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PUBLIC HEALTH ASSESSMENT
NORTHWEST PIPE AND CASING COMPANY
CLACKAMAS, CLACKAMAS COUNTY, OREGON


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The data provided in tables of Appendix A were collected by Ecology and Environment, Inc. for EPA. We evaluate those contaminants in the subsequent sections of the Health Assessment and determine whether exposure to them has public health significance.

Toxic Chemical Release Inventory (TRI) Data

We could not conduct a search of the EPA Toxic Chemical Release Inventory (TRI) for the facilities on the NWP&C site. Operations at the site were abandoned in 1985 prior to first year of TRI records in the database, 1987. However, site violations were reviewed at the State Department of Environmental Quality and are reported in the ambient air sections of on-site and off-site contamination. The TRI database serves as a record of reported chemical releases to the air, water, and land. A search was conducted for the local area by zip code (97015) and some similar contaminants were noted between local releases and site contaminants. Four years of the TRI database were searched: 1987 - 1990 (8). Although no releases to the water or land were found, there were many air releases by numerous companies in this zip code. Contaminants found both on and near NWP&C and released by other local industries were trichloroethylene, 1,1,1 trichloroethane, and tetrachloroethene. Other organic compound releases reported in TRI were not major contaminants or were not present in relation to NWP&C: these include sulfuric acid, butyl benzyl phthalate, freon 113, and glycol ethers. Several companies in the area reported airborne inorganic releases. One company reported airborne releases of aluminum, copper, and zinc fume or dust in 1987 and 1988. Another company reported yearly inorganic airborne releases including cadmium, cobalt, copper, chromium, manganese, and nickel compounds. The companies reporting inorganic releases are within several miles of NWP&C. Elevated metals in soil, sediment, and water were noted in the site data for NWP&C.

A. On-Site Contamination

Various site media were sampled from July 1988 through February 1990. The file data indicate soil, sediment, surface water and groundwater contamination by PAHs, VOCs, and some PCBs. Most of the testing conducted has been done on parcel B. A geophysical survey to delineate buried drums was conducted on parcel B only. Limited sampling, as discussed below, was conducted on parcel A prior to development. Sample locations are shown on Figures 3 through 8. Data has been summarized in Appendix A for the contaminants ATSDR selected for further evaluation. Pica children were not addressed on-site because of the sites industrial nature, lack of adjacent residences, and the unlikelihood that pica children would visit the site.

Waste Material

Solid chunks of coal tar are visible on Parcel B of NWP&C. Excess coal tar that fell off pipes or that was rendered unusable, due to the loss of volatile oils, was discarded as waste product (4). Some of this waste product was burned and buried on-site (4). Hazardous constituents in surficial soils are summarized in the section below.

Soil

Parcel A

Results of soil sampling on parcels A and B are summarized in Tables 1 through 3 (Appendix A) for the contaminants ATSDR selected for further evaluation. These results suggest a lack of contamination at concentrations greater than ATSDRs comparison values on parcel A. However, parcel A was not sampled in its entirety and is now covered predominantly by asphalt and buildings. No inorganic analyses of soil were conducted on this parcel.

Ten soil samples were taken on parcel A (Figure 3). A trace of toluene was found in five of these samples as well as in one of the background samples. Benzo(a)pyrene was detected at 3.9 ppm in one sample on the east side of the portion owned by Northwest Development Company. Northwest Development Company is on the portion that was the pipeyard. Based on reports from past employees, buried drums are not expected on parcel A; however, no extensive investigation has been conducted to confirm the lack of drums. One composite sample of Parcel A soil from Northwest Development was collected after the soil had been removed and placed on parcel B. No contaminants for parcel A exceed ATSDR comparison values for ingestion by children. Many PAHs were detected: acenaphthene, fluorene, anthracene, chrysene, benzo(b and k)fluoranthene, indeno(1,2,3-cd)pyrene and pyrene. Pentachlorophenol was detected once but was not found in any other soil analyses on either parcel. Sampling of the ODOT property showed a possibility of contamination by chrysene or benzo(a)anthracene.

Parcel B

The results of soil sampling are also included in Tables 1 through 3 (Appendix A). Sampling locations are shown in Figures 3 and 4. Soil samples were taken from surface to six inches below surface and in a grid pattern on parcel B (Figure 3).

Soil sampling results indicate surficial contamination by PAHs (Table 1) and a PCB, Aroclor 1254 (Table 2). The PAHs which exceed ATSDR comparison values for a child are anthracene, benzo(a)pyrene, fluoranthene, fluorene, and pyrene. Other organic compounds which were detected in several soil samples are dibenzofuran, tetrachloroethene (PCE), and trichloroethene (TCE)[Table 2]. Other organic compounds which were selected for further evaluation are shown in Tables 1 and 2. Although dioxin/furans could be present, particularly in areas containing PCBs, analyses for the majority of these contaminants have not been conducted.

Approximately five soil samples obtained on parcel B were analyzed for inorganic compounds. Metals which exceed background levels and ATSDR comparison values are antimony, arsenic, beryllium, and manganese (Table 3). Metals which exceed background in several samples but have no ATSDR comparison value are copper, iron, lead, nickel, sodium, and zinc. Copper, nickel, and zinc were used in the plant of NWP&C for brazing rod. Chromium and lead were used for welding tips (1). Zinc chromate was also used in the plant. All of the metals are found in background soil and some concentrations represent natural variations in the background. The background concentration for manganese exceeds the comparison value suggesting that background concentrations rather than contamination from the site needs to be evaluated. All metals listed are considered for further evaluation.

Sediment

Sediment samples were taken in the drainage ditches that border the east and west sides of NWP&C (Figures 4 and 5). The PAHs found in sediment which exceed ATSDR comparison values for ingestion by children are fluoranthene, pyrene, and benzo(a)pyrene. Carcinogenic PAHs more frequently exceed comparison values in sediments than the noncarcinogenic PAHs (Table 4). The maximum concentrations of PAHs found in sediment are less than the maximums found for on-site soils. This pattern suggests PAH contamination from on-site surface drainage. There are several organic compounds which were detected in sediment but not in soil: bis(2-ethyl hexyl)phthalate, 2-butanone, and dichloroethene (DCE) [Tables 1 and 5]. A background sediment sample from a local creek contained bis(2-ethyl hexyl)phthalate and 2-butanone. The presence of these contaminants in the background sample indicates other or additional sources of contamination. As in surficial soils, Aroclor 1254 was prevalent in sediment samples at concentrations exceeding the ATSDR comparison value (Table 5). Mercury was detected in sediment but not in soil (Table 6). Arsenic concentrations were found in most samples analyzed and exceeded background and the ATSDR comparison value.

Surface water

Four on-site surface water samples were taken: two in the east ditch and two in the west ditch (4) [Figure 5]. The contaminants (tetrachloroethene, trichloroethene, and vinyl chloride) which exceeded ATSDR comparison values for ingestion as drinking water were found in samples from the east ditch (Table 7). No PAHs were detected in surface water. Many metals were detected above background in on-site surface water (Table 8). For those inorganic compounds having an ATSDR comparison value, the following contaminants exceed those values for use as drinking water: barium, lead, and manganese. However, the background levels for these contaminants also exceeded the comparison values. Metals in surface water are evaluated further even though background sample concentrations are high.

Groundwater

There are seven monitoring wells on parcel B of the NWP&C site (Figure 6). The wells range in depth from 13 to 28 feet below ground surface or are completed in the shallow aquifer (2). The shallow and deep aquifers are discussed below. Both occur in the alluvial sediments. The deep aquifer is beneath a restricting clay layer in the alluvium. The ODOT well on parcel A, used for irrigation, is completed in the deep aquifer. Based on monitoring wells, shallow groundwater flow is north/northwesterly (2).

Shallow Aquifer

Approximately 8 to 12 groundwater samples were analyzed for contaminants in the shallow aquifer. Although PAHs were not detected in the background well, many PAHs were detected at elevated levels in on-site wells. The following noncarcinogenic PAHs exceed ATSDR comparison values for drinking water: acenaphthene, fluoranthene, fluorene, naphthalene, and pyrene (Table 9). The following carcinogenic PAHs exceed ATSDR comparison values: benzo(a)anthracene and benzo(a)pyrene. A total of 18 different PAHs were detected as shown in Table 9. Ten other organic compounds detected in on-site groundwater wells exceed ATSDR comparison values: benzene, carbon tetrachloride, chloroform, dibenzofuran, dichloroethene, PCB-Aroclor 1254, tetrachloroethene, trichloroethane, and vinyl chloride. Of these contaminants, the latter three are the most widespread (Table 10). Although the site is a source of these contaminants, traces of tetrachloroethene and trichloroethane are found in the background well, suggesting potential additional sources.

Eight groundwater samples were analyzed for inorganic compounds. Eleven metals exceed ATSDR comparison values: antimony, arsenic, barium, beryllium, chromium, copper, lead, manganese, nickel, vanadium, and zinc (Table 11). Although groundwater concentrations of some common earth crust metals (aluminum and iron) were also elevated, there are no ATSDR comparison values.

Deep Aquifer

The industrial well on the ODOT property was installed in 1978 (4). It is currently used for irrigating the property and is the only on-site well reaching the deeper aquifer. Metals which exceed an ATSDR comparison value for drinking water are arsenic, barium, lead, and manganese (Table 12). These metals concentrations may be within the range of background concentrations for this area. No contamination of the deep aquifer through site activities has been indicated.

Ambient Air

The historical record of site activities and records of violations at OR DEQ suggest that human exposure to air contaminants was likely during the operation of the pipe coating facilities. One company was cited in December of 1976 for excessive coal tar levels in on-site buildings (8) and had an occupational health or industrial hygiene problem with respect to coal tar emissions in 1976 through 1977 (8). Open burning of coal tar wastes and combustible refuse occurred (1). Fumes were emitted daily during the opening of the coal tar pots. This company was found in violation of Columbia Williamette Air Pollution Authority rules on August 24, 1971 for open burning of tar residues (8). Several violations were served for high tar pot opacity. Several fires occurred on-site: a PCB transformer fire on March 31, 1968, (8) and a fire in the warehouse building containing hay on April 18, 1990 (1). Dioxin/furans may be present on site due to the PCB transformer fire.

B. Off-Site Contamination

Soil

Locations of off-site residential and background soil samples are shown in Figure 7. The background soil samples appear to have been taken in an area which could receive sediment laden flood waters or air emissions from NWP&C. Additionally, the background samples are in the proximity of the railroad tracks and therefore, are unlikely to represent true background conditions.

Approximately 10 PAHs were detected in four residential soil samples (Table 13). The only PAH that exceeded an ATSDR comparison value for a pica child was benzo(a)pyrene. This contaminant was also detected in the background sample. Other organic compounds detected in residential soil are bis(2-ethyl hexyl)phthalate, di-n-octylphthalate, and methoxychlor (Table 14). The former two compounds were positively identified in the background sample. Additionally, none of these compounds were detected in on-site soils. Therefore, they are probably not site-related contaminants.

Four residential samples and a background sample were collected within a quarter mile radius of the site and analyzed for inorganic elements. Inorganic elements which exceed both the background concentration and the ATSDR comparison value are arsenic, barium, and manganese. However, the local background concentrations for these metals exceeds their comparison values for ingestion by a pica child as well (Table 15). The presence of these metals is probably not site-related but are natural variations in soil composition. Elevated levels of lead in soil were found off site but not on site.

Sediment

Five sediment samples were collected in off-site drainage ways, which receive runoff from the site (Figure 5). One off-site sediment sample was taken upgradient of the site. However, this area receives flood waters from the site (4). Another sample was taken to the east of the site.

Fourteen PAH's were detected in off-site sediment as shown in Table 16. They are probably site-related contaminants that have migrated from the site in the drainage ways. The concentration of benzo(a)pyrene in sediment exceeds the comparison value for ingestion by pica children.

The only organic compounds detected in the background sample as well as off-site sediment are bis(2-ethylhexyl)phthalate and 2-butanone (Table 17). Many samples contained the PCB, Aroclor 1254; one sample contained Aroclor 1260. Di-n-octyl phthalate, dichloroethene, tetrachloroethene, and trichloroethene were also found in off-site sediment. Di-n-octylphthalate and Aroclor 1260 were not detected in on-site sediment.

Eighteen inorganic elements or metals were detected in off-site sediment (Table 18). The maximum concentrations exceeded background concentrations with the exception of potassium. The maximum concentrations of arsenic, barium, and manganese exceed ATSDR comparison values. The background concentrations of arsenic and manganese also exceed their comparison values for ingestion by pica children. The data quality for antimony is not adequate to conclude that its concentration is also in excess of the comparison value. Compared to a background sample, there are elevated concentrations of copper and lead. It is unlikely these elevated concentrations of copper and lead are site related since maximum concentrations in off-site sediment far exceed levels of on-site sediment contamination.

Surface water

Surface water from the on-site drainage ditches on the east and west borders of the property discharges to Deer Creek. Deer Creek flows into Mount Scott Creek which eventually empties into the Clackamas River. Four off-site surface water samples were taken in drainage ways and local creeks (Figure 6). The only organic contaminant detected was tetrachloroethene; its concentration exceeds ATSDR's comparison value for drinking water (Table 19). No information on PAH's were found for review in off-site surface water. The maximum concentrations of barium and manganese as well as their background concentrations exceed their ATSDR comparison values (Table 20). Iron was found at elevated concentrations in off-site surface water. An on-site elevated concentration of iron in surface water was also found (Table 8). It appears that most metals are not a product of site contamination.

Groundwater

Six off-site groundwater locations were sampled in February 1990: two Camp Withycombe wells [GW1, GW2] on the National Guard property, two fire protection wells [GW3, GW4], one residential well [GW5], and one background well [GW6] (Figure 8). Additionally, two city of Milwaukie public supply wells were also sampled (Tables 12 and 21). Drinking water at Camp Withycombe is supplied by Clackamas City Water (9). Apparently, there are monitoring wells at Camp Withycombe which were used to monitor hydraulic fluid leaks from vehicle maintenance (10).

The only organic compound exceeding background in off-site wells was trichloroethene (TCE), found in wells previously used by the city of Milwaukie. Several wells were not contaminated with TCE and are still in use. Trichloroethene was also found in on-site groundwater in the shallow aquifer. Based on shallow groundwater flow direction, shallow on-site contamination could migrate toward the city of Milwaukie wells. However, there are many other potential sources of TCE and other organic compounds in the area. No other organics were detected in the six off-site wells. Currently, EPA is monitoring the groundwater beneath the NWP&C site.

Inorganic elements were analyzed for the city of Milwaukie wells currently in use (Table 12). The only metal found in groundwater from the deep aquifer which exceeds our comparison values is manganese. The range of background manganese concentrations in groundwater of the area has not been defined.

The inorganic analyses for other off-site groundwater wells showed the following metals in excess of background concentrations and ATSDR's comparison values for drinking water: barium, chromium, lead, manganese, vanadium, and zinc. However, only one of these wells is being used for drinking water and the source(s) of elevated metals has not been defined. Although groundwater concentrations of some common earth crust metals (aluminum and iron) were also elevated, there are no ATSDR comparison values.

Ambient Air

Odorous emissions from the tar pots are recorded by OR DEQ in the town of Clackamas in September, 1983 (11). No health complaints were found on record at OR DEQ or Oregon Health Division during an ATSDR file review in June 1992. Air emissions from the site are discussed in the On-site Ambient Air section.

C. Quality Assurance and Quality Control

Quality assurance and quality control (QA/QC) samples were taken during site-related sampling events. Split samples, replicates and duplicates were used and background samples were taken. In general, the detection limits are low enough and do not exceed ATSDR comparison values. However, if they exceed comparison values, this was noted in the contaminant tables in Appendix A.

D. Physical and Other Hazards

Surface debris (material from burned and unburned buildings, burn-pile material, and deposits of large tar chunks) is a physical and chemical hazard on site. Piles of hardened tar-like substances lie on the surface and appear to continue below ground. Tarry and charred remains of a burned building were observed during the site visit. Debris from metal buildings presents a physical hazard due to sharp edges on the scrap metal. Surficial coal tar solids and residues are a chemical hazard. Empty quonset huts, which made the site attractive to trespassers, have been demolished (5).

PATHWAYS ANALYSES

In this section of the public health assessment, the possible exposure pathways are evaluated to help determine whether persons have, are, or will be exposed to contaminants associated with the site. Pathway analysis consists of five elements:

  1. identifying contaminants of concern,
  2. determining whether contaminants have/are/will be transported through an environmental medium,
  3. identifying a point of exposure (i.e., a place or situation where humans might be exposed to the contaminated media),
  4. determining whether there is a plausible route of human exposure (i.e., can the contaminant enter the body?), and
  5. identifying an exposed population (i.e., how many people, if any, are at the point of exposure).

An exposure pathway is considered complete when there is good evidence that all five elements exist. The presence of a completed pathway indicates that human exposure to contaminants has occurred in the past, is occurring, or will occur in the future. When one or more of the five elements of an exposure pathway are missing, that pathway is considered potential. The presence of a potential exposure pathway indicates that human exposure to contaminants could have occurred in the past, could be occurring, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present. The completed and potential exposure pathways and estimates of the number of exposed individuals are presented below and in Appendix B, tables 22 through 24.

A. Completed Exposure Pathways

Completed exposure pathways are indicated if exposure to a contaminant has occurred, is occurring now, or will occur in the future. The completed pathways are air, soil, and deep groundwater as discussed below.

Ambient Air Pathway

Based on historical records (11), a completed exposure pathway via ambient air is indicated for former workers at NWP&C. A review of the records was previously presented in the On-site Contaminant Section, Ambient Air subsection. Coal tar vapors were emitted from pipe coating activities, coal tar pots, and waste burn areas. The vapors included phenol and formaldehyde fumes (12) and probably the more volatile PAHs such as acenaphthene, anthracene, fluorene, and phenanthrene. Former workers were exposed to these contaminants through inhalation of vapors, oil aerosols, and dusts. In December of 1976, state health officials cited the company for excessive coal tar levels in one building and insisted that workers use respirators and wear coveralls in all buildings until air emissions were reduced (11). Approximately 75 workers operated at the site during a given year; workers may have been exposed to air contaminants over a 20 year time span (1956- 1976).

Soil Pathway

The soil pathway is considered to be completed because there is good evidence that all five elements of an exposure pathway exist. On-site soils are contaminated with PAHs and other organics, including PCBs. PAHs and PCBs are found within the upper six inches of soil and are therefore, accessible to persons on the site. The site is accessible to trespassers and has been used for additional business activities prior to clean-up (truck driving school and hay storage). Residential soil samples indicate contamination of nearby yards. There are naturally-occurring high levels of some heavy metals. Contaminants can enter the body through ingestion or inhalation of soil or dust. A rough estimate suggests that approximately 40 people, exclusive of the former workers, may have been exposed to soil contaminants: a group of trespassers, several residents, 10 to 20 truck trainees, and several hay workers. Actual numbers of exposed individuals may be higher or lower than this estimate. Additionally, since ODOT and an industrial park exist on Parcel A of the site, there is potential for human exposure to contaminated dusts and volatile organics in air during soil disturbing activities.

Groundwater Pathway - Deep Aquifer

Groundwater is a completed exposure pathway for residents who used the city of Milwaukie water supply wells due to past contamination of the well field by trichloroethene (TCE). The routes of exposure are ingestion and inhalation. The source(s) of TCE contamination have not been defined. There are multiple sources of TCE in the area. The city of Milwaukie water supply served approximately 19,000 people (2).

B. Potential Exposure Pathways

Potential exposure pathways are indicated if exposure to a contaminant could have occurred, could be occurring now, or could occur in the future. Potential exposure pathways are ambient air, soil gas, sediment, surface water, and shallow groundwater as discussed below. It is unlikely that exposure at levels of health concern will occur via these potential pathways if proper remedial measures are taken.

Ambient Air Pathway

The ambient air pathway is considered a potential exposure pathway for nearby residents, such as those of Clackamas. No data were found to characterize possible past exposure but historical records suggest that coal tar emissions reached Clackamas. Human exposure to coal tar emissions could have occurred. In addition, current and future workers in the adjacent industrial parks could be exposed to contaminants in air during remedial activities if proper measures are not taken. It is estimated that the industrial parks employ thousands of people.

Soil Gas Pathway

A data gap exists with respect to the soil gas pathway as no soil gas data has been collected. Therefore, many of the components of pathway analysis lack evidence. However, it is considered a potential exposure pathway via inhalation because of the volatile organic compounds present in the surface soil, alleged burial of waste in the subsurface, and high contaminated groundwater table.

Sediment Pathway

The sediment in the drainage ditches bordering the site and off-site (Deer Creek and south of Mather Road) is contaminated with PAHs, PCBs, and other organic compounds. PAHs can enter sediment through runoff or can be attached to dust particles in air and deposited on the ground by snow or rainfall. They can be transported miles from their site of origin (13). The sediment pathway is considered to be a potential exposure pathway: Deer Creek may be used by the local population because it runs through a grassy field to the north of NWP&C. The flooded sediment area to the south is fairly accessible and close to a residential area. However, the drainage ditches are narrow (about 2' wide by 1.5' deep) and are not very accessible to children or adults. People could swallow contaminated sediment could be incidentally ingested while in the areas of contamination or transport it to their residences on their persons or clothes. Exposure could also occur during skin contact.

Surface Water Pathway

Although no large bodies of surface water lie close to the NWP&C site, there are local creeks (Deer and Mount Scott Creeks) which according to water rights may be used for drinking and irrigation (2). Local creeks eventually drain into the Clackamas River, which is used for drinking water and fishing. The drainage ditches along the property boundaries of NWP&C are not very accessible and do not always contain water. No data were available for review on surface water PAH contamination. A few organic compounds were detected which are probably not site related: tetrachloroethene, trichloroethene, and vinyl chloride. Due to the lack of evidence on widespread and site-related contaminants, the surface water pathway was considered to be a potential exposure pathway. Residents using the local creeks or ditches may be exposed to contaminants by ingesting water (accidentally swallowing or using as drinking water), inhaling volatiles during irrigation, or by skin contact during such activities as fishing, swimming, or irrigating.

Groundwater Pathway - Shallow Aquifer

Although groundwater reviews to determine water usage have been conducted, to date no shallow drinking water wells have been found within a mile radius of the site (2). However, a door-to-door survey has not been conducted. Most Clackamas residents are connected to the Clackamas District water system, a protected surface water source (2). Contaminated groundwater in the shallow aquifer is considered a potential exposure pathway because no receptor population has been identified to date.

Since private wells reach the deeper aquifer, which may have elevated levels of heavy metals (2), there could be a receptor population for the deeper aquifer. Therefore, groundwater is considered a potential exposure pathway for residents who have private wells in the deep aquifer.

Food Chain Pathways

No data have been collected with respect to the food chain. No agricultural areas were observed within a half-mile of the site during the ATSDR site visit. Since local creeks may be used for irrigation, crops may be irrigated with contaminated surface water. PAHs which have sorbed to sediment can be accumulated by bottom-dwelling fish and other invertebrates (13). There are on-site berry bushes. It is unlikely that local populations will ingest biota that may have taken up contaminants from the site at levels of public health significance. Therefore, the food chain pathway is considered a potential exposure pathway.

PUBLIC HEALTH IMPLICATIONS

A. Toxicologic Evaluation

Introduction

This section will discuss the health effects in persons exposed to specific contaminants (for completed pathways), discuss health outcome data and address specific community health concerns. To evaluate health effects, ATSDR has developed a Minimal Risk Level (MRL) for certain contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer adverse health effects are unlikely to occur. MRLs are developed for each route of exposure, such as ingestion and inhalation, and for the length of exposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (equal to or greater than 365 days). ATSDR presents these MRLs in Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status. MRLs for site-specific contaminants are presented in Tables 25 -28, Appendix C.

Since ATSDR has no methodology to determine the amount of absorption of chemicals through the skin, ATSDR does not have MRLs for skin exposure. For this reason, it is difficult to determine the health effects from skin exposure.

ATSDR has determined that former workers on site and any persons who have worked, played or trespassed on the site were probably exposed to several contaminants in soil. Residents who live near the site may have been exposed to contaminants in soil and well water. Evaluation of exposures in this public health assessment is limited to individual contaminant exposures. Those contaminants are listed in Tables 25 - 28, Appendix C. To estimate the exposure dose, it was assumed that adults, non-pica children and children with pica behavior would ingest 50, 100 and 5000 milligrams (mg) of soil per day respectively. Children aged 1-3 years old are those at increased risk for pica behavior. However, pica children are unlikely to have been on the site due to limited site accessibility. Trespassers (including adults and children) are considered those persons who accessed the site. For water, we used the intake rate of 2 L/day for adults and 1 L/day for children.

Although it is probable that people were exposed to more than one contaminant, scientific data are very limited on the health effects of multiple contaminant exposure. The effects of multiple contaminant exposure can be additive, synergistic (greater than the sum of the single contaminant exposures), or antagonistic (less than the sum of the single contaminant exposures). Also, simultaneous exposure to contaminants that are known or probable human carcinogens could increase the risk of developing cancer. Although the evaluation of contaminants may underestimate synergistic effects, the estimates are designed to be highly protective of public health (maximum concentrations are used in the estimates).

Polynuclear Aromatic Hydrocarbons (PAHs)

PAHs are naturally-occurring or man-made chemicals formed during the incomplete burning of fossil fuels such as coal, oil, and gas, and other organic matter (13). There is little known use for most of these chemicals except for research purposes. A few of the PAHs are used in medicine and to make dyes, plastics, and pesticides.

Former workers and trespassers on the site were probably exposed to several PAHs in soils (Table 25) and probably in air. In addition, nearby residents were and are probably exposed to PAHs in soils from residential yards (Table 28). However, noncarcinogenic health effects are unlikely to develop in workers, trespassers, and nearby residents because of the low levels of exposure. An increased risk of cancer is also low or unlikely at these exposure levels. Noncarcinogenic and carcinogenic effects are discussed below.

&nbsp &nbsp &nbsp &nbsp &nbsp Noncarcinogenic Effects

The probable ingestion exposure of former workers to acenaphthene, anthracene, fluoranthene, fluorene, pyrene, and benzo(a)pyrene in soils did not exceed EPA's RfDs (Table 25). Noncarcinogenic health effects are not likely to occur in the former workers and trespassers because of the low levels of exposure. There are no MRLs or RfDs for benzo(g,h,i,)perylene, naphthalene, phenanthrene, benzo(a)anthracene, benzo(b)fluoranthene, chrysene, dibenz(a,h)anthracene, and indeno(1,2,3-c,d)pyrene. However, the total ingestion dose of all these PAHs did not exceed the RfDs for either anthracene, fluoranthene, fluorene, acenaphthene, pyrene, or the acute MRL for benzo(a)pyrene (Table 25). In addition, the total dose is about 10,000 times lower than the dose of a mixture of PAHs that caused liver problems or aplastic anaemia in laboratory animals (13). Noncarcinogenic health effects are unlikely to occur in former workers and trespassers because of the low levels of exposure to PAHs.

The probable exposure of nearby residents to fluoranthene, pyrene, and benzo(a)pyrene in soils did not exceed EPA's RfDs or ATSDR's acute MRL (Table 28). Noncarcinogenic health effects are unlikely to occur due to the low levels of exposure. Although there are no RfDs or MRLs for benzo(g,h,i)perylene, phenanthrene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene and indeno(1,2,3-c,d)pyrene, the total doses for either children or adults is some 100,000 - 100,000,000 times lower than the dose of PAHs that caused liver problems or aplastic anaemia in laboratory animals (13). Noncarcinogenic health effects are unlikely to occur in residents because of exposure to the low levels of PAHs.

The probable inhalation exposure of former workers and trespassers on the site to PAHs in indoor or ambient air cannot be determined because environmental data and other information are unavailable. Exposure to PAHs in the ditches on and near the site is considered unlikely because of limited access as documented in the environmental sections. Remedial workers can avoid exposure to PAHs if they wear personal protective equipment and follow the proper regulatory guidelines.

         Carcinogenic Effects

The EPA and the International Agency for Research on Cancer (IARC) consider benzo(a) anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene and ideno(1,2,3-c,d)pyrene to be probable human carcinogens. ATSDR used the toxicity equivalency factor (TEF) methodology in conjunction with the benzo(a)pyrene dose-response model and the dose additivity assumption to obtain estimates of cancer risk associated with exposures of former workers and trespassers on site, and residents off site to PAHs in soils. Based on this evidence, our calculations indicate that former workers and trespassers who were probably exposed to PAHs in soils at the site may be at low or no apparent increased risk of developing excess cancer over a lifetime. Nearby residents including adults and children who were probably exposed to PAHs in soils from residential yards may have no increased risk of developing cancer over a lifetime.

Other Organic Chemicals

Former workers and trespassers could also have been exposed to benzene, dibenzofuran, PCBs, tetrachloroethylene (PCE), 1,1,1-trichloroethane (TCA) in soils at the site (Table 25). Nearby residents could have been and may be exposed to bis/di(2-ethylhexyl)phthalate, di-n-octylphthalate and methoxychlor in residential soils (Table 28). Remedial workers can avoid exposure to organics if they wear personal protective equipment and follow the proper regulatory guidelines. Except for mild skin problems associated with exposure to dibenzofuran and some possible mild depression in serum immunoglobulins associated with exposure to PCBs, no noncarcinogenic health effects are likely from these exposures. An increased risk of cancer is also unlikely at these exposure levels.

Benzene

Benzene is a clear, colorless, and highly flammable liquid with a strong sweet odor. Benzene evaporates into the air very quickly and dissolves easily in water. Benzene is produced primarily from petroleum sources and is used mostly in the manufacture of other chemicals used to make plastics, synthetic rubbers, fibers, and resins. Benzene is also used to make drugs, dyes, pesticides and other agricultural chemicals, lubricants, solvents, and cleaning products (14).

Although there are no MRLS or RfDs for benzene, the estimated ingestion doses of benzene in soils for former workers and trespassers who were probably exposed on site are some 10,000,000 times lower than experimental doses that caused white blood cell problems in experimental animals (14). It is unlikely that former workers and trespassers would suffer any noncarcinogenic health effects.

The EPA and IARC consider benzene to be a human carcinogen. According to IARC, many case reports and case series have described the association of leukemia with exposure to benzene, either alone or in association with other chemicals (15). ATSDR has determined that former workers and trespassers who were likely exposed to benzene in soils at the site may have no increased risk of developing excess cancer over a lifetime.

Bis/Di(2-ethylhexyl)phthalate (DEHP)

DEHP is a man- made chemical that is added to plastics to make them flexible. Other names for this chemical are Platinol AH, Octoil, Silicol 150, Bisoflex 81, and Eviplast 80. DEHP is a colorless liquid with a slight odor.

Residents who live near the site were probably exposed to DEHP in residential soils. The estimated ingestion dose for adults and non pica children do not exceed EPA's RfD (Table 28). Adults and non pica children are unlikely to suffer any noncarcinogenic health effects. The estimated ingestion dose for pica children exceed EPA's RfD (Table 28). Liver problems have been associated with DEHP in dialysis patients (16). However, the estimated dose is some 1,000 times lower than the experimental doses that caused minor or less serious liver enzyme problems in rats over a period of two years (16). It is unlikely that children with pica behavior would suffer any carcinogenic health effects from their exposure. However, DEHP was not found in soils at the site.

Dibenzofuran

Dibenzofuran is released into the environment in atmospheric emissions from the burning of coal, organic matter, refuse, and diesel fuel. The chemical has also been found in tobacco smoke.

Former workers and trespassers on the site were probably exposed to dibenzofuran in soils (Table 25). Dibenzofuran was also detected in the shallow aquifer on site (Table 10). There is no Toxicological Profile or health guidelines for dibenzofuran. However, the concentration (830 ppm) of dibenzofuran in soils at the site far exceeds the maximum concentration of 3.6 ppm of dibenzofuran in sediments collected in 1983 from Eagle Harbor near Puget Sound, Washington state, which had been receiving creosote effluents (17). Little is known of any human health effects as a result of long-term exposure to low concentrations. It is probable that workers in close contact with soils may experience mild forms of skin problems. However, the amount of dibenzofuran in groundwater on the site is low, and is not likely to cause health effects in any potentially exposed population in the future should the chemical migrate into wells off site.

Di-n-octylphthalate

Di-n-octylphthalate is released into the environment principally in industrial wastewater from its production and use in plasticizers. There is some evidence that some forms of the chemical might occur naturally in certain plants and organisms.

Nearby residents probably were and may currently be exposed to di-n-octylphthalate in residential soils. There is no Toxicological Profile or health guidelines for di-n-octylphthalate. Di-n-octylphthalate is generally considered to be of slight to moderate toxicity. In addition, the estimated doses for pica children, nonpica children and adults are approximately 10,000 - 10,000,000 times lower than the average probable lethal human oral dose (17). However, it is difficult to determine whether health effects would occur in nearby residents because health guidelines and other information are unavailable.

Methoxychlor

Methoxychlor is a man-made chemical currently used in the United States for controlling insects. Methoxychlor is also known as DMDT, Malate, or Metox. Pure methoxychlor is a pale-yellow powder with a slightly fruity or musty odor. It does not easily evaporate into air or dissolve in water.

Residents who live near the site were and may probably be exposed to methoxychlor in residential soils (Table 28). However, the estimated doses for nonpica children and adults do not exceed EPA's RfD (Table 28). Adverse health effects are unlikely to occur in adults and nonpica children because of exposure to low levels of methoxychlor. The estimated ingestion exposure of pica children exceeded EPA's RfD (Table 28). However, the estimated dose for pica children was some 10,000 lower than the highest dose that did not cause any adverse health effects in laboratory animals (18). Pica children are not likely to suffer any adverse health effects from exposure to the levels of methoxychlor in soils. However, methoxychlor found in residential soils cannot be traced to the site.

Studies in animals and humans are inconclusive about the possible carcinogenicity of methoxychlor. Therefore, IARC and the EPA have determined that methoxychlor is not classifiable as to its human carcinogenicity.

Polychlorinated Biphenyls (PCBs)

PCBs are a group of man-made chemicals that contain 209 individual compounds with varying harmful effects. There are no known natural sources of PCBs in the environment. PCBs are either oily liquids or solids and are colorless or light yellow in color. Since 1974, all uses of PCBs in the United States have been confined to closed systems such as electrical capacitors and transformers, vacuum pumps, and gas-transmission turbines. PCBs are no longer produced in the United States, except for limited research, and import and export of PCBs have not been allowed since 1979 (19).

Former workers and trespassers were probably exposed to PCB mixtures containing mainly Aroclor 1254 in soils (Table 2). The estimated ingestion doses of PCBs for adults and children exceed the MRL or RfD by 100 - 1000 times (25). The estimated ingestion dose, for children and adults, of PCBs detected in groundwater within the shallow aquifer on the site (Table 10) is also higher than the MRL or the RfD. It is possible that some mild depression in serum immunoglobulins might occur in former workers and trespassers who because of the high levels of PCBs in soils. Similarly, residents who use well water in Milwaukie might be adversely affected in future should the PCBs migrate from the shallow aquifer on site and contaminate any drinking water.

The EPA and IARC consider PCBs to be probable human carcinogens. A slight increase in the incidence of cancer, particularly melanoma of the skin, has been reported in a small group of men exposed occupationally to a PCB mixture of Aroclor 1254 (15). Former workers and trespassers who were probably exposed to PCBs might have a low or no apparent increased risk of developing excess cancer over a lifetime.

Tetrachloroethene (PCE)

PCE is a colorless, nonflammable liquid with an ether-like odor. It is practically insoluble in water. PCE is used practically in dry cleaning and textile processing. It is also used as cooling gas, insulating fluid, an anthelminthic, and in the manufacture of other chemicals and products including fluorocarbons, paint, adhesives, aerosols and coatings (15, 20).

The estimated ingestion doses of PCE in soils (Table 1) for former workers and trespassers who were probably exposed at the site do not exceed the RfD (Table 25). Former workers and trespassers are unlikely to suffer noncarcinogenic health effects because of exposure to low levels of PCE. PCE was also detected in groundwater within the shallow aquifer on site (Table 10). However, the amount in the aquifer is not likely to pose any health problems in future because of the low levels that might migrate with the contaminated groundwater. In addition, biodegradation processes will, over time, substantially reduce PCE in the shallow aquifer.

IARC considers PCE to be a possible human carcinogen. According to the EPA, there is limited evidence that PCE has caused cancer in at least one laboratory rodent species. Although some epidemiological studies suggest a possible association between long-term occupational exposure to PCE and increased lymphatic malignancies and urogenital cancers, the evidence is regarded by IARC as inconclusive because the workers were also exposed to petroleum solvents and other dry cleaning agents as well as PCE. However, workers and trespassers who were probably exposed to the highest level of PCE may have no apparent increased risk of developing excess cancer over a lifetime.

1,1,1-Trichloroethane

1,1,1-trichloroethane is a colorless man-made chemical which does not occur naturally. It has a sweet yet sharp odor, and evaporates quickly and becomes a vapor in the air.

Former workers and trespassers were probably exposed to 1,1,1-trichloroethane in soils (Table 25). However, the estimated doses for the former workers and trespassers do not exceed the RfD. Noncarcinogenic health effects are unlikely to occur in these persons because of the low levels of exposure. IARC and the EPA do not consider 1,1,1-trichloroethane to be a carcinogen (21).

Trichloroethene (TCE)

TCE is also known as Triclene, Vitran, and other names used in industry. It is a nonflammable, colorless liquid at room temperature with an odor similar to ether or chloroform. It is a man-made chemical that does not occur naturally in the environment.

Former workers and trespassers on the site were probably exposed to TCE in soils. However, although there are no chronic MRLs or RfD for TCE, the estimated ingestion doses do not exceed the intermediate MRL (Table 25). In addition, the highest estimated dose of TCE was some 100,000,000 times lower than the experimental dose that caused kidney problems in laboratory animals after 103 weeks of chronic/longterm exposure (22). It is highly unlikely that former workers and trespassers would suffer any noncarcinogenic health effects because of the low levels of exposure. In addition, information in the Environmental Contamination and Other Hazards section of this document indicates that trichloroethene found in groundwater within the shallow aquifer on site (Table 10) could contaminate the city of Milwaukie wells. However, the estimated ingestion doses for adults and children, who might be potentially exposed in future, do not exceed the intermediate MRL for TCE. Moreover, the estimated doses are about 1,000 - 10,000 times the experimental doses that caused minor kidney problems or inability to coordinate muscle movement in laboratory animals after 103 weeks of chronic/longterm exposure (22). In addition, the biodegradation products of TCE (dichloroethene and vinyl chloride) would also be insignificant because of the low levels of TCE in the shallow aquifer. Moreover, potential exposure to carbon tetrachloride, chloroform, 1,2-DCE, and vinyl chloride (Table 10) would also be insignificant due to degradation processes within the shallow aquifer. These processes would substantially reduce the levels that might migrate from the aquifer on site.

IARC does not consider TCE to be a human carcinogen. According to the EPA, there is limited evidence that TCE has caused cancer in at least one rodent species. Based on this evidence we estimate that former workers and trespassers who were probably exposed to the highest levels of TCE in soils or residents who could be exposed to TCE in groundwater near the site have no increased risk of developing excess cancer over a lifetime.

Metals

Former workers, trespassers, and nearby residents were probably exposed to various metals through one or more completed pathways (Tables 23 - 28). No adverse health effects are predicted from any of these exposures, except for copper and lead. Copper exposures in children may cause minor stomach irritations. It is difficult to determine which health effects could occur for lead because health guidelines and other information are unavailable. Metals in the City of Milwaukie wells were evaluated but were found unlikely to result in health effects.

Aluminum

Former workers and trespassers on the site, and nearby residents were probably exposed to to aluminum. The estimated ingestion doses of aluminum in soils for former workers and trespassers at the site do not exceed the RfD (Table 25). Therefore, they are unlikely to suffer any adverse health effects because of exposure to low levels of aluminum. Nearby residents who use well water are probably exposed to aluminum in water. However, the estimated ingestion dose of aluminum in well water did not exceed the RfD (Table 26). Therefore, adverse health effects are unlikely to occur because of exposure to low levels of aluminum. The ingestion dose of aluminum in well water for children exceeded the RfD. However, the estimated dose for the children was far lower than the dose of pure aluminum that caused no adverse health effects in laboratory animals after 390 days of exposure (23). In addition, the estimated dose for children is only approximately 10 per cent of the estimated daily ingestion of 20 mg/day. Moreover, retention rate of absorbed aluminum range from 0.3% - 10% only (23). Therefore, the children are unlikely to suffer any adverse health effects because of exposure to low levels of aluminum in well water.

Antimony

Former workers and trespassers were probably exposed to antimony in soils at the site (Table 25). However, the estimated ingestion exposure did not exceed the RfD for antimony. Moreover, the estimated doses of antimony were 100 - 10,000 times lower than the experimental dose that caused a less serious increase in serum cholesterol levels in laboratory rats after nearly 3.5 years of exposure (24). Adverse health effects are unlikely to occur because of the low levels of exposure.

Potential exposure to antimony in groundwater on site is also insignificant because of the low levels of antimony in groundwater (Table 12).

Arsenic

Former workers and trespassers, and nearby residents were probably exposed to arsenic in soils. However, the ingestion exposure of adults and children did not exceed the RfD (Tables 25 and 28). Moreover, the estimated doses of arsenic were some 10,000 times lower than dose that did not cause any adverse health effects in humans who were occupationally exposed to arsenic between 1-2 years (25). Adults and children are unlikely to suffer any noncarcinogenic health effects because of exposure to low levels of arsenic.

IARC and the EPA consider arsenic to be a human carcinogen. However, adults and children exposed to arsenic in soils at the site and residential yards may have no risk of developing cancer over a lifetime.

Potential exposure to arsenic in groundwater on site is also insignificant because of the low levels of arsenic in groundwater (Table 12).

Barium

Former workers, trespassers, and nearby residents were probably exposed to barium in soils (Table 25 and 28). Nearby residents (Table 26) who use private wells off site may be exposed to barium in well water. The ingestion exposure to barium in soils and well water did not exceed the RfD for children or adults. Children and adults exposed to barium in soils or groundwater on or near the site are unlikely to suffer any adverse health effects because of exposure to low levels of barium.

However, the probable ingestion exposure of pica children to barium in residential soils barely exceed the RfD. Little is known about the health effects of long-term exposure to small amounts of barium in humans. The estimated dose is lower than the dose that did not cause any adverse health effects in experimental animals after two years of exposure. Moreover, the estimated dose is also lower than the experimental dose that caused a minor increase in blood pressure in laboratory animals after 16 months of exposure (26). It is unlikely that pica children would suffer any adverse health effects because of the low levels of exposure. Potential exposure to barium in groundwater on and off site is also insignificant because of the low levels of barium in groundwater (Tables 12 and 21).

Beryllium

Although former workers and trespassers were probably exposed to beryllium in soils, their ingestion exposure did not exceed the RfD (Table 25). In addition, the estimated doses are some 10,000,000 times lower than experimental dose that either caused minor enhancement of urinary excretion of glucose or caused no adverse effects in laboratory animals after 3 years of chronic/longterm exposure (27). Former workers and trespassers are unlikely to suffer any adverse health effects because of exposure to low levels of beryllium.

IARC and the EPA consider beryllium to be a probable human carcinogen. The former workers and trespassers who were probably exposed to beryllium in soils at the site may have no increased risk of developing excess cancer over a lifetime.

Chromium

Former workers and trespassers on the site, and nearby residents were probably exposed to chromium III in soils (Tables 25 and 28). However, the ingestion exposure does not exceed the RfD. In addition, the estimated doses are between 1,000 and 10,000 times lower than experimental doses that caused no adverse health effects in laboratory rats after one year of exposure (28). Adverse health effects are unlikely to occur because of exposure to low levels of chromium. Chromium III has not been classified as a carcinogen by IARC and the EPA.

Cobalt

Former workers and trespassers on the site, and nearby residents were probably exposed to cobalt in soils (Tables 25 and 28). There are no MRLs or RfDs for cobalt. In addition, there is little information on the health effects of long-term ingestion in humans. However, the estimated doses of cobalt were some 100 to 1,000 times lower than doses that caused heart problems in humans after 12-32 weeks of intermediate exposure (29). Adverse health effects are unlikely to occur in adults and children who may have been exposed to cobalt in well water.

Copper

Former workers and trespassers on the site, and nearby residents were probably exposed to copper in soils (Tables 25 and 28). Nearby residents who use private wells may be exposed to copper in well water (Table 26). However, the estimated ingestion doses of copper in soils or well water do not exceed the estimated safe and adequate daily dietary intake (ADI) recommended by the NRC (30) for persons living in the United States (Tables 25, 26, and 28). In addition, the concentration of copper (0.028 ppm) in well water is far lower than either the PMCL/PMCLG (Table 21) or the ambient water quality criterion of 1 mg/L. Adverse health effects are unlikely to occur in adults because of exposure to low levels of copper through a single completed exposure pathway. Potential exposure to copper in groundwater on and off site is insignificant because of the low levels of copper in groundwater (Tables 21 and 21).

However, children were and may now be exposed to copper in residential soils as well as in well water. The total estimated ingestion dose is some 10 times higher than the dose that caused minor stomach pains or vomiting in humans after exposure for 1.5 years (31). The probability of the children experiencing any minor stomach irritations may depend on the magnitude of copper ingested from other sources, such as diet. According to IARC, copper is not classifiable as a human carcinogen.

Iron

Former workers and trespassers on the site, and nearby residents were probably exposed to iron in soils (Tables 25 and 28). Nearby residents may also be exposed to iron in well water (Tables 26 and 27). The ingestion exposure to iron in soils and well water in some residents near the site (Tables 26 and 28) did not exceed the RDAs established by the NRC for persons living in the United States (30). Moreover, the highest estimated ingestion dose is by far lower than iron ingested daily from ordinary diets in the United States. In addition, only 10% of iron ingested is absorbed. Adults and children are unlikely to suffer any adverse health effects because of the low levels of exposure to iron.

Lead

Former workers and trespassers on the site, and nearby residents were probably exposed to lead in soils (Tables 25 and 28). There are no MRLs or RfDs for lead. Inhaling or ingesting 500-1,000 micrograms of lead per gram of soil was previously considered by the CDC as a level that could cause elevated blood lead levels in children. The CDC has since withdrawn this guideline due to the seriousness of lead exposure among children in the United States.

Lead concentrations found in soils on and off site exceed background levels (Tables 3 and 15). However, only small concentrations of lead, below the action level were detected in off-site wells (Tables 26). Lead is one of the toxicants of concern associated with adverse effects on red blood cells, mental and physical development of infants and children exposed at very low environmental levels (32).

Experimental and epidemiological studies have indicated that blood lead levels in the range of 10-15 micrograms per deciliter, or lower, are likely to produce toxicity. The EPA has developed an uptake/biokinetic lead model that provides for the estimates of blood lead levels of children by evaluating intake from various environmental media, food, and paint. This model is still being evaluated by the EPA. It is difficult to determine which health effects could occur because health guidelines and other information are unavailable.

IARC and the EPA consider lead and inorganic compounds to be possible human carcinogens. Lead acetate and lead phosphate have also been determined by the National Toxicology Program (NTP), an organization within the U.S. Department of Health and Human Services, to cause cancer in humans. This conclusion is also based on animal studies.

Manganese

Former workers and trespassers on the site, and nearby residents were probably exposed to manganese in soils (Tables 25 and 28). Nearby residents and some residents in Milwaukie who use well water were probably also exposed to manganese (Tables 26 and 27). However, the estimated exposure doses do not exceed the RfD. Adverse health effects are unlikely to occur because of exposure to low levels of manganese (33). Potential exposure to manganese in groundwater off site is also insignificant because of the low levels of manganese in groundwater (Table 21).

Nickel

Former workers and trespassers on the site, and nearby residents were probably exposed to nickel in soils (Tables 25 and 28). The estimated ingestion dose of nickel levels in adults and children do not exceed the RfD. In addition, the estimated doses are some 1,000 -100,000 times lower than experimental doses that caused decreased liver weight in laboratory rats after two years of exposure (34). The amounts of nickel in soils are unlikely to cause any noncarcinogenic health effects. IARC and the EPA consider nickel compounds to be human carcinogens. However, persons exposed to nickel in soils may have no increased risk of developing excess cancer over a lifetime.

Vanadium

Former workers and trespassers on the site, and nearby residents were probably exposed to vanadium in soils (Tables 25 and 28). Nearby residents who have private well water and residents in Milwaukie who use municipal well water may be exposed to vanadium in well water (Tables 26 and 27). There are is no chronic MRL or RfD for vanadium. However, the estimated ingestion doses for adults and children do not exceed ATSDR's intermediate oral MRL. In addition, the highest estimated dose was some 1,000 times lower than the experimental dose of vanadium that caused less serious lung problems in laboratory animals after two generations of long-term exposure (35). Adverse health effects are unlikely to occur because of exposure to low levels of vanadium.

Zinc

Former workers and trespassers on the site, and nearby residents were probably exposed to zinc in soils (Tables 25 and 28). Nearby residents may also be exposed to zinc in well water (Tables 26 and 27). The are no MRLs or RfDs for zinc. However, the estimated exposure doses do not exceed the RDAs established by the NRC (28) for persons living in the United States (Tables 25 - 28). In addition, most of the estimated doses are some 10,000 times lower than the amount of zinc that caused less serious decrease of red blood cells in humans after eight years of exposure (36). Adverse health effects are unlikely to occur because of exposure to low levels of zinc. Potential exposure to zinc in groundwater off site is also insignificant because of the low levels of zinc in groundwater (Table 21).

B. Health Outcome Data Evaluation

The state of Oregon does not operate cancer/tumor or birth defects registries. However, the vital statistics unit of the Division of Health in the Department of Human Resources reported no increases in annual infant deaths in Clackamas county over state rates. Exposure to lead at this site is unlikely to cause perinatal mortality (deaths occurring before, during, and after and up to four weeks after birth). Specific health outcome data for the population living near the site is unavailable. Health outcome data for Clackamas county is not applicable because it is diluted by the large cosmopolitan population of the area. In addition, Clackamas county did report increases in causes of death over state rates. Mortality figures do not adequately describe exposure- death relationships.

C. Community Health Concerns Evaluation

We addressed each of the community concerns about health as follows:

  1. Will the health of children attending Clackamas Elementary School be affected by the site?

    The health of children attending Clackamas Elementary School is unlikely to be affected by the site. The Clackamas Elementary School is approximately 2000 feet southwest of the site. Children would have to cross a major road, 82nd Drive, railroad tracks, and walk a considerable distance to be in areas of known contamination. There have been on-site fires at Northwest Pipe and Casing. The direction and severity of the wind would have affected the magnitude of any fumes, smoke and particulate matter in ambient air. School officials and residents have not indicated that children were exposed to smoke or chemical fumes as a result of the site fires. Although contaminated dust may be generated during construction phases at the site, the use of proper dust suppression techniques should prevent exposures.



  2. Will the health of persons attending the annual rodeo event at Camp Withycombe be affected by the site?

    The health of persons attending the annual rodeo event at Camp Withycombe is unlikely to be affected by the site. The rodeo activity generates some dust and may expose participants and spectators to site contaminants in dust and ambient air. A toxicological evaluation indicates that even if people who attend the annual rodeo event are exposed to contaminants in soils off site, they will not be exposed at levels that could cause adverse health effects because of the low levels of exposure and the short duration of exposure.

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