PUBLIC HEALTH ASSESSMENT
FORMER NANSEMOND ORDNANCE DEPOT
III. DISCUSSION (Cont.)
Table 8 lists the chemicals that were detected in soil in the TCC Property area at least once above substance-specific soil CVs. For past exposures at the TNT Burial Site, ATSDR assumed that adults or teenagers might be at this area 5 times a week for 48 weeks of the year, or that 10-year-old soccer players might be at the area 3 times a week for half the year. ATSDR also assumed that each day they were on site, adults or teens accidentally ingested 100 milligrams (mg) of soil, and children accidentally ingested 200 mg of soil (see Appendix A for further exposure assumption details). Initial screening was performed by use of the maximum soil value detected before 1992. The resulting estimated exposure doses for arsenic and trinitrobenzene were lower than cancer and noncancer health guideline values, indicating that no health effects are expected. Evaluation of exposure to lead, TNT, and 2-amino-4,6-nitrotoluene follows below.
For present and future exposures, the same calculation was performed using the maximum soil value detected in post-removal sampling and assuming potential future residential use (i.e., small children could access the soil throughout the year). Estimated exposure doses of dieldrin, trinitrobenzene, and PAHs were lower than health guideline values. Evaluation of current and potential future exposures to arsenic, lead, and TNT follows.
|Contaminant||Maximum concentration in soil, parts per million (ppm)||Comparison Value (CV) in ppm||CV Source (defined in Appendix A)|
|1987*||1989†||1991 (Pre-removal)†||1992 (Post-removal) †||1998†||2003††|
|Arsenic||164||30||25||Not Detected||19||41||20/0.5||cEMEG / CREG|
|Dieldrin||Not Analyzed||Not Analyzed||Not Analyzed||Not Analyzed||0.24||Not Detected||3 / 0.04||cEMEG / CREG|
|2-Amino-4,6-Dinitrotoluene||47,000||1,500||Not Analyzed||Not Analyzed||Not Detected||1,470||16||R3 RBC|
|Trinitrobenzene||Not Analyzed||Not Detected||25.1||4.4||Not Detected||Not Detected||3||cRMEG|
|Trinitrotoluene (TNT)||140,000‡||Not Detected||28,600||650||Less than CV||Not Detected§||20||CREG|
|TEQ, PAHs||Not Analyzed||Not Analyzed||Not Analyzed||Not Analyzed||0.8||1.2||0.1||CREG|
|Sources: *; † ; †† .|
|‡ Sample was of obvious crystalline TNT present in soil. Source: .|
|§ Although TNT was not detected in the 2003 soil sampling, crystalline TNT in bags and in slab form is still encountered at this site.|
Further Evaluation of SoilTCC Property/TNT Burial Site
No health effects are expected from exposure to arsenic in soil at the TNT Burial Site. Exposure to the maximum concentration of arsenic was only slightly above the health guideline value for potential future residential exposures to small children. This dose was equal to the NOAEL observed in toxicological studies . The actual dose a child might get would be even lower because exposure would be to an average rather than the maximum concentration. Moreover, arsenic would not be as easily absorbed from soil as from the aqueous solutions used in toxicological studies. Arsenic is known to cause cancer. However, the estimated increase in the risk of cancer from a lifetime of exposure to arsenic in soil at the TNT Burial Site is so low as to be negligible.
As previously discussed, levels of 10 µg/dL and less in children's blood have been associated with small decreases in IQ and slightly impaired hearing and growth. The maximum concentration of lead detected in the TNT Burial Site soil before the removal action was 6,990 mg/kg (ppm). Epidemiological studies have determined soil slope factors that predict blood lead levels to increase from between 0.0007 and 0.0068 µg/dL per ppm increase in soil lead level for children 1-18 years old, and from 0.001 to 0.003 µg/dL per ppm for adults 18-65 years old . These wide ranges resulted from the presence of different sources of lead, different exposure conditions, and different exposed populations. The highest appropriate soil slope factor, corrected by the amount of time spent on site, indicates that adults and older teenagers would have a maximum increase in blood lead level of 14 µg/dL, and child soccer players could have an increase as high as 10 µg/dL. The actual blood lead level would be lower, however, because exposure is to an average, rather than to the maximum, lead concentration. The predicted blood lead increases are not expected to lead to any adverse health effects in adults or teenagers, who are more resistant than children to lead's effects. However, a child's increase could possibly result in some health effects, depending on the existing body burden of lead.
According to the limited post-removal sampling data, the lead concentration decreased, so that the current maximum level is 1,930 ppm. Use of a soil slope factor of 0.0068 µg/dL/ppm for children 1-18 years at this maximum lead concentration results in a child's blood lead level increase of 13.1 µg/dL. The health effects associated with such an increase would depend partly on the existing body burden of lead. The actual blood lead level would be much lower because children would be exposed to an average rather than the maximum lead concentration and because weather would decrease the percentage of time during which children would be able to contact the soil. However, the lead in soil at the TNT Burial Site could present a risk for small children who access the soil in residential conditions.
Exposure to TNT (trinitrotoluene) in high doses can result in liver problems and blood disorders. The estimated exposure doses for teens and adults who occasionally, in the past, contacted the maximum concentration of TNT were 0.2 and 0.1 mg/kg/day, respectively. Children playing soccer three times weekly would have received a dose similar to the teens. Toxicological studies have shown that a dose of 0.5 mg/kg/day over 6 months resulted in mild adverse liver effects in dogs . Therefore, and in light of the uncertainty associated with the differences between animals and humans, the estimated past exposures to TNT may have resulted in health effects. TNT has been classified as a possible human carcinogen. Exposure as described to the maximum concentration of TNT over a ten-year period would result in a low to moderate increased risk of cancer . It should be noted, however, that the actual exposure to TNT would be to an average concentration rather than to the maximum, and other exposure factors such as weather or soil cover could decrease the amount of soil ingested over a period of time .
The populations unusually susceptible to the toxic effects of TNT are very young children, individuals with impaired kidney or liver function, and individuals deficient in G6PD enzyme. Also at increased risk are individuals with sickle cell trait, genetically induced unstable hemoglobin forms, or congenital hypercholesterolemia .
Dermal exposure to the TNT in the soil may have irritated some people's skin. Some people develop an allergic reaction to TNT, especially after repeated exposure, a reaction that may cause itching and irritation. The concentration of TNT or duration of exposure necessary to cause this effect is unknown. TNT also presents a physical hazard, because in high concentrations it can explode or ignite.
A large quantity of TNT has been removed from the site. However, crystalline TNT in soil and in small bags used as fuses have been encountered at the site during recent investigations, suggesting that more sampling is needed to determine the extent of contamination.
To estimate potential future exposures, the maximum TNT concentration in soil after the removal was used. The estimated doses for small children and adults are 0.01 mg/kg/day and 0.002 mg/kg/day, respectively. Toxicological studies have shown that a dose of 0.5 mg/kg/day over 6 months resulted in mild adverse liver effects in dogs . Adverse human health effects from TNT exposure at the TCC Property/TNT Burial Site are unlikely. However, in light of the uncertainty associated with the differences between animals and humans, exposure to TNT by regular contact with the highest remaining concentration of TNT in soil might contribute to liver problems in sensitive individuals. The estimated doses likely overestimate actual potential exposure, because chronic exposure would be to an average rather than to the maximum concentration, and because TNT levels appear to be decreasing (the latest soil sampling did not detect TNT). Nevertheless, for the purpose of eliminating physical hazards, further sampling to identify and remove remaining concentrated TNT in the area is recommended.
Under reducing conditions, TNT can be degraded by the stepwise conversion of the nitro (NO2-) groups to amino (NH2-) groups. Before the removal, the first degradation product in this series, 2-amino-4,6-dinitrotoluene (ADNT), was detected in the surface soil at lower levels (maximum 47,000 mg/kg) than the levels of TNT. The estimated exposure doses for teens and adults who occasionally, in the past, contacted the maximum concentration of ADNT were 0.04 and 0.06 mg/kg/day, respectively. Children playing soccer three times weekly would have received a dose similar to the teens. Experiments on soil test organisms showed that the toxicity of TNT in soil decreased with aging and with conversion to its degradation products . Despite the uncertainties, it can be assumed that past exposure to the maximum concentration of ADNT may have led to health effects similar to those possible from exposure to TNT, as described above.
In the post-removal sampling, ADNT was detected at a maximum level of 1,470 mg/kg. To estimate potential future exposures, this maximum ADNT concentration was used to estimate doses for small children, teens, and adults of 0.04, 0.004, and 0.003 mg/kg/day, respectively. The estimated doses likely overestimate actual potential exposure, because chronic exposure would be to an average rather than to the maximum concentration. It is assumed that this exposure might contribute to liver problems in sensitive individuals, as with exposure to TNT.
b) Soil-James River Beachfront Landfill
For past soil exposures at the James River Beachfront Landfill, ATSDR assumed that adults or older children might be at this area four times a week throughout the year. ATSDR also assumed that each day adults were on site, they accidentally ingested 100 milligrams (mg) of soil and children accidentally ingested 200 mg each day on site (see Appendix A for further exposure assumption details). Initial screening was performed, using the maximum soil value detected before the removal. It should be noted that significant erosion of the beachfront area was and is occurring, so that waste and contaminants previously buried were being uncovered. It is possible that the maximum levels existing shortly before removal are not representative of actual concentrations people might have been exposed to in the more distant past. These maximum values were used, however, as a conservatively high estimate. The resulting estimated exposure doses for antimony, cadmium, and PAHs were lower than cancer and noncancer health guideline values, indicating that no health effects are expected from exposure to these contaminants. Evaluation of past exposure to arsenic, copper, iron, lead, phosphorus, and thallium follows below.
For present and future exposures, the same calculation was performed with use of the maximum soil value detected in post-removal sampling, assuming potential future residential use (i.e., small children could access the soil). The estimated exposure dose to arsenic was lower than health guideline values. Evaluation of current and potential future exposures to iron, lead, and PAHs follows. Table 8B presents a summary of all TCC Property surface soil contaminants found to be above comparison values.
|Contaminant||Maximum concentration in soil, parts per million (ppm) *||Comparison Value (CV) in ppm||CV Source (defined in Appendix A)|
|Before Removal||After Removal|
|Antimony||61||Less than CV||20||cRMEG|
|Arsenic||700||11.6||20 / 0.5||cEMEG / CREG|
|Cadmium||26||Less than CV||10||cRMEG|
|Copper||20,000||Less than CV||2,000||iEMEG|
|Phosphorus||1,100||Less than CV||1||cRMEG|
|Thallium||310||Less than CV||5.2||R9 PRG|
|TEQ, Polycyclic Aromatic Hydrocarbons (PAHs)||104||18.5||0.1||CREG|
|* Source: .|
Further Evaluation of SoilTCC Property/James River Beachfront Landfill
No health effects are expected from past exposure to arsenic in soil at the James River Beachfront Landfill. Occasional exposure of older children to the maximum concentration of arsenic was only slightly higher than the level shown to cause no adverse effects in toxicological studies . The actual dose that would have been received would be much lower because exposure would be to an average rather than to the maximum concentration, and arsenic would not be as easily absorbed from soil as from the aqueous solutions that toxicological effect levels are based on. Arsenic is known to cause cancer. If children or adults were exposed to the maximum level of arsenic in soil for 10 years, it would result in a low to moderate increase in the risk of cancer. However, the actual risk of cancer is considered unlikely to have been elevated because of the protective assumptions used in calculating risk.
If the property were developed for residential use, exposure to the post-removal maximum concentration of arsenic (12 ppm) results in a dose to small children lower than the health guideline, and the estimated increase in risk of cancer is so low as to be negligible. Therefore, no health effects would be expected from potential future exposures.
No health effects are expected from exposure to copper in soil at the James River Beachfront Landfill. Exposure to the maximum concentration of copper was above the health guideline value only for potential future residential exposures of small children. This dose, 0.06 mg/kg/day, corresponds to an intake of 0.6 mg/day. No health effects are expected because the intake is lower than the tolerable upper intake level of 1 mg/day [76,77]. The actual dose a child might get would be lower because exposure would be to an average rather than to the maximum concentration, and copper would not be as easily absorbed from soil as from the aqueous solutions used in toxicological studies.
The estimated past exposure dose of older children who occasionally contacted the maximum iron concentration in soil at the James River Beachfront Landfill is 0.6 mg/kg/day, higher than the health guideline of 0.3 mg/kg/day. However, no health effects are expected for this exposure. Long-term exposure to elevated iron can cause clinical effects such as accumulation of iron in the liver, but severe toxic effects are unlikely with exposures under 30 mg/kg of body weight . The estimated exposure dose conservatively overestimated actual exposure to iron, because the maximum concentration was used instead of the average and because iron may be less available in soil than in the media used in toxicological studies. Therefore, no health effects from past exposure to iron in soil at the James River Beachfront Landfill are expected. For estimating future exposures, ATSDR assumed that small children would be exposed throughout the year to the maximum iron concentration after removal. The dose thereby estimated for future exposure to iron in soil is 0.4 mg/kg/day. For the reasons described above, no health effects would be expected from future residential exposures to iron in soil at the James River Beachfront Landfill.
Lead was detected at a maximum concentration of 4,300 ppm in soil on the beachfront. Use of the highest appropriate soil slope factor, corrected by the amount of time spent on site, yields a prediction of increases in blood lead levels as high as 7 µg/dL and 17 µg/dL, respectively, for adults and older children. The actual blood lead levels would have been lower, because the exposure is to an average, rather than to the maximum lead concentration. The predicted blood lead increases are not expected to have led to any adverse health effects in adults, who are more resistant to lead's effects. However, the child increase could possibly have resulted in some health effects, depending on the existing body burden of lead .
In the future, if the Beachfront is developed for residential use, small children could contact lead in soil at levels up to the post-removal maximum, 600 ppm. Use of the highest blood lead soil slope factor of 0.0068 µg/dL/ppm (described previously) indicates that the maximum lead concentration measured in soil would be expected to increase blood lead levels by 4.1 µg/dL. The health effects associated with such an increase would depend partly on the existing body burden of lead. The actual blood lead level would be much lower, because children would be exposed to an average rather than to the maximum lead concentration and because weather and climate factors would decrease the percentage of time children would be able to contact the soil.
Phosphorus is a common component of larger compounds in the environment. It does not occur as an element naturally. The analysis of the soil sample did not distinguish the form of the elemental phosphorus (white, red, or black). Therefore, it is conservatively assumed in this evaluation that it was all white phosphorus, the most reactive and toxic form. White phosphorus is very reactive and may pose a fire and/or explosive hazard, but because of its reactivity will change to a less toxic compound when oxygen is present. For white phosphorus to be present in soil, it must either have a protective coating or it must be located below the surface where oxygen is not available .
At the maximum concentration of elemental phosphorus detected in soil before the removal (1100 ppm), the past chronic and intermediate exposure doses for older children and adults are approximately 200 times lower than the animal study dose at which no adverse health effect was noted . It is unlikely that past exposure to the phosphorus present in the soil was high enough to result in health effects . After the removal, phosphorus was not detected above the comparison value, so that potential future exposures are also not expected to result in any health effects.
Before the removal, the maximum concentration of thallium detected in soil was estimated to result in exposure doses to older children and adults of 0.0005 mg/kg/day and 0.0001 mg/kg/day, respectively, on the basis of occasional use. These doses are about 200 times lower than the lowest value that resulted in learning impairment in offspring of exposed rats . It is unlikely that past exposure to thallium in James River Beachfront Landfill soils would result in human health effects.
After the removal, thallium was not detected above the comparison value, and therefore potential future exposures are not expected to result in any health effects.
Polycyclic Aromatic Hydrocarbons (PAHs)
PAHs are a group of chemicals that are formed during the incomplete burning of organic substances; they can also be found in crude oil and creosote. Low levels of PAHs are found throughout the environment. Table 8B and other tables in this document show a TEQ, or toxicity equivalency quotient, which is the sum of all PAHs, weighted by their relative toxicity compared to benzo(a)pyrene, the most studied PAH compound. In the past, exposure to PAHs was too low to result in any health effects, mainly because of infrequent use of the site. To estimate risk from potential future residential exposure, exposure doses were calculated from the maximum post-removal TEQ listed in Table 8B. The resulting dose was thousands of times smaller than effect levels for noncancer effects seen in animal experiments. Some PAHs cause cancer. ATSDR's estimate of the increased risk of cancer, using the maximum post-removal TEQ and assuming daily contact over a 70-year lifetime, is a low increased risk. However, because of the conservative assumptions used, the actual risk is likely to be much smaller. Based on the post-removal concentrations, ATSDR does not consider the level of PAHs at the James River Beachfront Area to present an undue risk, even for residential scenarios.
c) SoilOther TCC Property Areas
For past and present exposures at other areas on the TCC Property, ATSDR assumed that adults and older children would access the area similarly to other recreational visitors (4 days a week throughout the year, 100 mg and 200 mg of soil ingested per day by adults and children, respectively). Estimated exposure doses for all COCs listed in Table 8C were lower than corresponding cancer and noncancer health guidelines. For potential future exposures, ATSDR estimated exposure of a small child to the maximum concentration every day throughout the year; the estimated doses were again lower than the health guideline values. Therefore, no health effects are expected from exposure to contaminants in soil at other areas on the TCC Property.
|Contaminant||Maximum concentration in soil, parts per million (ppm)||Comparison Value (CV) in ppm||CV Source (defined in Appendix A)|
|Track K / Tire Pile (after tire removal)*||Pesticide Drum Area (after drum removal)†|
|Arsenic||5.5||Not analyzed||20 / 0.5||cEMEG / CREG|
|Dieldrin||0.5||0.4||3 / 0.04||cEMEG / CREG|
|TEQ, PAHs||Less than CV||0.11||0.1||CREG|
|Sources: *; †|
Table 9 lists the chemicals in the TCC Property area that were detected in sediment (either from TCC Lake, J-Lake, or Streeter Creek) at least once above substance-specific CVs. For past exposures, ATSDR assumed that adults or older children might be on the property four times a week throughout the year. ATSDR also assumed that each day they were on site, adults accidentally ingested 10 mg of sediment and children accidentally ingested 20 mg of sediment (see Appendix A for further exposure assumption details). Initial screening was performed with use of the maximum sediment value. The resulting estimated exposure doses for all sediment COCs were lower than health guideline values, indicating that no health effects are expected. ATSDR was requested to evaluate potential future uses of the property, including residential use. For this evaluation, the dose calculation was repeated under the assumption that a smaller child is exposed throughout the year. These exposure doses were also lower than health guideline values, so that no health effects from sediment exposure are expected for potential future uses.
As part of EPA's general screening protocols, gross alpha and beta radiation were measured in sediments in TCC Lake and J Lake. The levels were similar to typical soil values. EPA does not consider these levels of radiation to indicate unusual radiation sources (personal communication, Harry Wheeler, TechLaw, Inc., August 2003).
|Contaminant||Maximum concentration in sediment, parts per million (ppm)||Comparison Value (CV) in ppm§||CV Source (defined in Appendix A)|
|TCC and J-Lakes:*|
|Arsenic||17.9||200 / 5||cEMEG / CREG|
|Arsenic||11.6||200 / 5||cEMEG / CREG|
|James River Beachfront Landfill (Before Removal):‡|
|Arsenic||Less than CV||200 / 5||cEMEG / CREG|
|§ Sediment CV calculated as ten times the soil CV. |
Sources: *; †; ‡
e) Surface Water and Groundwater
Tables 10 and 11 list the contaminants detected in surface water and groundwater, respectively, in the TCC Property area at least once above substance-specific drinking water CVs. For past exposures to surface water, ATSDR assumed that adults and older children contacted surface water 4 days a week for 6 months a year and that they accidentally swallowed some surface water. (See Appendix A for further details on the exposure assumptions used.) Estimated exposure doses of arsenic and lead resulting from this exposure are lower than health guideline values and therefore are not expected to result in health effects.
|Contaminant||Maximum concentration in surface water, micrograms per liter (µg/L)||Drinking Water Comparison Value in µg/L||CV Source (defined in Appendix A)|
|TCC and J-Lakes:*|
|Arsenic||9*||3 / 0.2||cEMEG / CREG|
|Arsenic||23*||3 / 0.2||cEMEG / CREG|
|Sources: *; †|
Groundwater data, shown in Table 11, are from two sources sampled on the TCC property: 1) TCC community wells, from which students and faculty could have drunk from 1960 until 1998, when the college was connected to the municipal system; and 2) groundwater in the TNT Burial Site, which has never been used for drinking purposes. For past exposures, ATSDR assumed that adults or teenagers drank 75% of their daily water from the community well and that they drank water containing the maximum concentration of each COC. See Appendix A for further details on the exposure assumptions used. The estimated exposure doses for arsenic, manganese, and diethylhexyl phthalate were lower than health guideline values and are not expected to significantly increase the risk of cancer, so that no health effects are expected from exposure to these contaminants in the drinking water. An evaluation of past TCC exposure to lead from community wells follows.
|Contaminant||Maximum concentration in groundwater, micrograms per liter (µg/L)||Drinking Water Comparison Value (CV) in µg/L||CV Source (defined in Appendix A)|
|TCC Former Drinking Water Wells (1989-1997):*|
|Arsenic||7||3 / 0.2||cEMEG / CREG|
|TNT Area (1992-2003 sampling):†|
|Arsenic||37||3 / 0.2||cEMEG / CREG|
|Sources: *[7,18,39,53,54]; †[39,42] |
‡ This contaminant is included even though EPA questions its single detection and even though the level is below the CV, because the detection suggests that contaminants from the TNT Burial Site may be reaching this former water source.
Further Evaluation of GroundwaterTCC Property (Past)
In the 1960s, students and faculty of Frederick College (and their families) lived on the site. No water supply data are available from that time period. Without such data, ATSDR is unable to determine conclusively whether substantive exposures occurred during that time. However, if contaminant levels were similar to the maximum levels detected from 1989-1997, no adverse health effects would be expected. This conclusion could be changed if more information about contaminant levels in the TCC drinking water from earlier time periods becomes available.
Groundwater–TCC Property (Potential Future)
ATSDR was requested to evaluate the TCC Property groundwater for potential drinking water use in the future. Using exposure assumptions described in Appendix A, ATSDR estimated exposure doses for all the COCs listed in Table 11, assuming that adults and small children might drink the TCC Property groundwater exclusively. The estimated exposure doses for RDX and diethylhexyl phthalate were lower than health guideline values, and those doses are not expected to increase the risk of cancer significantly. Therefore, no health effects are expected from exposure to these contaminants in groundwater. An evaluation of potential future exposure to arsenic, copper, iron, lead, manganese, dinitrobenzene, and trinitrotoluene in groundwater follows.
Further Evaluation of GroundwaterTCC Property (Potential Future)
The child dose from drinking the maximum level of arsenic in groundwater from the TCC Property is predicted to be about 0.004 mg/kg/day. This estimated dose is higher than the no observed adverse effect level of 0.0008 mg/kg/day but only about a third of the lowest level shown to cause skin changes in human epidemiologic studies, 0.014 mg/kg/day . The adult dose of 0.001 mg/kg/day would be less than a tenth of this lowest observed adverse effect level. A lifetime of drinking this level of arsenic in water would result in a moderately increased risk of developing cancer.
The estimated dose from using drinking water containing the maximum level of copper detected would be 0.031 mg/kg/day for a small child, only marginally higher than the health guideline value of 0.03 mg/kg/day. Drinking well water containing the maximum amount of copper is not likely to result in health effects .
The estimated potential future child dose from drinking TCC Property groundwater with the highest iron concentration is 2 mg/kg/day, higher than the health guideline of 0.3 mg/kg/day. The adult dose of 0.7 mg/kg/day is also higher than the health guideline. However, no acute health effects are expected from these exposures because severe toxic effects are not likely from exposure doses less than 30 mg/kg of body weight . However, long-term exposure to the maximum iron level could cause such clinical effects as accumulation of iron in the liver [58,59].
As discussed previously, lead levels in children's blood of 10 micrograms per deciliter (µg/dL), and perhaps lower, have been associated with small decreases in IQ and slightly impaired hearing and growth. A slope factor for the increase in blood lead concentration per increase in water lead concentration for infants has been calculated as 0.04 µg/dL blood per part per billion (ppb) lead at water lead levels above 15 ppb . The corresponding slope factor for school children is 0.03 µg/dL per ppb. Use of the maximum concentration of 65 ppb lead measured in the TCC Property groundwater indicates increases in blood lead concentrations of 2.6 µg/dL and 2.0 µg/dL for infants and school children, respectively. The health effects associated with such increases would depend partly on the existing body burden of lead.
Epidemiologic studies suggest an association between ingesting water containing elevated concentrations of manganese and the development of neurological symptoms. However, each of the studies had uncertainty regarding the exposure level or whether the effects were solely attributable to manganese, so that no effect levels based on human studies could be identified . Studies with rats have shown a lowest observed adverse effect level for neurological changes of 14 mg/kg/day, more than an order of magnitude higher than the estimated child dose of 0.1 mg/kg/day and also higher than the adult dose of 0.04 mg/kg/day. However, humans appear to be more sensitive to manganese than animals . Therefore, the estimated future child and adult manganese dose for this pathway could lead to adverse health effects.
The estimated potential future exposure doses from drinking TCC Property groundwater with the highest dinitrobenzene concentration for children and adults are 0.0004 mg/kg/day and 0.0001 mg/kg/day, respectively. These doses are thousands of times smaller than the lowest dose shown to cause symptoms consistent with hemolytic anemia in rats (0.75 mg/kg/day) . It is unlikely that this exposure would lead to health effects.
The estimated potential future exposure doses for children and adults from drinking TCC Property groundwater with the highest TNT concentration are 0.02 mg/kg/day and 0.005 mg/kg/day, respectively. Toxicological studies have shown that a dose of 0.5 mg/kg/day over six months resulted in mild adverse liver effects in dogs . Although adverse human health effects are unlikely, in light of the uncertainty in differences between animals and humans, the exposure to TNT by drinking this groundwater might contribute to liver problems in sensitive individuals.
Summary–Potential Future Use of TCC Property Groundwater for Drinking
The available data indicate that without treatment, the groundwater at the TCC Property area is not suitable for drinking purposes. The levels of several contaminants, especially arsenic, iron, lead, manganese, and TNT, are high enough to cause adverse health effects in children and/or adults.
f) FishTCC Lake and J-area Lake
Whole fish were sampled from TCC and J- Lakes in 1997, and fish filet samples were collected in 2000 [20, 50-52]. A summary of the contaminants detected in fish tissue composites is presented in Table 12. Although the whole fish measurements may overestimate or underestimate the concentration consumed if people eat only the filet, ATSDR used the whole fish data as well as the filet data to screen for chemicals that might be a health concern. ATSDR assumed that the concentration in the whole fish is similar to the concentration in the filet.
Although fishing activity at the lakes appears infrequent today, it may have been more common in the past, when people lived on the site and the land surrounding the lakes was not as overgrown. ATSDR assumed the 95th percentile fish ingestion rate for freshwater recreational anglers of 25 grams per day for adults . Small children weighing 10 kg were estimated to consume 12.5 grams of fish per day, on average. These assumptions are considered conservative for consumption of fish from TCC and J Lakes. It is possible that consumption of fish takes place at higher levels, especially from the Nansemond and James Rivers near the site, but no data are available for fish from these locations. ATSDR will, upon request, evaluate data on fish from these or other locations if they become available in the future.
|Contaminant||Highest Tissue Concentration, milligram per kilogram (mg/kg)||Estimated Highest Dose for Child, mg/kg/day||Health Guideline, mg/kg/day||HG Source (defined in Appendix A)||Excess Cancer Risk, if applicable||Exceeds Health Guideline?|
|Fish Filet Results ||Mercury||0.032||0.032||0.00001||0.0001||Oral RfD for methylmercury||NA||No|
|Total PAHs||0.0104||0.0132||0.00005||none||Not applicable (NA)||3 in 100,000||No|
|Total Chlordane||0.00035||Not measured||0.0000001||0.0005||Oral RfD||Less than 1 in 1,000,000||No|
|Total DDT||0.011||0.0013||0.000004||0.0005||Oral RfD||1 in 1,000,000||No|
|Total PCB||0.00224||0.00144||0.0000008||none||NA||2 in 1,000,000||No|
|Whole Fish Results ||Lead||0.68||0.53||0.0009||none||NA||NA||No|
|Manganese||23.1||Below DL||0.03||0.05||Oral RfD||NA||No|
|Mercury||0.05||0.04||0.00006||0.0001||Oral RfD for methylmercury||NA||No|
|Selenium||Below Detection Limit (DL)||0.83||0.001||0.005||Oral MRL||NA||No|
|Aldrin||0.00066||0.001||0.000001||0.00003||Oral MRL||6 in 1,000,000||No|
|Alpha-BHC||0.00051||0.00087||0.000001||0.008||Oral MRL||2 in 1,000,000||No|
|Alpha Chlordane||Below DL||0.0011||0.000001||0.0005||Oral RfD||Less than 1 in 1,000,000||No|
|DDD||0.037||0.0062||0.00005||none||NA||3 in 1,000,000||No|
|DDE||0.02||0.02||0.00003||none||NA||2 in 1,000,000||No|
|DDT||0.0016||0.0015||0.000002||0.0005||Oral RfD||Less than 1 in 1,000,000||No|
|Dieldrin||0.0034||0.0029||0.000004||0.0005||Oral MRL||2 in 100,000||No|
|Endosulfan II||0.00043||0.00053||0.0000007||0.006||Oral MRL||NA||No|
|Lindane||Below DL||0.00053||0.0000007||0.0003||Oral RfD||NA||No|
|Heptachlor Epoxide||0.00043||0.0005||0.0000006||0.00001||Oral RfD||2 in 1,000,000||No|
|Endrin Aldehyde||0.0018||0.00072||0.000002||0.0003||Oral MRL for endrin||NA||No|
All the estimated exposure doses were below health guideline values for adult and child doses. In addition, excess cancer risk calculated for the carcinogenic substances detected (both individually and cumulative) are within the range generally accepted as safe by EPA, typically less than 1 in 10,000. Lead, which has no established "safe" level, was detected only in the whole fish sampling event, and only at levels that would not be expected to cause elevated blood lead levels .
Drinking Water–Respass Beach Well Water
Five wells in the Respass Beach community were tested prior to 2000. In this historical testing, arsenic, sodium, and diethylhexyl phthalate were detected at least once above the corresponding CV. Uncertainty existed about whether the pre-2000 samples were collected before or after filtration (personal communication, Rob Thomson, EPA, February 2000). In 2002, eight wells in the Respass Beach community were sampled and analyzed for metals, PAHs, fluoride, nitrates, dinitrotoluene, explosives, pesticides and PCBs, and volatile and semi-volatile organic compounds. In this testing, several compounds, including sodium, methyl tert-butyl ether, nitrates, and various metals were detected; however, only two compounds (copper and sodium) were detected at concentrations above the corresponding ATSDR drinking water CV. The contaminants detected at least once at a level above the CV (in either sampling event) are evaluated further below.
|Contaminant||Maximum concentration in groundwater, micrograms per liter (µg/L)||Drinking Water Comparison Value (CV) in µg/L||CV Source (defined in Appendix A)|
|Arsenic||4.8*||3 / 0.2||cEMEG / CREG|
|Sources: *; †|
Further Evaluation of GroundwaterRespass Beach
The maximum concentration of arsenic detected in the few Respass Beach wells tested was 4.8 µg/L, less than EPA's Maximum Contaminant Level (MCL) for drinking water of 10 µg/L. Drinking water with the highest arsenic level would be unlikely to result in noncancer adverse health effects. The estimated increased risk of cancer from drinking water with the highest level of arsenic every day for a lifetime (70 years) would be 2 in 10,000. ATSDR classifies this as a low increased risk of cancer, but it should be noted that a number of uncertainties are inherent in estimating cancer risk. The estimated increased cancer risk therefore should be considered a worst-case estimate. See Appendix A for details . The arsenic in the Respass Beach wells may be naturally occurring, because the levels are similar to site background levels and no trend of increasing arsenic concentrations from before 2000 to 2002 was observed.
The estimated dose from using drinking water containing the maximum level of copper detected would be 0.05 mg/kg/day for a small child, higher than the health guideline value of 0.03 mg/kg/day. Animal studies have shown that copper can affect the liver when ingested in high doses. However, no effects were found in a study of human infants exposed to 0.315 mg/kg/day of copper . Therefore, drinking well water containing the maximum amount of copper is not likely to result in health effects.
Sodium is an element that occurs naturally in soil and groundwater and is also found in food products, such as table salt. It is not generally considered toxic, but some individuals need to restrict their sodium intake for medical reasons. The maximum concentration of sodium detected was 306,000 ppb. Individuals on sodium-restricted diets in this community should review their well test results (or have their wells tested) and then consult their physicians.
Diethylhexyl phthalate (DEHP)
DEHP is a man-made chemical commonly found in plastics. Sometimes, DEHP is a laboratory contaminant. In initial sampling, DEHP was not detected in duplicate samples, and re-sampling in 2002 did not show any detections of the compound. The highest DEHP concentration detected in the well water, 23 µg/L, corresponds to an exposure dose for children of 0.002 mg/kg/day. Drinking water with this concentration of DEHP would not be expected to cause noncancer adverse health effects, because the estimated dose is an order of magnitude smaller than EPA's reference dose of 0.02 mg/kg/day. DEHP is classified as a probable human carcinogen, but the estimated increase in cancer risk from drinking water with the highest level of DEHP over a 70-year lifetime is less than 1 in 100,000 .
Summary–Use of Respass Beach Well Water for Drinking
On the basis of the available well water sampling results, no health effects are expected from normal drinking of the Respass Beach well water. Periodic monitoring of this water is recommended, however, to ensure that the water remains unaffected by site contaminants and that it meets water quality standards.
The brick vaults present on the Dominion Lands may pose a physical hazard. At one time, as many as 30 uncovered vaults (both square and coffin-shaped) extending as far as 35 feet into the ground existed. Many vaults have been filled with soil, and it is expected that remaining vaults will be filled in or removed as development proceeds . However, heavy undergrowth in the area may allow undiscovered vaults to remain. These could pose a hazard in the future.
The World War II pier does not have curbs or railings. Parts of the deck planking are missing, and the far end of the pier appears to be very unstable. The pier is posted with signs warning "Use Pier at Own Risk". However, the pier is reportedly used often for fishing by both adults and children.
Debris continues to surface near the Nansemond and James River beachfront areas. These items could pose physical hazards to people using the areas.
FNOD was extensively used for transshipment, storage, and re-working of ordnance. During early operations, unserviceable ammunition was routinely dumped at sea or disposed of by defusing or burning. Since the facility was converted to private use in 1960, occasional discoveries of ordnance and explosive (OE)-related items have occurred. No detonations or injuries have resulted from the discoveries to date. To minimize the risk of such accidents, a concerted effort to recover OE items began in 1987 .
Of the hundreds of OE items discovered since 1960, many have been inert (not likely to detonate) . Types of OE recovered include crystallized explosives residue (resulting from steam-out and washout runoff), empty or demilitarized projectiles, fragments, and small arms ammunition. Live items, including grenades and artillery projectiles, have also been discovered. Most discoveries have been made within or in the immediate vicinity of known disposal areas or steam-out/burnout areas.
On the basis of surveys conducted within the past 15 years, OE disposal does not appear to have been evenly distributed throughout FNOD. However, any area where OE items have been found in the past has the potential for future encounters. The U.S. Army Corps of Engineers (ACE) has outlined a protocol for survey and clearance to maximize protection of the public. The protocol is based on varying types of future uses.
The following sections summarize the OE investigations and removals that have occurred since 1987. Following is a discussion of the possible extent of remaining OE items and ACE's suggested protocol for future use.
1987 TNT Burial Site Investigation
This investigation focused on a 3-acre area of the TNT Burial Site. The ACE investigation included a geophysical (magnetometer) survey to identify metal anomalies and an excavation of test pits. ACE also installed groundwater monitoring wells and collected soil samples. The locations for the test pits were based on available historical information and the results of the geophysical survey. Items recovered during the survey and associated removal included live small arms ammunition, projectiles and boosters, detonating and time fuses, and a several-ton slab of crystalline TNT. In addition, several hundred tons of scrap metal and 15 tons of contaminated soil were removed .
1992 Removal at James River Beach
ACE investigated 12 World War II-aged 155-millimeter (mm) projectiles found on the James River beach. The projectiles were examined by explosives removal experts and confirmed to be empty; one was removed, and eleven were left in place .
1993 Additional Removal at James River Beach
Recreational users of the James River Beach reported several additional OE items. Five empty 155-mm projectiles and 6 empty 170-mm projectiles were removed and disposed of. Two 55-gallon drums and two 1-ton containers were tested to ensure that they were free of chemical residues; they were also removed .
1995 Dominion Lands Survey
Dominion Lands Management conducted a survey in 1995 at 200 statistically selected locations on the Dominion Lands property. A total of 450 pieces of scrap and two unexploded ordnance items were removed. A further study located numerous inert items, including projectiles, small arms ammunition, and fragments .
1996 Construction Soil Pile Sifting for OE
In 1996, ACE sifted soil for the purpose of discovering OE. TCC had excavated the soil during construction of a storm water retention pond. From the sifting, 31,450 pounds of inert OE-related items were removed, including fuse adapters, booster cups, 20-mm and 37-mm artillery projectiles, and 60-mm mortar rounds .
1997 Survey of Areas of Concern
Areas of concern were identified from historical information including where ordnance disposals were known to have occurred, where OE items had previously been found, and aerial photos showing ground scars or other evidence of ordnance burials . Geophysical studies conducted in statistically chosen ¼-acre grids within the areas of concern identified several OE items, including live and inert projectiles, a live rocket, and two live smoke grenades. Test pits were dug at locations that had numerous anomalies in the geophysical study. The only ordnance-related items found were at the GE Main Burning Ground/ Steamout Pond. This study identified as a potential OE concern only 133 of the 975 total acres at FNOD [82,83]
1999 Survey of Derelict Pier Areas
The 1997 survey suggested that the underwater areas of the derelict piers might be sites of OE disposal. A study conducted in 1999 did not report any OE items .
OE Removal Activities Since 1999
EPA and ACE agreed to remove OE in designated areas of FNOD, including the James River and Nansemond River Beachfront Areas, the Dominion Lands, and the GE Main Burning Ground kick-out areas and burial/burn trenches .
Other OE Investigations Since 1999
Surface clearances and geophysical investigations have been initiated in several others areas of concern. OE has been found at the TNT Burial Site (where ordnance items, crystalline TNT, and TNT-filled fuses continue to be discovered). Clearance activities have also recently been held at the GE Main Burning Ground and Dominion Lands.
While clearance and removal activities are continuing, as of March 2002 over two-thirds of the land identified as a potential OE concern in 1997 had been investigated and found to be free of OE or cleared . However, it remains necessary to consider future land use due to the possibility that ordnance items may be discovered or encountered in the future.
The U.S. Army Corps of Engineers (ACE) has conducted surveys, sweeps, and clearances at the FNOD site on the basis of the best available information on potential locations for OE-related items. Numerous items, live and inert, have been recovered and disposed of. Still, it cannot be declared with certainty that all potential areas have been discovered and all items recovered.
Although live ordnance should always be considered dangerous and should be avoided when possible, injury is much more likely to occur only when the ordnance is tampered with [84,85]. Ordnance remaining in such areas of frequent use as residential areas poses a particularly high risk, especially for children and adolescents who are more likely to play or tamper with strange objects. This behavior makes it more likely for children than for adults to be injured by unexploded ordnance .
The ACE has developed a protocol of institutional controls, surveys, and removals for former military facilities opened to non-military use . The protocol, outlined below, is based on the types of uses intended. Included in the protective measures is a Memorandum of Agreement (MOA) to be enacted between the ACE, local governments, and the entities gaining control of the property. The purpose of the MOA is to ensure that the protocol is followed and that all future owners and users are aware of the potential for encounters with OE items and understand the potential for harm from any such encounters. Currently, all such land use controls as those listed below are voluntary. It is expected, however, that land use controls will be formalized upon signing of a Record of Decision (ROD) for the site (personal communication, Rob Thomson, EPA, June 26, 2003).
ATSDR supports formalization of land use controls to protect public health in the future. Without enforceable controls, any ordnance remaining on site will pose a public health hazard to future site users or residents.
ACE Standards for UXO/OE Clearance Based on Intended Future Use
Limited public access (e.g., park, livestock grazing, no construction or excavation anticipated)
Public Access Areas (e.g., farming, surface storage, general recreation, and vehicle parking)
Commercial or Residential Development (i.e., construction)
Health outcome databases can sometimes be evaluated in a public health assessment to identify whether a group of people who are exposed to site contamination have a higher rate of a specific disease or condition than unexposed people. This evaluation may occur when the following conditions are encountered: contamination is present, people are exposed to enough of the contamination that it may affect their health, and a suitable health outcome database is available for review. A few examples of health outcome databases are cancer registries, blood lead data from clinics, and birth defect registries.
Health outcome data were not reviewed for this public health assessment. While a possible public health hazard existed in the past (because of exposure to TNT and lead), the exposed population is not well defined, and the health effects, if any, would not have been recorded in a database. ATSDR may reconsider evaluating health outcome data if a historical database is discovered or if new data become available.
ATSDR recognizes that the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of their water, soil, air, or food. Children are at a greater risk than adults from certain kinds of exposures to hazardous substances emitted from waste sites and emergency events. They are more likely to be exposed because they play outdoors and they have more hand-to-mouth behaviors. They are more likely to come in contact with dust, soil, and heavy vapors close to the ground. Also, they receive higher doses of chemical exposure because of their lower body weights. In addition, the developing body systems of children can sustain permanent damage if toxic exposures occur during critical growth stages.
The possibility of health effects in children due to toxic exposures was evaluated in this public health assessment. In the past, it was assumed that small children did not have regular access to contaminated areas on the site. Because older children were only intermittently on the site, most past exposures were too small to result in health effects. The exceptions are exposure to soils: TNT exposure in soils at the TNT Burial Site could have increased the risk of liver problems or dermal reactions, and lead exposure in soils at the TNT Burial Site or the James River Beachfront Landfill might have increased the risk of slight neurological problems.
With future residential development possible, younger children could have frequent access to site areas that may still have elevated contaminant levels. Current information suggests that children may have an increased risk of developing health effects from residential exposure to lead in soil at the Dominion Lands, to lead and TNT in soil at the TNT Burial Site on TCC Property, and to lead in soil at the James River Beachfront Landfill on TCC Property. If children were to drink groundwater from the Dominion Lands or TCC Property areas, they could be at risk of severe adverse reactions to iron and other health effects from heavy metals and/or TNT.
ATSDR advertised and conducted a meeting on June 23, 1999, at the TCC campus so that citizens could meet with ATSDR staff and raise any health-related concerns about the site. In addition, a newspaper article in the Virginian-Pilot on June 24, 1999, described ATSDR's participation in the FNOD site and listed a toll-free number at which concerned citizens could reach ATSDR staff. A few local residents attended the meeting, and other citizens formerly associated with the site called ATSDR to report their concerns and questions. The health concerns expressed are listed below.
One person who spent some years on the site reported experiencing dizziness, internal pains, tumors, memory problems, thyroid disease, skin disorders, and liver and lung problems since leaving the site.
Response: From the chemical information reviewed in this public health assessment, ATSDR did not find levels of contaminants that would pose a health hazard to adults. TNT can cause abnormal liver function, but it is unlikely that an adult would have ingested sufficient TNT from the soil in the TNT Burial Site area to result in adverse health effects (see discussion on page 13). As investigations continue at the FNOD site, ATSDR will evaluate the public health implications of site contamination, as appropriate.
Another area resident reported E. coli bacteria violations in the TCC water supply in 1993 and said that many students experienced stomach distress and headaches.
Response: ATSDR did not find any bacteria violations in the well water data reviewed. If E. coli bacteria were present in the TCC drinking water, they could cause the symptoms reported. The college is currently connected to the municipal water system. Any bacterial contamination in the past would not be related to handling or processing of ordnance materials.
A resident of Respass Beach wondered whether their home well water might be the cause of adult and youth acne.
Response: The evaluation of the well water at Respass Beach is discussed on page 19. At the levels of contamination detected in the five wells, adverse health effects are not expected. Many types and causes of acne exist. A personal physician should be consulted to get a diagnosis of the type of acne and a recommendation for appropriate treatment.
A former faculty member, who resided on the site in the 1960s, reported lung and breast cancer in their family.
Response: The environmental data reviewed in this public health assessment indicated that past exposure to contaminants at the site would not cause an increased risk of the types of cancer mentioned. However, most of the sampling data are from the 1980s or 1990s and may not be applicable to the situation in the 1960s. For example, the source or quality of the water supply for the former students and faculty members of Frederick College is not known. The extent of exposure to disposal areas is not known. In addition, the amount of ordnance residue remaining in the converted bunkers/homes, if any, is not known. Therefore, ATSDR is unable to evaluate the excess cancer risk from that time.
An alumnus of Frederick College reported having a skin disorder called vitiligo, which affects the pigmentation, and wondered if other students had similar problems.
Response: ATSDR has not received any other reports of former students or faculty members developing vitiligo, although only a handful of health concerns have been received so far. Vitiligo is the appearance of non-pigmented white patches on otherwise normal skin. No cause of vitiligo is known, but the disorder may be associated with autoimmune or endocrine abnormalities. The disorder affects about 1% of the general population .
Vitiligo is indistinguishable from chemically-induced hypopigmentation (lack of pigmentation), which may result from contact with alkylphenol compounds . Based on our review of the site to date, these compounds were not detected in any significant quantity.
A former worker on the site was diagnosed with Parkinson's disease soon after leaving her job. She wanted to know if there was a connection to the site.
Response: The cause of Parkinson's disease is not known. Four mechanisms have been suggested as a cause: oxidative damage, environmental toxins, genetic predispositions, and accelerated aging. So far, no research has provided conclusive proof that an environmental toxin is the cause of the disease . The types of environmental chemicals being considered as possible causes include pesticides, metals, and industrial solvents . ATSDR is unable to evaluate any connection of Parkinson's disease to the site, because the connection to environmental contaminants has not been made.
A couple who both worked at the GE facility on-site in the 1970s did not report any health problems, but they were concerned about their possible exposure to site contaminants, especially in their drinking water.
Response: The GE facility received its water from the TCC wells up until 1997, when both GE and TCC were connected to the municipal water system. The available TCC well water data from 1989-1997 were reviewed in this document, starting on page 27. The level of contamination during that period was found not to have posed a health hazard. ATSDR did not locate any TCC well water data from the 1970s.
A former worker at the GE facility reported seeing a reddish-colored cloud on site.
Response: No record of an air release that might be consistent with this observation was found. Potential health issues associated with possible exposure to this cloud could not be evaluated because the chemical makeup of any air releases and their frequency and duration are unknown and cannot be estimated.
On December 4, 2003, ATSDR attended the FNOD RAB meeting to present the public comment release of the FNOD Public Health Assessment. Jill Dyken of ATSDR reviewed the public health assessment process then discussed the results of the FNOD PHA. Questions raised and information provided by the public attending the meeting were:
ATSDR has made the following classifications of the FNOD site based on exposure to chemical contaminants present at the site. Because past exposures to TNT and lead in soil were high enough to result in adverse health effects, ATSDR classifies FNOD as a past public health hazard. In the present, people are not in contact with contaminants at high enough levels to result in health effects; therefore, ATSDR classifies the site currently as no apparent public health hazard. Future residential development is likely at the site. Without proper cleanup or land use controls to prevent exposure to contaminants in soil or groundwater, the site could pose a future public health hazard.
Physical hazards currently at the site have the potential to cause injury and are therefore considered a public health hazard in the past, the present, and, if not addressed, the future. For the issue of ordnance and explosives on site, ATSDR acknowledges that significant improvements in safety have been made through removal and cleanup actions to date. However, because it is impossible to be certain every ordnance item has been removed, ATSDR considers ordnance and explosives at the site to pose a public health hazard.