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PETITIONED PUBLIC HEALTH ASSESSMENT

E.I. DU PONT DE NEMOURS
POMPTON LAKES, PASSAIC COUNTY, NEW JERSEY


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The tables in Appendix B list contaminants in each medium. Those contaminants are evaluated in subsequent sections of the public health assessment to determine whether exposure to them has public health significance. ATSDR selects and discusses contaminants based upon several factors. They include concentrations on and off site, the quality of the field and laboratory data, sample design, comparison of on- and off-site concentrations to background concentrations (if available), comparison of on- and off-site concentrations to public health assessment comparison values for noncarcinogenic and carcinogenic endpoints, and community health concerns.

The listing of a contaminant in the tables does not mean that it will cause adverse health effects if exposure occurs at the specified concentrations. Contaminants included in the tables are further evaluated in this public health assessment. The potential for adverse health effects resulting from exposure to contaminants of concern is discussed in the Public Health Implications Section.

Comparison values for ATSDR public health assessments are contaminant concentrations in specific media that are used to select contaminants of concern for further evaluation. ATSDR and other agencies developed those values to provide guidelines for estimating the media concentrations of a contaminant that are unlikely to cause adverse health effects, given a standard daily ingestion rate and standard body weight, (see Appendix C for a description of the comparison values used in this public health assessment update).

A. On-Site Contamination

Du Pont is currently implementing a Remedial Investigation Work Plan for on-site contamination (43). However, the investigations are not yet complete, so a full characterization of PLW site contamination is not possible at this time. The Remedial Investigation Work Plan was completed in November 1989 by Du Pont, and did provide some environmental monitoring data for on-site surface water. Additional on-site monitoring data were provided by the New Jersey Department of Environmental Protection and Energy (NJDEPE), as well as reports on Du Pont strategies to curb future migration of contamination off site. As more environmental monitoring data become available, an addendum to this public health assessment may be necessary.

Soil

The mercury fulminate area is a 400' by 400' section of PLW in the center of the PLW property. Acid Brook makes up the eastern border. In December 1991, Du Pont took 49 soil samples from the surface (0-6 inches) and depths of 18, 36, and 72 inches throughout the mercury fulminate area and analyzed them for lead and mercury. Surface levels, on the average, were the highest, with an average of about 200 mg/kg for lead and 300 mg/kg for mercury. The maximum level for lead at the surface was 1790 mg/kg. Mercury was 5930 mg/kg (31). See Table 1 in Appendix B. Overall, the highest levels of lead and mercury were in the northern area of the site. Access to the mercury fulminate area itself is unrestricted; however access to PLW is restricted by a gate and 24-hour security, (see Figure 4 in Appendix A).

Surface Water

Three on-site surface water bodies were identified and monitored for hazardous substances between 1984 and 1988 by Du Pont: the plant stream (which makes up the northern end of Acid Brook), the Shooting Ponds, and the lagoon (10). Elevated levels of heavy metals were detected in those areas. Elevated levels of chlorinated solvents were found in the lagoon only (43), (see Table 2 in Appendix B).

NJDEPE reports that the three main sources of off-site contamination have been contained. One of the shooting ponds has been remediated and closed under Resource Conservation and Recovery Act (RCRA) specifications. Sediment from the second shooting pond has been removed down to the bedrock. The third area, the mercury fulminate disposal area, is surrounded by berms to prevent runoff. Contaminated soils were removed and replaced with clean stone. In addition, two retention basins were created for flood control of Acid Brook and to prevent future migration of on-site contamination into residential areas. NJDEPE reports this interim remediation should be sufficient for preventing recontamination of remediated areas downstream from the site (36,37,43). As noted earlier, there a total of about 119 potential areas of concern at the site, and some of these areas could also be potential sources of heavy metal contamination. It should be noted that many of these areas are also in various stages of the remediation process to prevent recontamination of downstream areas (45).

Groundwater

Installation of PLW plant wells began in 1981, when 15 wells were installed on site. Du Pont installed nine more wells in 1984, and six more in 1985. Wells have been sampled quarterly or semiannually and analyzed for volatile organic compounds and metals. Du Pont followed the New Jersey Field Sampling Manual for all groundwater sampling events, (see Figure 5 for location of on-site monitoring wells)(10).

Groundwater monitoring indicated elevated levels of metals in on- site groundwater. Maximum levels found between 1982 and 1989 of lead and mercury were 15 mg/l and .01 mg/l, respectively. Levels of metals have dropped substantially since remediation of the Shooting Pond. Chlorinated solvents including dichloroethylenes, dichloroethylanes, tetra and trichloroethylene, 1,1,1-trichloroethylene, and vinyl chloride were also elevated. Because Du Pont installed these wells for monitoring purposes only and keeps them locked, it is unlikely that on-site groundwater is used for human consumption (10,43).

Air

No monitoring data were available for analysis of on-site air.

B. Off-Site Contamination

ATSDR also reviewed files from state and federal environmental agencies to obtain information on the extent of contaminants that may have migrated from PLW to the Acid Brook Area. ATSDR evaluated these data to help determine whether people beyond PLW may have been exposed to hazardous substances migrating off site in the past, or whether they may be exposed in the present. Off-site exposure to contaminated media will be evaluated in the Exposure Pathway Analyses Section. Available monitoring data are discussed in this section and summarized in the tables in Appendix B.

Acid Brook Area Soils and Sediments

In 1990, approximately 5,000 soil samples were taken in the Acid Brook Area. Each boring was analyzed at depths of 0 - 6, 18, 36, and 60 inches for heavy metals and base/neutral extractable (B/NE) compounds (includes semivolatile organic compounds and polyaromatic hydrocarbons) and acid base/neutral extractable (AB/NE) compounds. VOCs were not analyzed because initial sampling did not indicate a need. Elevated levels of lead and mercury were found at each of the depths, although levels were highest at the surface. Other heavy metals (barium, copper, selenium, and zinc) were elevated at the surface and at various depths, although not to the same degree as lead and mercury. B/NE and AB/NE were detected only at low levels (9). Since surface soil had the highest levels of contamination and is the most likely point of human exposure, surface soil sample results will be the focus of this public health assessment. The surface soil sample results are further categorized by those found in residential yards, gardens, and around Acid Brook, and are summarized in Table 3, Appendix B. The overall degree of lead and mercury contamination in the Acid Brook Area is further characterized in the tables below:

Distribution of Lead Surface-Soil Concentrations (2)

Concentration (ppm) Number of samples at 0 inch depth
250 - 499 286
500 - 999 159
1000 - 1999 90
2000 - 4999 19
5000 - 9999 6
10,000 10

Distribution of Mercury Surface-Soil Concentrations (2)

Concentration (ppm) Number of samples at 0 inch depth
200 - 499 43
500 - 999 20
1000 6

Results of Acid Brook Area sampling also indicated that soil contamination generally decreased with depth and distance away from the brook. Lead contamination was more widespread than mercury contamination. Mercury contamination was mostly confined to within 50 feet on either side of the brook.

Residential Yard Soils

Based on the sampling results found above, Du Pont developed a Remedial Action Work Plan for the Acid Brook Area. Lead and mercury were used as indicators to develop the remediation plan, since those contaminants were consistently the most elevated. The highest levels found in yards were 62,000 mg/kg lead and 540 mg/kg mercury. Areas with soil lead levels above 250 mg/kg and mercury levels above 14 mg/kg were originally targeted in the work plan. NJDEPE subsequently approved the plan, and remediation of residential areas began in September 1991; however, NJDEPE has since proposed changing the lead clean-up level to 100 mg/kg. This change has not been made final. As of July 1993, 87 homes had been fully remediated with clean soil. Signs are posted warning against contact with soil in the remaining areas (37,44). Remediation of the Acid Brook Area is scheduled for completion by December, 1995 (3,43).

One sample of basement soil from an Acid Brook home was taken. A lead level of 32,100 mg/kg was detected in that sample (9). It is unknown whether the sample was of dust or soil from an unfinished basement floor. Du Pont reports that the owner of the property was a plumber, and the lead contamination was probably related to work activities and not surface soil contamination (43). Du Pont conducted indoor wipe sampling for lead and mercury in basements following remediation of the home. Wipe sampling results are used to determine whether or not lead and mercury contamination is present. Many of the basements did have positive results for lead and mercury contamination, and they were cleaned and retested by Du Pont. Except for a few homes, lead and mercury wipe tests were negative following cleaning. Those homes where additional cleaning was needed had either unexplained or additional sources of lead contamination (46).

The highest levels of lead and mercury were detected along the banks of Acid Brook. They were 119,000 mg/kg for lead, and 8,060 mg/kg for mercury. Remediation of Acid Brook is also included in the workplan, giving top priority to areas with the most severe contamination. Warning signs are posted in areas awaiting remediation.

Garden Soils

Du Pont screened residential garden soil for six primary metals in March 1990. Four residential gardens were identified in the Acid Brook Area, and a total of seven samples were taken (five composite samples and two individual grab samples). Two blind duplicate samples served as controls (9). Background levels are average levels detected by NJDEPE (3). Copper, lead, and zinc all exceeded background soil levels, (see table 3 in Appendix B. These areas are included in the remediation plan).

Food Chain - Garden Vegetables

In the summer of 1990, Du Pont analyzed garden vegetables grown in the Acid Brook area for six heavy metals (barium, copper, lead, mercury, selenium, and zinc) (9). Sampling took place at various intervals during the summer when plants had fully matured so that contaminant levels would be representative of vegetables ordinarily consumed (9). Researchers reported using standard sampling and shipping procedures. A variety of dark green vegetables and tomatoes were collected and analyzed. Monitoring indicated low levels of barium, copper, and zinc in garden vegetables as shown in Table 6 in Appendix B. Selenium, lead, and mercury were not detected (9). Environmental comparison values for concentrations of heavy metals in garden produce do not exist; however, further analysis is found in the Public Health Implications section of this public health assessment.

Food Chain - Fish

Du Pont retrieved nine fish from Acid Brook with a backpack electrofishing unit and then analyzed the fish as whole body homogenates. After the fish were caught, they were labeled, placed in double ziplock bags, and stored on ice in insulated coolers for shipment to a laboratory. Fish were analyzed for six heavy metals; however, Food and Drug Administration (FDA) standards exist only for mercury. One fish exceeded the FDA standard of 1.0 mg/kg for mercury (1.3 mg/kg). Table 7 in Appendix B summarizes the monitoring data for fish tissue (9).

Twenty-four fish samples were caught from the Wanaque River with a backpack electrofishing unit and were transported the same way as Acid Brook fish. Analyses were performed for heavy metals, extractable organics, and dioxins/furans. Three rock bass showed mercury levels at or above the FDA level of 1.0 mg/kg (1, 1.1, and 1.3). Other heavy metal monitoring data for fish are found in Table 7 in Appendix B (9).

Fourteen fish samples were taken from the Pequannok River using a backpack electrofishing unit and were transported in the same way as the Acid Brook fish. Aside from heavy metals, no additional chemicals were tested. The heavy metal monitoring data for fish are found in Table 7 in Appendix B (9).

Fifty-five fish samples were collected in Pompton Lake through a variety of methods, but primarily through use of boat-mounted electrofishing gear. Methods for transporting fish were the same as those described above. Analyses were performed for heavy metals, extractable organics, and dioxins/furans, (see Table 7 in Appendix B for other results)(9).

Surface Water

Du Pont conducted surface water sampling for Acid Brook, Wanaque River, and Pompton Lake. The sampling is described below. Maximum concentrations for all these surface water bodies are found in Table 4 in Appendix B.

Du Pont conducted surface water sampling of Acid Brook in June 1990. Eleven surface water samples were hand-drawn just below the surface at well-mixed areas of flow. Samples were collected at relatively equal increments between the Du Pont plant boundary and the Pompton Lake delta. Samples were analyzed for six heavy metals; however, selenium was not detected (9).

NJDEPE collected and analyzed four surface water samples of Acid Brook in October 1990 for volatile organic compounds (VOCs), semivolatiles, polychlorinated biphenyls (PCBs), and metals. No contaminants were detected except for a mercury level of 0.0002 mg/L in one sample (38).

Du Pont sampled the Wanaque River in June 1990. Three samples were collected just below the water's surface in areas of well-mixed flows, and analyzed for six heavy metals and four VOCs. Copper, selenium, and the VOCs were not detected. No metals that were detected exceeded comparison values (9).

Du Pont conducted surface water sampling of Pompton Lake in June 1990. Two sampling locations were chosen and sampled at depths of one to two feet above the bottom, and half-way between the bottom and the surface. Two additional single grab samples were taken at shallower locations just below the surface. Samples were collected for both filtered and unfiltered metal analysis, and measurement of VOCs. Field parameters were also performed. No VOCs were detected. Among the heavy metals, mercury and selenium were not detected. No metals detected exceeded comparison values (9).

Groundwater - Private Wells

Water is naturally found in the earth's subsurface in the pore spaces and voids in geologic materials. As geologic materials are categorized into layers or units based upon their water-bearing properties, these units are called aquifers. A shallow aquifer underlies the southern portion of the plant and flow in a southeasterly direction from the Du Pont facility toward the residential section of Pompton Lakes (2). The shallow aquifer is unconfined (which means infiltration from the land surface to the upper portion of the aquifer is possible) and consists of silt, sand, gravel, and cobbles. The source of water supply for this aquifer is most likely direct infiltration of precipitation, and the discharge area is probably Pompton Lake.

Environmental investigations by Du Pont from 1983 to 1986 revealed that groundwater beneath the site was contaminated with solvents used at PLW, and that the contamination had also extended off site into residential areas. In late 1985 and early 1986, Du Pont sampled the wells of homeowners next to PLW, and subsequently paid to disconnect private wells that were contaminated if requested by the homeowner. A total of 28 wells were tested. Figure 5 in Appendix A depicts the sampling locations (10). Private wells were identified by assessment of billing records at the Borough of Pompton Lakes Municipal Utilities Authority (MUA). The depth of private wells was reported to be less than 30 feet by NJDEPE. Only two wells, private well numbers one and seven, were used as sources of drinking water. These wells have not been used for drinking water since 1985. By 1989, all homes with private wells identified through billing records were connected to the Borough of Pompton Lakes municipal water supply, including those that were not contaminated (37). Some private wells are still used for other purposes besides a drinking water supply.

Heavy metals and chlorinated solvents were detected above comparison values. Of the chlorinated solvents, the dichloroethylenes exceed comparison values in two of the private wells, and trichloroethylene and tetrachloroethylene exceed comparison values in over a third of the 28 private wells. Private well number 1, one of the two wells used for drinking water, had the worst contamination out of the 28 wells tested, (see Tables 5A and 5B in Appendix B for a summary of the results of private well monitoring data).

In 1990, Du Pont conducted additional off-site groundwater monitoring which included use of monitoring wells and private wells. Results, again, indicated the presence of chlorinated solvents in off-site groundwater, including chloroethane, 1,1-dichloroethane, 1,1-dichloroethene, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichloroethylene, and vinyl chloride. Tetrachloroethylene, trichloroethylene, and vinyl chloride were found at higher levels than originally found in 1985 and 1986, (see Table 5B in Appendix B)(43,10).

Municipal Water Supply

Three municipal wells, built by the MUA, are located approximately one half mile, three quarters of a mile, and a mile and a half south of the Acid Brook Area. Wells were tested in the fourth quarter of 1985 for volatile organics, metals, and other ions (10). Manganese was the only contaminant found slightly above comparison values. Municipal wells are tested routinely by MUA for bacteria, VOCs, heavy metals, pesticides, and herbicides. The MUA reports that water quality meets all state and federal standards (38). Recent water quality reports retrieved from the MUA confirms that no contaminants exceed ATSDR's comparison values (38).

Air in the Acid Brook Area

In July 1990, residential air sampling was conducted by Du Pont contractors to determine the presence of particulate-bound heavy metals in air. Sampling was completed by using low-flow pumps calibrated to obtain a flow rate of approximately three liters per minute. Investigators compared the sample tubes to blank tubes to ensure proper sampling. Residential areas with high levels of heavy metals in soils were chosen as monitoring stations. In addition, a busy roadway and residential area six blocks away were included. Screening for six primary metals was conducted. Mercury and selenium were not detected (9). The maximum barium level detected was lower than the comparison value for barium by a factor of eight. The maximum copper level was compared to an occupational standard for copper. Although that standard is set for a ten-hour worker exposure, copper is not a contaminant of concern, because the maximum concentration was about 53 times lower than the occupational standard. Lead was also not considered a contaminant of concern, because the maximum concentration was over 72 times lower than the National Ambient Air Quality Standard for lead. No comparison value was available for zinc; however, it is noted that the maximum concentration was less than measured background levels for the area, (see Table 8 in Appendix B for a summary of maximum concentrations and comparison values).

During remediation of yards and Acid Brook, dust monitoring is conducted by Du Pont. The monitor will alarm if ambient dust levels exceed half the state regulatory level for dust in air. Du Pont reports that this alarm has never gone off (44).

C. Quality Assurance and Quality Control (QA/QC)

All surface water monitoring reported by Du Pont followed EPA protocol. Fish, soil, and vegetation sampling procedures were described and are acceptable; however, no QA/QC reports were provided. Air sampling was consistent with the National Institute of Safety and Health (NIOSH) Method 7300. All analytical methods followed EPA methodology and are assumed to be adequate (9). NJDEPE evaluated the quality of the soil sample data provided by Du Pont in March 1991. "Several deficiencies were noted in the procedures used for the analysis of the data; for example, the failure to run any spikes or blanks of the samples." However, NJDEPE felt that the data were adequate for ATSDR to use in the development of a health consultation (2). Soil sample data are limited to that reported by Du Pont, so given NJDEPE's previous recommendation for the health consultation, ATSDR will use the available soil data for the public health assessment. No QA/QC data for groundwater or surface water data were reported; however, NJDEPE reports that past groundwater and surface water samples have been filtered for analyses. NJDEPE has recently required that Du Pont use unfiltered samples for analyses. NJDEPE reports that, overall, Du Pont has practiced adequate QA/QC in collection practices, and had only minor QA/QC problems with analyses practices (41).

D. Physical and Other Hazards

Physical Hazards

There are physical hazards on the PLW site, especially during remediation. Large bulldozers and other equipment were operating next to residential backyards. Access is restricted in this area by orange snow and chain link fences. No evidence of trespassing was noted during ATSDR site visits. Du Pont reports that they have not observed any trespassing.

Other physical hazards were noted by residents. One resident reported that following washing down of streets after removed soil was transported off site, the wet streets froze and created a driving hazard. Another resident complained about the large trucks driving through residential neighborhoods frequently.

Toxic Chemical Release Inventory

A search of the EPA Toxic Chemical Release Inventory (TRI) for PLW was conducted and the following information was obtained. No other industries reported releases in the area. Recorded below are the highest releases reported by PLW in the four year period of 1987 - 1990:

Summary of TRI Releases (lbs/year)

Contaminant non-point air point air water land
copper 0 5 750 5600
lead 30 60 1500 18000
1,1,1-TCA 7400 7400 7 0

Du Pont reports that they have modified processes so that water may be used, rather that 1,1,1-TCA (43).


PATHWAYS ANALYSES

To determine whether nearby residents are exposed to contaminants migrating from the site, ATSDR analyzes the environmental and human components that lead to human exposure. This pathways analysis consists of five elements: (1) a source of contamination; (2) transport through an environmental medium; (3) a point of human exposure; (4) route of human exposure, and (5) an exposed population. When these five elements are present simultaneously, they form an exposure pathway.

ATSDR classifies exposure pathways into three groups: (1) "completed pathways," that is, those in which exposure has occurred, is occurring, or will occur; (2) "potential pathways," that is, those in which exposure might have occurred, may be occurring, or may yet occur, and (3) "eliminated pathways," that is, those that can be eliminated from further analysis because one of the five elements is missing and will never be present, or in which no contaminants of concern can be identified. A summary of all the pathways for the Acid Brook Site and the contaminants of concern are summarized in Appendix B, Table 9.

A. Completed Exposure Pathways

Residential Surface Soil Pathways

Past and current exposures to lead and mercury contamination in residential surface soils in the Acid Brook Area have occurred for children or adults who work or play in these soils. Future exposures are also possible until remediation of the Acid Brook Area is completed.

PLW identified over 100 potential waste disposal areas on site (4). Migration of wastes from PLW disposal areas into the Acid Brook Area most likely occurred via Acid Brook. Acid Brook Area residences with contaminated surface soils generally correlate with the 100-year flood plain for Acid Brook. Therefore, periodic flooding in past years probably transported and deposited contamination from Acid Brook banks into residential yards (3). Currently, soil monitoring indicates that elevated levels of lead and mercury exist up to 60 inches below surface in the Acid Brook Area (see Figure 2 in Appendix A) (9); however, the highest levels are found at the surface. Since that is the most likely point of exposure, exposure assessment for that pathway will focus on surface soils.

Lead and mercury are both known to persist in soils for long periods of time, since both stick to dirt particles (23,25). Migration of contaminated soils to ambient air in the form of dust is possible, although given the moist climate and heavy vegetation, that is unlikely to be significant at this site. Elemental mercury forms mercury vapor at room temperature; however, the mercury found in the soil is not elemental, thus migration of mercury from soil to air is not a likely pathway (25).

Residential surface soil lead levels were highly variable, ranging from non-detect (the levels were so low the instruments could not measure the level) to 62,000 mg/kg. Three residential properties had soil lead concentration in excess of 10,000 mg/kg (2). Remediation levels for the Acid Brook Area were set at 250 mg/kg lead in soil, which is a commonly used clean-up level for lead in many areas of the country. NJDEPE proposed changing the level to 100 mg/kg lead in soil, but this has not been finalized, and may be subject to change (46). However, past chronic exposures to lead contaminated surface soils via ingestion represent a significant exposure pathway.

For lead- and mercury-contaminated residential yards, soil ingestion is the most significant route of exposure, especially for children between the ages of one and six. Although incidental soil ingestion occurs at any age, children under the age of six exhibit greater hand to mouth activity, and may ingest up to 200 mg soil per day. Infants (children less than one year old) may ingest 50 - 100 mg per day. Children who exhibit pica behavior (the tendency to eat non-food items such as dirt) are at special risk since they may ingest up to 5000 mg soil/day (16). Children playing in areas of poor grass cover may also be more exposed than children who play in areas with good grass cover. Grass cover in the Acid Brook Area yards was somewhat variable, although the yards generally had good grass cover. Adults at higher risk for exposure to contaminated soils are those that remain at home or in the community during the day (rather than going to a place of work), and those who garden or frequently work outdoors. Adults who smoke are also at increased risk, because of increased hand-to-mouth activity.

Exposure to elevated soil levels of other heavy metals via ingestion likely occurred. Elevated levels of barium, copper, selenium, and zinc were detected in soils near Acid Brook, although levels were not elevated to the same degree as mercury and lead. The data provided for these contaminants did not distinguish between residential and nonresidential soils (3).

Acid Brook Surface Soil/Sediment Pathway

In areas around Acid Brook and next to yards, past and present exposures to elevated levels of heavy metals in surface soils via ingestion have occurred, and may continue to occur in the future until remediation is completed. Incidental ingestion of soil by children is probable during play through normal hand-to-mouth activities (17). Children have been observed playing in and around Acid Brook, despite posted warning signs and health advisories (2).

Soil sampling results from nonresidential areas of Acid Brook showed the most severe heavy metal contamination. Although quite variable, lead and mercury soil levels were as high as 119,000 mg/kg and 8060 mg/kg, respectively (9). The widespread distribution of lead and mercury soil contamination around the Acid Brook Area (discussed in the previous section) indicates that exposures to elevated levels of mercury and lead were highly probable whenever children played outdoors. Elevated levels of barium, copper, selenium, and zinc were also detected.

Since this area of contamination is not located directly on residential properties, chronic exposures to nonresidential Acid Brook surface soils would not be expected. However, children who occasionally play in and around Acid Brook have been exposed to elevated levels of heavy metals in the soil on an acute or intermediate basis. Parents report that children have indeed played in these areas, especially the field next to the north end of Acid Brook, and in the brook itself. ATSDR observed toys and bike tracks along the banks of Acid Brook during the site visit.

Acid Brook Area surface soil exposures are not expected in the future, because the entire area is being remediated with clean soils. Therefore, this is a past completed exposure pathway, and will be considered a completed exposure pathway until remediation is completed.

Garden Soil and Vegetable Pathway

Exposure via ingestion to elevated residential garden soil levels of lead has occurred in the past, and may continue to occur until remediation takes place. Garden soil lead levels detected during monitoring ranged from 266 - 4120 mg/kg (9). Incidental ingestion of soil is probable during normal gardening activities, although the amount of soil ingested is difficult to estimate and likely to be very individualized. Other heavy metals (copper and zinc) were also slightly elevated above background soil levels expected for the area (9).

Uptake of heavy metals into garden produce may be possible, although in the case of lead, uptake is highly unlikely. Contamination of garden produce is more likely through deposition of lead contaminated soils on the surface of vegetation. Uptake and bioaccumulation of other heavy metals in garden produce is possible, too; however, results of testing of garden produce (dark green, leafy vegetables and tomatoes) in the Acid Brook Area found only low levels of barium, copper, and zinc.

Surface Water - Acid Brook

Past exposures to elevated levels of lead and mercury in Acid Brook surface water have occurred. Continued current and future exposures are possible until remediation is completed. Children have been observed wading and playing in Acid Brook in areas of known surface water contamination in the past, despite posted warning signs and health advisories (2). Incidental ingestion of Acid Brook surface water by children is possible during recreation (17). Surface water exposure pathways for Pompton Lakes, Pequannok River, and Wanaque River have been eliminated since the level of contamination in these surface waters does not exceed comparison values.

Acid Brook surface water was analyzed for six heavy metals; however, only lead and mercury were slightly elevated above EPA standards (9). PLW is the likely source of Acid Brook heavy metal contamination. Acid Brook originates north of PLW, flows directly through the PLW site, and discharges into Pompton Lake (1). Lead and mercury contamination on site probably migrated off site into Acid Brook via the plant stream. However, mercury, and especially lead, are heavy molecules that are prone to settling into sediments rather than remaining suspended in surface water (19). These physical properties may explain why soil and sediment contamination is much more severe than surface water contamination.

NJDEPE reports that Du Pont continues to institute interim measures to eliminate potential sources of recontamination downstream. Future exposures to elevated levels of heavy metals in Acid Brook are unlikely once remediation is completed (37).

Chronic exposures to Acid Brook surface water would not be expected because surface water exposures would vary seasonally. However, children who occasionally play in and around Acid Brook may have been intermittently exposed via ingestion of Acid Brook water containing elevated levels of lead and mercury.

Private Well Pathways

Residents who drank water from contaminated private wells were chronically exposed to contaminants in those wells (see Table 5 in Appendix B). The actual length of exposure to those contaminants depends on when the off-site groundwater became contaminated, which is unknown at this time. Ingestion exposures ceased in 1985, when private well numbers one and seven were connected to the municipal water supply (10).

Du Pont suspects that groundwater contamination is not the result of any single, identifiable source and suspects multiple sources (4). Du Pont previously stated that solvent contamination of groundwater apparently resulted from operations dating from World Wars I and II (38); however, they now believe that the solvent contamination occurred later (43). Groundwater contamination is downgradient from PLW with only a rural, sparsely populated area upgradient from the area of contamination, indicating that PLW was probably the most significant source of solvent contamination (1). In addition, several of the chlorinated solvents detected in on-site groundwater were also detected off-site in private wells and monitoring wells. These solvents include tetra and trichloroethylene, 1,1,1-trichloroethylene, 1,1-dichloroethane, 1,1-dichloroethylene, and vinyl chloride.

On-site groundwater solvent contamination probably resulted from leaching of surface contamination at the PLW site. Solvents identified in private wells are highly mobile in soil, and therefore, are prone to leaching to groundwater. The aquifer beneath the site is unconfined, which means there are no hydraulic barriers between the site surface and the shallow aquifer. On-site surface contamination can easily filter through the soil and into the groundwater. Many of the solvents found will persist for long periods of time in groundwater, especially trichloroethylene (TCE) and tetrachloroethylene (PCE) (19).

Investigations in 1984 by Du Pont identified contamination in the shallow, unconfined aquifer directly below PLW. Contamination consisted primarily of elevated levels of solvents at the south end of the PLW property, and heavy metals under the Shooting Pond. In 1985, Du Pont completed a hydrogeologic investigation and found that the aquifer generally flows in a southeasterly direction. Later, Du Pont monitored private wells in residential areas southeast of PLW, and detected elevated levels of solvents and heavy metals (4).

Twenty-eight private wells were tested, and some were found to be contaminated with solvents and heavy metals. Very few exposure data were available to ATSDR; however, community members report that some private well water was not used for household consumption, but rather for watering lawns or filling pools. Du Pont reports that two of the private wells tested were used for drinking water, and those were private wells numbers one and seven (38,43). The total exposed population is estimated to be approximately 5 people (43).

Exposure to elevated levels of solvents occurred via ingestion, inhalation, and skin contact. Since some solvents tend to volatilize into the air from contaminated water during showers and baths, persons become exposed to solvents as they breathe the air in their bathrooms. In addition, solvents tend to absorb through the skin during showers and baths, thus increasing exposure. Absorption of solvents while swimming in pools filled with private well water is also possible, although unlikely to be significant, since these solvents will volatilize from an open pool. Generally, ingestion of contaminated drinking water is the most significant exposure route for both solvents and heavy metals (19).

Food Chain - Fish

Past exposure pathways were possible, and current and future exposure pathways are possible through consumption of contaminated fish caught in Acid Brook, Pompton Lake, Wanaque River, and Pequannok River.

The source of contamination evident in fish is difficult to pinpoint. Pompton Lake is fed by rivers that flow throughout the county, and both the Wanaque and Pequannok rivers also meander for long distances (1). Fish could have been exposed to contamination at various points and then migrated into Pompton Lakes. This theory is supported by the presence of various pesticides in fish tissue, and the fact that PLW operations generally did not involve the use of pesticides (9). However, it is possible that PLW has contributed to mercury contamination of fish, especially those found in Acid Brook.

The form of mercury in fish is predominantly methylmercury, which occurs because mercury in the water ecosystem is converted to methylmercury by bacteria. As smaller animals that are contaminated with methylmercury are eaten by larger animals, methylmercury moves up the food chain. This is called bioaccumulation. Thus, those residents that have consumed fish contaminated with methylmercury and other contaminants have bioaccumulated methylmercury.

However, since many of these substances are suspected carcinogens and are known to bioconcentrate in fish tissue (especially heptachlor, lindane, and PCBs), heavy metal and pesticide contamination of fish tissue will be discussed further in the Public Health Implications Section (19).

NJDEPE reports that local residents have been frequently observed fishing in all four water bodies. In addition, subsistence fishing may have taken place, resulting in a chronic exposure to elevated levels of contaminants in fish, assuming that fish are consumed regularly. No fishing signs were posted in May, 1991 and reposted in 1993; however, the Fish and Game Commission continues to stock lake for fishing. Residents report people still continue to fish in the area, and ATSDR staff observed a resident fishing during their site visit. NJDEPE plans to coordinate with the State Game and Fish Commission on this advisory (46).

B. Potential Exposure Pathways

Indoor Dust Pathway

Heavy metal contamination of residential soils has been identified. The potential exists for outdoor soil particles with heavy metal contamination bound to them to have migrated indoors through various routes, such as through tracking indoors on shoes. Chronic exposure to heavy metal-contaminated indoor dusts via ingestion and inhalation is possible, although at the time of this writing there are no monitoring data to substantiate the possibility of exposure through this pathway.

In the case of lead, recent research has shown that outdoor soil contamination may be an important source of indoor dust contamination (33), although current research is limited. Contaminated residential soils may be migrating indoors through transportation on shoes and clothing, or seeping into houses through doors and windows. Several studies have shown a relationship between workplace dust inadvertently brought home by lead battery plant workers, household contamination, and elevated blood lead levels in children (32). These studies support the theory that contaminated soils may be tracked in by children and adults from yards after playing or working in the yards, and may result in significant indoor dust contamination. Du Pont is cleaning all the basements on contaminated properties and conducting post cleaning sampling to ensure that no future exposures to indoor lead or mercury contaminated dust occur (43, 46). The extent of past indoor contaminated dust exposure is unknown at this time.

Indoor dust exposure has also been identified as a significant exposure point, since dust can either be inhaled or ingested. Results of recent lead exposure studies have found significant correlations between indoor lead contaminated dusts and lead on the hands of children (32). Some studies have identified indoor lead-contaminated dusts as one of the most significant sources of exposure for children (31,32). However, without historical monitoring data, it is impossible to fully assess the significance of the indoor dust pathway.

PLW Surface Water Pathway

Acute exposure via ingestion of and dermal contact with elevated levels of heavy metals and methylene chloride in the plant stream, lagoon, or Shooting Pond at PLW may have occurred. Future exposures are also possible until environmental remediation at PLW is completed. If children are gaining access to the site and playing around the plant stream, Shooting Pond, or the lagoon, incidental ingestion of contaminated surface water during play is possible. Workers may also incidentally ingest this surface water accidentally while working around these areas. However, the extent to which children or workers may have been exposed to PLW surface water is unknown, but Du Pont reports that they have found no evidence of trespassing. Currently, remedial workers have been provided with a health and safety plan for working on PLW remediation, and Du Pont reports that workers are complying with that plan. Residents report that the lagoon and shooting pond are a sufficient distance into the PLW property to make trespassing by children highly unlikely.

PLW Surface Soil Pathway

Workers and children trespassing may have had acute exposures via ingestion to elevated levels of mercury fulminate and lead containing compounds within the mercury fulminate area. Future exposures are also possible until remediation takes place. Children playing or employees noncompliant with the health and safety plan and who work in this area may incidentally ingest soils through normal hand-to-mouth activity. Access to this area is restricted, although trespassing is still possible through gates next to residential areas or by climbing the fence. The extent to which children may be exposed in these areas is unknown. Again, this pathway is probably unlikely since 24-hour security is enforced at the PLW property and workers have been in compliance with the worker safety plan (43).


PUBLIC HEALTH IMPLICATIONS

A. Toxicological Evaluations

The preceding section has indicated that exposure to contaminants has probably occurred (through several completed exposure pathways) for some people residing in the Pompton Lakes Works (PLW) area. Before residences using private well numbers one and seven were connected to city water supplies in 1985, exposure to low levels of several contaminants occurred through drinking water, most notably to chlorinated solvents. Other important pathways of exposure include exposure to metals (e.g., barium, copper, lead, and mercury) in soils in both the residential yards and the Acid Brook Area. In addition, people who regularly consume fish from the Wanaque River or from Acid Brook have probably been exposed to contaminants, mainly methylmercury. Contaminants were also found at levels of concern in surface water on the PLW property, in Acid Brook water, and in soil on the PLW property. However, those exposures would not be significant from a public health standpoint, unless Acid Brook water or PLW plant surface water were to be used as a source of drinking water or unless children were to wade there regularly.

The toxicological evaluations that follow are concerned with possible illness and disease in persons exposed to identified contaminants of concern. These evaluations are accomplished by estimating the amount (or dose) of those contaminants that a person might come into contact with on a daily basis. This estimated exposure dose is then compared to established health guidelines. People who are exposed for some crucial length of time to contaminants of concern at levels above established health guidelines are more likely to have associated illnesses or diseases.

Comparison values and health guidelines are developed for contaminants commonly found at hazardous waste sites, see Appendix C. Examples of health guidelines are the ATSDR Minimal Risk Level (MRL) and the EPA reference dose (RfD). When exposure (or dose) is below the MRL or RfD, then non-cancer health effects are unlikely to occur. MRLs are usually generated for each route of exposure (e.g., ingestion and inhalation), and for the length of exposure (i.e., 14 days or fewer for acute exposure; 15-364 days for intermediate exposure, and 365 days or more for chronic exposure). ATSDR presents many of those health guidelines in Toxicological Profiles, which also provide chemical-specific information on health effects, environmental transport, and human exposure. ATSDR Toxicological Profiles were consulted for the following toxicological evaluations.

Mercury and Lead

Lead and mercury are particularly toxic to children because those metals affect physiological systems important to children's development and maturation (23,25). Exposure to high levels of lead and mercury in soil can result in elevated concentrations in the blood and urine. Exposure of children and adults to mercury and lead has occurred through contact with soils. Exposure to methylmercury may also have occurred through the ingestion of contaminated fish.

In order to estimate possible exposures to residents, we assume that for residential soils and soils from the Acid Brook Area, adults ingest 50 mg of soil per day, children ingest 200 mg of soil per day, and children with pica behavior (excessive ingestion of non-food items) ingest 5000 mg soil per day. For consumption of fish, we assume that one 13-ounce fish meal per week (or up to 54 grams of fish per day) are consumed (subsistence fishing or regular fishing for nourishment would increase exposure several fold) (16). More than 80% of the mercury in freshwater fish occurs as methylmercury. Therefore, we will assume that the total mercury measurement for fish consists of methylmercury. Although information in human beings is limited, it is important to point out that inorganic mercury compounds are not readily absorbed in the gut after ingestion (less than 30%). On the other hand, organic mercury compounds, such as methylmercury, are readily absorbed (more than 80%) (25).

Assuming the exposure patterns described above, past exposure to lead and mercury of people residing in the PLW area may result in unfavorable health effects. Those health effects are more likely in children, especially children with pica behavior, who may be exposed to the high levels of lead and mercury found in soil in residential yards and/or soils in the Acid Brook Area. Adverse health effects are also possible, if fish contaminated with mercury from the Wanaque River or Acid Brook are consumed on a regular basis. Fish advisories and soil remediation activities that are currently in place or underway should limit current and future exposure to lead and mercury.

Mercury. At exposure levels above health guidelines, organic or inorganic mercury can damage the brain, liver, kidneys, and developing fetuses. Chronic exposure to high levels of inorganic mercury (as may be possible with pica behavior seen in some children) can cause loss of appetite, abdominal cramps, damage to the stomach lining, and liver disease. Over time, the mercury concentrates in the kidneys, resulting in reduced kidney function (e.g., degeneration of the convoluted tubules, reduced filtration, and edema). Neurologic signs may be irreversible, and may include tremors, insomnia, decreased motor function, decreased muscular reflexes, headaches, lowering of peripheral nerve conduction velocities, and loss of short-term memory (25).

Methylmercury. The major toxicity of chronic organic mercury exposure is degeneration of nerve cells in the brain. This nerve damage can be observed as tingling of extremities, tunnel and impaired vision, altered senses of taste, hearing, and smell, slurred speech, muscle weakness and incoordination, irritability, memory loss, and depression. Kidney damage may result from long-term, chronic exposure to organic mercury, and could include tubular necrosis, fibrosis, and inflammation. Organic mercury can also be toxic to a developing fetus, affecting basic central nervous system development, possibly resulting in a reduction of fetal survival rates. In addition, postnatal development of the eyes can be impaired, as can learning ability and hearing (25).

Lead. Lead primarily affects the peripheral and central nervous systems, blood cells, and vitamin D and calcium metabolism. Effects of lead on the nervous system include decreased nerve conduction speeds, lowered IQ, and lowered coordination and motor skills. At high lead exposures, kidney damage can occur, with proximal tubular impairment, leading to a gout-like condition. Lead affects reproduction by reducing sperm counts and motility. Lead crosses the placenta, possibly increasing the number of miscarriages and stillbirths, and affects the viability and development of the fetus. Lead affects the blood, producing anemia, hypertension, and reduced hemoglobin synthesis. It also affects vitamin D hormonal activities regulating calcium storage and mobilization. During times of stress (e.g., sudden weight loss or pregnancy) lead that has accumulated in bones over time can be released into the blood stream (23).

It is critical to point out that the development of toxicity and its effects depend upon the amount or dose received, the duration of exposure (acute, intermediate or chronic), and individual variation. The severe toxic effects from exposure to mercury, methylmercury, and lead described above are only relevant for the most elevated exposure scenarios, as is possible in children who may consume unusually large amounts of soil (pica behavior). Because Acid Brook area soil was extensively contaminated with elevated levels of mercury and lead, serious concern for the most susceptible group in the affected population is warranted. Finally, there is growing public health concern that chronic low-level exposure to lead and mercury could have significant behavioral effects on children, such as delayed or impaired learning (23).

Chlorinated Solvents

Exposure to chlorinated solvents through inhalation, skin contact, and ingestion has occurred in PLW residents who used contaminated private well water before 1989. For drinking water ingestion, exposure to those chlorinated solvents (i.e., 1,1-dichloroethylene, 1,2-trans-dichloroethylene, trichloroethane, trichloroethylene, tetrachloroethylene, and vinyl chloride) has occurred at levels above health guidelines. Several other chlorinated compounds were found in the private well samples, but at levels below public health concern.

Tables 5A and 5B (in Appendix B) present the levels of contaminants found in residential private wells. The results for private well 1 are highlighted because it was the only well that appeared to be contaminated with vinyl chloride. Although private well 1 is clearly the most severely affected, it is evident from Table 5B that several private wells are contaminated with a number of solvents. In fact, trichloroethane, trichloroethylene, and tetrachloroethylene were detected at elevated levels in several of the wells tested.

In general, the levels of chlorinated solvents found in the private wells do not appear to be of public health concern for short-term (14 days or fewer) ingestion exposure, but this may not be the case for intermediate (15-364 days) or long-term (365 days or more) ingestion exposures. Exposure to relatively high doses of chlorinated solvents (ethanes and ethenes) has been shown to have adverse effects on the central nervous system, liver, kidneys, skin, and on reproduction (26, 27, 28, 29). It should be noted that intermediate and long-term exposures are only a concern for the ingestion exposure route, exposures through showering and washing with this contaminated water are only of public health concern if these exposures are concurrent with a drinking water exposure (45).

Tetrachloroethylene and 1,1-dichloroethylene are currently classified by the EPA as probable and possible human carcinogens, respectively. These classifications indicate there is evidence in studies with rats and mice that the compounds cause leukemia (cancer of the white blood cells) and liver and kidney cancer, but evidence in humans is inadequate or not yet available. Based on the available evidence in animal studies, and if it is assumed that water from the contaminated private wells was consumed for 10-20 years, there may be a low to moderate increased risk of cancer for residents whose drinking water was supplied by the contaminated private wells (27, 28).

Vinyl chloride, which is classified by the EPA as a known human carcinogen, was found at a relatively high level in one private well. The liver appears to be the most sensitive organ to the long- and short-term effects of vinyl chloride. Vinyl chloride has received special attention because of the convincing evidence that chronic exposure of both human workers and animals results in a rare liver cancer (i.e., angiosarcoma). Chronic consumption of water contaminated with vinyl chloride and other solvents from this specific well could result in a significant elevated risk of cancer (29).

Heavy Metals

Some private well samples contained somewhat elevated levels of copper and zinc, and one private well sample contained cadmium. At low levels, copper and zinc are essential elements in the human diet. The levels of zinc and copper in private wells were higher than those typically expected in drinking water, but were not above levels of public health concern (22, 30). On the other hand, cadmium is not known to have any beneficial nutritional effects, and the level in the one well (0.29 mg/L) exceeded the ATSDR chronic oral MRL for cadmium (0.0002 mg/kg/day) based on dose calculations. Long-term exposure to cadmium at this level could produce kidney damage that, although not life threatening, could lead to some health problems (e.g., kidney stone formation) (21).

B. Health Outcome Data Evaluation

UMDNJ has reported summary results (39,40) of the biological investigation for a total of 65 adult and 22 child (less than 12 years) blood and urine samples. All samples were collected and analyzed according to standard laboratory practices by the Roche Diagnostic Laboratory.

Screening for Lead

Blood lead (PbB) is considered a primary measure of current lead exposure. PbB is not an accurate measure of cumulative, chronic- duration lead exposure, half of the lead in human blood will be gone 28-36 days after exposure (23). All PbB levels reported by UMDNJ were below 15 micrograms per deciliter (µg/dL) with the exception of one individual with a value of 19 µg/dL. The average PbB for 65 adults was 6.7 µg/dL with a standard deviation of 3.9 µg/dl (i.e. plus or minus about 4 µg/dL). The average PbB for 22 children was 6.04 µg/dL with a standard deviation of 3.44 µg/dL. A standard deviation is the square root of the variance of a given set of values. Four of the PbB values in children were above 10 µg/dL but none exceeded 14 µg/dL. According to the guidance provided in the Centers for Disease Control document," Preventing Lead Poisoning in Young Children", no additional testing is needed if a blood lead level below 10 µg/dL is found (32). However, cognitive and developmental deficits, a low Intelligence Quotient (IQ), and an increase in blood pressure have been reported at blood lead levels of 6 to 35 µg/dL in populations who have had long-term exposures of more than a year. Two blood lead screenings, within a period of six months are required to make a conclusion regarding the possibility of adverse health effects in the screened population. Current Centers for Disease Control (CDC) guidelines recommend that children with PbB values in the range of 10-14 µg/dL be screened more frequently (32).

Review of erythrocyte protoporphyrin (EP) levels indicated that all levels seen in children and adults in Acid Brook were in the normal range. The only exception was one elderly woman with an EP level of 59 µg/dL. The EP level reflects the inhibitory effect of lead on enzymes that convert protoporphyrin to heme and ultimately to hemoglobin, which is a part of the red blood cells. In other words, the EP test is not a direct measure of blood lead content, but a measure of an effect that lead has on red blood cells. Only 23 adults and 12 children were able to provide twenty-four-hour urine samples for estimation of urinary lead. The reported mean lead excretion for adults was 13.1 µg/24 hours, and for children 13.8 µg/24 hours. The maximum reported value for an adult was 29 µg/24 hours, and for a child it was 44 µg/24 hours. That child had a PbB of 11 µg/dL. Urinary lead shows the ability of the body to excrete lead, and is not a measure of lead exposure. Ninety-five percent of the lead in the body is stored in the bones and is mobilized periodically. Lead is released from the bones and then excreted in the urine. Hence, we cannot determine if the lead in urine came from recent exposure or from the bones. Additionally, there are no guidelines for interpreting the values.

The screening is indicative of current exposures to lead up to a period of six weeks. Blood lead testing occurred between April, 1990 and August, 1992. Sixty-two percent of these tests occurred during colder months (October to March) (44). Screening performed during these months may not represent exposures which are likely to occur during the summer months and therefore maybe an underestimation. In addition, this self-selected volunteer population is not representative of the entire community, and a large percentage of these tests happened several months after the advisory, so residents may have already taken action to mitigate exposures.

Screening for Mercury

Summary results for blood mercury (B-Hg) and urinary mercury (U-Hg) were reported for 79 members (including adults and children) of the Pompton Lakes community. Results for children were not reported separately.

Urinary mercury results:

In non-occupationally exposed individuals, a value above 20 µg/L of U-Hg is evidence of excessive exposure, and for occupational exposure 50 µg/L of U-Hg is considered excessive. Urinary mercury was in the 0-6 µg/L (low-normal) range for all individuals including those reported to have above-average B-Hg.

Studies have reported an increased prevalence of slight tremor and of biological signs of renal dysfunction in workers excreting more than 50 µg/L of U-Hg (42). The screened urinary mercury levels in this population do not indicate current exposure. In addition, an urinary mercury level by itself is not considered an useful index of exposure to environmental mercury.

Blood mercury results:

The average B-Hg was 0.29 µg/dL with a standard deviation of 0.59 µg/dl. Levels of B-Hg in the range of 0-2 µg/dL are considered normal(42). Levels above 2.8 µg/dL are considered significant by the NJDOH, and indicate repeated testing and follow up.

Of the 79 people screened, 3 had B-Hg levels above the normal ranges. One person had themselves retested within 6 weeks and the results were < 2 µg/dL, the other two declined to have repeat testing. Several studies have indicated that on a group basis there is a correlation between the intensity of recent exposure to mercury vapor and the concentration of mercury in blood, urine, and saliva. Such a relationship holds only when exposure lasts for at least for one year (42). We have no quantitative information on the duration of exposure of this screened population, and none on the intensity of exposure to mercury. With urinary mercury results indicating no evidence of current exposure and a repeat B-Hg level for the individual who had a B-Hg level greater than 3 µg/dL showing B-Hg level less than 2 µg/dL upon repeat testing, it is difficult to make conclusions regarding possible health effects at the B-Hg levels observed in this population. Please refer to the toxicological evaluation section for more information on the toxicity of mercury.

Birth Defects Registry

Birth defects information for the Acid Brook Area for the years 1986 through 1989 has been requested from the New Jersey State Birth Defects Registry. Data will be reviewed and incorporated into the public health assessment, as soon as they are available.

Learning Disabilities

The Lenox Elementary School was targeted to assess current rates of learning disabilities since it serves many of the children in the Acid Brook area, and elementary-age children are highly vulnerable to health effects related to lead exposure. The Director of Special Services for Lenox Elementary School reported that approximately nine percent of the student population receives special education services, which is below the district average of 11.8% and the federal average of 12% (32). The most common classification of learning disabilities at the Lenox school are defined as being perceptually impaired and neurologically impaired.

Learning disabilities have been associated with exposure to both methylmercury and lead during fetal development. Mercury exposure can also result in other neurologic effects. Even though the percentage of the student population receiving special education services is below both the district and federal average, at this time and with inadequate data, we are unable to determine the cause of the existing learning disabilities in Lenox Elementary School, or whether rates of learning disabilities have historically been elevated.

C. Community Health Concerns Evaluation

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

1. Citizens of Pompton Lake are concerned about the availability of physicians for monitoring lead and mercury exposures during remediation of the citizens yards.

Du Pont has a program to provide biomonitoring for residents concerned about environmental exposures to contaminants during remediation through the New Jersey University of Medicine and Dentistry. ATSDR encourages residents to take advantage of those services, or consult their family physician. Any physician in the area who needs additional information about hazardous substances discussed in this public health assessment may contact ATSDR for further information.

2. Citizens perceive an excess of unexplained illnesses in the community.

ATSDR is unable to evaluate this concern until cancer and registry data are provided and analyzed. ATSDR will continue to work with the New Jersey Department of Health to better evaluate this concern, (see the Public Health Action Plan in the Recommendation Section).

3. Citizens worry that their children are not doing well in school and want their children's elementary school health unit educated for signs of learning disabilities.

The Pompton Lakes School System employs a specialist in learning disabilities who thoroughly evaluates all children referred to him by using the most recent methods of assessing learning disabilities. Teachers are trained and kept up-to-date on new information regarding assessment of learning disabilities. ATSDR will inform the school specialist of any new findings on the relationship between environmental health and learning disabilities through the Division of Health Education.

4. Citizens are concerned about lead contamination in the school water supply. They want the school water tested for lead.

The school receives its water from the Pompton Lakes municipal water supply. This water supply is not connected with the contaminated groundwater at PLW. The municipal water supply meets all current federal and state standards for lead (.015 mg/L, EPA Action Level).

The Pompton Lakes Borough Municipal Utilities Authority (MUA) reports that the Lenox Elementary School was last tested at five locations in 1991. Any citizen still concerned about the lead content of school water can request assistance from ATSDR in arranging to have the school water tested. The school principal of Lenox Elementary reports that custodians run all tap water for ten minutes every morning, as a precautionary measure to flush out any residual lead that might leach into the water overnight or over the weekend.

5. Citizens are concerned about exposure to mercury-contaminated soils. They want cleanup levels for mercury to be lower, more surface samples to be taken, and more biomonitoring to be done.

Controversy surrounds cleanup levels for lead and mercury for this site. Part of this controversy is due to a proposed change in the clean up level for lead in soil from 250 mg/kg to 100 mg/kg by the NJDEPE. Setting clean-up levels is difficult for lead for at least two reasons. First, natural soils in the eastern United States have lead levels that range between < 10 mg/kg to 300 mg/kg (16). Second, the element of lead serves no useful purpose in the human diet and may be harmful to children even at relatively low levels (10 ug/dl in blood) (32). In other words, the more lead removed from the environment, the better protection for public health.

Both levels of 250 and 100 mg/kg fall within the range of lead levels naturally occurring in soils, and both are unlikely to present a health hazard in residential areas. Of course, the advantage of cleaning up to 100 mg/kg of lead in soil is that, at least theoretically, risks to public health are further minimized. The disadvantage is that it also increases the chance for confusion as to whether this level of lead is naturally occurring or the result of pollution, and this can cause further confusion in determining the boundaries for clean-up activities. ATSDR will stay in contact with NJDEPE about the clean-up level for lead in soil for this site. Residents of the Acid Brook Area should continue to maintain good grass cover to minimize lead exposure as they have in the past.

ATSDR has concurred with a mercury cleanup level of 14 mg/kg. A previous ATSDR consultation addressed concerns about the appropriate cleanup levels for mercury (2).

In regards to the number of surface soil samples taken, it is always helpful to have as much environmental data as possible to best characterize an area. ATSDR received enough data on the contaminated media to make public health conclusions and recommendations for this site, see the Public Health Action Plan in the Recommendations Section for further information about follow-up activities to address health concerns).

6. NJDOH relayed concerns from residents about the effect that exposure to site contaminants might have on residents' health. Residents are specifically concerned about:

  1. the current health status of all of the residents in the affected area.
  2. lead and mercury levels of residents, and about assuring treatment where appropriate.
  3. illnesses or deaths that may have resulted from chronic exposures to environmental contamination (13).

The current and past health status of community members cannot be fully evaluated at this time. ATSDR will continue to collaborate with the New Jersey Department of Health in studying rates of disease among Acid Brook Area residents, see the Public Health Action Plan in the Recommendations Section.

7. The Mayor of Pompton Lakes said that people are concerned that increased incidence of multiple sclerosis, learning disabilities, and blood diseases such as anemia is the result of exposure to chemicals at the site (14).

The Lenox Elementary School reports that the rate of learning disabilities is currently about 9% of the school population, which is below district and federal averages. However, even though the percentage of student population receiving special education services is below both the district and federal averages, at this time and with inadequate data, we are unable to determine the cause of the existing percentage of learning disabilities. However, learning problems have been associated with exposure to lead contaminated soil at levels similar to those found in the Acid Brook area. Any associated illness or disease depends on the extent to which exposures occurred, and for how long. For more information, see the Health Outcome Data Evaluation and Toxicological Evaluations Sections of this document. For follow-up activities related to this concern, see the Public Health Action Plan in the Recommendation Section.

ATSDR does not have data or information on rates of blood diseases or multiple sclerosis for Pompton Lakes; however, current information has never indicated that the contaminants at this site could cause leukemia or multiple sclerosis in humans. This concern can not be addressed further without information on these rates.

8. Several residents expressed concern regarding increased rates of some kinds of cancer (breast, interstitial, brain) and learning problems (12).

During the public health assessment process, ATSDR investigated the percentage of children with learning disabilities at Lenox Elementary, and found that, at present, the percentage is lower than the district and federal level as stated in response to Question 7. However, ATSDR recognizes that this information is a preliminary assessment of the health status of this community, and does not consider historical information. ATSDR recommended that a health study is needed, and NJDOH will be following up on this recommendation in the future.

As far as increased rates of cancer, it is possible that there is an increased risk of cancer related to exposure to certain chlorinated solvents found in private well water, depending on the extent to which exposure occurred, and for how long. Again, ATSDR has recommended a health study to investigate health outcomes in this community. For more information, see the Toxicological Evaluations and Recommendations Section.

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