Skip directly to search Skip directly to A to Z list Skip directly to site content

PUBLIC HEALTH ASSESSMENT

MCADOO ASSOCIATES
MCADOO, SCHUYLKILL COUNTY, PENNSYLVANIA


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

The tables in this section list the contaminants of concern. We evaluate these contaminants in the subsequent sections of the public health assessment and determine whether exposure to them has public health significance. PADOH selects and discusses these contaminants based upon several factors which include: (a) concentration of chemicals on site and off site, (b) comparison of on-site and off-site concentrations with public health assessment comparison values for carcinogenic and non-carcinogenic endpoints, and (c) community health concerns.

Comparison values for public health assessments are contaminant concentrations in specific media that are used to select contaminants for further evaluation. These values include Environmental Media Evaluation Guides (EMEGs), Reference Dose Environmental Media Evaluation Guides (RMEGs), Cancer Risk Evaluation Guides (CREGs), and other relevant guidelines such as Maximum Contaminant Level Goals and Maximum Contaminant Levels.

EMEGs and RMEGs are calculated from ATSDR's Minimal Risk Levels (MRLs) and EPA's Reference Doses (RfDs), respectively. Both of those comparison values are based on levels of a contaminant that are not expected to cause adverse, non-cancer health effects upon exposure. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons exposed over a lifetime (70 years). CREGs are calculated from EPA's cancer slope factors. EPA's Maximum Contaminant Level Goal (MCLG) is a drinking water health goal. EPA believes that the MCLG represents a level that no known or anticipated adverse effect on the health of persons should occur and allows an adequate margin of safety. Proposed Maximum Contaminant Level Goals (PMCLGs) are MCLGs that are being proposed. Maximum Contaminant Levels (MCLs) represent contaminant concentrations that EPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water per day.

To identify possible facilities that could contribute to air, soil, and surface water contamination near the McAdoo site, PADOH searched the 1987 and 1988 Toxic Chemical Release Inventory (TRI). TRI is developed by EPA from the chemical release (air, water, and soil) information provided by certain industries. TRI did not contain any site-related information on toxic chemical release in McAdoo, Pennsylvania, or in the zip code where the site is located.

In the data tables which follow in the On-Site Contamination and Off-Site Contamination sections, the listed contaminant does not mean that it will cause adverse health effects from exposure. Instead, the list indicates which contaminants will be evaluated further in the public health assessment. When selected as a contaminant of concern in one medium, that contaminant will be reported in all media.

The data tables include the following acronyms:

(a)

- Upgradient
(b) - Downgradient
B - Not detected substantially above the level reported in laboratory or field blanks.
Cd - Child
CREG - Cancer Risk Evaluation Guide
EMEG - Environmental Media Evaluation Guide
RMEG - Reference Dose Media Evaluation Guide
J - Analyte present. Reported value may not be accurate or precise.
L - Analyte present. Reported value may be biased low. Actual value is expected to be higher.
MCL - Maximum Contaminant Level
mg/kg - Milligram per Kilogram
mg/L - Milligram per Liter
NA - Not Available
ND - Not Detected
NT - Not Tested
P - Analyte present. As values approach the instrument detection limit, the quantitation may not be accurate.
PMCL - Proposed Maximum Contaminant Level
PMCLG - Proposed Maximum Contaminant Level Goal
PSMCL - Proposed Secondary Maximum Contaminant Level
ppm - Parts per Million
SMCL - Secondary Maximum Contaminant Level

A. On-Site Contamination

Detailed descriptions of media sampled and results of the sampling analyses are discussed in this section. In general, subsurface soils subsurface soil and very limited surface soil contamination was identified prior to remediation at the MKT location. Groundwater contamination was identified at that location, but no contaminants were detected above background levels in air monitoring samples.

Polynuclear aromatic hydrocarbons (PAHs) were identified in pre-remedial soil samples at the MBS location. Low levels of PAHs were in the post-remedial subsurface soil samples, but concentrations are below levels of concern. No groundwater data are available for the MBS location.

MKT Location

Soil (0.5 - 34 feet)

In 1984, site soil sampling was obtained during a Remedial Investigation. Thirty-three (33) soil samples were collected from 0.5 feet to 34 feet (subsurface). No surface samples were obtained. Table 1 indicates the maximum concentrations of contaminants of concern.

In 1988, as part of a Soil Sampling Analysis Plan (SSAP), samples were collected at depths of 0 to 22 feet by the grid pattern method (see Table 2) (5).

Also, as part of the SSAP, six (6) Surface Soil Samples (0-6") were taken around the old incinerator foundation and analyzed for chlorinated dibenzo-p-dioxins and the maximum (equivalent) was 0.01 ppb (5).

All of the drums and all site fixtures were removed from the MKT location beginning in January 1981. The soil remediation was completed, by limited excavation of the contaminated soil, by May 1990 and a soil cap was completed in November 1991 (2)(8).

Air

During the 1984 remedial investigation, on-site toxic organic vapor concentrations did not exceed off-site background levels (1,4,6). Air monitoring scans were performed over a

Table 1. Maximum Contaminant Concentration in On-Site Soil (MKT Location)
(1984)
(4)

CONTAMINANT # OF HITS/
# OF SAMPLES*
CONC.
(PPM)
COMPARISON VALUE
PPM
Source
Chloroethane
ND
ND
NA

1,2-Dichloropropane
4/33
0.0065
5,000
EMEG
1,1,1-Trichloroethane
4/33
0.0236
NA

Bis(2-ethyhexyl)phthalate
13/33
960
50.0
CREG
Polychlorinated Biphenyls (PCB)
2/33
3.06
0.09
CREG
Polynuclear Aromatic Hydrocarbons
(PAH) (Total)
4/33
4
NA

Aluminum
33/33
11,200
NA

Barium
32/33
107
4,000
RMEG
Cadmium
13/33
137
10
EMEG
Chromium
8/33
1,370
300
RMEG
Iron
33/33
72,600
NA

Lead
25/33
2,830
NA

Manganese
32/33
735
300
RMEG
Nickel
11/33
1,720
NA

*# OF HITS/# OF SAMPLES = NUMBER OF TIMES A CONTAMINANT WAS DETECTED/# OF SAMPLES ANALYZED

Table 2. Maximum Contaminant Concentration in On-Site Soil (MKT Location)
(1988)
(5)

CONTAMINANT # OF HITS/
# OF
SAMPLES*
CONC.
(PPM)
COMPARISON VALUE
PPM
SOURCE
Chloroethane
0/6
ND
NA

1,2-Dichloropropane
0/6
ND
5,000
EMEG
1,1,1-Trichloroethane
1/6
0.12
NA

Total Phthalates
66/79
697.0
NA

Polychlorinated Biphenyls (PCB)
33/79
7.8
0.09
CREG
Polynuclear Aromatic Hydrocarbons
(PAH) (Total)
17/79
37.3
NA

Aluminum
NT
NT
NA

Barium
NT
NT
4,000
RMEG
Cadmium
NT
NT
10
EMEG
Chromium
NT
NT
300
RMEG
Iron
NT
NT
NA

Lead
NT
NT
NA

Manganese
NT
NT
300
RMEG
Nickel
NT
NT
NA

*# OF HITS/# OF SAMPLES = NUMBER OF TIMES A CONTAMINANT WAS DETECTED/# OF SAMPLES ANALYZED

12-acre area on and near the site. During the remediations, air monitoring also was performed, and no levels above background were detected (2).

Groundwater

During the 1991 RI, two rounds of Monitoring Well (MW) samples were collected - December 1990 and February 1991. MW #1 and #2 are upgradient along the site border. MW #5 and #9 are in the mine pool. MW #1, #2, #3, and #4 are screened in the Pottsville Formation. These MWs are the same wells used during the 1984 RI/FS. In 1984, very few and only low-level organics were detected (4).

Table 3. Maximum Contaminant Concentration in On-Site Monitoring
Wells in 1984 and 1991 (MKT Location)
(3,4)

CONTAMINANT CONCENTRATION (PPM) COMPARISON VALUE
1984 RI 1991 RI PPM SOURCE
Chloroethane
ND
ND
NA

1,2-Dichloropropane
ND
0.400
0.005
MCL
1,1,1-Trichloroethane
ND
0.150
0.200
MCLG
Bis(2-ethyhexyl)phthalate
ND
0.010
0.0025
CREG
Polychlorinated Biphenyls (PCB)
ND
ND
NA

Polynuclear Aromatic Hydrocarbons
(PAH) (Total)
ND
ND
NA

Aluminum
60.0
86.4
0.200
PSMCL
Barium
0.20
5.36
0.700
RMEG
Cadmium
ND
0.012
0.002
EMEG
Chromium
0.30
0.144
0.050
RMEG
Iron
49.0
136.0
0.300
SMCL
Lead
ND
0.305L
0.0
PMCLG
Manganese
7.80
6.65
0.050
RMEG
Nickel
0.240
1.836
0.100
PMCL

On-site groundwater, particularly the mine pool, is contaminated with acid mine drainage - low-level organics and various inorganic metals. The water is very acidic and not aesthetically acceptable (3). Well yields would be low (2).

MBS Location

Tanks

Four underground storage tanks were sampled in May 1981. The contents were listed as wastes, including petroleum distillates and PAHs (2,5,6). These were pumped out in 1982. A fifth underground tank was discovered in 1984 and contents were removed in March 1985. The five tanks were excavated in March 1985 (2,6,7).

Soils (Subsurface - 12 feet)

Phase I soil samples were collected in 1985 from the pits during excavation of the tanks. Predominant contaminants were PAHs (maximum total concentration 5.27 ppm), lead (maximum concentration 26.7 ppm), and bis(2-ethyhexyl)phthalate (maximum concentration 6.50 ppm) at an approximate depth of 12 feet (3).

After excavation of the contaminated soil in June 1985, Phase II soil sampling was performed. Those samples identified only low-level PAHs, present below EPA's soil remediation criteria (2).

Groundwater

No on-site groundwater data are available. This is a data gap.

B. Off-Site Contamination

Details of off-site sampling that has been conducted are discussed in this section. In general, private wells near the MKT location have been tested. Contamination that is not believed to be site related was found in some private wells. Likewise, mine discharges appear to contribute more to the surface water and sediment contamination than the site contributes.

A public water supply system was tested near the MBS location. No site-related contamination was detected. Surface water was also tested near the MBS location. Some volatile organic chemical (VOCs) contamination was detected.

MKT Location

Groundwater-Residential Wells

In 1983, four upgradient residential wells on Silverbrook Road and one private business well southwest of the site on Route 309 were sampled. These samples were negative for organics except for the business well which indicated bis(2-ethyhexyl)phthalate present at a maximum concentration of 0.022 ppm. This exceeds the CREG of 0.0025. That well was not resampled in later investigations. The inorganics are listed on Table 4.

In March 1990, residential wells were sampled as part of a community relations activity and again in December 1990 as part of the RI. A total of seven wells were sampled including three wells along Silverbrook Road and four wells along Still Creek Road (Figure 7) (3). Both a well and a tap sample were collected in the December 1990 event. Table 4 indicates maximum concentrations of contaminants of concern.

Surface Water, Sediment and Mine Discharge

Ten surface water/sediment locations were sampled in December 1990. Samples included three background locations along Lofty Creek and seven along the Little Schuylkill River, including the Silverbrook Discharge (Figure 6) (2). The Little Schuylkill River has been, and continues to be, severely affected by acid mine drainage (3). Table 5 indicates maximum concentrations of contaminants of concern in surface water, and Table 6 indicates maximum concentrations of contaminants of concern in sediment.


Table 4. Maximum Contaminant Concentration in Off-Site
Residential Wells (MKT Location)
(3,4)

CONTAMINANT CONCENTRATION (PPM) COMPARISON
VALUE
1983 1990
WELL1
1990 TAP PPM SOURCE
Chloroethane
ND
NT
ND
NA

1,2-Dichloropropane
ND
NT
ND
0.005
MCL
1,1,1-Trichloroethane
ND
NT
0.001
0.200
MCLG
Bis(2-ethyhexyl)phthalate
0.022
NT
ND
0.0025
CREG
Polychlorinated Biphenyls
(PCB)
ND
NT
ND
NA

Polynuclear Aromatic Hydro-
carbons (PAH) (Total)
ND
NT
ND
NA

Aluminum
ND
0.186(a)P
0.297(a)
0.200
PSMCL
Barium
0.15
0.091(b)P
0.104(b)
2.000
MCL
Cadmium
ND
0.002(b)L
0.006(b)B
0.002
EMEG
Chromium
0.011
ND
0.014(a)L
0.05
RMEG
Iron
ND
0.326(b)L
0.754(b)
0.300
SMCL
Lead
0.008
0.036(b)
0.041(b)
0.015
PMCL-
TAP
Manganese
0.095
0.421(a)
0.934(a)
0.050
SMCL
Nickel
0.082
0.052(b)
0.056(b)
0.100
PMCL
1Organics tested only at the tap.


Table 5. Maximum Contamination Concentration in Off-Site Surface
Water (MKT Location)
(3)

CONTAMINANT CONCENTRATION (PPM) COMPARISON VALUE
SURFACE
WATER
MINE
DISCHARGES
PPM SOURCE
Chloroethane
ND
0.032
NA

1,2-Dichloropropane
ND
ND
0.005
MCL
1,1,1-Trichloroethane
ND
ND
0.200
MCLG
Bis(2-ethyhexyl)phthalate
0.016L
0.200
0.0025
CREG
Polychlorinated Biphenyls
(PCB)
ND
ND
NA

Polynuclear Aromatic
Hydrocarbons
(PAH) (Total)
ND
0.300
NA

Aluminum
4.390
4.730
0.200
PSMCL
Barium
0.029P
0.027
2.000
MCL
Cadmium
ND
ND
0.002
EMEG
Chromium
ND
ND
0.05
RMEG
Iron
4.860
10.900
0.300
SMCL
Lead
0.002B
0.003
NA

Manganese
1.050
1.250
0.050
SMCL
Nickel
0.047
0.059
0.100
PMCL



Table 6. Maximum Contaminant Concentration in Off-Site
Sediment (MKT Location)
(3)

CONTAMINANT CONCENTRATION COMPARISON VALUE
PPM PPM SOURCE
Chloroethane
ND
NA

1,2-Dichloropropane
ND
5,000
EMEG
1,1,1-Trichloroethane
ND
NA

Bis(2-ethyhexyl)phthalate
0.2L
500
CREG
Polychlorinated Biphenyls (PCB)
ND
0.09
CREG
Polynuclear Aromatic Hydrocarbons (PAH) (Total)
4.8
NA

Aluminum
3.34
NA

Barium
0.077
4,000
RMEG
Cadmium
0.009
10
EMEG
Chromium
0.333
300
RMEG
Iron
90.60
NA

Lead
0.135
NA

Manganese
4.25
300
RMEG
Nickel
0.009
NA

MBS Location

Groundwater

The Honeybrook Water Company water supply wells are located southwest of the MBS location. Surface water flow is north.

No organics were detected. Of the inorganic contaminants of concern, only lead (maximum 0.004 ppm) and nickel (maximum 0.049 ppm) were detected.

Surface Water

Five (5) samples of surface water were collected from four (4) sampling points from a stream adjacent to the MBS location. Organics were detected at only one location downstream of a sewer pipe outfall (3). Table 7 indicates the maximum concentrations of contaminants of concern in the off-site surface water at the MBS location.


Table 7. Maximum Contaminant Concentration in Off-Site Surface
Water (MBS Location)
(3)

CONTAMINANT CONCENTRATION COMPARISON VALUE
PPM PPM SOURCE
Chloroethane
ND
NA

1,2-Dichloropropane
ND
0.005
MCL
1,1,1-Trichloroethane
0.200
0.200
MCLG
Bis(2-ethyhexyl)phthalate
0.004
0.0025
CREG
Polychlorinated Biphenyls (PCB)
ND
NA

Polynuclear Aromatic Hydrocarbons
(PAH) (Total)
ND
NA

Aluminum
ND
0.200
PSMCL
Barium
ND
2.0
MCL
Cadmium
0.003
0.002
EMEG
Chromium
ND
0.050
RMEG
Iron
ND
0.300
SMCL
Lead
ND
0
PMCLG
Manganese
ND
0.050
SMCL
Nickel
ND
0.100
PMCL
NOTE: Organics were detected at only one location downstream of a sewer pipe outfall.

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

In preparing this public health assessment, PADOH relies on the information provided in the referenced documents and assumes that adequate quality assurance and quality control measures were followed regarding chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn for this public health assessment are determined by the availability and reliability of the referenced information. The QA/QC data summary sheets stated that field data and sampling quality during the site assessments were satisfactory.

D. Physical and Other Hazards

No physical hazards exist at either McAdoo location.


PATHWAY ANALYSES

To determine whether nearby residents are exposed to contaminants migrating from the site, PADOH evaluates the environmental and human components that lead to human exposure. This pathway analysis consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and an exposed population.

PADOH categorizes an exposure pathway as a completed or potential exposure pathway if the exposure pathway cannot be eliminated. In a completed exposure pathway, the five elements exist and exposure has occurred, is occurring, or will occur in the future. In potential exposure pathways, however, at least one of the five elements is missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present.

As presented in the Environmental Contamination and Other Hazards section, remediation has taken place at both the MKT and MBS locations. At the MKT location, drums and site fixtures were removed, the soil was remediated, and a soil cap was completed in November 1991 (2)(8). Contamination was found in subsurface soils, to which people, except unprotected remediation workers, would not be exposed. Surface soil contamination was not identified at levels of concern. Therefore, no one is believed to have been exposed to contaminated soils.

On-site groundwater, particularly the mine pool, is contaminated with acid mine drainage - low-level organics and various inorganic metals. The water is very acidic and not aesthetically acceptable (3). Well yields would be low (2). It is widely known and accepted that high concentrations of inorganics are normally found in waters impacted by acid mine drainage. The mine pool has been impacted by acid mine drainage since mining began in the early 1900's; consequently, the mine pool has contained high concentrations of organics for a long time. It is possible that the former waste activities at the MKT location have further impacted the mine pool with respect to inorganics; however, the contribution of inorganics from the MKT location is unknown (2). The long-standing knowledge of the mine pool aquifer and acid mine drainage as part of the hydrogeology make the use of this aquifer for potable water very unlikely; therefore, exposure through use of the mine pool aquifer can be eliminated.

A. Completed Exposure Pathways

Private Well Pathway (MKT)

There are no site-related completed pathways. This conclusion is supported by several hydrogeological investigations. The residential wells located along Silverbrook Road and Still Creek Road draw water from the water-bearing zones within the Mauch Chunk Formation (see Figure 3), which is not present at the surface at the MKT location. However, the hydrogeologic relationship was re-evaluated during the 1991 RI.

Groundwater elevations measured in December 1990 in residential areas indicated a generally southerly hydrologic gradient with the highest water elevations measured in the Silverbrook Road residences, lower water elevations in the MKT location wells (decreasing from north to south across the MKT location), and the lowest measured levels occurring in the residential wells along Still Creek Road (2).

Based on water level information, the Silverbrook Road residential wells are hydrologically upgradient from the wells at the MKT location. In addition to occurring hydrologically upgradient from the MKT location, the residential wells along Silverbrook Road are situated "across geologic structure" from the MKT location. Groundwater movement in sedimentary or meta-sedimentary rocks is likely to occur along, rather than across, planer structural zones such as bedding planes and faults. Also, the well cemented rock structure of the Pottsville Formation has been reported to act as a barrier to groundwater movement in the area (2). Therefore, private wells on Silverbrook Road are not likely to ever be impacted by site contaminants.

The residential wells along Still Creek Road are south of the MKT location, which is considered hydrologically "downgradient." However, the occurrence of the Little Schuylkill River and its proximity to the residential wells induces groundwater flow towards the river, or to the southwest on the eastern side of the river. Geological study has determined that in order for groundwater from the MKT location to reach the residential wells located along Still Creek Road, it would have to flow across several intercepting zones, including bedding planes and four large fault zones, which is unlikely (2).

In conclusion, given the MKT location and regional geology and hydrogeology, the residential wells are not hydrologically connected to the MKT location. Consequently, there is no complete groundwater migration pathway between the MKT location and nearby residential wells (2).

Although there are no site-related completed pathways, the residential well sampling results did indicate three inorganics (aluminum, iron, and manganese) above the Secondary Maximum Contaminant Levels and lead above the EPA's Action Level. Those elements are commonly found at elevated levels in mining areas. Because the lead in some samples was higher at the tap than in the well water, the home water distribution system may also be contributing to lead found in water taken from the tap. The people who use these wells are exposed to aluminum, iron, manganese, and lead through ingestion of the elements present in their water supply.

B. Potential Exposure Pathways

Sediment Pathway (MKT)

A past, current, and future potential exposure pathway is through incidental ingestion of and dermal contact with sediment contaminated with PAHs in the Little Schuylkill River downgradient from the mine discharge. Contaminated sediment particles are not likely to become airborne; therefore, inhalation is not a likely route of exposure. The river at this area is severely affected by the acid mine drainage, as demonstrated by the fact that no aquatic life is present. Although it is unlikely that children would play in this water, especially on a continual basis, the possibility of that happening has not been eliminated.

Soil Pathway (MBS)

The deeper soils (12 feet) at the MBS location may still contain some PAHs. A future potential exposure pathway may exist for any workers who should directly contact or incidentally ingest the soil (to 12 feet or greater) during construction activities. Inhalation of airborne particulates is also possible. The levels of PAHs detected after the last remediation were at or below detection limits; however, extensive analyses were not done and some doubt exists as to how extensive the contamination may be (2).


PUBLIC HEALTH IMPLICATIONS

Introduction

In this section, we discuss the health effects that may occur in persons exposed to site contaminants, evaluate the relevance of state health data bases to provide information for the McAdoo Associates site, and evaluate community health concerns.

A. Toxicologic Evaluation

As reported in the Environmental Contamination and Other Hazards section, the contaminants of concern are inorganics and PAHs.

To evaluate health effects, either a Minimal Risk Level (MRL) for contaminants developed by ATSDR or a Reference Dose (RfD) developed by EPA has been used. The MRL is an estimate of daily exposure (mg/kg/day) to a contaminant below which non-cancer adverse health effects are unlikely to occur. The RfD is also an estimate of a daily exposure (mg/kg/day) to the general public (including sensitive groups) that is likely to be without an appreciable risk of harmful, non-cancer effects during a lifetime exposure (chronic RfD). Also because of possible cancer effects that may result from a site, we develop an estimate of cancer risk based on EPA's cancer slope factor.

EPA developed Maximum Contaminant Levels (MCLs) for drinking water. Primarily, MCLs are federal drinking water standards declared under the Safe Drinking Water Act. Generally, an MCL for a toxic chemical represents the allowable lifetime exposure to the contaminant for a 70-kg adult who is assumed to ingest 2 liters of water per day. In addition to health factors, an MCL is required by law to reflect the technological and economic feasibility of removing the contaminant from the water supply. A Secondary Maximum Contaminant Level (SMCL) is a guideline for contaminants in drinking water that primarily affect the aesthetic qualities relating to the public acceptance of drinking water. At considerably higher concentrations of these contaminants, health implications may also exist (9).

Aluminum and Iron

These inorganic chemicals are considered to have low toxicity as regards to human health effects (9). Aluminum has a proposed SMCL of 0.200 mg/L and the maximum level detected in a residential well was 0.297 mg/L. Iron SMCL is 0.300 mg/L and the maximum level detected in a residential well was 0.754 mg/L (9). No adverse health effects are expected to result from exposures to aluminum and iron at the levels detected in the residential wells.

Manganese

Manganese is a natural component of most food and water. There is no direct evidence that manganese is beneficial or essential in humans, but ingestion of manganese compounds is known to be required for good health in animals (15). Exposure to manganese at the maximum of 0.934 mg/L found in a private well would exceed the RfD established by EPA (15). However, ingestion of that level would result in a dose below the normal daily diet intake for this mineral (15). The RfD is derived by incorporating uncertainty factors and may result in an estimate with uncertainty spanning an order of magnitude (15). Because the maximum levels detected in private wells is below the normal daily diet intake, adverse health effects are not likely to occur through ingesting the manganese. If an individual is very sensitive to manganese, and perhaps is exposed to high levels of manganese through other sources, adverse, non-cancer health effects may occur. Exposures to levels much higher than those detected in wells may result in weakness, stiff muscles, and trembling hands. Animal data suggest that the potential for carcinogenic effects in humans upon exposure to manganese is small (15).

Lead

The lead exposure that has occurred and is occurring through some of the residential wells exceeds EPA's Proposed Maximum Contaminant Level Goal (PMCLG) of zero. The 0.041 mg/L maximum level of lead detected in drinking water also exceeds EPA's Action Level of 0.015 mg/L at the tap. While ATSDR has no MRLs and EPA has no RfD for lead, exposures to this level of lead should be reduced to avoid adverse health effects from chronic exposure. The exposure to lead should be reduced to the lowest level possible, preferably zero. Lead exposure can cause a decrease in intelligence quotient (IQ) scores, slow growth and cause hearing problems. Lead exposure is especially dangerous for young children under 6 years and for unborn children because they can be harmed during fetal development. Pregnant women exposed to lead can transfer lead to unborn children, causing premature birth, low birthweight, and miscarriages (10). EPA classifies lead as a probable carcinogen. That classification is based on animal studies (10).

Polycyclic Aromatic Hydrocarbons (PAHs)

PAHs are a class of organic compounds formed when complex organic substances are exposed to high temperatures or pressures. They are natural components of most fossil fuels including coal (11). PAHs are ubiquitous in the environment. Generally, the PAHs have a low degree of acute toxicity to humans and the most significant endpoint of PAH toxicity is cancer. Some of the PAHs are classed as probable human carcinogens, some are classed as possible human carcinogens and others are considered noncarcinogens. Benzo (a) pyrene is considered as one of the most potent carcinogens among the PAHs (11). Exposure to the levels of contamination detected in the river sediment over a lifetime could result in a low increased risk of developing cancer. The stream is contaminated with acid mine drainage and is not an aesthetic stream. Therefore, it would have no attraction for recreational use reducing the likelihood that persons would be exposed to the sediment. The MBS site at 12 feet below surface could expose construction workers to low-level PAHs; however, no acute health effects and no increased risk of cancer would be expected to occur (11).

B. Health Outcome Data Evaluation

The McAdoo Associates site consists of two areas approximately 3 miles apart. One area, in the Borough of McAdoo covers less than one acre. The other in Kline Township covers 8 acres.

The McAdoo area has been analyzed for cancer mortality on at least three separate occasions. Two of these analyses were reported to the local representatives. The first analysis was reported to the representatives on December 31, 1985. That analysis was on cancer data for the period 1979-1981 for McAdoo Borough and Kline Township (12,13).

The second analysis was reported on September 13, 1989. This cancer study included McAdoo Borough and 13 contiguous municipalities around McAdoo Borough. This study investigated 15 different cancers over the 1979-1989 time period.

In both of these studies, the cancer mortality outcome was negative - observed cancer deaths were less than the expected number. Both studies calculated observed and expected deaths for cancer and cancer sites by the indirect method of adjustment and used a Poisson Variable for indicating outcome (14). This method is used in many statistical presentations throughout the world, but a full explanation is beyond the purpose of this public health assessment. An explanation of an expected death and a description of the indirect method will be addressed in the latest analysis performed by the Division of Environmental Health.

Twenty-one years of all cause mortality and cancer mortality (total cancer and eight cancer sites) were collected for McAdoo Borough, Kline Township, and Rush Township. The 1979-1989 municipality data was analyzed using Pennsylvania's 1979-1981 mortality experience as a standard and the 1980 Census population for age and sex.

Total death (all causes) were above the expected number of deaths for the 1979-1989 period for the three municipalities. There were 1,114 deaths observed for the period and 1,053 deaths would be expected. (An "expected" death is a statistical term used for measuring mortality among a specified population. In this case, the age-sex specific death rates by 5 year age groups for a selected cause of death for Pennsylvania is applied to the same age-sex population in the municipality to obtain an "expected" number of deaths. This tells the investigator how many deaths one would expect to see in a municipality if the mortality experience was the same as in the standard population - Pennsylvania.)

Total cancer deaths in the 1979-1989 period for the three municipalities was close to the expected number of cancer deaths when compared to Pennsylvania's age-sex specific cancer rates. There were 250 cancer deaths observed in the three municipalities and 238 deaths expected. None of the eight cancer sites analyzed differed greatly in the number of deaths observed in either McAdoo Borough, Kline Township, or Rush Township when compared to the number of deaths expected based on Pennsylvania's mortality experience. The cancer sites were: (1) buccal cavity and pharynx; (2) digestive system; (3) respiratory system; (4) bone, connective tissue, skin and breast; (5) genitourinary system; and (6) other and unspecified sites; (7) leukemia and (8) other lymphatic and hematopoietic tissues. These eight cancer sites are those routinely reported on and made available through the State Health Data Center (12,13).

C. Community Health Concerns Evaluation

Community interest and concern about the site has been steady and relatively high throughout EPA's involvement at the site (2). We have addressed the community concerns about health as follows:

  1. Are the citizens' private wells near the MKT location contaminated from the site, and has the Honeybrook Water Corporation's water supply been contaminated by the MBS location?

    Two remedial investigations, geologic, and hydrogeologic studies conclude that there is no connection between the MKT location and local wells (e.g., Silverbrook Road). Also concluded by these studies is the fact that the residential wells in the area tap the deeper aquifer (Mauch Chunk) and are not connected to the contaminated aquifer. The Silverbrook Road area is also upgradient of the MKT location. The inorganic metals detected in the residential wells are typical of metals found in the waters near mining areas. The wells of the Still Creek Road residences also tap the deeper aquifer and are not in danger of contamination from the MKT site (2).

    The Honeybrook Water Company groundwater was tested during the RI in 1990 and not found to be contaminated. They are also required as a public water supply company to test routinely for contamination. The water company's wells are hydrogeologically upgradient and geologically separated from the MBS location. The shallow groundwater flow is northerly, away from the wells (1,2).

  2. Are the odors that can be occasionally smelled coming from the MKT location a health hazard?

    Air monitoring was performed during the 1984 RI and no levels above background were found at that time. An air monitoring program has been in place since then whenever any construction activities are ongoing. Preliminary data from this air monitoring has not detected any organic compounds; therefore, there is no evidence that exposure to what may cause the odors is of public health concern (2).

  3. Will a health survey be conducted?

    This public health assessment is being done by evaluating all available data concerning the McAdoo site in order to assess any past, current, or future impact on public health. No exposures to site-related contaminants have been identified. In order for people to get sick from contaminants in the environment, they must be exposed to the contaminants. Because no exposures have been identified, no health surveys are planned. Information will be provided to the community about lead that is present in drinking water.

  4. Is there an increase in the number of cancers in the population around the McAdoo site?

    No. Several investigations have been done by PADOH to ascertain if there is any increase in cancer deaths near the McAdoo site. In all investigations, the cancer mortality outcome was negative - that is, the observed cancer deaths, compared to the number of cases that would be expected, do not differ. (See Health Outcome Data Evaluation section.)

The Health Assessment was made available for public comment from March 12, 1993, through April 14, 1993, and no other comments were received.


Next Section      Table of Contents

  
 
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

A-Z Index

  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #