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PUBLIC HEALTH ASSESSMENT

WASHINGTON NAVY YARD
WASHINGTON, DISTRICT OF COLUMBIA


APPENDIX A. SUMMARY OF INVESTIGATION SITES AT WASHINGTON NAVY YARD

Site Site Description/Waste Disposal History Investigation Results/ Environmental Monitoring Results Corrective Activities and/or Current Status Evaluation of Public Health Hazards
Operable Unit 1
Basewide Groundwater
The basewide groundwater will be investigated as a single unit for the entire Washington Navy Yard (WNY). Various industrial operations have occurred at the facility since its establishment in 1799. All of the identified sites in this table and other potential off-site sources may be impacting the groundwater at WNY. There are no known potable groundwater sources existing on or near the WNY. Groundwater:Solvents, metals, PCBs, pesticides, polycyclic aromatic hydrocarbons (PAHs), dioxins, and other chemicals have been identified on the WNY. Chloroform (up to 12 ppb) was the only VOC detected above ATSDR comparison values for drinking water. Acetone, 1,2-dichloroethene (total), acenaphthene, fluorene, butylbenzylphthalate, bis(2-ethylhexyl)phthalate, and di-n-octylphthalate were frequently detected at concentrations at or below ATSDR comparison values. Methylene chloride was detected above ATSDR comparison values at concentrations up to 17 ppb. Metals detected above ATSDR comparison values in groundwater included arsenic (up to 31.2 ppb), iron (up to 84,000 ppb), and lead (up to 2,950 ppb). Beryllium was also detected up to 7.8 ppb, but this figure is below the ATSDR comparison value. Pesticides, PCBs, TPH, and oil and grease were not detected or were detected below ATSDR comparison values for drinking water. Bis(2-ethylhexyl)phthalate was detected (up to 5 ppb), but this detect is not considered to be a site contaminant because bis(2-ethylhexyl)phthalate is a common laboratory contaminant and it was detected in the associated quality assurance/quality control samples. Current Status:
• The Navy is planning further investigations to characterize the extent and magnitude of the contamination.
Groundwater: There is no known public exposure to WNY groundwater.

ATSDR concludes that WNY groundwater poses no apparent public health hazard.

Site 1
Building 22
Site 1 is comprised of a multi-storied brick building, Building 22, and the soils directly adjacent to the building. Surrounding areas consist of pavement, concrete, and other buildings. It is the location of a former foundry for the manufacture of brass cannons, shells, and shot. Other machinery has also been constructed where Building 22 currently is located. Activities in this building included a 6-inch gun shop, miscellaneous shop, an erecting shop, a general machine shop, and a laundry facility. Groundwater:No groundwater was collected from Site 1.
Soil: Maximum detected contaminant concentrations exceeding ATSDR comparison values were arsenic (5.9 parts per million [ppm]), beryllium (4.6 ppm), and lead (58.2 ppm). The following were also detected, but below ATSDR comparison values: aluminum (15,300 ppm), barium (59.6 ppm), chromium (18.6 ppm), and manganese (203 ppm).
Surface Water: There is no surface water at Site 1.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 1.
Soil: Surface soil is largely inaccessible because Site 1 is paved and developed.

ATSDR concludes that Site 1 poses no public health hazards.

Site 2
Buildings 33, 36, 37, 39, 109
Site 2 is a multi-storied brick structure, that includes Buildings 33, 36, 37, 39, 109, and the adjacent soils. The surrounding area consists of pavement, concrete, and other buildings. Building 33 was constructed in 1855 as part of the major expansion of the manufacturing complex at the WNY. Building 33 has been converted from a gun carriage shop to a general machine shop, a civil defense storage, a storage/supply, and is presently a general warehouse. An acid room and flammable storage area existed in Building 33A, as well as a mechanical room, restroom, and locker room. Potential hazardous substances associated with general machine shop operations may be assumed to include solvents, such as carbon tetrachloride, and metals used in paint spraying. Other buildings at Site 2 were storage and warehousing locations. Groundwater: Maximum detected contaminant concentrations were arsenic (5.8 ppb), beryllium (2.9 ppb), lead (51.8 ppb), manganese ( 1,460 ppb), and methylene chloride (2,400 ppb), all of which exceed ATSDR comparison values.
Soil: Maximum detected contaminant concentrations for arsenic (11.2 ppm) exceeds ATSDR comparison values, while the maximum detected concentration of iron (63,600 ppm) does not.
Surface Water: There is no surface water at Site 2.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 2.
Soil: Surface soil is largely inaccessible because Site 2 is paved and developed.

ATSDR concludes that Site 2 poses no public health hazards.

Site 3
Building 40/41
Site 3, a sloped, grassy area, is the former location of Building 40/41, which was a multi-storied building. The surrounding area consists of pavement, concrete, and other buildings. Gun pits, the depths of which ranged from approximately 24 feet to 69 feet below the lower floor, were filled with rubble or granular material. Additionally, underground rooms beneath Dahlgren Avenue were left in place after demolition of Buildings 40/41. Through the years, Building 40/41 was transformed from a gun shop to a plating shop, and then to offices until it was demolished in 1977. Typically, a large variety of heavy metals, acids, cleaners, and caustics are used during plating operations. Groundwater:Maximum detected contaminant concentrations that exceed ATSDR comparison values were arsenic (6.0 ppb), beryllium (5.9 ppb), bis(2-ethylhexyl)phthalate (5.0 ppb), iron (27,300 ppb), lead (57.2 ppb), and manganese (746 ppb).
Soil: Maximum detected contaminant concentrations that exceed ATSDR comparison values were arsenic (4.2 ppm) and beryllium (4.2 ppm). The maximum concentration detected for iron (55,700 ppm) did not exceed ATSDR comparison values.
Surface Water: There is no surface water at Site 3.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 3.
Soil: Visitors may infrequently be exposed to Site 3 soils via dermal contact and incidental ingestion. Such infrequent exposure to contaminant concentrations detected in Site 3 soils, however, is unlikely to result in adverse human health effects.

ATSDR concludes that Site 3 poses no apparent public health hazards.

Site 4
Buildings 44, 46, 108, 67
Site 4 includes Buildings 44, 46, 108, 67, and the soil adjacent to these buildings. They are multi-storied, brick buildings. Surrounding areas consist of pavement, concrete, and other buildings. Building 46 was used as a copper rolling mill, cartridge case shop, metal pressings shop, Navy Exhibit Center, offices, and warehouse. Currently, the building contains the Navy Exhibit Center, shop, and warehouse. Building 46 also contains waste channels, scale pits, and other pits under the flooring of the building.

Building108 was originally used in 1872 as an Anchor and Faggoting Shop. The building also was used for a cartridge case shop, chemical laboratory, seamen shop, offices, and storage. Based on historic operational processes associated with Building 108, residues may be present. Wastes associated with the processes listed above may include solvents, phenols, and metals. In addition, it should be noted that an industrial sewer line, apparently used for conveying industrial waste, ran north and south between Buildings 108 and 67.

The Building 67 site can be traced back to 1898. The building was used as a cartridge case shop, primer shop, furnace room, metal pressings shop, storage, and Navy Exchange Center. Acid baths in above ground tanks pits were also located in the northern portions of the building. Building 44 lies between Dahlgren Avenue and Harwood Streets, but its historical use is unknown.

Groundwater: Maximum detected contaminant concentrations were beryllium (5.8 ppb), chloromethane (42.0 ppb), lead (38.2 ppb), manganese (1,640 ppb), methylene chloride (18.0 ppb), and nickel (532 ppb), all of which exceed ATSDR comparison values.
Soil: Maximum detected contaminant concentrations were arsenic (8.1 ppm), which exceeds ATSDR comparison values, and beryllium (1.3 ppm) and iron (33,200 ppm), which do not.
Surface Water: Samples from the sewer line at Site 4 contained maximum detected contaminant concentrations of copper (3,550 ppb), lead (3,570 ppb), mercury (810 ppb), and PCBs (3.8 ppb), all of which exceed ATSDR comparison values.
Sediment: Samples from the sewer line at Site 4 contained maximum detected contaminant concentrations of mercury (810 ppm) and PCBs (3.8 ppm), which exceed ATSDR comparison values, and copper (3,780 ppm) and lead (3,570 ppm), which do not.
Corrective Activities:
• In 1996, the Navy began conducting sediment removal actions. These removal actions continued through 2001 and included sediment at Site 4.
Current Status:
• A Resource Conservation and Recovery Act (RCRA) Work Plan is being prepared.
Groundwater: There is no public exposure to groundwater at Site 4.
Soil: Visitors may infrequently be exposed to Site 4 soils via dermal contact and incidental ingestion. Such infrequent exposure to contaminant concentrations detected in Site 4 soils, however, is unlikely to result in adverse human health effects.
Surface Water: There is minimal, if any, public exposure to the sewer line at Site 4.
Sediment: There is minimal, if any, public exposure to the sewer line sediment at Site 4.

ATSDR concludes that Site 4 poses no apparent public health hazards.

Site 5
Building 73
Site 5 includes Building 73 and the adjacent soils. Building 73 is a multi-storied brick building. Surrounding areas consist of pavement, concrete, and other buildings. The Building 73 location can be traced back to 1845 when an ordnance laboratory was established on this site. The 1872 Plan of the WNY shows the area to be a vacant lot. The 1898 Plan indicates that underground storage tanks were present on this site. Building 73 was constructed during 1901-1902 and used as a specialized gun mount shop. The building also was utilized as a secondary mount shop, rough in shop, erecting shop annex, broadside mount shop annex, Shop 28 Annex 2, and an aluminum cleaning facility containing 10 above ground storage tanks used for iridite, alkaline for etching, degreasing with sump pumps, deoxidizers, and alkaline for nonetching.

Historically, it is know that solvents, phenols, and metals were used in cleaning, cooling, and paint spraying activities. During the period when the building was utilized as an aluminum cleaning facility, a variety of wastes could have been generated.

Groundwater:Maximum detected contaminant concentrations were arsenic (61.7 ppb), beryllium (6.9 ppb), chloromethane (22.0 ppb), copper (3,910 ppb), lead 1,080 ppb), manganese (4, 170 ppb), methylene chloride (14.0 ppb), and nickel (3,190 ppb), all of which exceed ATSDR comparison values. Aluminum (23,100 ppb) was also detected, but at a concentration below ATSDR comparison values.
Soil: Maximum detected contaminant concentrations were arsenic (83.6 ppm) and benzo(a)pyrene (0.29 ppm), which exceed ATSDR comparison values, and beryllium (1.1 ppm), iron (53,900 ppm), and lead (4,420 ppm), which do not.
Surface Water: There is no surface water at Site 5.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 5.
Soil: Surface soil is largely inaccessible because Site 5 is paved and developed.

ATSDR concludes that Site 5 poses no public health hazards.

Site 6
Building 116/118, 197
Site 6 is surrounded by perimeter fencing and includes Buildings 197, 116, and 118 and the adjacent soils. These are multi-storied brick buildings that are currently under re-construction. Surrounding areas consist of pavement, concrete, and other buildings. Prior to construction of Building 197, an old scale pit, a fuel oil tank, Building 126, Building 127, and Building 150 were scheduled to be removed to facilitate the placement of the building's foundation. A gun pit situated 12 feet below the ground floor level was installed in the northern end of the building. The building was utilized as a gun assembly shop and currently is abandoned. It is known that solvents such as carbon tetrachloride were used for cleaning, while metals (lead, chromium, cadmium, and antimony) were used in paint-spraying operations. Fuel oils, greases, metals, and solvents may have contributed to the contamination found in the soil and groundwater at Site 6.

The area of Buildings 116 and 118 can be traced back to 1904 as it was gradually filled in with fill of unknown materials prior to 1902. Building 116 has operated as the boiler house since its construction and Building 118 has operated as the WNY power plant. An ash sedimentation pit used for the ash from the coal-fired boilers was located south of Building 116. It was converted to create a portion of a coal storage area in later years.

Groundwater: Maximum detected contaminant concentrations were beryllium (9.8 ppb), bis(2-ethylhexyl)phthalate (9.0 ppb), cadmium (5.8 ppb), lead 469 ppb), manganese (432 ppb), methylene chloride (17.0 ppb), and nickel (232 ppb), all of which exceed ATSDR comparison values.
Soil: Arsenic (31.1 ppm) was detected in excess of ATSDR comparison values. Maximum detected contaminant concentrations which did not exceed ATSDR comparison values were benzo(a)anthracene (1.6 ppm), benzo(a)pyrene (1.2 ppm), benzo(a)fluroanthene (2.2 ppm), beryllium (1.3 ppm), dibenz(ah)anthracene (0.33 ppm), indeno(1,2,3-cd)pyrene (1.1 ppm), and lead (730 ppm).
Surface Water: Maximum detected contaminant concentrations were arsenic (65.4 ppb), cadmium (7.2 ppb), lead (305 ppb), manganese (990 ppb), and PCBs (2.2 ppb), all of which exceed ATSDR comparison values.
Sediment: Maximum detected contaminant concentrations which exceed ATSDR comparison values were arsenic (52.6 ppm), benzo(a)pyrene (1.3 ppm), cadmium (2.4 ppm), PCBs (38 ppm), and 1,2,4-trichlorobenzene (490 ppm). Additionally, chrysene (2.1 ppm) dibenz(ah)anthracene (0.32 ppm), lead (567 ppm), mercury (1.2
Corrective Activities:
• At the Coal Storage Yard (south of Building 116), the Navy conducted soil removal actions and abatement of PCBs, dioxins, heavy metals, PAHs, and other detected contaminants. Corrective activities were completed in November 1997.
• In 1996, the Navy began conducting sediment removal actions. These removal actions, continued through 2001, have included sediment at Site 6.
Current Status:
• A RCRA Work Plan is being prepared.
Groundwater: There is no public exposure to groundwater at Site 6.
Soil: Due to perimeter fencing surrounding the site, there is minimal, if any, public exposure to Site 6 soils.
Surface Water: There is minimal, if any, public exposure to the sewer line at Site 6.
Sediment: There is minimal, if any, public exposure to the sewer line sediment at Site 6.

ATSDR concludes that Site 6 poses no apparent public health hazards

Site 7
Building 126
Site 7 includes Building 126 and the adjacent soils. Building 126 is a multi-storied brick building. Surrounding areas consist of pavement, concrete, and other buildings. The Building 126 site can be traced back to 1939 when it was in operation as the receiving station laundry. Offices and the Naval Command System Support Activity also utilized this facility. The laundry facility was used for wet cleaning only and did not use dry cleaning processes. Groundwater: Maximum detected contaminant concentrations were arsenic (16.9 ppb), lead (656 ppb), manganese (237 ppb), and methylene chloride (14.0 ppb), all of which exceed ATSDR comparison values.
Soil: Maximum detected contaminant concentrations which exceed ATSDR comparison values were arsenic (11.3 ppm), benzo(a)anthracene (21 ppm), benzo(a)pyrene (25 ppm), benzo(b)fluroanthene (22 ppm), and benzo[k]fluroanthene (9.8 ppm). Not in excess of ATSDR comparison values were beryllium (0.62 ppm), chrysene (21 ppm), dibenz(ah)anthracene (0.45 ppm), and indeno (1,2,3-cd)pyrene.
Surface Water: There is no surface water at Site 7.
Current Status:
• A revised final Investigation Work Plan was submitted in January 1999 for Site 7.
• A site removal evaluation indicated that a removal action was not warranted.
Groundwater: There is no public exposure to groundwater at Site 7.
Soil: Even though the site is mostly paved and developed, visitors may infrequently be exposed to Site 7 soils via dermal contact and incidental ingestion. Such infrequent exposure to contaminant concentrations detected in Site 7 soils, however, is unlikely to result in adverse human health effects.

ATSDR concludes that Site 7 poses no apparent public health hazards.

Site 8
Building 211
Site 8 includes Building 211 and the adjacent soils. Building 211 is a single-story building. Surrounding areas consist of the Anacostia River, grass, pavement, concrete, and other buildings. Building 211 can be traced back to 1942 when it was utilized for paint and oil storage. In addition, it has been used to store other flammables and chemicals. Presently, Building 211 is a CPO Club. Based on past activities and the possibility of spills, residues from the products stored on these premises may have contributed to the contamination found in the soils at Site 8. Groundwater:No groundwater was collected from Site 8.
Soil: Maximum detected contaminant concentrations were arsenic (22.4 ppm) and benzo(a)pyrene (0.51 ppm), which were in excess of ATSDR comparison values, and beryllium (0.94 ppm) and dibenz(ah)anthracene (0.14 ppm), which were not.
Surface Water and Sediment: One sediment sample was taken in the vicinity of Site 8. VOCs were not detected. Pesticides, PCBs, and metals were detected below ATSDR comparison values. All detected SVOCs were below ATSDR comparison values for soil, including acenaphthene (740 ppb), chrysene (3,100 ppb), fluoranthene (13,000 ppb), fluorene (1,300 ppb), phenanthrene (11,000 ppb), and pyrene (10,000 ppb).
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 8.
Soil: Surface soil is inaccessible to the general public. Not only is Site 5 mostly paved and developed, it also lies on the far southwest corner of WNY, far removed from visitor locations.
Surface Water and Sediment: Contaminant concentrations are too low to pose a public health hazard. Additionally, public exposure to Site 8 sediments and the Anacostia River is minimal, if it occurs at all.

ATSDR concludes that Site 8 poses no public health hazards.

Site 9
Building 219/220
Site 9 includes Buildings 219 and 220 and the adjacent soils. Both Buildings 219 and 220 are multi-storied brick buildings. Surrounding areas consist of grass, pavement, concrete, and other buildings. Building 219 can be traced back to 1944 when it was known as the Gauge Laboratory Building. The building also operated as offices, a chemical laboratory, and the home of the Naval Weapons Quality Assurance Officer. Building 219 may have served as a machine shop. It was constructed with wooden floors overlying a concrete floor. Groundwater: The maximum detected contaminant concentrations were beryllium (5.3 ppb), lead (7.6 ppb), manganese (440 ppb), and nickel (1,880 ppb), all of which exceed ATSDR comparison values
Soil: Arsenic (4.3 ppm) was detected in excess of ATSDR comparison values. Beryllium (0.68 ppm) was also detected, but did not exceed ATSDR comparison values.
Surface Water: There is no surface water at Site 9.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 9.
Soil: Even though the site is mostly paved and developed, visitors may infrequently be exposed to Site 9 soils via dermal contact and incidental ingestion. Such infrequent exposure to contaminant concentrations detected in Site 9 soils, however, is unlikely to result in adverse human health effects.

ATSDR concludes that Site 9 poses no public health hazards.

Site 10
Admirals Row
Admirals Row is the designation given to a group of buildings located along Warrington Avenue. These buildings currently are used as housing for officers of the Navy and include Quarters A, B, C, D, E, F, G, H, K, L, M, M-1, N, O, P, R, S, T, U, V, W, Y, Buildings 1, 59, 61, and Leutze Park. These buildings are multi-storied residences with adjacent areas consisting of grass, pavement, concrete, and other buildings. Maintenance of these buildings with lead-based paint is believed to be the source of lead-contaminated soil. Groundwater:No groundwater was collected from Site 10.
Soil: The maximum detected lead concentration (18,700 ppm) exceeded the ATSDR comparison value of 400 ppm. The greatest lead concentrations were in surface soils adjacent to Admiral's Row quarters.
Surface Water: There is no surface water at Site 10.
Corrective Activities:
• The Navy will conduct abatement activities to remove lead from the soil.
Current Status:
• An Engineering Evaluations/Cost Analysis (EE/CA) report was finalized in February 1998.
Groundwater: There is no public exposure to groundwater at Site 10.
Soil: Currently, surface soil at Site 10 is inaccessible to the general public due to perimeter fencing and land use restrictions. In the past, however, children may have been exposed to lead soil levels of potential concern, especially to those under 6 years of age.

ATSDR concludes that Site 10 is a past completed exposure pathway. Present and future exposures are prevented.

Site 11
Incinerators
A 1979 Naval Facilities Engineering Command drawing shows that three incinerators were removed along with the top 6 inches of soil. Prior to demolition, these former incinerators were located south of Building 166 and east of Building 218. The present day use of this site is as a parking lot. Adjacent areas to this location consist of pavement, concrete, and other buildings. At least one of the incinerators was a self-contained incinerator for classified documents.. Groundwater:No groundwater was collected from Site 11.
Soil: Maximum detected contaminant concentrations which exceed ATSDR comparison values were arsenic (33.2 ppm), benzo(a)athracene (15.0 ppm), benzo(a)pyrene (12.0 ppm), benzo(b)fluroanthene (20.0 ppm), beryllium (5.4 ppm), benzo(k)fluroanthene (5.0 ppm), and dibenz(ah)anthracene (3.9 ppm). Also detected, but not in excess of ATSDR comparison values were chrysene (13.0 ppm), indeno (1,2,3-cd)pyrene (7.1 ppm), and lead (851 ppm).
Surface Water: There is no surface water at Site 11.
Current Status:
• A revised final Investigation Work Plan was submitted in January 1999 for Site 11.
• A site removal evaluation indicated that a removal action was not warranted.
Groundwater: There is no public exposure to groundwater at Site 11.
Soil: Even though the site is mostly paved and developed, visitors may infrequently be exposed to Site 11 soils via dermal contact and incidental ingestion. Such infrequent exposure to contaminant concentrations detected in Site 11 soils, however, is unlikely to result in adverse human health effects.

ATSDR concludes that Site 11 poses no apparent public health hazards.

Site 12
Stormwater Lines from Site 4 and Outfall 5
Site 12 consisted of the stormwater line running from the area of Site 4 to outfall 5. The potential source of this contaminated sediment may have included past releases from Site 4. Site 12 is currently considered past of Site 4. The site contained elevated levels of metals, PAHs, and PCBs (see Site 4). See Site 4. See Site 4.
Site 13
Building 290
Site 13 includes Building 290 and the soil adjacent to the building. It is located south of Admirals Row and north of Building 40/41. A transformer was housed north of the building in the past, where PCBs have been found in the soil. Groundwater: No groundwater was collected from Site 13.
Soil: Maximum detected contaminant concentrations were PCBs (10.0 ppm), which exceeds ATSDR comparison values.
Surface Water: There is no surface water at Site 13.
Current Status:
• PCB-contaminated soil north of the building has been removed from the site.
Groundwater: There is no public exposure to groundwater at Site 13.
Soil: Even though the site is mostly paved and developed, visitors may have been infrequently exposed to Site 13 soils via dermal contact and incidental ingestion in the past. Such infrequent exposure to contaminant concentrations detected in Site 13 soils, however, is unlikely to result in adverse human health effects.

ATSDR concludes that Site 13 poses no public health hazards.

Site 14
Building 292
Site 14 includes Building 292 and the adjacent soils. It is a small single story building. Surrounding areas consist of paved parking and other brick buildings. Groundwater:Groundwater concentrations were below ATSDR comparison values for drinking water.
Soil: Maximum detected contaminant concentration was PCBs (20.0 ppm) in surface soil.
Surface Water: Analytical results of a standing water sample from the Building 292 basement did not indicate detectable concentrations of SVOCs or pesticides/PCB; only low levels of TPH were detected. All contaminant concentrations are below ATSDR comparison values for drinking water.
Corrective Activities:
• The Navy completed a soil removal action and abatement of PCBs in November 1997.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 14.
Soil: Even though the site is mostly paved and developed, visitors may infrequently be exposed to Site 14 soils via dermal contact and incidental ingestion. Such infrequent exposure to contaminant concentrations detected in Site 14 soils, however, is unlikely to result in adverse human health effects. There is no current exposure because all contaminant concentrations are below ATSDR comparison values for soil.
Surface Water: There is no public exposure to contaminated surface water at Site 14.

ATSDR concludes that Site 14 poses no public health hazards.

Site 15
Stormwater Lines from Site 6 to Outfall 10
Site 15 consists of the stormwater line running from the area of Site 6 to outfall 10. The potential sources of Site 15 contaminants may have included Site 6 and off-site contaminated soil from the General Services Administration property. Site 15 is currently considered part of Site 6. Site 15 contained levels of PCB, PAHs, and metals in sediment above EPA screening criteria (see Site 6). See Site 6. See Site 6.
Site 16
Building 71
The area defined as Site 16 is a paved parking lot area located in the south-central portion of the WNY, adjacent to the Anacostia River. Site 16 encompasses Building 71 and its current and former underground storage tanks; existing monitoring wells; stormwater lines traversing the site; and an area where free-phase mercury was discovered in the subsurface. The stormwater lines that run through the site terminate at outfalls 5 and 6.

At one time, 13 underground storage tanks existed at Site 16, both within and surrounding Building 71.

Groundwater: Groundwater underlying Site 16 has been impacted by petroleum products from underground storage tanks. Shallow groundwater has also been impacted by contamination in fill. VOCs, PAHs, phthalates, pesticides, and PCBs were found to have limited extent and most of these compounds were not detected above screening levels adjacent to the river (Navy 2000). Dioxins and metals above screening levels persist to the river (Navy 2000).

Soil: Visible liquid mercury was found in a confined subsurface soil area at Site 16, approximately 5 or 6 feet below ground surface and very close to the water table. Contamination in fill includes metals and dioxin.

Corrective Activities:
• Removal actions for the mercury source are complete. Soil contaminated with mercury has been removed.
• Remedial activities to remove petroleum products from groundwater began in April 2000.
Current Status:
• The Navy is conducting additional sampling to further characterize site groundwater contamination.
• Limited areas of contaminated fill still exist.
• Beginning in 1993 and continuing until late March 1994, seven underground storage tanks were removed and the remaining six were abandoned in place in accordance with Washington, D.C., regulations.
Groundwater: Shallow groundwater at Site 16 discharges to the Anacostia River. No known potable wells are located on or near the WNY. Therefore, no known human exposures to contaminated groundwater are occurring. However, fish in the river may be impacted by contamination from site 16. Fishing advisories for the Anacostia River should continue to be observed.
Soil: Surface soil is inaccessible at Site 16 because the area is paved. The subsurface mercury was inaccessible to the public. Contaminated fill is inaccessible to the public. Future plans for this site do not include residences.

ATSDR concludes that Site 16 poses no apparent public health hazards.

Site 17
(Formerly Building 201
This site includes Site 17 and the adjacent soils. It is a two-story concrete and brick building. It was constructed as a maintenance facility for automotive equipment and official Government cars. Site 17 was investigated because past and current public works operations are suspected of contributing to the contamination found in site soil and groundwater. Groundwater: Two groundwater samples were collected from Site 17. No volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), pesticide/polychlorinated biphenyls (PCBs), total petroleum hydrocarbons (TPHs), or oil and grease were detected in either of the groundwater samples. Some metals exceeded the Agency for Toxic Substances and Disease Registry (ATSDR) comparison values for drinking water: antimony up to 23.6 parts per billion (ppb), arsenic up to 10.2 ppb, iron up to 43,500 ppb, lead up to 51.2 ppb, and manganese up to 555 ppb.
Soil: Surface soil samples have not been collected at Site 17.
Surface Water: There is no surface water at Site 17.
Current Status:
• No Further Action site.
Groundwater: There is no public exposure to groundwater at Site 17.
Soil: Surface soil is inaccessible because Site 17 is paved and developed.

ATSDR concludes that Site 17 poses no public health hazards.

References: NFEC 1996 and 1999; CH2MHILL 1998 and 1999; Navy 2001.


APPENDIX B. ATSDR'S ASSESSMENT METHODOLOGY AND COMPARISON VALUES

Human Exposure Pathway Evaluation and the Use of ATSDR Comparison Values

The Agency for Toxic Substances and Disease Registry (ATSDR) assesses a site by evaluating the level of exposure in potential or completed exposure pathways. An exposure pathway is the way chemicals may enter a person's body to cause a health effect. It includes all the steps between the release of a chemical and the population exposed, including: (1) a chemical release source, (2) chemical movement, (3) a place where people can come into contact with the chemical, (4) a route of human exposure, and (5) a population that could be exposed. In this assessment, ATSDR evaluates chemicals in environmental media that people residing near a site may consume, inhale, or contact.

Health assessors use comparison values (CVs) as screening tools to evaluate environmental data that are relevant to the exposure pathways. CVs represent media-specific contaminant concentrations that are used to select contaminants for further evaluation to determine the possibility of adverse health effects. CVs used in this document include ATSDR's environmental media evaluation guide (EMEG) and cancer risk evaluation guide (CREG). CVs are derived from available health guidelines, such as ATSDR's minimal risk levels and EPA's cancer slope factor.

CVs used in this public health assessment include:

Cancer Slope Factor (CSF)
Usually derived from dose-response models and expressed in mg/kg/day, CSFs describe the inherent potency of carcinogens and estimate an upper limit on the likelihood that lifetime exposure to a particular chemical could lead to excess cancer deaths.

Cancer Risk Evaluation Guide (CREG)
Estimated contaminant concentrations that would be expected to cause no more than one excess cancer in a million (10-6) persons exposed over a 70-year life span. ATSDR's CREGs are calculated from EPA's cancer potency factors.

EPA Region III Risk-Based Concentration
EPA combines reference doses and carcinogenic potency slopes with "standard" exposure scenarios to calculate risk-based concentrations, which are chemical concentrations corresponding to fixed levels of risk (i.e., a hazard quotient of 1, or lifetime cancer risk of 10-6, whichever occurs at a lower concentration) in water, air, fish tissue, and soil.

Lowest Observed Adverse Effect Level (LOAEL)
The lowest dose of a chemical that produced an adverse-effect when it was administered to animals in a toxicity study.

Maximum Contaminant Level (MCL)
The MCL is the drinking water stand established by EPA. It is the maximum permissible level of a contaminant in water that is delivered to a free-flowing outlet. MCLs are considered protective of human health over a lifetime (70 years) for individuals consuming 2 liters of water per day.

Minimal Risk Levels (MRL)
MRLs are estimates of daily human exposure to a chemical (i.e., doses expressed in mg/kg/day) that are unlikely to be associated with any appreciable risk of deleterious noncancer effects over a specified duration of exposure. MRLs are calculated using data from human and animal studies and are reported for acute (< 14 days), intermediate (15-364 days), and chronic (> 365 days) exposures. MRLs are published in ATSDR Toxicological Profiles for specific chemicals.

The derivation of a CV uses conservative exposure assumptions, resulting in values that are much lower than exposure concentrations observed to cause adverse health effects; thus, insuring the CVs are protective of public health in essentially all exposure situations. That is, if the concentrations in the exposure medium are less than the CV, the exposures are not of health concern and no further analysis of the pathway is required. However, while concentrations below the CV are not expected to lead to any observable health effect, it should not be inferred that a concentration greater than the CV will necessarily lead to adverse effects. Depending on site-specific environmental exposure factors (for example, duration of exposure) and activities of people that result in exposure (time spent in area of contamination), exposure to levels above the CV may or may not lead to a health effect. Therefore, ATSDR's CVs are not used to predict the occurrence of adverse health effects.

The CVs used in this evaluation are defined as follows: The CREG is a concentration at which excess cancer risk is not likely to exceed one case of cancer in a million persons exposed over a lifetime. The CREG is a very conservative CV that is used to estimate cancer risk. Exposure to a concentration equal to or less than the CREG is defined as an insignificant risk and is an acceptable level of exposure over a lifetime. The risk from exposure is not considered as a significant risk unless the exposure concentration is approximately 10 times the CREG and exposure occurs over several years. The EMEG is a concentration at which daily exposure for a lifetime is unlikely to result in adverse noncancerous effects.

Selecting Contaminants of Concern

Contaminants of concern (COCs) are the site-specific chemical substances that the health assessor selects for further evaluation of potential health effects. Identifying COCs is a process that requires the assessor to examine contaminant concentrations at the site, the quality of environmental sampling data, and the potential for human exposure. A thorough review of each of these issues is required to accurately select COCs in the site-specific human exposure pathway. The following text describes the selection process.

In the first step of the COC selection process, the maximum contaminant concentrations are compared directly to health-based CVs. ATSDR considers site-specific exposure factors to ensure selection of appropriate health CVs. If the maximum concentration reported for a chemical is less than the health CV, ATSDR concluded that exposure to that chemical is not of public health concern; therefore, no further data review is required for that chemical. However, if the maximum concentration is greater than the health CV, the chemical is selected for additional data review. In addition, any chemicals detected that do not have relevant health CVs are also selected for additional data review.

CVs have not been developed for some contaminants, and, based on new scientific information, other CVs may be determined to be inappropriate for the specific type of exposure. In those cases, the contaminants are included as COCs if current scientific information indicates exposure to those contaminants may be of public health concern.

The next step of the process requires a more in-depth review of data for each of the contaminants selected. Factors used in the selection of the COCs included the number of samples with detections above the minimum detection limit, the number of samples with detections above an acute or chronic health CV, and the potential for exposure at the monitoring location.


APPENDIX C. ESTIMATES OF HUMAN EXPOSURE DOSES AND HEALTH EFFECTS

Derivation of ATSDR's Estimated Exposure Doses

To determine whether non-cancer and cancer effects are a concern, the Agency for Toxic Substances and Disease Registry (ATSDR) estimated adult and child exposure doses or body burdens for Washington Navy Yard (WNY) completed exposure pathways. Specifically, ATSDR evaluated child (past) exposure to lead in surface soil and adult and child (past, current, and future) exposure to polychlorinated biphenyls (PCBs) and chlordane in fish.

Past Exposure to Lead in Surface Soil

Lead was identified as the contaminant of primary concern in surface soil at Admiral's Row. Currently, health-based criteria are not available for evaluating the non-cancer effects of lead exposure. ATSDR and U.S. Environmental Protection Agency (EPA) have not developed health-based criteria, largely because a threshold level (a level at which no adverse health effects will occur) for many non-cancer health effects has not been identified in infants and younger children (i.e., the most sensitive populations).

Correlations between blood lead levels and adverse effects are fairly well understood, however, and are studied to evaluate the potential for adverse health effects (e.g., nervous system effects, slowed child growth, and developmental brain damage). The Centers for Disease Control and Prevention considers children to have an elevated level of lead if the amount of lead in the blood is at least 10 µg/dL. Medical evaluations and environmental investigations and remediation should be performed when blood lead levels in children reach 20 µg/dL. Medical treatment may be necessary in children if the lead concentration in blood is higher than 45 µg/dL.

In the absence of measured blood lead levels in children who lived at WNY (no blood lead studies or other health outcome studies were conducted in the past), ATSDR applied an approach that has been devised to estimate blood lead levels from known, media-specific contaminant concentrations. The approach has been developed based on the results of numerous studies that have attempted to correlate environmental lead levels with blood lead levels. The model that has been developed to estimate blood lead levels considers the extent to which lead in water, soil, air, and food may cause blood lead levels to rise. ATSDR regards the model as a useful screening tool and used it to evaluate lead exposures at WNY.

ATSDR estimated the possible contribution of soil lead to blood lead using soil concentrations measured during recent site investigations, based on a maximum detected concentration of 18,700 ppm lead. Studies have generally concluded that, for every 0.0007 to 0.0068 µg/dL increase in blood lead levels, there is a linear increase of 1 part per million (ppm) in soil lead concentrations (ATSDR 1999b). Using this screening approach, ATSDR estimated that past blood lead levels may have ranged between 13 µg/dL and 127 µg/dL in children who lived at WNY. Based on these estimates, blood lead levels for children living at WNY may have been elevated.

This calculation, however, is extremely conservative and likely over estimates child blood lead levels. It assumes that all WNY soil contained the maximum detected lead level of 18,700 ppm. In reality, however, many areas in Admiral's Row contained lead levels below 400 ppm (which would not be expected to be associated with adverse health effects). Furthermore, it assumes that 100% of this lead was bioavailable (i.e., readily available for absorption in the body). Lead bioavailability is affected by a number of factors including solubility, particle size, and medium. Other factors affecting the relationship between soil and blood lead levels include the depth of soil sampled, sampling method, soil characteristics, specific land uses, cleanliness of the home, age and mouthing activities of the children, and many other factors. In addition, impacts from other possible lead sources were not considered. Without detailed knowledge about WNY past conditions, ATSDR's estimates cannot be used to draw any firm conclusions, but provide some perspective regarding the results of possible past exposures.

Current and future exposures to lead in surface soil have been eliminated because children no longer have access to the contaminated soils at Admiral's Row.

Past, Current, and Future Exposures to PCBs and Chlordane from Consumption of Locally-Caught Fish

Evaluation of Potential Public Health Hazards

ATSDR used the following equation to estimate exposure doses from Anacostia River fish:

mathematical equation

where:

Conc = Maximum concentration in fish (mg/kg)
IR = Ingestion rate: 0.032 kg/day (approximately five 8-ounce meals per month), average consumption of fish and shellfish from estuarine and freshwater by sport fisherpersons for the general U.S. population.
FI = Fraction ingested from contaminant source (assumed 100%)
EF = Exposure frequency, or number of exposure events: 365 days
ED = Exposure duration, or the duration over which exposure occurs: adult = 30 years
BW = Body weight (kg): adult = 70 kg (154 pounds)
AT = Averaging time, or the time period over which cumulative exposures are averaged 30 years for non-cancer effects; 70 years for cancer effects)

Determination of Human Health Effects

PCBs

Non-cancer Effects

PCBs were the contaminants detected at the highest concentrations and posing the greatest potential health hazard to individuals eating fish caught in the lower Anacostia River. Local anglers in the Washington, D.C. area reportedly eat catfish more often then eels, so ATSDR based its estimated exposure dose on a sport angler who eats an average of 32 grams of catfish a day (or five 8-ounce meals a month) contaminated with the maximum PCB concentration (2.4 ppm). The estimated dose of 1.1 x 10-3 mg/kg/day for adults exceeds ATSDR's minimal risk level (MRL) for PCBs (Aroclor 1254) of 2 x 10-5 mg/kg/day for non-cancer health effects.

Evidence documenting adverse effects in humans from oral exposure to PCBs is at best suggestive, but a variety of adverse effects have been observed and are well documented in animal studies. The difference between human and animal studies may be attributed to differences in species susceptibility, or more likely, the fact that most animal studies administer doses that greatly exceed those found in human exposure scenarios. Animal toxicity studies of oral PCB exposure have documented numerous adverse effects, including hepatic, gastrointestinal, hematological, dermal, immunological, neurological, developmental, and reproductive problems. Other effects of oral PCB exposure include body weight loss and thyroid toxicity. There is increasing evidence that babies born to women with high PCB exposures before and during pregnancy experience development delays. Some of the behavioral problems, which included delayed motor skills and memory problems, persisted for years (ATSDR 2000). Mothers of these infants, however, may have been exposed to other chemicals. Research into possible environmental effects of on children is ongoing.

Nonetheless, effects reported in the literature were seen at exposures greater than those estimated for lower Anacostia River fish consumers. As such, adverse effects reported in the literature are not expected from ATSDR's conservatively estimated PCB exposure from the consumption of lower Anacostia River fish. The estimated exposure dose for consuming lower Anacostia River fish is approximately one order of magnitude lower than the most conservative No Observed Adverse Effect Level (NOAEL) found in other chronic oral animal studies, and approximately three orders of magnitude lower than the NOAELs in the majority of chronic oral animal studies (ATSDR 2000). Therefore, ATSDR does not expect any adverse non-cancer effects to result from consuming lower Anacostia River fish with the reported levels of PCB contamination. In order to ensure the protection of public health, however, ATSDR recommends that people continue observing the Washington, D.C., Department of Health no consumption fish advisory warning for the Anacostia River.

Cancer Effects

A number of experimental studies have demonstrated the ability of PCBs to cause cancer in animals, but epidemiological studies in humans do not provide enough information to determine if PCBs are carcinogenic in humans. Several reviews of epidemiological studies (primarily, worker exposures to PCBs) have been inconclusive or have not shown an association between PCBs and cancer (Cogliano 1998; Danse et al. 1997; Kimbrough 1995; Longnecker et al. 1997; Smith 1997; Swanson et al. 1995; Vater et al. 1995; Ward et al. 1997 [as cited in ATSDR 2000]). Compared to the cancer effect level found in animal studies, ATSDR's estimated human exposure dose of 4.7 x 10-4 mg/kg/day for adults is approximately four orders of magnitude lower than the administered doses that induced cancer effects in rats. Rats that ingested certain PCB mixtures over their lifetimes developed liver cancer. Based on these animal studies, EPA classifies PCBs as a Category B2 carcinogen, indicating that it is a probable human carcinogen. The EPA's National Center for Environmental Assessment recommended that a cancer slope factor of 2.0 (mg/kg/day)-1 be used for PCBs in biota. Therefore, the theoretical cancer risk from eating catfish from the lower Anacostia and Potomac Rivers under the assumed exposure scenario would be (ATSDR 2000):

2.0 (mg/kg/day)-1 x (4.7 x 10-4 mg/kg/day) = 1 x 10-4

This risk level (1 x 10-4) is just within the range typically acceptable for the general population, and may be even lower or possibly zero (EPA 1996). However, it should also be noted that the risk level calculation is extremely conservative and likely overestimates exposures. For example, it does not account for the fact that people may eat only the meat of a fish and not the skin (where fat tissue and PCBs are primarily stored). In this case, the theoretical risk is greater than the actual risk. Moreover, given the inconclusive link between oral PCB exposure and human cancer, it is highly unlikely that the consumption of lower Anacostia River fish is going to result in adverse cancer effects for the local population. As a prudent public health measure, however, ATSDR, recommends that people continue to observe the no fish consumption advisory for the Anacostia River.

Chlordane

Non-cancer Effects

ATSDR identified chlordane as another potential contaminant of concern to individuals eating fish caught in the lower Anacostia River. It was detected at a maximum concentration of 0.622 ppm in catfish caught in the WNY vicinity. Chlordane is a very fat soluble compound; therefore, it is generally detected in fish with high body fat content (e.g., eels and catfish) and concentrated in the fish skin and other fatty tissues. Numerous animal and human studies have investigated the toxic effects of chlordane. Chronic studies of chlordane in animals have considered and found the liver to be the primary target organ, whereas occupational studies of workers with chronic chlordane exposure have not established any effect (neurologic, hepatic, or hematotoxic). Recent epidemiological results from a non-occupationally exposed cohort, however, show evidence of neurotoxicity, including tension, depression, anger, vigor, fatigue, and confusion. Epidemiological studies also suggest that chronic exposure to low levels of chlordane affects the liver (ATSDR 1994).

As described above for PCBs, ATSDR based its estimated exposure dose on a sport fisherperson who eats an average of 32 grams of catfish a day contaminated with the maximum chlordane concentration (0.622 ppm). The estimated dose of 2.8 x 10-4 mg/kg/day for adults does not exceed ATSDR's chlordane MRL of 1 x 10-3 mg/kg/day for non-cancer health effects. The estimated dose for lower Anacostia River anglers is approximately four to five orders of magnitude lower than the lowest doses resulting in observable health effects in animals (ATDSR 1994). Such limited exposure to chlordane from the consumption of locally caught fish will not likely result in an increased risk of adverse non-cancer effects.

Cancer Effects

A number of animal studies have examined the possibility of chlordane causing cancer, but epidemiological studies in humans do not provide enough information to determine if chlordane is carcinogenic. The results of animal studies sufficiently show that oral chlordane treatment induces benign or malignant liver tumors in mice. The liver is also the target organ for cancer in rats. The evidence for chlordane exposure leading to cancer in humans is tentative, but based on the animal studies, EPA classifies chlordane as a Category B2 carcinogen (probable human carcinogen). The EPA's National Center for Environmental Assessment recommended that a cancer slope factor of 1.3 (mg/kg/day)-1 be used for chlordane in biota. Therefore, the theoretical cancer risk from eating catfish from the lower Anacostia River under the assumed exposure scenario would be (ATSDR 1994):

1.3 (mg/kg/day)-1 x (1.2 x 10-4 mg/kg/day) = 2 x 10-5

This risk level (2 x 10-5) is within the risk range typically acceptable for the general population, and may even be lower or possibly zero (EPA 1996). This risk level calculation is extremely conservative and likely overestimates exposures. For example, it does not account for the fact that people may eat only the meat of a fish and not the skin (where fat tissue and chlordane are primarily stored). In this case, the theoretical risk is greater than the actual risk. Moreover, given the inconclusive link between oral chlordane exposure and human cancer, it is highly unlikely that the consumption of fish from the lower Anacostia River is going to result in adverse cancer effects for the local population (ATSDR 1994). As a prudent public health measure, however, ATSDR, recommends that people continue to observe the no fish consumption advisory for the Anacostia River.


APPENDIX D. GLOSSARY

Adverse Health Effect:
A change in body function or the structures of cells that can lead to disease or health problems.


The Agency for Toxic Substances and Disease Registry (ATSDR):
ATSDR is a federal health agency in Atlanta, Georgia that deals with hazardous substance and waste site issues. ATSDR gives people information about harmful chemicals in their environment and tells people how to protect themselves from coming into contact with chemicals.


Background Level:
An average or expected amount of a chemical in a specific environment. Or, amounts of chemicals that occur naturally in a specific-environment.


Carcinogen:
Any substance that may produce cancer.


Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA):
CERCLA was put into place in 1980. It is also known as Superfund. This act concerns releases of hazardous substances into the environment, and the cleanup of these substances and hazardous waste sites. ATSDR was created by this act and is responsible for looking into the health issues related to hazardous waste sites.


Comparison Values (CVs):
Concentrations or the amount of substances in air, water, food, and soil that are unlikely, upon exposure, to cause adverse health effects. Comparison values are used by health assessors to select which substances and environmental media (air, water, food and soil) need additional evaluation while health concerns or effects are investigated.


Concentration:
How much or the amount of a substance present in a certain amount of soil, water, air, or food.


Contaminant:
See Environmental Contaminant.


Dose:
The amount of a substance to which a person may be exposed, usually on a daily basis. Dose is often explained as "amount of substance(s) per body weight per day".


Environmental Contaminant:
A substance (chemical) that gets into a system (person, animal, or the environment) in amounts higher than that found in Background Level, or what would be expected.


Environmental Contamination:
The presence of hazardous substances in the environment. From the public health perspective, environmental contamination is addressed when it potentially affects the health and quality of life of people living and working near the contamination.


Environmental Media:
Usually refers to the air, water, and soil in which chemicals of interest are found. Sometimes refers to the plants and animals that are eaten by humans. Environmental Media is the second part of an Exposure Pathway.


U.S. Environmental Protection Agency (EPA):
The federal agency that develops and enforces environmental laws to protect the environment and the public's health.


Exposure:
Coming into contact with a chemical substance.(For the three ways people can come in contact with substances, see Route of Exposure.)


Exposure Pathway:
A description of the way that a chemical moves from its source (where it began) to where and how people can come into contact with (or get exposed to) the chemical. ATSDR defines an exposure pathway as having 5 parts:

  • Source of Contamination,
  • Environmental Media,
  • Point of Exposure,
  • Route of Exposure, and
  • Receptor Population.


When all 5 parts of an exposure pathway are present, it is called a Completed Exposure Pathway. Each of these 5 terms is defined in this Glossary.


Hazardous Waste:
Substances that have been released or thrown away into the environment and, under certain conditions, could be harmful to people who come into contact with them.


Indeterminate Public Health Hazard:
The category is used in Public Health Assessment documents for sites where important information is lacking (missing or has not yet been gathered) about site-related chemical exposures.


Ingestion:
Swallowing something, as in eating or drinking. It is a way a chemical can enter your body (See Route of Exposure).


Media:
Soil, water, air, plants, animals, or any other parts of the environment that can contain contaminants.


Minimal Risk Level (MRL):
An estimate of daily human exposure - by a specified route and length of time -- to a dose of chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects.


The National Priorities List (NPL) (Which is part of Superfund) :
A list kept by the U.S. Environmental Protection Agency (EPA) of the most serious, uncontrolled or abandoned hazardous waste sites in the country. An NPL site needs to be cleaned up or is being looked at to see if people can be exposed to chemicals from the site.


No Apparent Public Health Hazard:
The category is used in ATSDR's Public Health Assessment documents for sites where exposure to site-related chemicals may have occurred in the past or is still occurring but the exposures are not at levels expected to cause adverse health effects.


No Public Health Hazard:
The category is used in ATSDR's Public Health Assessment documents for sites where there is evidence of an absence of exposure to site-related chemicals.


Point of Exposure:
The place where someone can come into contact with a contaminated environmental medium (air, water, food or soil). For examples: the area of a playground that has contaminated dirt, a contaminated spring used for drinking water, the location where fruits or vegetables are grown in contaminated soil, or the backyard area where someone might breathe contaminated air.


Public Health Assessment (PHA):
A report or document that looks at chemicals at a hazardous waste site and tells if people could be harmed from coming into contact with those chemicals. The PHA also tells if possible further public health actions are needed.


Public Health Hazard Criteria:
PHA categories given to a site which tell whether people could be harmed by conditions present at the site. Each are defined in the Glossary. The categories are:
  • Urgent Public Health Hazard
  • Public Health Hazard
  • Indeterminate Public Health Hazard
  • No Apparent Public Health Hazard
  • No Public Health Hazard

Public Health Hazard:
The category is used in PHAs for sites that have certain physical features or evidence of chronic, site-related chemical exposure that could result in adverse health effects.


Potentially Exposed:
The condition where valid information, usually analytic environmental data, indicates the presence of contaminant(s) of a public health concern in one or more environmental media contacting humans (i.e., air, drinking water, soil, food chain, surface water), and evidence exists that some of those persons have an identified route(s) of exposure (i.e., drinking contaminated water, breathing contaminated air, having contact with contaminated soil, or eating contaminated food).


Parts per Billion (ppb)/Parts per Million (ppm):
Units commonly used to express low concentrations of contaminants. As example of each, one part per billion (ppb) of trichloroethylene (TCE) equals one drop of TCE mixed in a competition-size swimming pool and one part per million (p.m.) equals one ounce of trichloroethylene (TCE) in one million ounces of water.


Receptor Population:
People who live or work in the path of one or more chemicals, and who could come into contact with them (See Exposure Pathway).


Reference dose (RfD):
An estimate, with safety factors (see safety factor) built in, of the daily, life-time exposure of human populations to a possible hazard that is not likely to cause harm to the person.


Risk:
In risk assessment, the probability that something will cause injury, combined with the potential severity of that injury.


Route of Exposure:
The way a chemical can get into a person's body. There are three exposure routes:
- breathing (also called inhalation),
- eating or drinking (also called ingestion), and
- or getting something on the skin (also called dermal contact).


Safety Factor:
Also called Uncertainty Factor. When scientists don't have enough information to decide if an exposure will cause harm to people, they use "safety factors" and formulas in place of the information that is not known. These factors and formulas can help determine the amount of a chemical that is not likely to cause harm to people.


Source (of Contamination):
The place where a chemical comes from, such as a landfill, pond, creek, incinerator, tank, or drum. Contaminant source is the first part of an Exposure Pathway.


Urgent Public Health Hazard:
This category is used in ATSDR's Public Health Assessment documents for sites that have certain physical features or evidence of short-term (less than 1 year), site-related chemical exposure that could result in adverse health effects and require quick intervention to stop people from being exposed.


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