![[logo] US EPA](https://www3.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Human Health Risk Assessment
Executive Summary
July 1999
This Human Health Risk Assessment (HHRA) has been developed by the US Environmental Protection Agency (EPA) to characterize the current and future potential risk and hazard to human health primarily due to polychlorinated biphenyl (PCB) exposure on and adjacent to Rogers Island, located in the Hudson River immediately west of the Village of Fort Edward, New York. Exposure to non-PCB chemicals is also examined. This HHRA considers the physical characteristics of the site and the likely exposure routes in which residents may be exposed. The HHRA uses standard EPA-approved exposure models and health protective assumptions about exposure conditions. Assuming no remedial action, these are used to generate reasonable maximum exposure (RME) estimates of the baseline health risks and hazards associated with the chemical contamination of the soil and sediment on the Island.Rogers Island, formerly known as Bradley's Island and located in the Hudson River immediately west of the Village of Fort Edward, New York, is approximately 65 acres in size. It is linked to the Village of Fort Edward and the Town of Moreau by bridges for the Amtrak Railroad and New York State Route 197. The northernmost end of the Island is principally residential, being comprised of approximately 24 homes and a village park that contains a ball field, boat ramp, picnic tables and a swimming pool. The remnants of the former Mobil Oil storage and barge docking facility are located between New York State Route 197 and the AMTRAK railroad tracks. The southern end of the Island, approximately 49 acres in size and located south of the AMTRAK railroad tracks, is predominantly undeveloped except for the Idle Hour Social Club, a private club consisting of an estimated 70 members. Approximately 40 acres of the Island are listed on the National Registry of Historic Places.
Approach
In the fall of 1998, under authority of the Comprehensive Response, Compensation, and Liability Act (CERCLA) of 1980, and as amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986, EPA initiated a sampling program to collect the data necessary to determine if a risk or hazard to human health exists on Rogers Island due to the presence of PCBs. This HHRA evaluates the current risk and hazard to human health, presents the potential future risk and hazard to human health of proposed development plans on the Island, and presents information that may be used to aid in the determination of whether or not any portion of the Island satisfies criteria for a removal action. EPA initiated a phased sampling approach consisting of the following steps.
-
Approximately twenty surface soil samples from each residential property, the ball field, the swimming pool area, and the boat launch area were collected (totaling 600 samples). In addition, PCB Aroclor analyses and a limited number of PCB congener analyses were performed to more fully understand PCB contamination in the residential areas;
-
Soil samples were collected at 100 foot intervals south of the Amtrak railroad tracks since this is a location targeted for future development;
Additional core samples (surface to native soil) were collected from locations suspected to contain dredge spoils to determine potential concentrations of PCBs in subsurface soil that could potentially become a source of exposure should these locations be commercially or residentially developed; wp="BR2">
-
Sediment samples, including full core and ponar surface samples, were collected from locations around the Island to characterize PCB concentrations in these sediments.
Contaminants of concern (COC), which are compounds and chemical classes for which a quantitative risk assessment was performed, were identified in soil and sediment on the basis of their frequency of occurrence, demonstrated relationship to site activities, local and regional background levels, and availability of toxicological parameters for calculating risk. Those chemicals for which toxicological data are not evaluated are discussed qualitatively in the risk characterization.Based on the COCs, RME scenarios have been developed for adults and children. The RME for the current and future use of residences on the Island were calculated using the chemical specific contaminant concentration based on the 95percent Upper Confidence Limit (UCL) on the mean (or maximum when the 95percent UCL is exceeded) to represent the concentration of the chemical which people may contact during exposure. This concentration is combined with information regarding current and future use exposure pathways (i.e., activities that may result in an individual contacting soil, sediment, etc.) to develop reasonable pathways of exposure. The exposure analyses consider how frequently the individual is exposed to the COC, the quantity of COC that is ingested, inhaled, or absorbed through skin contact, and the period of time for which the individual is exposed to the COC. The result is a calculated dose for cancer and non-cancer assessments that can be combined with appropriate toxicity values to calculate cancer risk and non-cancer hazard.Based on the National Contingency Plan (NCP), EPA's regulations for the evaluation of risk at Superfund sites, the cancer risk range is from 10-4 (one in ten thousand) to 10-6 (one in a million excess risk of developing cancer). For non-cancer hazard, the exposure dose is compared to a Reference Dose. A Reference Dose is an estimate of an exposure level for the human population which is likely to be without appreciable risk of deleterious effects over the course of a lifetime. The exposure doses for chemical specific pathways are compared to a chemical specific Reference Dose to determine whether the Reference Dose is exceeded. The total Hazard Quotient or Hazard Index (HI) for an individual is calculated by combining the HIs for all of the different chemicals and exposure pathways assessed. An HI above 1 is considered to be of potential concern.The analyses performed in this HHRA are based on the total effects of the exposure pathways for both cancer and non-cancer health effects. Total health risk and hazard are based upon the summation of the risk for an individual over all exposure pathways. These exposure pathways include inhalation, dermal contact and ingestion.
Results
The following is a summary of cancer risk and non-cancer hazard listed by media and scenario, and the area or scenarios with the highest levels of that risk and hazard. Section 6 discusses more fully both the cancer risk and the non-cancer hazard for all scenarios and locations. The total risk for cancer based upon media type are listed in the following table.
| Summary of Highest Total Cancer Risk Primarily Due to PCBs by Media | ||
| Media | Total Cancer Risk | Location/Scenario |
| Surface Soil- Residential | 2.3 x 10-4* | Lot R-5, R-6, R-7: Flood Plain/ Child Risk |
| Subsurface Soil- Residential | 2.3 x 10-4* | Lot R-8/ Child Risk |
| Surface Soil- Current/Future Use Scenario | 2.5 x 10-4* | Visitor Center Worker Scenario/ Adult Risk |
| Subsurface Soil- Current/Future Use Scenario | 3.4 x 10-5 | Hotel Worker Scenario/ Adult Risk |
| Sediment- Current/Future Use Scenario | 1.6 x 10-5 | Recreational Trespassers Scenario/ Adult Risk |
* Exceeds EPA's cancer risk range of 10-4 to 10-6In many instances, however, non-cancer hazard exceeds the EPA threshold with HI's greater than 1. The highest total HI's for each media and future/current use scenario are listed in the following table.
| Summary of Highest Total Hazards Primarily Due to PCBs by Media | ||
| Media | Total Hazard Index (HI) | Location/Scenario |
| Surface Soil- Residential | 35.2* | Lot R-5, R-6, R-7: Flood Plain/ Child Risk |
| Subsurface Soil- Residential | 65.5* | Lot R-8/ Child Risk |
| Surface Soil- Current/Future Use Scenario | 29.3* | Visitor Center Construction Worker Scenario/ Adult Risk |
| Subsurface Soil- Current/Future Use Scenario | 4.5* | Lot R-8 Construction Worker Scenario/ Adult Risk |
| Sediment- Current/Future Use Scenario | 4.5* | Hotel Construction Worker |
* Exceeds EPA's non-cancer hazard level (HI = 1)Furthermore, there are a few other locations and scenarios that are of concern when considering total non-cancer hazard. Whereas EPA considers an HI equal to 1 to be protective of human health, only locations and scenarios with an HI greater than 10 are listed in the following table. Locations having HIs between 1 and 10, along with their component pathways (dermal, inhalation, ingestion) may be examined more closely in Tables 6-1, 6-2, and 6-3, which are located and discussed in Section 6 of this report.
| Total Hazard Indices Greater Than 10 for Non-Cancer Hazards Primarily Due to PCBs | ||
| Media | Total Hazard Index (HI) | Location/Scenario |
| Surface Soil- Residential | 32.6 | Lot R-6/ Child Risk |
| Surface Soil- Residential | 26.8 | Lot R-7/ Child Risk |
| Surface Soil- Residential | 18.6 | Lot R-8/ Child Risk |
| Surface Soil- Residential | 35.2 | Lots R-5, R-6, R-7- Flood Plain/ Child Risk |
| Surface Soil- Current/Future Use Scenario | 17.3 | Visitor Center Worker Scenario/ Adult Risk |
| Surface Soil- Current/Future Use Scenario | 29.3 | Visitor Center Construction Worker Scenario/ Adult Risk |
| Surface Soil- Current/Future Use Scenario | 10.8 | Hotel Construction Worker Scenario/ Adult Risk |
| Subsurface Soil- Residential | 65.5 | Lot R-8/ Child Risk |
ConclusionsThe evaluation performed in this HHRA provides the following conclusions listed below. Note that the analyses are summarized fully in Sections 6 and 7 of the report, and are further illustrated in Tables 6-1, 6-2, and 6-3.
A limited number of locations in the residential section of Rogers Island show levels of cancer risk above EPA's cancer risk range (10-4 to 10-6);
There are a number of locations in the residential section of Rogers Island that significantly exceed EPA's non-cancer hazard level (HI = 1). The most notable areas are those that are located in the flood plains and evaluated for child exposure on the northeastern shoreline of the Island;
One future scenario, Visitor Center Worker, shows a level of cancer risk above EPA's cancer risk range (10-4 to 10-6);
For the Construction Worker future scenario, which includes the evaluation of construction activities for different areas of the Island, the Hotel Construction Worker (for the southern portion of the Island) and the Visitor Center Construction Worker scenarios significantly exceed EPA's non-cancer hazard level (HI = 1);
There are several future scenarios, primarily visitor and construction worker scenarios, that exceed EPA's non-cancer hazard level (HI = 1).
Note that this HHRA document does not evaluate potential remedial or removal actions on Rogers Island. This HHRA is intended to be a tool in which to aid in the decision making process by providing an assessment of the potential risk and hazard to human health. Analysis is based upon EPA's Fall 1998 sampling program of Rogers Island and the NCP guidelines. Any decisions regarding potential actions on Rogers Island will be made public at a time separate from the release of this document.