 70 year increased lifetime cancer risk based on exposure to arsenic inhouse dust. Because the San Francisco Bay Area has a relatively high background level of arsenicthat occurs naturally in the soil (14 - 22 mg/kg), we also compared the increased lifetime cancerrisk due to exposure to arsenic in house dust with the increased lifetime cancer risk due to exposureto background levels of arsenic in the soils of the San Francisco Bar Area.

ATSDR Child's Health Initiative

ATSDR recognizes that infants and children may be more sensitive to exposures than adults incommunities with contamination in their water, soil, air, or food. This sensitivity is a result of anumber of factors. Children are more likely to be exposed to soil or surface water because they playoutdoors and often bring food into contaminated areas. For example, children may come intocontact with and ingest soil particles at higher rates than adults do; also, some children with abehavior trait known as "pica" are more likely to ingest soil and other non-food items. Children areshorter than adults, which means they can breathe dust, soil, and any vapors close to the ground. Also, they are smaller, resulting in higher doses of chemical per body weight. The developing bodysystems of children can sustain permanent damage if toxic exposures occur during critical growthstages. Because children depend completely on adults for risk identification and managementdecisions, ATSDR is committed to evaluating their special interest at applicable sites as a part of the ATSDR Child Health Initiative.


DISCUSSION

Summary and Toxicological Interpretation of Individual Dust Data

In this section, we will summarize the results and discuss the potential non-cancer and canceradverse health effects due to exposure to lead and arsenic in house dust in the individual units andthe common areas. For each unit, the locations with the highest levels of lead and arseniccontamination, identified by the dust wipe samples, are listed. Then, using the exposure parameterslisted in Table 1 and the process described in Appendix C - Sample Calculations, we calculate anage-specific "exposure concentration." This exposure concentration is a weighted concentration ofcontaminant (lead or arsenic) to which an individual is exposed that is based on the approximateconcentration of contaminant in dust on each component (floors, sills, other), the fraction from eachcomponent of the total amount of dust that a person of a particular age ingests, and the total amountof dust that a person of a particular age ingests. The lead exposure concentration is then used as theinput value for house dust in the blood lead computer model. The arsenic exposure concentration iscompared to the age-specific screening value.

Samples were collected from twelve units, as well as common areas including the hallways, offices,community/laundry room, and bathrooms. The levels of contamination measured in each unit aresummarized in Tables 2 and 3 in this section. Table 2 summarizes the results of the dust wipe andmicrovac testing. Table 3 summarizes the results of the lead-based paint testing. For copies of thecomplete data sheets (58 pages), please contact the authors.

In the next section, we evaluate the potential adverse health effects in Coop residents exposed to leadand arsenic in the house dust in their individual units. Each unit is considered individually, withchildren and adults being evaluated separately in each unit.

Toxicological Evaluation of Exposure Pathway

Unit A

Dust Testing

Six dust wipe samples were collected from the floor of Unit A, ranging in concentration from non-detect to 190 micrograms per square feet (µg/ft2) of lead, and from non-detect to 36 µg/ft2 of arsenic. One dust wipe sample was collected from the window sill, with a concentration of 17,000 µg/ft2 oflead and <80 µg/ft2 of arsenic. Two dust samples were collected from "Other" locations, withconcentrations of 12,000 µg/ft2 and 88 µg/ft2 of lead, and 130 µg/ft2 and 32 µg/ft2 of arsenic. Theconcentration of lead in the microvac sample was 4,800 mg/kg. The concentration of arsenic in the microvac sample was 110 mg/kg. See Table 2 for a summary of the results of the dust testing.

From these results, we calculated exposure concentrations for the five age categories for lead andarsenic. None of the age categories have an estimated blood lead level that exceeds 10 µg/dL (Table4). Therefore, we do not expect the current occupants of this unit to experience adverse healtheffects due to exposure to lead in this unit. The estimated exposure concentration of arsenic exceedsthe screening value only for the infant age category (Table 5). However, according to the releasethat the resident signed before this unit was tested, no children of this age live in this unit. Therefore, we do not expect that anyone currently living in this unit would experience non-canceradverse health effects due to exposure to arsenic in house dust in this unit. However, if in the future,infants live in this unit, then they might experience adverse health effects.

The increased lifetime cancer risk to an adult exposed to the arsenic in the house dust in this unit foran average 70 year lifetime is 3 in 100,000, which is considered to be a very low increased risk(Table 5). This is comparable to the increased lifetime cancer risk due to exposure to backgroundlevels of arsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (48 out of 54) had nodetectable levels of lead (Table 3). However, both lead-based paint and lead-containing paint weredetected. Deteriorated lead-based paint was found on the white wood door in the studio and on thewhite wood window sill in the bathroom. These are lead hazards, and are sources of lead-contaminated dust in this unit. Deteriorated lead-containing paint was also detected in this unit. These locations are also potential sources of lead-contaminated dust.

A paint chip was collected from the beige wood ceiling. The concentration of lead was 1,100mg/kg, and the concentration of 56 mg/kg (Table 3). This paint chip sample did not come from lead-based paint.

Unit B

Dust Testing

Four dust wipe samples were collected from the floor of Unit B, all of which had non-detectable concentrations of lead, and with non-detectable concentrations of arsenic in three samples and 28 µg/ft2 arsenic in the fourth. Two dust samples were collected from window sills, both of which had non-detectable levels of lead and arsenic. Three dust wipe samples were collected from "Other" locations, with concentrations of lead ranging from non-detect to 310 µg/ft2, and concentrations of arsenic ranging from non-detect to 40 µg/ft2. The concentration of lead in the microvac sample was 5,000 mg/kg. The concentration of arsenic in the microvac sample was 950 mg/kg. See Table 2 for a summary of the results of the dust testing.

From these results, we calculated exposure concentrations for all five age categories for lead andarsenic. None of the five age categories have estimated blood lead levels that exceed 10 µg/dL(Table 4). Therefore, we do not expect the current occupants of this unit to experience adversehealth effects due to exposure to lead in this unit. The estimated exposure concentrations of arsenicexceed the screening values for the infant, toddler, and young child's age categories (Table 5). However, according to the release that this resident signed before this unit was tested, no children ofthese ages live in this unit. Therefore, we do not expect that anyone currently living in this unitwould experience non-cancer adverse health effects due to exposure to arsenic in this unit. However, if in the future, infants, toddlers, and/or young children live in this unit, then they mightexperience adverse health effects.

The increased lifetime cancer risk to an adult exposed to the arsenic in the house dust in this unit for an average 70 year lifetime is 2 in 10,000, which is considered to be a low increased risk (Table 5). This risk is somewhat higher than the increased lifetime cancer risk due to exposure to background levels of arsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most of the locations tested (97 out of 129) hadno detectable levels of lead (Table 3). However, both lead-based paint and lead-containing paintwere detected. Intact lead-based paint was detected in several locations. While not considered to bea hazard, such surfaces can become a hazard in the future of they become deteriorated. Deterioratedlead-based paint was found at several locations, including the white metal window mullions in theliving room, the white wood sliding door casing and tan wood sliding door beam in the dining room,and the white metal window mullion in the laundry room. These are lead hazards, and are sourcesof lead-contaminated dust in this unit. Deteriorated lead-containing paint was found at severallocations. These locations are also potential sources of lead-contaminated dust in this unit.

Two paint chip samples were collected from this unit (Table 3). The first was taken from the whitewood ceiling beam in the kitchen, and contained 1,000 mg/kg of lead and 37 mg/kg of arsenic. Thispaint chip did not come from lead-based paint. The second paint chip sample was taken from thekitchen floor, and contained 130 mg/kg of lead and less than 20 mg/kg of arsenic. This paint chipsample did not come from lead-based paint.

Unit C

Dust Testing

Five dust wipe samples were collected from the floor, with four having non-detectable levels of leadand one having 20 µg/ft2 of lead, and with all five having non-detectable of arsenic. Two dust wipesamples were collected from the window sills, with concentrations of lead of 560 µg/ft2 and 66µg/ft2, and with concentrations of arsenic of 86 µg/ft2 and 25 µg/ft2. No dust wipe samples werecollected from "Other" locations. The concentrations of both lead and arsenic were below detectionlimits in the microvac samples. See Table 2 for a summary of the results of the dust testing.

From these results, we calculated exposure concentrations of lead and arsenic for all five age categories. None of the age categories have estimated blood levels that exceed 10 µg/dL (Table 4). Therefore, we do not expect the current occupants of this unit to experience adverse health effects due to exposure to lead in this unit. The estimated exposure concentrations of arsenic exceed the screening values for the infant and toddler's age categories (Table 5). However, according to the release that this resident signed before this unit was tested, no children of these ages live in this unit. Therefore, we do not expect that anyone currently living in this unit would experience non-cancer adverse health effects due to exposure to arsenic in this unit. However, if in the future, infants and/or toddlers live in this unit, then they might experience adverse health effects.

The increased lifetime cancer risk to an adult exposed to arsenic in this unit for an average 70 yearlifetime is 1 in 10,000, which is considered to be a low increased risk (Table 5). This increased riskis somewhat higher than the increased risk due to exposure to background levels of arsenic in theSan Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (44 out of 59) had nodetectable levels of lead (Table 3). However, both lead-based paint and lead-containing paint weredetected. None of the lead-based paint was intact. Deteriorated lead-based paint was detected on thebeige wood door jamb in the main studio; the blue wood door and black metal pipe riser in thekitchen; the brown and white brick walls, white wood door, and pink metal pipe riser in the darkroom; the red wood window sill in the bathroom/storage area; and the yellow metal and gray metalrafters, white drywall, and gray wood in the loft. These are all lead hazards, and are sources of lead-contaminated dust in this unit. Deteriorated lead-containing paint was also detected. These locations are also potential sources of lead-contaminated dust in this unit.

Two paint chip samples were collected from this unit (Table 3). The first was collected from thebeam above the window access to the roof, and contained 19,000 mg/kg of lead and 65 mg/kg ofarsenic. This paint chip came from lead-based paint. The second paint chip sample came from backarea of the beige wood ceiling in the loft, and contained 18,000 mg/kg of lead and 62 mg/kg ofarsenic. This paint chip sample came from lead-based paint.

Unit D

Dust Testing

Two dust wipe samples were collected from the floor, with concentrations of lead of non-detect and 87 µg/ft2, and concentrations of arsenic of non-detect and 30 µg/ft2. One wipe sample was collected from the window sill, with a concentration of lead of 120 µg/ft2 and a concentration of arsenic of non-detect. One dust wipe sample was taken from an "Other" location, with a concentration of lead of 50 µg/ft2 and non-detectable level of arsenic. The concentration of lead in the microvac sample was 430 mg/kg. The concentration of arsenic in the microvac sample was 68 mg/kg. See Table 2 for a summary of the results of the dust testing.

From these results, we calculated exposure concentrations for the five age categories for arsenic and lead. None of the age categories have estimated blood lead levels that exceed 10 µg/dL (Table 4). Therefore, we do not expect the current occupants of this unit to experience adverse health effects due to exposure to lead in this unit. The estimated exposure concentration of arsenic exceeds the screening value for the infant age category (Table 5). However, according to the release that this resident signed before this unit was tested, no children of this age live in this unit. Therefore, we do not expect that anyone currently living in this unit would experience non-cancer adverse health effects due to exposure to arsenic in this unit. However, if in the future, infants live in this unit, then they might experience adverse health effects.

The increased lifetime cancer risk to an adult exposed to the arsenic in the house dust in this unit foran average 70 year lifetime is 4 in 100,000, which is considered to be a very low increased risk(Table 5). This increased risk is comparable to the increased risk due to exposure to backgroundlevels of arsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (31 out of 44) had nodetectable levels of lead (Table 3). However, both lead-based paint and lead-containing paint weredetected. Intact lead-based paint was detected on the white metal support post and structural beam inthe living area, and the white wood support beam in the loft. While intact lead-based paint is not ahazard, it can become a hazard if it deteriorates. Deteriorated lead-based paint was detected on thewhite wood ceiling and white wood rafter in the loft, the white wood ceiling in the kitchen, and thewhite wood rafter in the loft. These locations are lead hazards, and are sources of lead-contaminateddust in this unit.

One paint chip sample was collected from the beige ceiling of this unit, which had a concentration oflead of 46 mg/kg and a concentration of arsenic of 63 mg/kg (Table 3). This paint chip sample didnot come from lead-based paint.

Unit E

Dust Testing

Seven dust wipe samples were collected from the floor of this unit, with non-detectable concentrations of lead in six of the samples and with 68 µg/ft2 of lead in the seventh, and with non-detectable levels of arsenic in all seven samples. One dust wipe sample was collected from the window sill, with 25 µg/ft2 of lead, and non-detectable levels of arsenic. Two dust wipe samples were collected from "Other" locations, with 31 µg/ft2 and 74 µg/ft2 of lead, and non-detectable levels of arsenic in both. The concentration of lead in the microvac sample was 300 mg/kg. The concentration of arsenic in the microvac sample was 73 mg/kg. See Table 2 for a summary of the results of the dust testing.

From these results, we calculated exposure concentrations for the five age categories for arsenic andlead. None of the age categories have estimated blood lead levels that exceed 10 µg/dL (Table 4). Therefore, we do not expect the current occupants of this unit to experience adverse health effectsdue to exposure to lead in this unit. The estimated exposure concentrations of arsenic exceed thescreening values for the infant and toddler's age categories (Table 5). However, according to therelease that this resident signed before this unit was tested, no children live in this unit. Therefore,we do not expect that anyone currently living in this unit would experience non-cancer adversehealth effects due to exposure to arsenic in this unit. However, if in the future, infants and/ortoddlers live in this unit, then they might experience adverse health effects.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 5 in 100,000, which is considered to be a very low increase risk (Table5). This increased risk is comparable to the increased risk due to exposure to background levels ofarsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (117 out of 129) had nodetectable levels of lead (Table 3). However, both lead-based paint and lead-containing paint weredetected. Deteriorated lead-based paint was detected at two locations on the white metal windowcasings in the living room. These locations are lead hazards, and are a source of lead-contaminateddust in this unit. Intact lead-containing paint was detected on the white wood door in the small lab,the white concrete lower wall and white wood door in the wine room, the white wood mid-board anddoor in the living room, the ceiling and lower door in the bedroom, the gray wood door trim in the back study, and the ceiling in the bathroom.

Two paint chips were collected from this unit (Table 3). One paint chip was collected from the entryfloor, and contained less than 100 mg/kg of lead and 45 mg/kg of arsenic. The second paint chipwas collected from the window mullion, and contained 7,400 mg/kg of lead and 68 mg/kg ofarsenic. The second paint chip sample came from lead-based paint.

Unit F

Dust Testing

Seven dust wipe samples were collected from the floor of this unit, with concentrations of lead ranging from non-detect to 1,200 µg/ft2, and concentrations of arsenic ranging from non-detect to 110 µg/ft2. One dust wipe sample was collected from the window sill, with non-detectable levels of lead and arsenic. One dust wipe sample was collected from an "Other" location, with a concentration of 890 µg/ft2 of lead, and 100 µg/ft2 of arsenic. The concentration of lead in the microvac sample was 880 mg/kg, The concentration of arsenic in the microvac sample was 140 mg/kg. See Table 2 for a summary of the results of the dust testing.

From these results, we calculated exposure concentrations for the five age categories for lead and arsenic. The estimated blood lead level for infants/toddlers (10.7 µg/dL) slightly exceeds 10 µg/dL, but the estimated blood lead levels for the other age categories are less than 10 µg/dL (Table 4). The release that this resident signed before this unit was tested indicated that no children of this age live in this unit. Therefore, we do not expect that anyone currently living in this unit would experience adverse health effects due to exposure to lead in this unit. The estimated exposure concentrations of arsenic exceed the screening values for the infant and toddler's age categories (Table 5). As no children of this age live in this unit, we do not expect that anyone currently living in this unit would experience adverse health effects due to exposure to arsenic in this unit.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 7 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is only slightly higher than the increased risk due to exposure to background levels ofarsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most of the locations tested (64 out of 73) hadno detectable levels of lead (Table 3). However, both lead-based paint and lead-containing paintwere detected. Intact lead-based paint was detected on a white structural steel support in the studioand on the yellow metal truss in the kitchen. While not considered a hazard, intact lead-based paintshould be watched to ensure that it does not deteriorate in the future and become a lead hazard. Deteriorated lead-based paint was detected on the white window mullion in the studio. This isconsidered to be a lead hazard. Intact lead-containing paint was detected on green wood door trim inthe small bedroom, and the white drywall ceiling in the bathroom. Deteriorated lead-containingpaint was detected on the white wood beam and ceiling in the studio, and the white wood ceiling inthe kitchen.

One paint chip sample was collected from the ceiling of this unit (Table 3). This paint chip sample had a lead concentration of 1,700 mg/kg, and a concentration of arsenic of 32 mg/kg. This paint chip sample did not come from lead-based paint.

Unit G

Dust Testing

Four dust wipe samples were collected from the floor of this unit, all of which had non-detectablelevels of lead and arsenic. One dust wipe sample was collected from the window sill, which hadnon-detectable levels of lead and arsenic. Two dust wipe samples were collected from "Other"locations, with non-detectable levels of lead and arsenic in both. The concentration of both lead andarsenic in the microvac sample was less than 100 mg/kg. See Table 2 for a summary of the resultsof the dust testing.

None of the dust wipe or microvac samples contained detectable levels of lead or arsenic (Table 2). Estimating the concentration of lead and arsenic at ½ of the limit of detection, we calculatedexposure concentrations for lead and arsenic for the five age categories. None of the age categorieshave estimated blood lead levels that exceed 10 µg/dL (Table 4). Therefore, we do not expect thatanyone currently living in this unit would experience adverse health effects due to exposure to leadin this unit. None of the screening values for arsenic are exceeded (Table 5). Therefore, we do notexpect that anyone currently living in this unit would experience adverse health effects due toexposure to arsenic in this unit.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 2 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is slightly lower than the increased risk due to exposure to background levels ofarsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most of the locations tested (44 out of 67) had no detectable levels of lead (Table 3). However, both lead-based paint and lead-containing paint were detected. Deteriorated lead-based paint was detected on the black metal truss in the bathroom, and the white metal truss and window mullion in the loft. These locations are lead hazards, and are sources of lead-contaminated dust. Intact lead-containing paint was detected on the white wood wall in the office. Intact lead-containing paint was detected on several places in the studio. Deteriorated lead-containing paint was detected on the white metal insulation pipe in the office, the white wood ceiling in the bedroom, the white wood skylight casing in the bathroom, the white wood door in the bathroom, the varnished tread on the stairs, the black metal pipe in the bathroom, the white wood wall and the drywall in the loft, the blue wood access door, and the white wood ceiling in the loft. These locations are also potential sources of lead-contaminated dust.

No paint chip samples were collected from this unit.

Unit H

Dust Testing

Four dust wipe samples were collected from the floor of this unit. The concentration of lead rangedfrom 37 µg/ft2 to 250 µg/ft2, and the concentration of arsenic ranged from non-detect to 36 µg/ft2. No dust wipe sample was collected from the window sill. One dust wipe sample was collected froman "Other" location, with a concentration of lead of 470 µg/ft2 and a concentration of arsenic of 56µg/ft2. The concentration of lead in the microvac sample was 950 mg/kg. The concentration ofarsenic in the microvac sample was 150 mg/kg. See Table 2 for a summary of the results of the dusttesting.

From the results of the dust wipe testing and the microvac testing (Table 2), we calculated exposure concentrations for lead and arsenic for the five age categories. The estimated blood lead level for infants/ toddlers (10.7 µg/dL) slightly exceeds 10 µg/dL. The estimated blood lead levels for the other age categories are less than 10 µg/dL (Table 4). The release signed by this resident before this unit was tested indicates that no children of this age live in this unit. Therefore, we do not expect that any current occupants of this unit would experience adverse health effects due to exposure to lead in this unit. The estimated exposure concentrations of arsenic exceed the screening values for the infant and toddler's age categories. The screening values for the other age categories are not exceeded (Table 5). However, no children of this age live in this unit. Therefore, we do not expect that anyone currently living in this unit would experience adverse health effects due to exposure to arsenic in this unit.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 7 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is slightly higher than the increased risk due to exposure to background levels ofarsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most of the locations tested (20 out of 30) hadno detectable levels of lead (Table 3). However, both lead-based paint and lead-containing paintwere detected. No intact lead-based paint was detected. Deteriorated lead-based paint was detectedon the white metal support and brace under the loft, the white metal truss and window mullion in theloft, and the white metal support post and truss in the main studio. These locations are lead hazards,and can generate lead-contaminated dust. No intact lead-containing paint was detected. Deteriorated lead-based paint was detected on the white concrete wall and thewhite wood ceiling in the area under the loft, the red wood floor in the loft, ant the white wood trussin the main studio.

One paint chip sample was collected from this unit (Table 3). The concentration of lead in this paintchip was 520 mg/kg. The concentration of arsenic in this paint chip was 40 mg/kg. This paint chipdid not come from lead-based paint.

Unit I

Dust Testing

Four dust wipe samples were collected from the floor of this unit. The concentrations of lead rangedfrom three samples with non-detectable levels of lead to 48 µg/ft2, and with non-detectable levels ofarsenic in all four samples. Two dust wipe samples were collected from the window sills of this unit,with concentrations of lead of 110 µg/ft2 and 20 µg/ft2, and with concentrations of arsenic of 28µg/ft2 and 14 µg/ft2. No dust wipe samples were collected from "Other" locations. Theconcentration of lead in the microvac sample was 1,800 mg/kg. The concentration of arsenic in themicrovac sample was 110 mg/kg. See Table 2 for a summary of the results of the dust testing.

From the results of the dust wipe and microvac testing (Table 2), we calculated exposure concentrations for lead and arsenic for the five age categories. The estimated blood lead levels for infants/toddlers and young children exceed 10 µg/dL, but the estimated blood lead levels for the other age categories do not exceed 10 µg/dL (Table 4). According to the release this resident signed before this unit was tested, no young children live in this unit. Therefore, we do not believe that any current occupants of this unit will experience adverse health effects due to exposure to lead in this unit. The estimated exposure concentration of arsenic exceeds the screening value for the infant age category (Table 5). However, no infants live in this unit. Therefore, we do not expect that any current occupants of this unit would experience adverse health effects due to exposure to arsenic in this unit.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 5 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is comparable to the increased risk due to exposure to background levels of arsenic inthe San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most of the locations tested (35 out of 49) haveno detectable levels of lead (Table 3). No intact lead-based paint was detected. Deteriorated lead-based paint was detected on the gray metal window mullion in the studio. This location is a hazard,and can generate lead-contaminated dust. No intact lead-containing paint was detected. Deteriorated lead-containing paint was detected on the vinyl gray floor and the white wood doorjamb in the study closet; the white wood window sill, the gray metal window mullion, the whitewood baseboard, white brick wall, and the white concrete window sill in the study; the white brickwall in the bathroom; the white plaster wall in the bathroom closet; and the white wood rafters,ceiling, and stained wood floor in the loft. These locations are potential sources of lead-contaminated dust.

Four paint chip samples were collected from this unit (Table 3). The first paint chip was collectedfrom the window sill, and contained 19,000 mg/kg of lead and 140 mg/kg of arsenic. This paintchip came from lead-based paint. The second paint chip was collected from the floor, and contained280 mg/kg of lead, and 42 mg/kg of arsenic. This paint chip did not come from lead-based paint. The third paint chip came from a wall, and contained 6,100 mg/kg of lead, and 45 mg/kg of arsenic. This paint chip came from lead-based paint. The fourth paint chip was collected from the ceiling,and contained 1,700 mg/kg of lead, and 29 mg/kg of arsenic. This paint chip came from lead-basedpaint.

Unit J

Dust Testing

Five dust wipe samples were collected from the floor of this unit. The concentrations of lead ranged from non-detect to 390 µg/ft2, and the concentrations of arsenic ranged from non-detect to 38 µg/ft2. Two dust wipe samples were collected from the window sills, with the concentrations of lead of 1,200,000 µg/ft2 and 200 µg/ft2, and the concentrations of arsenic of 700 µg/ft2 and 245 µg/ft2. Two dust wipe samples were collected from "Other" locations, with lead concentrations of 42 µg/ft2 and 3,500 µg/ft2, and arsenic concentrations of non-detect and 120 µg/ft2. The concentration of lead in the microvac sample was 3,600 mg/kg. The concentration of arsenic in the microvac sample was 320 mg/kg. See Table 2 for a summary of the results of the dust testing.

From the results of the dust wipe testing and microvac testing (Table 2), we calculated exposure concentrations of lead and arsenic for all age categories. The estimated blood lead level for young children (10.1 µg/dL) is slightly higher than 10 µg/dL. The estimated blood lead levels for the other age categories are less than 10 µg/dL (Table 4). According to the release that this resident signed before this unit was tested, no children of this age live in this unit. Therefore, we do not expect that anyone currently living in this unit would experience adverse health effects due to exposure to lead in this unit. None of the arsenic screening values for any of the age categories are exceeded (Table 5). Therefore, we do not expect that anyone currently living in this unit would experience non-cancer adverse health effects due to exposure to arsenic in this unit.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 9 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is somewhat higher than the increased risk due to exposure to background levels ofarsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (40 out of 63) had nodetectable levels of lead. However, both lead-based paint and lead-containing paint were detected(Table 3). Intact lead-based paint was detected on a black metal I-beam, the window casing, and thewindow jamb in the studio. Intact lead-based paint is not considered a hazard, because it does notgenerate lead-contaminated dust. However, such surfaces should be watched to ensure that they donot become deteriorated in the future. Deteriorated lead-based paint was detected on the beige woodceiling and joist in the kitchen, the gray metal upper hoist trunk, the gray wood window casings, andthe beige wood ceiling in the equipment room. These locations are considered lead hazards. Intactlead-containing paint was detected on the white metal upper door and green metal door header, theblack wood ceiling and joist and beige wood window casing in the studio. Deteriorated lead-containing paint was detected on the gray metal door jamb and white wood counter in the kitchen,the gray metal I-beam in the equipment room, and the beige lower drywall in the studio. Theselocations are potential sources of lead-contaminated dust.

Two paint chip samples were collected from the ceiling of this unit (Table 3). The first paint chipsample contained 310 mg/kg of lead, and 24 mg/kg of arsenic. This paint chip did not come fromlead-based paint. The second paint chip contained 47,000 mg/kg of lead, and 39 mg/kg of arsenic. This paint chip came from lead-based paint.

Unit K

Dust Testing

Five dust wipe samples were collected from the floors of this unit. The concentrations of lead and arsenic were all non-detect. Two dust wipe samples were collected from the window sills of this unit, with concentrations of lead of 620 µg/ft2 and 170 µg/ft2, and with concentrations of arsenic of 99 µg/ft2 and 62 µg/ft2. One dust wipe sample was collected from an "Other" location, with a lead concentration of 46 µg/ft2 and with non-detectable concentration of arsenic. The concentration of lead in the microvac sample was 640 mg/kg. The concentration of arsenic in the microvac sample was < 90 mg/kg. See Table 2 for a summary of the results of the dust testing.

From the results of the dust and microvac testing, we calculated exposure concentrations for lead and arsenic for the five age categories. The estimated blood lead levels for all five age categories are less than 10 µg/dL (Table 4). Therefore, we do not expect that anyone currently living in this unit would experience adverse health effects due to exposure to lead in this unit. None of the arsenic screening values are exceeded for any of the age categories (Table 5). Therefore, we do not expect that anyone currently living in this unit would experience non-cancer adverse health effects due to exposure to arsenic in this unit.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 2 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is slightly less than the increased risk due to exposure to background levels of arsenicin the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (70 out of 83) have nodetectable levels of lead. However, both lead-based paint and lead-containing paint were detected(Table 3). Intact lead-based paint was detected on the green metal window sash and the emergencyexit ladder in the living room. No deteriorated lead-based paint was detected. Intact lead-basedpaint is not considered a hazard, because it does not generate lead-contaminated dust. However,such surfaces should be watched to ensure that they do not become deteriorated in the future. Intactlead-containing paint was detected on the white wood door casing and white drywall in the kitchen,the wood baluster and wood stringer on the north stair case, the white wood ceiling and white woodbaseboard in the living room, and the green wood baseboard, window sill, and window sash in thebathroom. Deteriorated lead-containing paint was detected on the white ceiling support beam in thebathroom. These locations are potential sources of lead-contaminated dust if they becomedeteriorated in the future.

One paint chip sample was collected from a ceiling beam this unit. This paint chip sample contained3,600 mg/kg of lead, and 54 mg/kg of arsenic (Table 3). This paint chip did not come from lead-based paint.

Unit L

Dust Testing

Five dust wipe samples were collected from the floors of this unit. The concentrations of lead ranged from non-detect to 13 µg/ft2, and the concentrations of arsenic were all non-detect. Two dust wipe samples were collected from the window sills of this unit. The concentrations of lead were 86 µg/ft2 and 68 µg/ft2, and the concentrations of arsenic were 36 µg/ft2 and 76 µg/ft2. Two dust wipe samples were collected from "Other" locations. The concentrations of lead were 14 µg/ft2 and 580 µg/ft2 and the concentrations of arsenic were 14 µg/ft2 and 120 µg/ft2. The concentration of lead in the microwave sample was 210 mg/kg. The concentration of arsenic in the microvac sample was 150 mg/kg. See Table 2 for a summary of the results of the dust testing.

From the results of the dust wipe and microvac testing (Table 2), we calculated exposure concentrations for arsenic and lead for all five age categories. The estimated blood lead levels for all age categories are less than 10 µg/dL (Table 4). Therefore, we do not believe that anyone currently living in this unit would experience adverse health effects due to exposure to lead in this unit. None of the arsenic screening values for any age category are exceeded (Table 5). Therefore, we do not expect that anyone currently living in this unit would experience non-cancer adverse health effects.

The increased lifetime cancer risk to an adult exposed to arsenic in the house dust in this unit for anaverage 70 year lifetime is 3 in 100,000, which is considered to be a very low increase risk. Thisincreased risk is comparable to the increased risk due to exposure to background levels of arsenic inthe San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (39 out of 43) have nodetectable levels of lead (Table 3). However, both lead-based paint and lead-containing paint weredetected. Intact lead-based paint was found on the white metal brace in the bedroom. Nodeteriorated lead-based paint was detected. Intact lead-based paint is not a hazard, because it doesnot generate lead-containing dust. However, such surfaces should be watched to ensure that they donot become deteriorated in the future. No intact lead-containing paint was detected. Deterioratedlead-containing paint was detected on the white plaster wall and white wood door jamb in the office,and the white wood rafter in the bedroom.

Four paint chip samples were collected from this unit (Table 3). The first paint chip was collectedfrom the ceiling, and contained 1,200 mg/kg of lead, and 32 mg/kg of arsenic. This paint chip didnot come from lead-based paint. The second paint chip was collected from the window sill, andcontained 2,100 mg/kg of lead, and 65 mg/kg of arsenic. This paint chip did not come from lead-based paint. The third paint chip was collected from a wall, and contained 2,500 mg/kg of lead, and81 mg/kg of arsenic. This paint chip did not come from lead-based paint. The fourth paint chip wascollected from a window, and contained 1,800 mg/kg of lead, and 55 mg/kg of arsenic. This paintchip did not come from lead-based paint.

Common Areas - Hallways

 

Dust Wipe Testing

Ten dust wipe samples were collected from the hallways of the Coop. Eight of the samples had non-detectable levels of lead, one contained lead at a concentration of 7.8 µg/ft2, and one contained lead at a concentration of 5.8 µg/ft2. Eight of the samples contained non-detectable levels of arsenic, one contained arsenic at a concentration of 5.2 µg/ft2, and one contained arsenic at a concentration of 5.7 µg/ft2. No window sills were sampled in the hallways. One dust wipe sample was collected from an "Other" location. The concentration of lead in this sample was 860 µg/ft2, and the concentration of arsenic in this sample was 180 µg/ft2. The concentration of lead in the microvac sample was 130 mg/kg. The concentration of arsenic in the microvac sample was 690 mg/kg. See Table 2 for a summary of the results of the dust testing.

From the results of the dust wipe and microvac testing (Table 2) we calculated exposure concentrations for lead and arsenic for the five age categories. None of the age categories have estimated blood lead levels that would exceed 10 µg/dL. Therefore, we do not expect that anyone exposed to dust in the hallways would experience adverse health effects due to exposure to lead. None of the arsenic screening values for any of the age categories is exceeded (Table 5). Therefore, we do not expect that anyone exposed to dust in the hallways would experience adverse health effects due to exposure to arsenic.

The increased lifetime cancer risk to an adult due to exposure to arsenic in the dust in the hallways is 2 in 1,000,000, which is considered to be a very low increased risk. This estimate is based on an average 70 year lifetime, but also accounting for the fact that people typically spend only a limited amount of time in the hallways. This increased risk is considerably less than the increased risk due to exposure to background levels of arsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations (135 out of 148) had nodetectable levels of lead. However, both lead-based paint and lead-containing paint were detected(Table 3). Intact lead-based paint was detected on the white metal support beam in the hallway nearunits 30 and 32, on the white metal support column in the north/south hallway near unit 29, on awhite metal beam in the north/south hallway near units 27/28, and on the white lower concrete wallin the hallway near units 17, 20, and 22. Intact lead-based paint is not considered a hazard, becauseit does not generate lead-contaminated dust. However, such surfaces should be watched to ensurethat they do not become deteriorated in the future. Deteriorated lead-based paint was detected on thewood green door in the entry, the white wood wall in the hallway near the communityroom/restroom, the white concrete wall in the hallway near units 22 and 23, on the black woodopening in the hallway near units 22 and 23, and on the black metal door in the north/south hallwaynear unit 25. Deteriorated lead-based paint is a hazard because it generates lead-contaminated dust. Intact lead-containing paint was detected on the center white concrete wall in the entry area. Deteriorated lead-containing paint was detected on the white drywall, an on the black metal doorcasing in the hallway near units 17, 20, and 22, and on the white wood baseboard in the hallwaynear units 22 and 23.

Two paint chip samples were collected from the hallways (Table 3). The first paint chip wascollected from the ceiling near unit 49, and contained 1,100 mg/kg of lead, and 56 mg/kg of arsenic. This paint chip sample did not come from lead-based paint. The second paint chip sample wascollected from the joist near unit 49, and contained 1,100 mg/kg of lead, and 43 mg/kg of arsenic. This paint chip sample did not come from lead-based paint.

Common Areas - Bathrooms

Dust Wipe Testing

Two dust wipe samples were collected from the floor of the bathrooms, both of which contained non-detectable levels of lead and arsenic. One dust wipe sample was collected from the widow sill of thelarge bathroom. This sample contained non-detectable levels of lead and arsenic. No dust wipesamples were collected from "Other" locations in the bathrooms. The concentration of lead in the microvac sample was less than 200 mg/kg. The concentration of arsenic in the microvacsample was 6,400 mg/kg. See Table 2 for a summary of the results of the dust testing.

From the results of the dust wipe and microvac testing (Table 2), we calculated exposureconcentrations for lead and arsenic for the five age categories. The results for lead show that none ofthe five age categories have estimated blood lead levels that exceed 10 µg/dL (Table 4). Therefore,we do not expect that anyone exposed to lead in the dust in the bathrooms would experience adversehealth effects. The results for arsenic show that none of the screening values for the five agecategories are exceeded (Table 5). Therefore, we do not expect that anyone exposed to arsenic in thedust in the bathrooms would experience adverse health effects.

The increased lifetime cancer risk to an adult due to exposure to arsenic in the dust in the restrooms is 2 in 1,000,000, which is considered to be a very low increased risk. This estimate is based on an average 70 year lifetime, but also accounting for the fact that people typically spend only a limited amount of time in the restrooms. This increased risk is considerably less than the increased risk due to exposure to background levels of arsenic in the San Francisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead based paint testing show that most locations tested (15 out of 22) had nodetectable levels of lead. However, both lead-based paint and lead-containing paint were detected(Table 3). No intact lead-based paint was detected. Deteriorated lead-based paint was detected on the white metal window mullion in the large restroom, and on the white wood doorin the small bathroom. Deteriorated lead-based paint is a hazard because it can generate lead-contaminated dust. Intact lead-containing paint was detected on the white plaster walls in the largebathroom, and on the white wood shower door casing and the white baseboard in the shower room. No deteriorated lead-containing paint was detected.

One paint chip sample was collected from the bathrooms (Table 3). This paint chip sample wascollected from the ceiling of the large bathroom, and contained <100 mg/kg of lead, and 45 mg/kgof arsenic. This paint chip did not come from lead-based paint.

Common Areas - Offices/Community Room

Dust Wipe Testing

Two dust wipe samples were collected from the floor of the offices/community room, both of which had non-detectable levels of lead and arsenic. Two dust wipe samples were collected from the window sills, both of which contained 16 µg/ft2 of lead and non-detectable levels of arsenic. One dust wipe sample was collected from an "Other" location, and contained 150 µg/ft2 of lead and 37 µg/ft2 of arsenic. The concentration of lead in the microvac sample was 48 mg/kg. The concentration of arsenic in the microvac sample was 240 mg/kg. See Table 2 for a summary of the results of the dust sampling.

From the results of the dust wipe and microvac testing (Table 2), we calculated exposure concentrations lead and arsenic for the five age categories. None of the estimated blood lead levels for all age categories exceeds 10 µg/dL (Table 4). Therefore, we do not expect that anyone exposed to lead in dust in the office/community room would experience adverse health effects. None of the arsenic screening values are exceeded for any age category (Table 5). Therefore, we do not expect that anyone exposed to arsenic in the dust in the offices/community room would experience adverse health effects.

The increased lifetime cancer risk to an adult due to exposure to arsenic in the dust in theoffice/community room is 2 in 1,000,000, which is considered to be a very low increased risk. Thisestimate is based on an average 70 year lifetime, but also accounting for the fact that peopletypically spend only a limited amount of time in these common areas. This increased risk isconsiderably less than the increased risk due to exposure to background levels of arsenic in the SanFrancisco Bay Area (3 - 5 in 100,000).

Lead-Based Paint Testing

The results of the lead-based paint testing show that most locations tested (20 out of 28) had no detectable levels of lead. However, both lead-based paint and lead-containing paint were detected (Table 3). No intact lead-based paint was detected. Deteriorated lead-based paint was detected on the blue metal window mullion and the green wood door in the community room, and the white metal window mullions in the office. Deteriorated lead-based paint is a hazard because it generates lead-contaminated dust. Intact lead-containing paint was detected on the white drywall on the center wall in office number 3, and on the green drywall on the center wall, and the green plaster wall in office number 2. Deteriorated lead-containing paint was detected on the white wood baseboard in the community room.

One paint chip sample was collected from the ceiling in the office/community room, and contained2,900 mg/kg of lead, and 26 mg/kg of arsenic (Table 3). This paint chip sample did not come fromlead-based paint.

Limitations of Toxicological Evaluations

There are several limitations to this study which must be considered. The first is that the exposuremodel used (see Appendix C) to evaluate individuals' exposures to lead and arsenic in the housedust in the tested units is a screening tool. As such, these are not precise measurements, but high-endestimates of exposure. We use high estimates of the amount of dust, soil, air, and water to which aperson of a particular age is exposed. For example, the estimate of the amount of tap water that anadult drinks per day (2 liters per day (L/day)) is the amount that the upper 5% of the populationdrinks. In addition, the estimated blood lead levels (Table 4) are also 95% estimates (meaning that5% of the population would be expected to have blood lead levels higher than this value). By usingthese high estimates, we can be relatively certain that if the estimated blood lead level is less than 10µg/dL, or if the exposure concentration is less than the screening value, then no adverse healtheffects will occur. However, if the estimated blood lead level exceeds 10 µg/dL, or if the exposureconcentration exceeds the screening value for arsenic, adverse health effects do not automaticallyoccur. Such a situation must be evaluated more thoroughly. For each individual unit occupants, wewent into more detail when an estimated exposure exceeded its screening value

The second is that these exposure estimates are based upon an essentially infinite source ofcontaminated dust within a unit. This assumption may not always be valid. Cleaning in the unit, aswell as, to a lesser degree, incidental exposure over an extended period of time, will eventuallydeplete much of the contaminated dust in a unit. However, if there is deteriorated lead-based paintor lead-containing paint, then there is the potential to replenish the supply of lead-contaminated dustin a unit. Arsenic contamination may be replenished from arsenic in the soils of the area as well asarsenic in deteriorated paint. Additionally, certain arts and crafts also have the potential to emit leadand arsenic contamination. Thus, it is not possible to draw definitive conclusions regarding whetheror not the reservoir of contamination in a particular unit may be replenished or not.

The third is that estimating exposure to contaminants in house dust is a difficult process, and thereare no standard methods available at this time to evaluate such exposures.

The fourth is that these data cannot be used to identify the source of contamination found in a unit. The dust testing can only be used measure the levels of lead and arsenic, and thus to estimatepotential adverse health effects, not identify where that contamination came from, such asautomobile exhaust, industrial emissions in the area, fugitive emissions form Sherwin-Williams, lead-based paint, or from certain arts and crafts. While lead-based paint testing doesidentify a particular source of lead within a unit, it does not specify whether lead-contaminated dustin a particular location within a unit is dust from lead-based paint.

Fifth, the conclusions regarding possible future exposure are based on the condition of the unit whenit was tested. Changes in the unit that would affect the amount of dust in the unit such asremoving/covering lead-based paint or cleaning contaminated surfaces, would change the potential for the development of adverse health effects in the future.


CONCLUSIONS

The conclusions of this document are that current occupants of the 45th Street Artists' Cooperativeare not likely to be exposed to levels of arsenic or lead that would cause adverse health effects. The conclusions are summarized below.

  1. No estimated blood lead levels greater than 10 µg/dL are expected to occur in the current residents of any of the tested units.


  2. The estimated blood lead level for infants, toddlers, and young children exceed 10 µg/dL in some of the tested units, but no children of those ages (up to 12 years old) live in those units at this time.


  3. Some of the tested units had wipe samples that showed very high levels of lead.


  4. Exposure to arsenic in the house dust in the tested units would not be expected to cause non-cancer adverse health effects in any of the current residents of the tested units.


  5. The arsenic screening values for infants, toddlers, and young children were exceeded in some of the tested units, but no children of those ages (up to 12 years old) live in those units.


  6. The increased lifetime cancer risk due to a lifetime exposure to a arsenic in the house dust in the tested units is generally comparable to or only slightly higher than the increased lifetime cancer risk due to exposure to background levels of arsenic in the San Francisco Bay Area. This is a very low increased lifetime cancer risk (up to 9 x 10-5).


  7. There is a low increased lifetime cancer risk (just above 1 x 10-4) due to a lifetime exposure to arsenic in house dust in a few of the tested units.


  8. Evaluation of arsenic and lead concentrations in the microvac samples


    1. The concentration of arsenic in the dust samples lies, with two exceptions, within the range of non-detect to 150 mg/kg. These include interior units with no windows or outside access, and units that have windows on the outside of the building. Of the two exceptions, the concentration of arsenic was 320 mg/kg in one unit, and the concentration of arsenic was 950 mg/kg in the second unit. Both of these units are units that face the outside of the building. Based on the data that we evaluated, the concentration of arsenic seems to be relatively constant throughout the 45th Street Building of the Coop.


    2. The concentration of lead in the dust samples ranges from approximately non-detect to 6,400 mg/kg. Five of the 15 locations tested (12 units, hallways, bathrooms, offices/community room) had levels of lead that exceeded 1,800 mg/kg. In general, the units with the highest levels of lead are all units that have windows on the outside of the building. The units with the lower levels of lead are mostly interior units with no windows or other outside access.


  9. The results of biological testing, conducted in 1997, showed no elevated levels of lead or arsenic. This biological testing is not discussed in detail in this document. However, the results of the 1997 biological monitoring are consistent with the conclusions of this document that current occupants of the 45th Street Artists' Cooperative are not likely to be exposed to levels of arsenic or lead that would cause adverse health effects.

PUBLIC HEALTH RECOMMENDATIONS AND ACTIONS

The Public Health Recommendations and Action Plan (PHRAP) for this site contains a description of actions taken, to be taken, or under consideration by ATSDR and CDHS at and near the site. The purpose of the PHRAP is to ensure that this health consultation not only identifies public health hazards, but also provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. CDHS and ATSDR will follow-up on this plan to ensure that actions are carried out.

Actions Completed

  1. CDHS has presented Coop residents whose units were tested with the results of the testing for their units.


  2. Coop residents have been provided with information on contractors in the area who canperform lead risk assessments and who can perform lead abatement work. Residents alsohave the opportunity to receive training from the Alameda County Lead PoisoningPrevention Program on how to protect family members from lead contamination, how toclean up lead-contaminated dust, and how to perform "lead-safe" construction andremodeling activities in their units. Alameda County Lead Poisoning Prevention Programoffered the Coop a high-efficiency vacuum cleaner, on the condition they receive training for its use.

Current Activities

CDHS and Alameda County Lead Poisoning Prevention Program staff are available to answerquestions from Coop residents.


PREPARES OF REPORT

Health Assessors

F. Reber Brown, Ph.D.
Research Scientist II
Impact Assessment Inc.
Consultant to Environmental Health Investigations Branch
California Department of Health Services

Marilyn C. Underwood, Ph.D.
Staff Toxicologist
Environmental Health Investigations Branch
California Department of Health Services


ATSDR Regional Representative

William Q. Nelson
Gwendolyn Eng
Regional Representatives, Region IX
Agency for Toxic Substances and Disease Registry

Tammie A. McRae, M.S.
Technical Project Officer/Environmental Health Scientist
Agency for Toxic Substances and Disease Registry


REFERENCES

  1. U.S. Department of Health and Human Services, Agency for Toxic Substances and DiseaseRegistry. Public Health Assessment for Sherwin Williams, Emeryville, Alameda County,California. June 1999.


  2. Sampling Plan for Exposure Investigation - 45th Street Artists' Cooperative. Prepared for California Department of Health Services Environmental Health Investigations Branch by Health Science Associates, Emeryville, California. January, 1999.


  3. California Environmental Protection Agency - Department of Toxic Substances Control -Health and Ecological Risk Division. "Assessment of Health Risks from Inorganic Lead inSoil - Lead Risk Assessment Spreadsheet": www.cwo.com/~herd1/ledspred.htm),LeadSpread 6.


  4. U.S. Department of Health and Human Services, Agency for Toxic Substances and DiseaseRegistry. Toxicological Profile for Lead - Draft for Public Comment. August 1997.


  5. U.S. Department of Health and Human Services, Agency for Toxic Substances and DiseaseRegistry. Toxicological Profile for Arsenic. April 1993.


  6. Protocol for Determining Background Concentrations of Metals in Soils at LawrenceBerkeley National Laboratory (LBNL). Lawrence Berkeley National Laboratory,University of California. August, 1995.


  7. Levine, Fricke, Recon, Air Monitoring Plan for Remediation of Arsenic-Affected Soils in the Vicinity of Sherwin-Williams Facility. May, 1997


  8. Levine, Fricke, Recon, Completion Report - Excavation and Disposal of Arsenic-AffectedSoils in the Vicinity of the Sherwin-Williams Facility, Emeryville, CA. March, 1999

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