PUBLIC HEALTH ASSESSMENT
SOUTH MACOMB DISPOSAL AUTHORITY #9, 9A
ST. CLAIR SHORES, OAKLAND COUNTY, MICHIGAN
|Macomb Township, Michigan|
|% Asian or|
|% Age 65|
|Macomb Township, Michigan|
|% Persons in|
|Median rent paid,|
* A household is an occupied housing unit, but does not include group quarters such as militarybarracks, prisons, and college dormitories.
Benzene is especially harmful to tissues that form blood cells. Benzene and its metabolites,chemicals formed from benzene by biological processes, localize in bone marrow, deplete its redblood cell supply, and produce various toxic effects on blood. Thus, long term exposure tobenzene may affect normal blood production resulting in incomplete development of the bonemarrow, internal bleeding, or aplastic anemia (11). Aplastic anemia is the reduced production ofall blood components. Development of aplastic anemia has been observed following chronicexposure to benzene in occupational situations (high levels of benzene).
Human and animal studies indicate that benzene is detrimental to the immune system, thusincreasing the chance for infections and perhaps decreasing the body's defense against tumors. Most human studies involve occupational exposures with inhalation as the primary route ofexposure. Several studies show altered immune system components. These altered components,along with benzene's ability to affect blood cell production, help explain why individualsexposed to benzene may succumb to infection.
Exposure to benzene has been linked with genetic and developmental changes in both humansand animals. Benzene and its metabolites may cause numerical and structural chromosomalaberrations in lymphocytes. A study of 52 workers exposed to benzene found chromosomalbreaks and translocations in peripheral blood lymphocytes at 2-3 times the rate found in controls(11). In addition, an increased frequency of chromosomal breaks was found in lymphocytestaken from 14 children of women occupationally exposed to benzene (11). This supports theevidence that benzene crosses the placenta, therefore risking exposure of the fetus to benzene. Animal studies indicate that benzene can cause low birth weight, delayed bone formation, andbone marrow damage in unborn animals (11).
Methylene chloride has produced benign mammary tumors and malignant liver and lung tumorsin various animal species following chronic exposure (13). These carcinogenic responses wereobserved to occur after both inhalation and ingestion. Epidemiological and occupational studieson humans have failed to prove that methylene chloride is a human carcinogen. However, basedon animal experiments, the EPA classifies methylene chloride a probable human carcinogen.
Evaluation of arsenic toxicity is complicated because arsenic can exist in several different forms. An additional complexity is that laboratory animals are not good models for arsenic toxicity inhumans; animals appear to be less susceptible to arsenic's toxic effects (15).
In humans, chronic oral doses below 1 µg/kg/day are not likely to cause adverse noncancerhealth effects (15). In the general population, the main route of arsenic exposure is by ingestionof arsenic-contaminated food and water. The average dietary intake of arsenic by adults in theUnited States has been estimated to be 50 µg/day (range 8-104 µg/day) (15). Soluble forms ofarsenic are well absorbed from the gastrointestinal tract (60-90%). Absorption by inhalation hasnot been determined, but is also believed to be within that range. Dermal absorption isgenerally negligible; however, effects from dermal absorption have been reported inoccupational settings.
The effects of oral exposure to arsenic most likely to be of human health concern aregastrointestinal irritation, peripheral neuropathy, vascular lesions, anemia, skin diseases, andskin cancer. Most noncancer effects are observed at chronic exposures ranging from 0.01 to 0.1mg/kg/day, and at intermediate exposures ranging from 0.05 to 0.5 mg/kg/day (15). Estimatesof the minimum lethal oral dose in humans range from 1 to 3 mg/kg/day (15). Increased risk ofcancer is the effect of greatest public health concern related to arsenic exposure by inhalation. Other effects, such as respiratory irritation, nausea, and skin problems, may also occur, but areunlikely below a concentration of 0.1-1.0 mg/m3 (15).
Chronic gastrointestinal effects are seen predominately after arsenic ingestion. Increasedpermeability of the small blood vessels, leading to fluid loss and hypotension, is the primarygastrointestinal effect. Other effects include inflammation and necrosis of the mucosa andsubmucosa of the stomach and intestine (15). Damage to the mucosa may lead to nausea,vomiting, and diarrhea.
The health effects resulting from short- or long-term human exposure to water containingspecific concentrations of ammonia via ingestion are not known. Exposure to concentratedammonia, such as ammonia used for household cleaning, may cause coughing or eye irritation. It is unknown if ammonia causes cancer or birth defects.
Ingestion of 1,2-DCA can result in adverse gastrointestinal, hepatic, renal, CNS, and respiratoryeffects in humans (19). Those effects have been observed primarily after intentional exposure tolarge, unknown doses. Gastrointestinal effects include nausea, vomiting, and diarrhea.
Little information exists on the development of cancer after humans are exposed to 1,2-DCA. However, because animals have developed cancer in some studies, 1,2-DCA cannot be ruled outas a human carcinogen. Therefore, EPA has classified 1,2-DCA a probable human carcinogen.
Detailed toxicity data on lead is in the "Toxicological Evaluation" section.
Methyl Ethyl Ketone
MEK has a low toxicity following both acute and chronic exposures (21). The informationavailable on adverse health effects is primarily from occupational studies.
Cadmium toxicity may produce proximal renal tubular and tiny blood vessel damage (CS). Cadmium may also cause a disturbance in calcium and phosphate metabolism which could leadto kidney stone formation and demineralization of bones.
Adverse skeletal effects such as bone pain, softening of the bones, and osteoporosis that canresult from cadmium exposure are likely due to calcium excretion. These effects were greatlystudied in postmenopausal women living in a cadmium-contaminated area in Japan. The effectson bones are considered to be a consequence of cadmium-induced renal disease (23).
Impairment of lung function is associated with chronic inhalation exposure to low cadmiumlevels (23). Bronchiolitis and alveolitis may occur and impaired respiratory function andemphysema have been observed in workers exposed to cadmium.
The comments listed here were received by ATSDR in response to the public comment period(July 5 - August 4, 1994) for the South Macomb Disposal Authority #9, 9A Public HealthAssessment. The list of comments does not include editorial comments concerning wordspellings, sentence syntax, etc. It also does not include comments on accuracy of stated facts. Ifthe accuracy of a statement was questioned, the statement was verified or corrected. Commentswhich requested that additional information be added to the document without providingdocumented sources of that information are not addressed here. Also, political and legal issuesare not addressed.
- In the ninth paragraph under "Demographics, Land Use, and Natural ResourceUse,"..."None of these 14 residences are receiving bottled water, nor should they, sincethe document states the potential for contamination is considered highly unlikely. ...Those who continue to use domestic wells are either outside of the expected impactarea or do not want a municipal water connection due to ongoing litigation or personal reasons."
- This information has been added.
- Under "Groundwater Pathways-Environmental and Human Exposure Pathways" it isstated that contaminants migrate freely down to the lowest aquifer. Yet a futureparagraph only mentions plumes in the shallow and intermediate aquifers only. Themonitoring data (Table 2) supports only a small contamination impact on the loweraquifer, not as great an impact as on the upper two aquifers.
- Reference 9 identifies plumes in the upper two aquifers only. A sentence stating that aplume has not been identified in the lower aquifer has been added to the document. Also, a reference has been added referring the reader back to Table 2 data.
- In recommendation #1 the statement that additional well contamination is "consideredhighly unlikely" should be included. Any well, anywhere in the country has thepotential to become contaminated, however most will probably not. This sentenceshould be reworded and clarified.
- The sentence "Although sampling up to 1991 has indicated non-detects, the potential forthese wells to become impacted still exists" has been deleted.
- Citizens near the site were promised over two and one half years ago that a fence wouldbe put up, but so far nothing has been done.
- This is reflected in our recommendation #3.
- The maximum concentration of nitrates detected in private wells was 16,000 ppb, not21,000 ppb.
- The maximum concentration of 16,000 ppb does not exceed the comparison values of60,000 ppb (adult RMEG) and 20,000 ppb (child RMEG). Nitrates have been removedfrom Table 4 and from the Toxicologic Evaluation section.
- I have contacted 11 of the residents affected by the SMDA landfills and can find no onethat refused a health survey, in fact we asked for one many times.
- The MDPH offered to conduct a disease and prevalence survey in the area surroundingSMDA in 1986. However, the MTSCC and many area residents indicated that they didnot want the survey performed. It is not known exactly which residents turned down the study.
- Any health education that has occurred was done solely on our own. I know of nogovernment agency that has volunteered help without our constant prodding.
- Community health education has occurred in the past by the MDPH, the MTSCC, andthe EPA. The MDPH mailed out letters to area citizens over the years (starting in 1983)advising them not to use private water sources as their wells were found to be impacted. MTSCC meetings in which in-depth discussions of health threats took place wereattended by community representatives during the 1980s. In addition, the EPA has heldmeetings which were well attended by area citizens. Extensive local news coveragealso occurred.
- Site 9 contained two spring-feed ponds in the bottom of the sand pits. One pond wasapproximately 8 acres and 30 feet deep, the other was 5 acres and 17 feet deep. Theseponds contained clean water and fish. The landfill wastes were dumped into these ponds.
- Most of the background information for this document came from the RI report VolumeI. Ponds were never mentioned in the RI.
- The first leachate was noticed in the McBride Drain in 1970, not 1971.
- Volume I of the RI (page ES-3) states "Leachate was reportedly first observed inMcBride Drain in 1971..." The word "reportedly" has been added to the sentence in this document.
- In the Background section of the document is stated "The same kind of reddish growthswere found in McBride Drain upstream from the landfill." The reddish growths werenot found upstream in the McBride Drain but downstream past my house.
- ATSDR cannot verify this, but wanted to state this eyewitness account.
- Nothing has been done to clean up the landfill.
- Interim remediation activities at and around the site have included the installation of aleachate collection system, a slurry wall, and the connection of most area residences to amunicipal water supply.
- This document never addressed the constant strain on our lives from years of living nextto the landfill and leachate and our constant worry about clean well water.
- This issue has been added as question 7 in the Community Health Concerns Evaluation section.
- I lived 1/2 mile from the landfill. One of my daughters had blood cancer, my wife hadsquamous cell carcinoma of the cervix, and a neighbor died of cancer. Doesn't thisseem strange to the U.S. Public Health Service?
- Information regarding expected cancer rates in the population of concern cannot bedetermined. Cancer information is discussed in the "Health Outcome Data Evaluation" section.
- The document does not address the possibility that manufacturing wastes from platingcompanies and factories were dumped in the landfill.
- Volume I of the RI (page ES-1) states that "general municipal wastes" were dumped in the landfill.
- Currently, several new houses are being constructed on Foss Road and their owners arenot aware of the potential contamination they might receive when they begin to use their wells.
- A bacterial test and a partial chemical test are run on new private wells. Additionalsampling would have to be requested by the well owner (30). Also, please share thisdocument with new residents.
- In the last paragraph in the Site Description and History section, it is stated thatresidences 1/2 mile north on Foss Road were to be provided municipal water. To date,no attempt has ever been made to connect residents on Foss Road to a municipal watersupply.
- The phrase "1/2 mile north on Foss Road" has been removed.
- Under the Groundwater Pathways subsection the sentence "There is a crock well locateda couple hundred yards southeast (downgradient) of the site which may becomecontaminated" is vague.
- The house where this crock well was has been demolished (30). Thus, it is unlikelyanyone is using the well. The following sentences have been deleted from thedocument: "There is a crock well located a couple hundred yards southeast(downgradient) of the site which may become contaminated. This well is reportedlyused for domestic uses other than drinking water (10). Exposure could therefore occurthrough the inhalation and dermal routes."