PETITIONED PUBLIC HEALTH ASSESSMENT
LAFARGE CORPORATION - ALPENA PLANT
ALPENA, ALPENA COUNTY, MICHIGAN
The primary benchmarks against which exposures are evaluated for their potential for causing non-cancer adverse health effects are the Minimal Risk Levels (MRLs), developed by ATSDR, and Reference Doses (RfDs) and Reference Concentrations (RfCs), developed by the U.S. EPA. It is generally accepted that a person exposed to a dose of a chemical less than an MRL, RfD, or RfC is not likely to experience noncancerous adverse health effects. The MRLs, RfDs, and RfCs are lower than the observed threshold exposures, with safety factors included to allow for different responses between species and between individuals. However, these values may not be protective for individuals who are hypersensitive to chemical exposures, including the very young, the very old, individuals whose bodies are under stress from illness, and individuals who have an allergic response to the chemical.
When MRLs, RfDs, and RfCs are not available, the threshold exposures may be used to evaluate the risk of actual exposure. The threshold exposures include Lowest Observed Adverse Effect Levels (LOAELs) and No Observed Adverse Effect Levels (NOAELs). In a given experiment, with exposure route, species, and health effect specified, the LOAEL is the lowest exposure at which an adverse effect was observed, and the NOAEL is the highest exposure at which no effect was observed.
For chemicals which may cause cancer, the risk is evaluated in a different manner from non-cancer health risks. As described above,(14) the risk of contracting cancer is generally presumed to have no threshold exposure levels. That is, any exposure to a cancer-causing chemical poses some increased risk of contracting the disease in one's lifetime. The risk from any exposure is estimated by multiplying the exposure by published potency factors. The potency factors are derived from laboratory or epidemiological data using various mathematical models to yield an upper bound for the actual risk, which might be much lower and even zero. For this assessment, the risk of cancer is considered significant if it is estimated that a lifetime exposure to the chemical under the circumstances specified would result in one extra case of cancer among 1,000,000 people exposed.
Exposure doses for this assessment are computed using the following standard assumptions (52):
- an adult weighing 70 kilograms (154 pounds) who drinks 2 liters (approximately 2 quarts) of water, incidentally ingests 100 milligrams of soil, and breathes in 23 cubic meters of air each day
- a 10-year-old child who weighs 30 kilograms (66 pounds), drinks 1 liter (approximately 1 quart) of water, incidentally ingests 100 milligrams of soil, and breathes in 15 cubic meters of air each day
- an infant weighing 10 kilograms (22 pounds) who drinks 1 liter (approximately 1 quart) of water, incidentally ingests 200 milligrams of soil, or, if subject to pica behavior,(15) deliberately ingests 5,000 milligrams of soil, and breathes in 3.8 cubic meters of air each day.
Exposure doses due to dermal absorption from soil are estimated using the standard exposure values for dermal exposure in Reference 52, Appendix D, Exhibit D.6, and the recommended absorption factor values from Reference 53.
The environmental concentrations used in these evaluations are the maximums found in each medium, a reasonably conservative assumption. For media in which data are available over a period of time, the maxima will be compared with acute and intermediate-term exposure MRLs. The medians over time will be compared with chronic exposure MRLs and RfDs and will be used to estimate cancer risks.
The concentration of benzene in the air samples collected during both sampling periods consistently exceeded the ATSDR CREG; however, they were less than the EMEG for intermediate-term exposure of 15-364 days (Table 12) (23, 24). The concentrations were within the range typically found in air in urban areas (Reference 46, Table 5-2), primarily due to evaporation from gasoline. The observed concentrations were considerably below the levels at which any adverse health effects have been observed in epidemiologic studies of humans or laboratory studies of animals (46).
The concentration of bromomethane in one sample collected from North Point on December 11, 1995, slightly exceeded the EMEG (or MRL) for chronic exposure, but not the EMEGs/MRLs for acute or intermediate-term exposure (both 190 µg/m3) (Table 12). Bromomethane was only found in samples collected on four sampling days out of a total of 78 in either sampling period (23, 24). Therefore, the documented potential exposure was for only a short period, and the intermediate-term exposure MRL is the appropriate standard. It is not likely that anyone would incur any adverse health effects from the bromomethane in the air. There is no evidence available linking bromomethane exposure to cancer (54).
Carbon tetrachloride was only occasionally found in the 1995-1996 samples; however, it was consistently found in the 1997-1998 samples at concentrations above the CREG but below the EMEGs for acute or intermediate-term inhalation exposure (there is no EMEG/MRL available for chronic inhalation exposure). The concentrations were within the range typically found in urban or rural areas. There are no natural sources for carbon tetrachloride. It is currently primarily made as an intermediate stage in the production of other chemicals. However, it was widely used in the past in household products such as cleaning fluids and pesticides. The chemical is highly volatile and breaks down very slowly in the environment. It is now found in the air all over the world whether there are nearby sources or not. The concentrations observed in the air in Alpena were considerably lower than those at which adverse health effects have been observed to occur (55).
The hepta-, and octachloro- dibenzodioxins and dibenzofurans found in many air samples in the 1995-1996 sampling are among the least toxic of the congeners, from 100 to 1,000 times less toxic than 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), considered the most toxic of the class. Only one sample, collected on April 15, 1995, at Lincoln School, contained 2,3,7,8-TCDD. However, the measured 2,3,7,8-TCDD concentration did not exceed the CREG. Toxicity Equivalency Factors (TEFs) are used to derive 2,3,7,8-TCDD Toxic Equivalents (TEQ) for the concentrations of dioxins and furans detected in the air. A TEQ is greater than the CREG for the sample collected on April 15, 1995 only (23). There are no specific data available on adverse health effects from inhalation of chlorinated dibenzodioxins and dibenzofurans. The CREG used in this document was derived from a U.S. EPA-published unit risk for inhalation of a mixture of hexachlorodibenzodioxins which was derived in turn from data on oral exposure of laboratory animals (56). Applying similar assumptions to these data indicates that the doses of dioxins and furans that people in Alpena would have experienced from breathing the air between March 1995 through March 1996 would not likely have equaled the MRLs for oral exposure and would have been much less than the doses at which adverse health effects have been observed in epidemiological studies of humans or laboratory studies of animals. Some people exposed to chlorinated dibenzofurans and some laboratory animals fed chlorinated dibenzodioxins developed liver cancer at increased rates. The U.S. EPA has classified mixtures of hexachlorodibenzodioxins as probable human carcinogens (U.S. EPA Class B2). The International Agency for Research on Cancer has determined that 2,3,7,8-TCDD can cause cancer in humans. The U.S. Department of Health and Human Services has determined that it is reasonable to expect that 2,3,7,8-TCDD can cause cancer (57, 58). However, because the documented exposure period to the most toxic dioxins was very short, any increased risk of contracting cancer from exposure to dioxins or furans in the air of Alpena is unlikely.
The maximum concentrations of chloroform, 1,2-dichloroethane, methylene chloride, 1,1,2,2-tetrachloroethane, trichloroethylene, and vinyl chloride found in these air samples exceeded their respective CREGs, though they did not exceed their EMEGs, RfCs, or LOAELs for non-cancer health effects (Table 12) (30, 59, 60, 61, 62, 63). Benzyl chloride, dibenzo(a,h)anthracene, 1,4-dichlorobenzene, and nickel were also detected at concentrations below their EMEGs, RfCs, or LOAELs for non-cancer health effects and are considered to be carcinogens, but there are no CREGs available for inhalation exposure (47, 56, 64, 65). However, all these chemicals only exceeded the CREGs, or were detected at all, in a very few samples collected during the two sampling periods (23, 24). The average concentrations were probably much less than the CREGs, and no resident of Alpena would be likely to incur any apparent increased risk of contracting cancer from their exposure to these chemicals in the air.
For other chemicals detected in the air of Alpena, there are no health standards available to evaluate the risk of adverse health effects from exposure by inhalation. There may be no data available relating inhalation of a chemical to adverse health effects. As described above for dioxins and furans, the health risks from inhalation of a chemical could be extrapolated from information on health effects from ingestion of the chemical. However, there are uncertainties about the relative efficiency of absorption through the lungs compared to the gastrointestinal tract.
Assuming that chemicals are absorbed from the lungs as efficiently as from the gastrointestinal tract, no one was likely to breathe in enough acenaphthene, anthracene, barium, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chlorobenzene, chrysene, 1,2-dichlorobenzene, dichlorodifluoromethane, fluoranthene, fluorene, indeno(1,2,3-c,d)pyrene, pyrene, 1,2,4-trichlorobenzene, trichlorofluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, or zinc from the air in Alpena between March 1995 through March 1996, or May 1997 through May 1998, (Table 12) to exceed ATSDR MRLs, U.S. EPA RfDs, or to incur any apparent increased risk of contracting cancer (23, 24,47, 56, 66, 67, 68, 69).(16)
There is no information available on the health effects from inhalation or ingestion of acenaphthylene, 1-ethyl-4-methylbenzene, 2-methylnaphthalene, perylene, phenanthrene, 1,2,4-trimethylbenzene, or 1,3,5-trimethylbenzene (31, 47, 56, 70).
The above discussion addresses the large number of airborne chemicals on an individual basis. People living in Alpena are likely to have been exposed to all or some of the chemicals simultaneously. The health effects from exposure to various mixtures might differ from the exposure to the individual chemicals, either in the magnitude of toxic response or in the type of response. The health risk from exposure to a mixture of chemicals that act on the body by similar mechanisms might be proportional to the total concentration of the mixture rather than the concentrations of the individual components. The health risk based on the total concentrations of several families of chemicals, such as PAHs and chlorinated straight-chain hydrocarbons (e.g., carbon tetrachloride, chloroform, 1,2-dichloroethane, and trichloroethylene), are estimated to be relatively low.
It is possible that chemicals might also interact and cause the following: increase the risk above that which was calculated by addition of individual chemical risks; decrease the risk; or, generate an adverse health effect that the individual chemicals do not produce. There is very little information available on such interactions.(13) The generally low concentrations of the chemicals found in the air in Alpena suggests that such synergistic or antagonisitc effects are not likely to occur. The molecules of the two chemicals are not likely to meet or reach the target organ within the time range necessary to produce the enhanced or subdued reaction.
Particulate matter in the air can cause inflammation of the lungs and aggravate asthma when inhaled. Very fine particles, such as those 2.5 µm and smaller, may pose a greater risk than larger particles. Some epidemiologic studies indicate that there is no threshold level for these effects, and that they may occur to some extent whenever there are particles in the air. There have been few direct studies of the health effects of air containing concentrations of particles similar to those found in Alpena. The conclusion that there is no threshold is based on data from studies of incidents of much higher particle concentration. The particle concentrations measured in Alpena air did not exceed the current U.S. EPA standards (49). The U.S. EPA has proposed a revision to the standards, specifically setting standards for fine particles smaller than 2.5 µm in diameter (50).
In addition, the available data for Alpena is total suspended particulates and particulate matter less than 10 µm in diameter. It is not possible to estimate the concentration of fine particles in the air from this data, beyond the obvious conclusion that the concentration of the particles smaller than 2.5 µm is going to be less than the total concentration or the concentration of particles smaller than 10 µm. The MDEQ plans to install a monitor to measure the concentration of particulate matter less than 2.5 µm in Alpena.
The analysis of the surface water samples collected from Thunder Bay at the shore of the CKD yielded distinctly different results between the total concentrations of metals in unfiltered samples and the concentrations of dissolved metals in filtered samples. The unfiltered samples contained a wide range of metals, some at concentrations above ATSDR Comparison Values and U.S. EPA MCLs. The only metal that was found in the filtered samples was aluminum, which was found at lower concentrations than in the unfiltered samples (Table 5). It appears that the majority of the metals found in the unfiltered samples were bound in the suspended particles which were removed by the filtering process. It can be argued that the dissolved concentrations are most relevant to human health considerations. The metals bound in the particles are likely to be in compounds that are not soluble in water, and therefore are not likely to be absorbed in the intestines should anyone drink the water. On the other hand, the stomach generates some fairly strong acid, which might leach out some metals that had remained in the particles and thereby liberate the metals for absorption. As a conservative assumption, we will consider exposures based on the total concentrations of the metals in the water.
The most likely exposure to the water directly offshore from the CKD pile is going to be recreational, boaters, anglers, swimmers, water skiers, and the like. Any ingestion of lake water by these people is going to be incidental and infrequent. They are not likely to ingest as much of any of the metals found in the water as has been observed to cause adverse health effects. The measured pH of the water from the bay did not exceed the level at which skin contact is considered hazardous (14).
The only known drinking water intake on Thunder Bay is approximately 3 miles southwest from the CKD pile. It is possible that there are other private intakes along North Point east of the CKD pile. These possible intakes would be 1 mile or more east of the CKD pile. It is likely that the metals at the CKD pile would be diluted and dispersed to below the MCLs before they would reach the possible intakes. In addition, the Thunder Bay River flows into the bay between the CKD pile and the Alpena municipal water system intake. The cross current from the river's flow is likely to help prevent water from the area of the CKD pile from reaching the municipal water intake.
Municipal Water System
On March 22, 1995, as seen in Table 17, the concentration of chloroform, and hence the total trihalomethane concentration, in Alpena city water exceeded both the MCL and ATSDR's EMEG for chloroform. The concentration of chloroform and other trihalomethanes in the water on other days was generally much lower than the MCL and EMEGs. A child drinking the water on March 22, 1995, might have ingested enough chloroform to slightly exceed the MRL for chronic exposure, though he or she would not be likely to ingest enough to exceed the acute or intermediate-term MRLs. No one would have been likely to ingest enough chloroform or other trihalomethanes from the city water to incur any adverse non-cancer health effects. A lifetime of drinking water containing the amounts of chloroform and other trihalomethanes found in Alpena city water is not likely to result in any apparent increased risk of contracting cancer (30, 32, 33).
No one is likely to ingest as much arsenic from the soil on the site as has been observed to cause adverse health effects.(17) A lifelong resident of Alpena might incidentally ingest enough arsenic from the soil to incur a low increased risk of contracting cancer (28). Nonetheless, arsenic in these soils is not considered a health hazard because it is unlikely that constant or even frequent contact with the localized areas of contamination will occur, especially since the area soils are usually covered with snow for several months of the year.
A child subject to pica behavior might ingest enough cadmium each day from the soil in some areas of Alpena to exceed the MRL for chronic exposure (there are no MRLs available for acute or intermediate-term ingestion of the metal). However, he or she would not be likely to ingest as much of the element as has been seen to cause adverse health effects in humans or animals. Some laboratory animals whose food contained high concentrations of cadmium developed cancer of the prostate or leukemia. There is some inconclusive evidence from studies of workers who breathed cadmium dust in their employment that links exposure to cadmium with cancer of the lungs and of other organs. Some laboratory animals who breathed air containing cadmium compound dusts developed lung cancer at higher rates than animals not exposed to cadmium. The U.S. EPA has classified cadmium as a probable human carcinogen (U.S. EPA Class B1). There is not sufficient information available about cadmium to evaluate the increased risk of contracting cancer after ingesting the element (71).
Chromium is found in the environment primarily in compounds, rather than as the pure metal. When chromium combines with other elements, it may end up in any of several oxidation or valence states, the most common of which are trivalent (or chromium(III)) and hexavalent (or chromium(VI)). Chromium in the trivalent state is an essential nutrient. Trivalent chromium compounds are practically nontoxic except when ingested in extremely large amounts. Exposure to the trivalent compounds has not been linked to cancer. Hexavalent chromium compounds can irritate the skin on contact, can irritate the respiratory tract when breathed in, and can damage the kidney and liver when ingested in large amounts. Workers who breathed hexavalent chromium compounds developed lung cancer more often than workers who were not exposed to the compounds. Trivalent chromium compounds are more common in the environment. Naturally-occurring chemical reactions tend to convert hexavalent chromium compounds to trivalent chromium compounds. The analyses cited in this assessment reported the concentrations of all chromium found in the samples, and did not distinguish between or identify the valence levels found. A child subject to pica behavior might ingest enough chromium from the soil in a day in some residential areas of Alpena to exceed the RfD for chronic ingestion of hexavalent chromium (there are no MRLs available for acute or intermediate-term ingestion of the metal). No one would be likely to ingest more chromium from the soil than has been observed to cause adverse health effects in epidemiologic studies of humans or laboratory studies of animals exposed to compounds of the metal in either valence state. It is not likely that anyone would come into contact with as much hexavalent chromium compounds in the soil in Alpena as has caused dermal reactions in humans or laboratory animals. There is not enough information available on chromium to evaluate the risk of developing cancer after ingesting hexavalent chromium (29).
No one is likely to ingest as much copper in a day from the soil in Alpena as has been seen to cause adverse health effects in epidemiologic studies on humans or laboratory studies on animals. Ingestion and other exposure to copper has not been linked to cancer (72).
After high concentrations of lead, up to 2,600 ppm, were found in soil samples collected on the Lincoln School grounds in late 1992 (Tables 8 and 10), that soil was removed and disposed of properly. The concentrations of lead in soil samples collected from residential areas of Alpena in other sampling rounds (up to 595 ppm, Tables 7, 8, 9) were similar to the concentrations typically found in smaller urban areas. The lead in these areas is generally attributed to the historic use of gasoline and house paints that contained lead. Some children living in areas where the lead concentrations in the soil are similar to those found in Alpena have been found to have elevated amounts of lead in their blood, bones, and other organs of their bodies. Children can ingest lead from several sources over the same time period. Soil lead levels in the range found in Alpena generally do not pose any health hazard unless interior house dust or paint in the child's residence also contain high concentrations of the metal. Because lead tends to accumulate in the body, many cities, counties, and states have programs to monitor the lead levels in the blood of children in areas where similar levels of lead might be expected in the soil or the housing is old enough that lead-based interior paint is likely to be present (51). The incidence of adverse health effects related to exposure to lead is not likely to be higher in Alpena than in other urban areas. The MDCH and the district health department serving Alpena both have programs in place to monitor children's blood lead levels and to address the potential health problems from childhood lead exposure.
The concentrations of mercury found in Alpena soil samples were within the range found in background soil samples in Michigan (15). There are no MRLs or RfDs available for ingestion of mercury in general, though there are comparison values for a few specific mercury compounds, including mercuric chloride, methylmercury, and phenylmercuric acetate. No one is likely to ingest enough mercury from the soil in Alpena to exceed the MRLs or RfDs for these mercury compounds. No one is likely to ingest or absorb through the skin as much mercury from the soil in Alpena as has been observed to cause adverse health effects in epidemiological studies of people or laboratory animal studies. Some laboratory animals whose food contained high concentrations of mercury compounds developed cancers of the stomach (mercuric chloride) or kidneys (methylmercuric chloride, phenylmercuric acetate). The U.S. EPA has classified methylmercury compounds as possible human carcinogens (U.S. EPA Class C) and has decided that inorganic mercury compounds are not classifiable as to their carcinogenicity (U.S. EPA Class D). There is not sufficient information available to evaluate the cancer risk from exposure to mercury (73). The incidence of adverse health effects related to exposure to mercury is not likely to be higher in Alpena than elsewhere in Michigan.
No one is likely to ingest as much nickel in a day from the soil in Alpena as has been seen to cause adverse health effects in epidemiologic studies on humans or laboratory studies on animals. Some workers in nickel refineries and sintering plants who breathed dusts and fumes containing nickel and nickel-containing compounds developed cancers of the lungs and nose. Some laboratory animals who breathed air containing nickel oxide or nickel subsulfide (Ni3S2) dust developed lung and adrenal cancer. The U.S. EPA has classified nickel refinery dust and nickel subsulfide as known human carcinogens (U.S. EPA Class A) by the inhalation route. There is not sufficient evidence available to determine whether ingestion of nickel or nickel compounds is related to cancer (64).
A child subject to pica behavior might ingest enough zinc each day from the soil in some areas of Alpena to exceed the MRL for non-cancer adverse health effects on chronic or intermediate-term exposure (there is no MRL available for acute exposure). However, he or she would not be likely to ingest as much zinc in a day from the soil as has been observed to cause adverse health effects in epidemiological studies of humans or laboratory animal studies over any duration. Zinc is also an essential nutrient. There is no evidence linking exposure to zinc with cancer (67).
Soils - Cement Kiln Dust pile
No one is likely to spend so much time on the cement kiln dust pile east of the Lafarge Alpena plant that they would incidentally ingest soil, absorb through the skin, or inhale fugitive dust containing so much of any of the metals found in the cement kiln dust which exceeds any health-based standards for any relevant term of exposure. No one is likely to be exposed to metals at levels of contaminants that have been observed to cause adverse health effects in epidemiologic studies of humans or laboratory studies of animals (28, 29, 31, 51, 56, 64, 67, 68, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80).
The very high alkalinity of the CKD, reflected in the high pH of water in contact with the material, can cause irritation and even corrosion of skin it comes into contact with when wet (14).
Thunder Bay Fish
To evaluate the potential human health hazards from consuming fish from Thunder Bay, we assume the maximum concentrations of the contaminants found (a conservative assumption) in edible-portion (fillet) samples, since humans rarely eat fish without cleaning them. Our standard meal will be 0.5 pound (227 grams) of fish, eaten 4 times a week to represent a person who uses the fish as a major part of their diet.
Several of the contaminants found in fish from Thunder Bay are considered probable human carcinogens: chlordane, chlorinated dibenzodioxins and dibenzofurans, and polychlorinated biphenyls (PCBs). As mentioned above, any exposure to a carcinogen is usually presumed to increase one's risk of contracting cancer by a finite amount, and health agencies frequently differ as to what increased cancer risk is considered acceptable or how the risk is to be calculated. A person who follows the MDCH Sportfish Consumption Advisories might ingest as much of these carcinogenic contaminants as the ATSDR considers to pose a "moderate" increased risk of contracting cancer (57, 58, 81, 82).
A person eating Thunder Bay catfish as a major portion of their diet might ingest enough chlordane to exceed the MRLs for non-cancer adverse health effects on acute, intermediate-term, or chronic exposure, although they would not be likely to ingest as much chlordane has been observed to cause adverse health effects in epidemiologic studies of humans or laboratory studies of animals. Some laboratory animals whose food or water contained chlordane developed liver cancer. The U.S. EPA has classified chlordane as a probable human carcinogen (U.S. EPA Class B2). A lifetime of subsistence eating of fish containing the chlordane concentration found in Thunder Bay catfish might result in a high increased risk of contracting cancer (81).
A person eating lake trout or lake whitefish from Thunder Bay (or from anywhere in Lake Huron) as a major portion of their diet might ingest enough chlorinated dibenzodioxins and dibenzofurans to exceed the MRLs for non-cancer adverse health effects on intermediate-term or chronic exposure, although they would not be likely to ingest as much of the chemicals as has been observed to cause adverse health effects in epidemiologic studies of humans or laboratory animals. Some laboratory animals whose food or water contained chlorinated dibenzodioxins developed cancers of the liver, thyroid, lung, and palate. The U.S. EPA has classified chlorinated dibenzodioxins as probable human carcinogens (U.S. EPA Class B2). A lifetime of subsistence consumption of lake trout or lake whitefish from Thunder Bay, or anywhere in Lake Huron, might result in a high increased risk of contracting cancer from the chlorinated dibenzodioxins ingested (57, 58).
Mercury in fish is most likely to be in an organic compound. A person eating smallmouth bass, walleye, or catfish from Thunder Bay or Lake Besser as a major portion of their diet might ingest enough mercury to exceed the MRLs for adverse non-cancer health effects from acute or intermediate-term ingestion of organic mercury compounds (there is no MRL for chronic ingestion available), although they would not be likely to ingest as much of the metal as has been observed to cause adverse health effects. Some laboratory animals whose food contained high concentrations of mercury compounds developed cancers of the stomach (mercuric chloride) or kidneys (methylmercuric chloride, phenylmercuric acetate). The U.S. EPA has classified methylmercury compounds as possible human carcinogens (U.S. EPA Class C) and has decided that inorganic mercury compounds are not classifiable as to their carcinogenicity (U.S. EPA Class D). There is not sufficient information available to evaluate the cancer risk from exposure to mercury (73).
A person who eats channel catfish or carp from Thunder Bay might ingest as much PCBs each day, body weight for body weight, as has been observed to affect the immune system, liver, blood, and the development of the young in laboratory animals whose feed contained PCBs for a year or more. A person who follows the consumption advisories in the last column of Table 2 would not be likely to ingest enough PCBs to exceed the MRLs or RfD for non-cancer adverse health effects. Some laboratory animals whose feed contained PCBs developed cancer of the liver. The U.S. EPA has classified PCBs as probable human carcinogens (U.S. EPA Class B2). A person who eats catfish from Thunder Bay as a major part of his diet for his lifetime might ingest enough PCBs to incur a very high increased risk of contracting cancer (82).
As shown in Table 1, approximately 25% of the population of Alpena was under 17 years of age and approximately 6% was under 4 years of age according to the 1990 U.S. Census. These children are included in the population considered in the "Soil - Alpena residential," "Ambient Air," and "Surface Water - Municipal Water" exposure pathways.
Children can be particularly vulnerable to environmental toxicants. Some unique vulnerabilities of children to environmental toxicants in general are discussed below.
Before birth, children are forming the body organs that need to last a lifetime. This is the time when chemical injury may lead to serious adverse health effects. Injury during key periods of growth and development may lead to malformation of organs (teratogenesis), disruption of function, and premature death. Exposure of the mother may lead to exposure of the fetus, via the placenta, or may affect the fetus because of injury or illness sustained by the mother (83).
After birth, children may have greater exposures to environmental toxicants than adults. Pound for pound of body weight, children drink more water, eat more food, and breathe more air than adults. For example, children in the first 6 months of life drink 7 times as much water per pound as the average adult living in the United States. Two characteristics of children further magnify their exposures to toxicants in the environment: (1) play activities close to the ground, which increase their exposure to toxicants in dust and soil plus toxicants in airborne particulate matter, and (2) typical hand-to-mouth behavior, which increases intakes of any toxicants. In addition, teenagers may accidentally wander or deliberately trespass onto or into restricted locations. The obvious implication for environmental health is that children can experience substantially greater "doses" than adults to toxicants that are present in soil, water, or air. This fact has been demonstrated very clearly for children's exposures to pesticides in the diet (83).
Lead and mercury, two chemicals of concern in this assessment, have been seen to interfere with the neurological and mental development of young children. The documented concentrations of lead and mercury in the soil in Alpena (Tables 7, 8, 9) are comparable to those typically found in urban areas (51, 73). The MDCH and the district health department serving the city have programs in place to monitor the levels of lead in children's blood and to address the potential health effects from exposure to lead.
In 1993, in response to a request from the Health Officer and Medical Director of the District Health Department serving Alpena County, the Michigan Department of Public Health Division of Health Statistics reported that the total rate of death from cancer of all kinds in Alpena County during 1991 was not significantly higher than the rate in the State as a whole (84). Data from 1992-1994 supports this conclusion (85). This very preliminary analysis is limited, because it is based on only one or a few years of data. Countywide statistics may not identify more localized areas where cancer incidence may be high, and statistics on the rates of incidence of cancer may not identify specific kinds of cancer that may occur at high rates.
Residents of the City and the County of Alpena have expressed concern about the occurrence of cancer, asthma, and birth defects, among other adverse health effects, in their communities. The MDCH, Environmental Epidemiology Division, Site Assessment Section obtained Alpena health outcome data from the MDCH Division for Vital Records and Health Statistics (Vital Records). Vital Records compiled cancer incidence data from the Michigan Cancer Registry and mortality data from the Michigan Resident Death Files. In addition, Vital Records compiled asthma-related hospitalization data from the Michigan Inpatient Database and birth defect data from the Michigan Birth Defect Registry. They provided data for Alpena County as a whole and for the postal ZIP code that contains the City of Alpena (49707).
MDCH Vital Records Division provided the numbers of cases of cancer and deaths involving cancer occurring in 20 commonly-affected organs between 1985 through 1995 in both Alpena County and the zip code that contains the City of Alpena (49707). The numbers of cases and deaths were compared with those that occurred in the State of Michigan over the same period, adjusting for the population, age, sex, and racial characteristics of the county or ZIP code area. The ratios between the numbers of cases or deaths that were found to those which are found in a similar population in the state as a whole are referred to as the standardized incidence ratios (SIR) and the standardized mortality ratios (SMR), respectively.
The SIR and SMR calculations showed that incidence and mortality rates for cancers of 20 commonly-affected organs did not increase over time and were generally less in Alpena County than in the State of Michigan as a whole during the time period. However, the occurrence of cancers of the rectum or cervix did appear to be more frequent in the county during part of the time under investigation. The SIRs for rectal cancer in the county or ZIP code were statistically significantly above 1.0 in 1986 and 1987. During 5 other years, the SIRs for rectal cancer exceeded 1.0 but were not of statistical significance. MDCH Vital Records Division reviewed the records and determined that the apparent incidence of these cancers was falsely elevated due to misdiagnoses during those years. Colon cancers are commonly misdiagnosed as rectal cancers. Therefore, rectal and colon cancers are often combined into one category for investigation purposes. Despite the difficulty of misdiagnosis, the MDCH Vital Records will monitor rectal cancer SIRs for Alpena County annually. Colorectal cancer SIRs and SMRs in Alpena County and ZIP code 49707 were significantly greater than 1.0 during 1987 only, and did not increase over the eleven-year period.
Alpena County and ZIP code 49707 SIRs for cervical cancer were significantly greater statistically than 1.0 during 1985 and 1988 only, and showed no significant trends over the period. MDCH Vital Records Division reviewed the records and determined that the reported incidences of these cancers were also inflated due to misdiagnosis. Pre-invasive cervical disease is frequently misdiagnosed as cervical cancer. The SIRs were not significantly above 1.0 during any year using the corrected statistics.
Analysis of cancer incidence and mortality data does have limitations. The Michigan Resident Death Files and the Michigan Cancer Registry data from before 1985 are not as reliable as later data. Therefore, time trends in cancer incidence and mortality cannot be determined before 1985. Also, for uncommon cancers, SMRs or SIRs can be greater than one but not statistically significant. This makes it difficult to decide if certain elevated SMRs or SIRs are associated with environmental exposures or are due to chance alone.
The 1996 asthma-related hospitalization rate for Alpena County residents was lower than the 1996 hospitalization rate for residents of the entire State of Michigan. The rate was lower for county residents than in the state as a whole for each age group: 0-14 years, 15-44 years, 45-64 years, and 65 years and older. The data from the Michigan Inpatient Database is categorized by the home address of the patient and not by location of the hospital. Therefore, hospitalizations of Alpena County residents outside Alpena County are still attributed to Alpena County.
Analysis of asthma-related hospitalization data also has limitations. Asthma-related hospitalizations are dependent on many variables other than environmental exposures. Physicians from various geographical locations differ in their definition and treatment of asthma, and their tendency to hospitalize patients with asthma. This results in variable hospitalization rates due to case management rather than environmental exposures.
The number of Alpena County residents born from 1992 through 1996 who were diagnosed with one or more specified defects before their second birthday was compared with the number of similar birth defects that occurred over the same time period in a population of similar size, maternal age, and sex of white Michigan residents. Again, if the ratio of observed to expected birth defects is approximately equal to 1.0, the specific birth defect or group of birth defects does not occur more or less frequently in Alpena County than in the State of Michigan as a whole. A ratio of observed to expected birth defects greater than 1.0 indicates that the birth defect or group of birth defects was more common in Alpena County than in the State of Michigan as a whole. Similarly, a ratio of observed to expected birth defects that is less than 1.0 indicates the birth defect or group of birth defects was less common in Alpena County than in the State of Michigan as a whole. All reportable birth defects combined and all reportable congenital anomalies combined were less common in Alpena County residents than in residents of the State as a whole. Each reportable anomaly, classified by organ system, and each specific major congenital anomaly either did not occur at all, was less common, or was only slightly more common, but not beyond chance occurrence, in the county than in the state over that time period.
Analysis of birth defect data has limitations similar to those of cancer data. The Michigan Birth Defect Registry was established in 1992. Therefore, trends in birth defect numbers and rates cannot be determined before 1992. Also, because birth defects occur infrequently, elevations in birth defect numbers are seldom statistically significant. This makes it difficult to determine if certain elevated birth defect numbers or rates are associated with environmental exposures or are due to chance alone.
The available health outcome data does not indicate any readily apparent increases of cancer, asthma, or birth defects in Alpena County compared against the State of Michigan as a whole. The incidence of rectal cancer in the county appeared to be high in 2 years, 1986 and 1987, of the 11 years investigated. It can be difficult to distinguish colon cancers from rectal cancers, and medical statisticians and researchers prefer to combine statistics on the two cancer sites. The MDCH will monitor the SIRs for rectal, colon, and colorectal cancer in the county annually.
A large number of health and environmental concerns have been voiced by community members. The following is a summary of some of these concerns (in bold face) followed by MDCH's response. Each concern is listed once; however, some have been expressed as a concern by more than one member of the Alpena community. Other community concerns, as listed in the "Community Health Concerns" section above, will be addressed in future sections of this Public Health Assessment.
Lafarge and other Local Industry
Several concerns have been expressed about the possible harmful contents of the fill material historically provided free of charge to Alpena citizens by Abitibi (now ABT Co.). Citizens have voiced concern that the fill contained fly ash and heavy metals including lead. The possibility of lead poisoning, especially in children, has been raised by the citizens. There may be no complete or accurate record of where in the Alpena area the Abitibi fill material was used, raising concerns about whether all the potentially affected individuals could be identified. Preliminary analysis of data on Abititi fly ash (Table 11) found that though it contained high concentrations of lead compared to the background, the lead concentrations were not of public health concern. The ash did contain arsenic concentrations at levels of public health concern. MDCH will address the health concerns more fully in a separate Health Consultation.
In a comment on the Health Consultation, a citizen noted, "Thunder Bay Manufacturing is not listed in the chart on page RS-15 [of the Health Consultation (Reference 2)]. It is a source of methanol . . . Please refer to toxic release inventories to determine what Thunder Bay Manufacturing contributes to the toxic chemicals in Alpena's air."(8) Our original search of the U.S. EPA's Toxic Chemicals Release Inventory (TRI) database through the Right to Know Network did not return any reports from Thunder Bay Manufacturing in Alpena. A later search using the Environmental Defense Fund Scorecard World Wide Web site provided the information needed to locate these reports, which are summarized in Table 4 (12, 86).
One concern about the HCl released from Lafarge is that it might combine with formaldehyde from other plants to form phosgene gas (8). We have investigated this possibility, and have found that any phosgene generated by a reaction between hydrogen chloride and formaldehyde in the atmosphere is not likely to contribute any significant increased health risk. Thermodynamic considerations predict that only a very small amount of phosgene would be produced by that mechanism. The reaction between formaldehyde and hydrogen chloride to form phosgene and hydrogen:
2HCl + H2CO > 2H2 + Cl2CO
is very endothermic at room temperature, that is, the reaction must absorb energy to occur. The reverse reaction is somewhat more likely to occur, and the ultimate, equilibrium state is going to favor HCl and formaldehyde over phosgene and hydrogen by a significant amount. The final phosgene concentration would be roughly one-millionth that of the hydrogen chloride. That is, if the initial concentration of HCl was 1 part per million (ppm) and the initial concentration of formaldehyde was 0.5 ppm, there would be approximately 1 part per trillion phosgene and 2 parts per trillion hydrogen produced. The OSHA standard for workplace exposure to phosgene is 0.1 ppm, and 2 ppm phosgene in the air is considered Immediately Dangerous to Life and Health (87). The equilibrium phosgene concentration under the conditions cited is approximately 100,000 times lower than the OSHA workplace standard. To produce a phosgene concentration of even 1 per cent of the OSHA workplace standard (0.001 ppm) requires a HCl concentration of at least 1,000 ppm or a formaldehyde concentration of at least 500 ppm, substantially above the levels of Immediate Danger to Life and Health (HCl - 50 ppm, formaldehyde - 30 ppm ).
A great deal of concern has been expressed about perceived elevated rates of cancer for the general community and for those employed by local industries (2). See above under "Health Outcome Data Analysis" for a preliminary evaluation of the available data on cancer incidence and mortality. More complete and thorough evaluation of available cancer data will be carried out as the Public Health Assessment process continues.
Concerns have been expressed that the State of Michigan Cancer Registry may not capture the number of cancer cases in Alpena because many people have sought treatment outside of the area. The MDCH cancer registry does collect information on the residences of the patients. Its county and health district incidence and mortality statistics are based on the usual place of residence of the patients, and not on the location of their treatment. There are limits to the reliability of the reports, as stated in MDCH, Cancer Incidence and Mortality, Michigan 1994, p. 55:
It is not possible to accurately estimate the completeness of case ascertainment by county. Consequently, it is recommended that county and health district comparisons of incidence data should be attempted with caution. Observed differences between counties may be the result of factors other than a true difference in incidence, including: . . . the lack of universal interstate and provincial exchange agreements with most states and Canada to permit the sharing of data. Michigan has developed exchange agreements with Wisconsin, Illinois, Florida, New York, Pennsylvania, California, Ohio, and Indiana under which cases among Michigan residents reported to these registries are forwarded to and added to the Michigan registry of cases. This exchange with the other states resulted in improved reporting generally throughout the state (85).
It can also be noted that the cancer incidence and death rates in Emmet, Saginaw, Washtenaw, or Wayne Counties, the locations of major hospitals that attract patients from Alpena seeking advanced treatment, were not significantly higher than the rates in Michigan as a whole in 1992 through 1994 (85).
More complete and thorough evaluation of available cancer data will be carried out as the Public Health Assessment process continues.
Other Symptoms and Diseases
Citizens have expressed the concern that there may be elevated rates of Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder (ADD/ADHD), Lupus, Multiple Sclerosis (MS), amyotrophic lateral sclerosis (ALS, also known as "Lou Gehrig's Disease"), and Parkinson's Disease in the community, and that these conditions may be related to contaminants in the environment. Some scientists believe that toxins in the environment may disrupt the development of brain processes, which may lead to ADHD. Lead is one such possible toxin. Some animal studies suggest that children exposed to lead may develop symptoms associated with ADHD, but only a few such cases have been found (88). It is wise to use caution when considering why any individual or group has ADD/ADHD, because very little is known about what actually causes ADD/ADHD. There are too many possibilities to determine any single cause and more research is needed.
Several studies have found that exposure to various environmental contaminants might contribute to the development of Parkinson's Disease. No contaminant has yet been firmly identified as a cause, however (89).
According to current research, neither lupus nor MS has been linked to environmental contaminants, though the causes of both diseases are not known. Research is going on to identify the causes of these diseases (90, 91). There is a high incidence of ALS in Guam and Japan, suggesting that the disease might be related to an environmental toxin. No toxin has yet been connected to any case of ALS; however, the fact that the incidence of ALS is uniform elsewhere in the world tends to argue against an environmental cause. The cause of ALS is also not known at this time, though research is going on to identify the cause or causes (92, 93). Additional information will be made available in the site repository at the Alpena Public Library. Information on ADHD, ALS, Lupus, and Parkinson's Disease may be obtained through the World Wide Web sites listed in the Reference list (88, 89, 90, 92, 93).
Students at one Alpena school are perceived to experience a large number of incidents of seizure disorders. Alpena Public Schools nursing staff have told MDCH staff that they have also noticed an increased incidence of seizure disorders in the last two years among the students at the school in question. They have also observed that the number of students treated for asthma and upper respiratory infection has increased over the past 5-6 years with a concomitant increase in asthma attacks (94).
MDCH is evaluating the relationship between environmental contaminants and asthma or seizure disorders.
More complete and thorough evaluation of available data on other health effects will be carried out as the Public Health Assessment process continues.
- The fact that children are more susceptible to chemical exposures was identified as a major concern. ATSDR and MDCH share the citizens' concern that children are more susceptible to chemical exposures. The section "ATSDR Child Health Initiative" above addresses these issues.
- Concerns over rumors of napalm being transported to Alpena to be burned in Lafarge's kilns have been raised. According to all available information, these were only rumors, and there were never any documented plans by anyone to burn napalm in the Lafarge kilns.
- Concerns about declining game fish in Thunder Bay and the Thunder Bay River have been expressed. According to MDNR Fisheries Division staff, fish populations in Thunder Bay are generally very strong. The populations of some species are at relatively low levels, largely attributed to natural cycles and interspecies competition. The CKD pile might have buried a prime spawning ground for yellow perch, although it is but one place around the bay where wetlands that perch spawn may have been filled. Whitefish also spawn on a reef within a couple of hundred yards from the CKD pile, and they might take up contaminants from the pile (10).
- The MDCH has issued an advisory that people should strictly limit their consumption of lake trout taken from Lake Huron (see Table 2 for details), in part because of dioxin contamination (9). This dioxin might come in part from the Lafarge plant, although there have been several other documented or potential sources of the contaminants within the watershed of the lake. The contaminants relatively recently appeared in the fish. People in Alpena perceive that this appearance coincided with the first burning of hazardous waste in the Lafarge kilns (10). Lake trout and lake whitefish collected from the entire length of Lake Huron contain similar concentrations of chlorinated dibenzodioxins and dibenzofurans (all generally referred to as "dioxins"). The oldest dioxin analysis from Thunder Bay on record (date not available, between 1983 and 1988) found higher concentrations of dioxins than did later analyses of similar samples (Table 20) (35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45). There are other locations where dioxins have been found in the environment within the Lake Huron watershed from potential sources other than Lafarge. Lafarge may not be the only possible source of dioxins in the Alpena area. On the days when relatively high concentrations of dioxins were detected in the air at Lincoln School, the wind was from the northwest to west or southeast, not from the direction to the plant from the school (east northeast) (95).
- Concerns over adverse impact of environmental contaminants on garden plants have been raised. No direct sampling of plants in the Alpena area has come to MDCH's attention. The soil in residential areas of the city has been found to contain several metals, including antimony, arsenic, barium, beryllium, cadmium, copper, lead, manganese, mercury, nickel, and zinc (Tables 7, 8, 9). Many of these occur naturally in the environment or can be traced to the combustion of fossil fuels. Cadmium is the most mobile of these metals in an aqueous environment and, therefore, the most likely to be absorbed and accumulated by plants. The cadmium concentration in the soil of Alpena residential areas ranged from not detectable to 2.8 ppm. While the maximum concentration is higher than the natural soil concentrations, generally less than 1 ppm with an average of 0.4 ppm (71), it is not so much higher that the plants in the area would be likely to accumulate enough cadmium to pose a health risk.
- Many concerns related to the health of domestic and wild animals, including contaminated Bald Eagle eggs at South Point, have been raised.
MDCH has passed the citizens' concerns about wild animals, birds, and fish on to the Michigan Department of Environmental Quality and Michigan Department of Natural Resources. We will discuss with them the interrelationships between the conditions of wildlife and of human health in the same area.
The MDCH has begun to address and investigate the other concerns expressed by the citizens of Alpena, and will report any and all future findings in future documents updating this Public Health Assessment. An information repository has been established at the Alpena Public Library. In addition to the information contained in this Health Assessment, MDCH fact sheets on hydrogen chloride and cancer clusters, and information about ADD/ADHD, lupus, and MS have been placed in this repository.