PRELIMINARY PUBLIC HEALTH ASSESSMENT
PACIFIC SOUND RESOURCES
SEATTLE, KING COUNTY, WASHINGTON
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
Tables in this section list contaminants of concern. Contaminants listed in subsequent sections of this preliminary public health assessment are evaluated in order to determine whether exposure could have an effect on the public's health. Contaminants of concern are selected according to the following factors:
In order to determine contaminants of concern, maximum contaminant concentrations in soil are compared to available comparison values. Contaminant concentrations in soil which exceed noncarcinogenic or carcinogenic comparison values were selected for further evaluation.
Contaminants listed in the following tables are determined to be of concern using the above method. Comparison values are screening values, and the listing of a contaminant in the following tables does not mean an adverse health effect will result from exposure. Potential health effects from exposure to contaminants listed in the following tables are evaluated in the Public Health Implications section of this preliminary public health assessment.
Contaminants requiring further evaluation are selected using medium-specific comparison values. Comparison values used to determine noncarcinogenic and carcinogenic contaminants of concern include Environmental Media Evaluation Guides (EMEGs), Reference Dose Media Evaluation Guides (RMEGs), and Cancer Risk Evaluation Guides (CREGs). EMEGs are calculated from ATSDR chronic Minimal Risk Levels (MRLs) using exposure variables such as ingestion rate and body weight. Currently, EMEGs only exist for soil, water, and air. The MRL is an estimate of daily human exposure to a contaminant below which noncancer adverse health effects are unlikely to occur. MRL-based comparison values were calculated and used to screen contaminants for further evaluation based on noncarcinogenic health effects. Comparison values were calculated using chronic RfDs for chemicals which did not have chronic MRLs. These values are called RMEGs. RfDs represent an estimate of daily human exposure to a contaminant below which noncancer, adverse health effects are unlikely. CREGs are estimated contaminant concentrations based on the probability that one additional cancer case may occur in excess of the number that will be expected to occur among one million people (assuming they have been exposed to the contaminant for a lifetime).
Toxic Chemical Release Inventory
To identify possible facilities that could contribute to contamination near the PSR site, the WDOH searched the Toxic Chemical Release Inventory (TRI) Database by zip code for all available years (1987, 1988, 1989, 1990 and 1991). TRI was developed by the Environmental Protection Agency from information regarding chemical releases into air, water and soil, as provided according to law by certain industries. TRI contained information documenting over 40 chemical releases which occurred at PSR site located at 2801 S.W. Florida Street, Seattle, WA 98516.
Environmental investigations of the PSR site have identified wood preserving chemicals in surface soils, subsurface soils, groundwater, and marine sediments. Potential contamination sources include current and historical treatment and storage areas such as retorts, transfer table areas, drip areas, chemical storage tanks, retort and transfer table discharge pits, treated stock storage areas, spill areas, storm water discharge areas, and loading areas (1).
Soils
Although a number of environmental investigations have been conducted at the PSR site, soil data evaluated for this preliminary public health assessment was limited. Soil data for the PSR site was collected during a transfer table investigation (1984); during phase 1 and phase 2 RCRA investigation (1988); EPA environmental sampling investigation (1988); ETI Risk Assessment (1990); and during a hydrogeologic data collection report investigation (1990), and during two additional supplemental borings investigations (1991).
Using existing data, it was not possible to determine the depth of all contaminants of concern detected in soil borings. Soil data were presented as composites for various boring depths. Although surface soils are believed to be contaminated with wood preserving contaminants, no data was available for on-site surface soils at a depth of three inches or less.
Contaminants were detected in soil samples collected from soil borings located throughout the PSR site. The process area, located north of S.W. Florida street, appears to have the most highly contaminated soils on-site (Figure 5) primarily in areas around the transfer table and in treated wood storage areas. Concentrations of PCP (4,100 ppm) were detected 1.5 feet below ground surface, PAHs (12,190 ppm) were detected three feet below ground surface, and arsenic (11,679 ppm) were detected 1.5 feet below ground surface in the transfer table pit process area (soil from the transfer table has been excavated). The highest soil contaminant concentrations from areas south of S.W. Florida street were PAH's (1,018 ppm), and PCP (2.0 ppm) 1.5 feet below ground surface. The highest concentrations of arsenic from the area south of S.W. Florida street were (26.3 ppm) at a depth of 16.5 feet below ground surface.
A total of 28 soil borings were conducted during the transfer table investigation. Twelve of the boring were drilled in the transfer table pit and sixteen borings were drilled around the perimeter of the transfer table pit (15). Soil samples were analyzed for PAHs, tetra and penta polychlorinated phenol, arsenic, chromium, copper and zinc, dibenzodioxins and dibenzofurans. In 1990, contaminated soil was excavated from under the transfer table and stockpiled on the PSR site (15).
The phase 1 RCRA investigation consisted of six soil borings, two of which were located in tank area 2, and the other four located southeast of the tie mill area. Phase 2 of the RCRA investigation consisted of 16 soil borings, nine of which were located west of the west shed and three were located in tank area 1, and four were located in tank area 2 and 3. Soil samples from the phase 1 and 2 investigation were analyzed for arsenic, chromium, copper, zinc, PCP, and PAHs. Soil samples were analyzed for arsenic, chromium, copper, and zinc, PCP, and PAHs. Laboratory QA/QC data documentation was not available for the phase 1 investigation (15).
A total of 84 soil borings have been made on-site during the supplemental boring investigations from 4.5 feet to 105 feet below ground surface (15). Detailed logs have been maintained for 67 of the borings. Soil samples were analyzed for metals (arsenic, chromium, copper, and zinc), total petroleum hydrocarbons, semi-volatile organic compounds, PAHs, pentachlorophenol, cyanide, and dioxins (15). Analytical soil data from the borings investigations is being compiled and was not available for review.
According to the Current Conditions Report for PSR, the distribution of contaminants indicate leaks and spills in the process area have had the greatest impact on shallow soils. Creosote, and elevated levels of PAHs were identified in under the main shed, the dock area, and in tank area 2 and 3. Elevated concentrations of arsenic were identified beneath the transfer table (prior to removal) and tank area 2 and 3, and PCP was also documented in tank area 2 and 3 (15).
Table 1 contains maximum contaminant concentrations of on-site soils at PSR. Although the soil data for the PSR site does not characterize the extent of surface soil contamination, it represents the only data available from the PSR study area, and has been evaluated despite this limitation.
TABLE 1 - Range of Contaminant Concentrations in On-site Soils (1).
| Contaminant | Minimum Concentration (mg/kg) |
Maximum Concentration (mg/kg) |
Depth Inches |
Comparison Value (ppm) |
Source |
| Arsenic | 0.100 | 11679.0 | 18.0 | 0.4 | CREG |
| *PAH's | 0.001 | 300.0 | 72.0 | 0.1 | CREG |
| Lead | 12.0 | 340.0 | None | None | |
| Mercury | 13.0 | 47.0 | None | None | |
| Pentachlorophenol | 0.005 | 4100.0 | 18.0 | 6.0 | CREG |
Groundwater
Groundwater monitoring wells were installed on-site during four investigations which were conducted between 1983 and 1990. A total of 36 monitoring wells have been identified on-site which have well construction information, and 25 monitoring wells were identified on-site but have limited information available (1). At the north end of the PSR site the general groundwater flow direction is north/northwest and toward the west at the south end of the PSR property (1). The deepest monitoring wells on-site are approximately 61 feet below ground surface (1). Dense non-aqueous phase liquids (DNAPLs) as well as light non-aqueous phase liquids (LNAPLs) have been detected in on-site monitoring wells located near the process area north of Florida street.
The highest contaminant concentrations in groundwater monitoring wells occur in the process area north of Florida street, while contaminant concentrations in monitoring wells located south of Florida street are substantially lower than those north of Florida street (1).
Contamination of property surrounding the PSR site is presently being evaluated as part of the Southwest Harbor Redevelopment Project. Large portions of property surrounding the PSR site are presently used for industrial activities, and other portions of property also consist of currently abandoned industrial property. A number of sites exist in this area and are being investigated under state and federal cleanup laws.
C. Quality Assurance and Quality Control
This preliminary public health assessment relies upon information provided in the referenced documents and assumes that adequate quality assurance and quality control measures were followed regarding chain of custody, laboratory procedures, and data reporting. The validity of the analysis and conclusions drawn in this preliminary public health assessment are dependent upon the completeness, relevance, and reliability of the referenced information.
Existing ground cover at the PSR facility consists of soil, wood, cement, and asphalt. Leaks, spills,
and drippings from treated wood make wood surfaces on the west and main slip areas slippery,
particularly following incidents of precipitation. These areas do not have railings and are therefore
considered a potential safety hazard for site workers. Uncovered retorts and wood debris are piled
in treated wood drip areas. These piles of debris also represent a potential physical hazard to site
workers. Although the PSR site is fenced on two sides, on-site debris and slippery wood surfaces
in the main and west slip areas represent physical hazards primarily to on-site workers and
trespassers accessing the site by boat or from the areas of the site which are not restricted by a fence.
In order to determine if exposure to contaminants from the PSR site has occurred in the past, is currently occurring, or may occur in the future, exposure pathways are evaluated in this section. An exposure pathway contains the following five elements:
Completed exposure pathways contain all five elements and indicate that exposure to a contaminant has occurred in the past, is currently occurring, or may occur in the future. Potential exposure pathways must have at least one element missing, but the potential to exist. Potential exposure pathways indicate that contaminant exposure may have occurred in the past, could presently be occurring, or could possibly occur in the future. An exposure pathway is removed from consideration if one of the five elements is missing and will never be present.
A. Completed Exposure Pathways
Presently, no completed human exposure pathways have been identified for the PSR site. The completeness of environmental data from previous PSR environmental investigations varies significantly and there is limited laboratory quality assurance/quality control information available for soil data (1).
B. Potential Exposure Pathways
A number of potential human exposure pathways exist at the PSR site involving wood preserving contaminants present in surface soil, subsurface soil, groundwater, seafood, and sediments. Potential human exposure pathways which may have occurred in the past, may be currently occurring, or may occur in the future at the PSR site are listed in Table 2.
Surface Soil Pathway
Potential routes of exposure are ingestion and dermal contact with contaminated surface soil, and inhalation of contaminated wind-born dust by on-site workers or remedial workers in present or historic product storage or process areas. The extent of surface soil contamination within the PSR upland area is presently unknown. This represents a data gap. Characterization of upland surface soils (0 - 3 inches in depth) at PSR site is necessary to assess the public health implications of the surface soil pathway.
Subsurface Soil Pathway
Contaminated subsurface soil may be exposed if contaminated areas are excavated. Exposure routes of potential concern for subsurface soil include ingestion and dermal contact with excavated contaminated subsurface soil, and inhalation of wind-born contaminated dust by on-site workers or remedial workers in present or historic product storage or process areas. Subsurface soil investigations have been conducted to determine the extent of contamination in the PSR study area. However, the quality of the analytical data reported is inconsistent (15). Although the data is used to qualitatively identify areas of contamination, this data is not sufficient to evaluate human exposure. This represents a data gap. Further characterization of subsurface soils at PSR is necessary to adequately assess the public health implications of the subsurface soil pathway.
Groundwater Pathway
Exposure to potentially contaminated groundwater depends upon use of contaminated wells. Potential routes of exposure to contaminated groundwater include inhalation and dermal contact. Groundwater at the PSR site is not considered potable drinking water due to high salinity. The number of wells located on or within a one mile radius of the PSR site which could be used for occupational purposes is presently unknown. Groundwater usage on-site or within a one mile radius of the site is presently unknown, and is necessary to determine the public health implications of the groundwater pathway. The extent of groundwater contamination and flow direction in the PSR study area is presently being evaluated under a RI/FS supervised by EPA.
Sediments Pathway
Surface water runoff is a primary transport mechanism for contaminated soils into surface water and sediments. Storm drains are also a major source of sediment contamination. Potential routes of future human exposure from contaminated sediments may include dermal contact by remedial workers during site cleanup activities. If future use of the PSR includes creation of public beaches for recreational use, recreational beach users may be exposed to contaminated sediments via dermal contact.
Bottomfish/Shellfish
Past, current, and future exposure from ingestion of contaminated bottomfish and shellfish harvested from PSR off-shore area is possible. Consumption of seafood may represent an important exposure if seafood is harvested from the PSR study area. During the site visit no signs were observed recommending against consumption of seafood from PSR shoreline areas.
TABLE 2 - POTENTIAL EXPOSURE PATHWAYS
| Pathway Name | Environmental Pathway Elements | Time | ||||
| Source | Environmental Media |
Point of Exposure | Route of Exposure | Exposed Population |
||
| Surface Soils | Retorts, chemical spills and leaks in storage & treated wood transfer areas. | Surface Soils | Present & Historic Process and Storage Areas | Ingestion Inhalation Dermal Contact | On-site & Remedial Workers | Past Present Future |
| Subsurface Soils | Retorts, chemical spills and leaks in storage & treated wood transfer areas | Subsurface Soils | Present & Historic Process and Storage Areas | Ingestion & Dermal Contact | On-site & Remedial Workers | Past Present Future |
| Intertidal Sediments | Retorts, chemical storage and treated wood transfer areas | Sediment | Industrial and Public Beaches | Dermal Contact | Recreational Users & Remedial Workers | Past Future |
| On-site wells | Retorts, chemical storage and treated wood transfer areas | Groundwater | On-site Wells | Inhalation & Dermal Contact | On-site & Remedial Workers | Past Present Future |
| Bottomfish | Retorts, chemical storage and treated wood transfer areas | Bottomfish Tissue | Southern shore of Elliott Bay | Ingestion | Recreational & Subsistence Consumers | Past Present Future |
| Shellfish | Retorts, chemical storage and treated wood transfer areas | Shellfish Tissue | Southern shore of Elliott Bay | Ingestion | Recreational & Subsistence Consumers | Past Present Future |
There are currently no indications of completed exposure pathways for the PSR site. The depth of soil samples could not be determined for all of the contaminants of concern. Therefore, contaminants of concern were assumed to be at least equivalent to contaminant levels present in PSR on-site surface soils, which are considered to be less than three inches in depth.
Populations having potential for exposure to PSR contaminants include on-site workers, trespassers, remedial workers, recreational beach users, recreational and subsistence fisherman and family members consuming bottomfish or shellfish. On-site workers may have become exposed to contaminants present in surface soil and subsurface soil from ingestion or dermal contact. Remedial workers involved in upland and sediment cleanup may also become exposed to contaminants present in surface soils and subsurface soils through ingestion or dermal contact. On-site workers and remedial workers may be exposed to contaminants present in groundwater from inhalation or dermal contact. Specific health effects likely to occur from past exposure to contaminants cannot be determined because the extent of past exposure is uncertain. Seafood consumption information is necessary to determine the duration and level of exposure expected from subsistence consumption of bottomfish or shellfish harvested from the PSR study area.
This section examines health effects which may occur in individuals potentially exposed to contaminants present at the PSR site. In order to evaluate potential health effects, health guidelines (MRLs or RfDs) are compared to exposure dose estimates to determine if adverse health effects are likely to occur from exposure to contaminant concentrations present in surface soil. MRLs are estimates of daily human exposure to a chemical that is likely to be without an appreciable risk of deleterious effects (noncancerous) over a specified duration of exposure. MRLs are derived by ATSDR, and are based on systemic, noncarcinogenic effects. RfDs are derived by EPA, and are estimates of the daily exposure to a contaminant that is not likely to result in adverse noncarcinogenic health effects. Comparing estimated exposure doses to MRLs, RfDs, and other information, allows for an evaluation of health effects which may result from exposure to contaminants present at the PSR site.
If an MRL or RfD is not available to evaluate a contaminant, the estimated contaminant exposure is still reviewed in this section. To evaluate possible health effects, estimated daily exposure doses are compared to exposure levels (NOAELs) below which no adverse health effects have been observed or to lowest exposure levels (LOAELs) at which adverse health effects have been observed in experimental studies. Data from human studies is used preferably, but animal studies can be used to indicate possible human health effects.
The following are descriptions and definitions of concepts and terminology used to describe potential adverse human health effects of individual compounds. Health effects discussed in this section may result from acute, intermediate, and chronic exposures to individual contaminants. Acute exposure refers to an exposure duration of minutes to less than 14 days, intermediate exposure refers to a longer duration of 15 days to 364 days, and chronic exposure refers to an exposure duration of more than 364 days. A person may be exposed to a chemical through many different routes; inhalation (breathing), ingestion (eating or drinking), or dermal exposure (contact with and/or absorption by the skin). Health effects resulting from exposure to a compound depend upon the route of exposure. Exposure may occur by an individual route or by several routes concurrently.
This section examines compounds thought to cause cancer (carcinogens) as well as compounds which may cause noncancer adverse health effects if exposure occurs from ingestion or dermal contact with contaminants present in surface and subsurface soils at the PSR site. Many carcinogens can also have noncarcinogenic effects. Noncarcinogens are assumed to have a dose below which no adverse effect occurs. Above the threshold the severity of effects are determined by the dose.
Environmental contaminants may have many different toxic effects on the human body. The type and severity of effect produced by a compound varies depending upon the dose. Noncarcinogenic exposure for adult ingestion of soil is calculated using the maximum contaminant concentration in soil, an ingestion rate of 100 mg and a body weight of 70 kilograms. Carcinogenic excess lifetime cancer risk is calculated using the estimated exposure, the cancer slope factor, and exposure factors including a 25 year exposure duration and a 70 year lifetime. On-site workers are assumed to be on-site five days per week, 50 weeks per year, for 25 years.
EPA has reviewed available data from human and animal studies to determine the carcinogenic potential of specific chemicals in order to determine slope factors for oral and inhalation exposure routes. Cancer slope factors are used to evaluate the potency of a chemical in order to determine the excess risk of developing cancer as a result of contaminant exposure. A cancer slope factor converts the estimated daily exposure dose averaged over a lifetime, to an incremental risk of an individual developing cancer over a lifetime of 70 years. In a normal population of 1,000,000 people about 250,000 are expected to develop cancer. Excess lifetime cancer risk is derived by multiplying the cancer slope factor of a chemical by the estimated daily exposure dose.
The excess lifetime cancer risk discussed in this section represents the anticipated increase above what would normally be anticipated to occur in a normal population. Excess lifetime cancer is qualitatively expressed as "no increased risk"; "no apparent increased risk"; "low increased risk"; "moderate increased risk"; "high increased risk"; and "very high increased risk".
Arsenic
CAS #: 7440-38-2
Arsenic is used in the production of wood preservatives, and agricultural chemicals including insecticides and herbicides. Additional uses for arsenic include the production of glass, alloys, and use in the electronics industry (10). Arsenic can exist in both an organic and inorganic form. The inorganic form is usually more toxic than the organic form.
At the PSR site, the estimated potential daily exposure calculated for ingestion of soil by site workers exceed chronic health guidelines (MRL) for inorganic arsenic. Past exposure to arsenic may have occurred to on-site workers through ingestion of soils and inhalation of soil dust.
Exposure to arsenic may potentially result in health effects such as abdominal pain, nausea, vomiting, diarrhea, skin lesions, hyperpigmentation, keratosis, and vascular complications. ATSDR has an oral MRL for inorganic arsenic of 0.0003 mg/kg/day for chronic exposure.
In order to evaluate possible health effects, estimated potential daily exposure doses were compared to the NOAEL of 0.0008 mg/kg/day and LOAEL of 0.014 mg/kg/day in humans from which the chronic MRL is derived. The adult estimated exposure dose to arsenic is slightly above the NOAEL, and well below the LOAEL. If on-site workers were exposed to the maximum concentrations of arsenic in on-site soils, they would not likely experience noncarcinogenic health effects.
Arsenic is a human carcinogen which can result in skin cancer from ingestion. Increases in skin cancer have been observed in persons chronically ingesting arsenic contaminated water. It is estimated that if on-site workers consume 100 mg of soil per day from the PSR site for 25 years, they may have a "moderate increased risk" of developing cancer over a lifetime of 70 years. In addition to skin cancer, studies suggest arsenic ingestion increased the risk of liver, bladder, kidney, and lung cancer.
Polycyclic Aromatic Hydrocarbons
CAS #: 50-32-8
Polycyclic Aromatic hydrocarbons, abbreviated PAHs, make up a group of chemically related compounds. PAHs are formed during the incomplete combustion of fossil fuels and often occur together in the environment. PAHs are commonly found in grilled meat, cigarette smoke, and coal tar. Several PAHs, including benzo(a)pyrene (BaP), benzo(a)anthracene (BaA), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), chrysene, indeno(1,2,3-cd)pyrene and dibenzo(a,h)anthracene have been shown to be carcinogens in animal studies. Exposure to coal tar pitch volatiles is associated with an excess of kidney, bladder, and lung cancer in humans. Benzo(a)pyrene is likely to be the most potent carcinogen of the PAHs present in soil at the PSR site. Benzo(a)pyrene was also evaluated for noncarcinogenic effects.
Exposure of on-site workers may have occurred in the past to benzo(a)pyrene contaminated soil. Workers can be exposed to benzo(a)pyrene through ingestion of soils and inhalation of soil dust. The maximum concentration of benzo(a)pyrene in soil borings was 300 mg/kg at the PSR site. Currently, no chronic oral MRL or RfD are available for benzo(a)pyrene. Until adequate toxicological data are available, potential noncarcinogenic effects cannot be predicted for on-site workers who may have been chronically exposed to the maximum concentrations of benzo(a)pyrene in soil. The estimated potential daily exposure calculated for ingestion of soil by on-site workers does not exceed acute health guidelines (MRL) for benzo(a)pyrene.
EPA classifies benzo(a)pyrene as a probable human carcinogen. It is estimated that if on-site workers consume 100 mg of maximum contaminant concentrations of benzo(a)pyrene contaminated soil per day from the PSR site for 25 years, they may have a have "low increased risk" of developing cancer over a lifetime.
Lead
CAS #: 7439-92-1
Lead is a naturally occurring metal used in the manufacture of storage batteries. Lead is a component of gasoline, pipe, and paints. Lead exists in both organic and inorganic form, but primarily in the inorganic form (12).
There are currently no health-based guidelines (MRL or RfD) available for lead, because of the difficulty in identifying a clean threshold for lead below which there are no risks of adverse health effects. The majority of human data on lead health effects are expressed in terms of micrograms per deciliter of blood lead levels, rather than daily exposure doses expressed in mg/kg/day.
Lead is a probable human carcinogen, based on inadequate human data but sufficient data from animal studies. Results of animal studies indicate that chronic exposure to lead causes kidney cancer in rodents (12). It was not possible to calculate an estimated excess lifetime cancer risk from ingestion of soil because an oral slope factor has not yet been established for lead.
Mercury
CAS #: 7439-97-6
Mercury is used in thermometers, barometers, and pressure sensing devices (13). In addition, mercury lamps are used for outdoor lighting (including floodlights and streetlights), for health treatment, and photography. Mercury is also used in soaps, paint pigments, refining, lubrication oils, and dental amalgams (13).
Site workers may have been exposed to mercury through ingestion of soils and inhalation of soil dust. There are no health guidelines (MRL or RfD) available for mercury. Until adequate toxicological data are available, potential noncarcinogenic effects cannot be predicted for on-site workers who may have been chronically exposed to the maximum concentrations of mercury in soil at the PSR site. There is no evidence from epidemiological studies that indicate inhalation of metallic mercury produces cancer in humans (13).
Pentachlorophenol (PCP)
CAS #: 87-86-5
PCP has been used extensively as a pesticide and wood preservative (14). Exposure of on-site workers may have occurred in the past to pentachlorophenol contaminated soil. Workers can be exposed to pentachlorophenol through ingestion of soil and inhalation of soil dust. The maximum concentration of pentachlorophenol in soil borings from the PSR site was 4100 mg/kg. The estimated exposure calculated for adult ingestion of soil exceeds intermediate health guidelines (MRL). Intermediate or chronic exposure of an adult to the maximum levels of PCP in soils may result in adverse noncarcinogenic health effects such as increased liver weight and changes in liver glycogen levels (14). The estimated acute exposure doses are below the level at which adverse health effects are determined to occur in animal exposure studies (14). Acute exposure of site workers to levels of PCP in on-site soil would not likely result in any adverse noncarcinogenic health effects.
Pentachlorophenol is considered a probable human carcinogen based on evidence of carcinogenicity observed in animal studies. Data from human studies is insufficient to determine if PCP is a carcinogen from oral exposure. Epidemiological human studies are complicated by the fact that PCP often contains polychlorinated dibenzo-p-dioxins and dibenzofurans as impurities. Ingestion of PCP in animal studies has been associated with cancer of the liver and spleen in mice (14). Based on these animal studies, it is estimated that individuals consuming maximum contaminant concentrations of PCP in 100 mg of soil per day from the PSR site for 25 years, may have a "low increased risk" of developing cancer over a lifetime of seventy years.
B. Health Outcome Data Evaluation
No health outcome data were evaluated for the PSR site as there are no completed human exposure pathways or community health concerns documented alleging health effects from exposure to contaminants present at this site.
C. Community Health Concerns Evaluation
The following community health concerns are individually addressed below.
Inhalation represents a potential pathway of human exposure for on-site workers and residents living in close proximity of the PSR site. However, existing air quality information within the area surrounding the PSR site is limited. Existing air information is not sufficient to determine the extent of air contamination. Additional ambient air monitoring data from maximum predicted exposure locations is necessary to adequately assess possible human exposure from inhalation of ambient air.
Precautions such as dust control measures during removal and remedial actions reduce the potential for exposure from inhalation of contaminated airborne dust. Air monitoring data collected from areas on and surrounding the PSR site where individuals may be exposed prior to, during, and following completion of removal actions may determine if contaminant levels are present in ambient air at levels which could cause adverse human health effects.
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