ND = Chemical not detected                  µg/L = micrograms per liter
¹ = Noncancer Screening Level calculated by ODH
² = U.S.EPA Maximum Contaminant Level
³ = Cancer risk Guide calculated by ODH
⁴ = U.S.EPA Action Level
Those in bold exceeded screening levels.

TABLE 4
1984, 1985, & 1987 OFF-SITE GROUNDWATER MONITORING WELL DATA

A. Toxicologic Evaluation

There is often little information about the health effects caused by low level environmental exposures. Most human exposure studies use information from industrial exposures, where the doses are much higher. Industrial exposure data normally do not include precise information about the dose, the purity of the chemicals, their interactions with other substances, and the duration of the exposure. For some chemicals, there is no information available on the effects in people therefore, we use data collected from studies using laboratory animals. Animals do not necessarily show the same responses that humans do when exposed to toxic substances. However in animal experiments using carefully controlled doses and time periods, researchers observe health effects that they believe may also occur in people.

In order to compare the amounts of a substance that may be taken into the body to known standards, this section uses comparison doses. These doses are based on the amount of a substance that is consumed per day (milligrams/kilogram body weight/day, mg/kg/day). Comparison doses used in this section include the ATSDR Minimum Risk Level (MRL), which represents an estimate of daily human exposure to a dose of a chemical that is likely to be without adverse effects (for noncancerous effects) over a specified duration of exposure, and the U.S.EPA Reference Dose, which is an estimate of the daily exposure of people to a potential hazard that is likely to be safe during a lifetime (that does not include cancer). These doses represent levels at which harmful effects are unlikely to occur. They are calculated using safety factors for the most sensitive human populations, and if based upon animal measurements, additional factors are used.

The pathways and potential pathways of exposure to chemicals at the MCI Superfund site are through the water supply and surface soil. People can be exposed directly by drinking contaminated water. Most of the chemicals can evaporate from water. People who are exposed to contaminated water may also be breathing air that has been contaminated during such activities as cooking, bathing, and washing dishes.

Tetrachloroethene (PERC)

Two private wells and on-site monitoring wells were contaminated with maximum concentrations of tetrachloroethene at 15 and 130 µg/L, respectively. There are no data to indicate that people are currently being exposed to PERC, however some wells haven't been sampled since 1985. By 1992, most of the area residents with contaminated wells were provided with public water. People can be exposed to PERC by drinking contaminated water, inhaling vapors released from water during household use, and coming in contact with the water through showering.

If a homeowner with PERC in his/her well were to drink two liters of this water a day for most of his/her life, the estimated dose would be much lower than the point at which health effects are likely to occur. If a person were to drink two liters of water containing the highest level of PERC found on site for their entire life, the estimated dose would still be lower than the point at which health effects are likely to occur. The exposure should not cause health problems or increase the risk of developing cancer. This estimated dose does not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use.

PERC has a sharp, sweet odor (dry cleaner's odor), which most people can begin to smell when it is present in the air at a level of 1000 µg/m³ or more and when it is in water at 300 µg/L. People would not have been able to smell it at the levels found in private or commercial wells. PERC can enter your body when you drink water, or breath air containing it. Most of it leaves your body rapidly when you breath it out. A small amount stays in your body tissues and some of this can be changed into other chemicals that may also be harmful.

The health effects to people of breathing air or drinking water with low levels of PERC are however, unknown. PERC in drinking water in combination with other VOCs has been associated with childhood leukemia, deaths around the time of birth, childhood disorders, recurrent infections, respiratory disorders, and congenital abnormalities (Lagakos, 1986 and Byers et al., 1988). These studies, however, did not provide sufficient evidence that PERC causes these harmful health effects, because the people were exposed to more than one chemical simultaneously. It is difficult to determine which chemical or combination of chemicals would be associated with the various adverse effects. Moreover, information on other risk factors for these adverse effects was not included in this study. The people in this study could have been exposed for ten years or longer.

1,2-Dichloroethene (1,2-DCE)

Private wells and on-site monitoring wells contained DCE up to 350 and 2,500 µg/L, respectively. Seven private wells contained DCE. Off-site monitoring wells also contained high levels of DCE. By 1992, most area residents with contaminated wells were provided with public water and there are no data which indicate that people are currently being exposed to DCE. People can be exposed to DCE by drinking contaminated water, inhaling vapors released from water during household use, and coming in contact with the water through showering. DCE is found in two chemical forms, a cis- and a trans- form (termed an isomer).

If a person were to drink two liters of this groundwater containing the highest level of DCE found on site for their entire life, the estimated dose for children (0.16 mg/kg/day) and adults (0.07 mg/kg/day) would be higher than the U.S.EPA reference dose of 0.009 mg/kg/day for mixed isomers of DCE. The estimated doses for exposure to DCE in the residential wells (0.02 mg/kg/day for children and 0.01 mg/kg/day for adults) would also be above the reference dose. This reference dose is based on an animal study where changes in the liver and in the blood occurred after exposure (McCauley et al., 1990, Baines et al., 1985). We cannot say with any certainty that people exposed to DCE would experience liver or blood changes, but that they could be at risk of these effects if they were exposed. Reference doses are an estimate of daily exposure to the chemical that is likely to be without adverse health effects. The estimated doses do not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use. DCE levels were also higher than the U.S.EPA MCL.

There are no human data available for either short- or long-term exposure to 1,2-DCE. A recent animal study has suggested that a fetus exposed to 1,2-DCE may not grow as rapidly as one that is not exposed. One of the most sensitive effects of 1,2-DCE in animal experiments is blood changes. Low concentrations of 1,2-DCE, in drinking water in combination with other VOCs, have been associated with congenital mouth and nervous system defects (Bove et al., 1992), and childhood leukemia, deaths around the time of birth, childhood disorders, congenital abnormalities, recurrent infections, and with heart disease (Lagakos, 1986; Byers et al., 1988; and Goldberg, 1990). These studies, however, do not provide sufficient evidence that 1,2-dichloroethene causes these adverse health effects, because the people were simultaneously exposed to more than one chemical. It is difficult to determine which chemical or combination of chemicals would be associated with the various adverse effects. Moreover, information on other risk factors for these adverse effects was not included in these studies.

1,2-DCE is a flammable liquid with a sharp, harsh odor. It evaporates rapidly and part of it may break down into vinyl chloride, which is a more hazardous chemical. You can begin to smell it at 17,000 µg/L. People that had contaminated wells would not have been able to smell DCE. DCE can enter your body through your digestive tract if one drinks contaminated water, through your lungs if it is in the air, and through your skin if one come into contact with it.

1,1-Dichloroethene (1,1-DCE)

There were two private wells that contained 1,1-DCE, with the highest concentration at 7.5 µg/L. By 1992, most area residents with contaminated wells were provided with public water and there are no data which indicate that people are currently being exposed to DCE. People can be exposed to 1,1-DCE by drinking contaminated water, inhaling vapors released from water during household use, and coming in contact with the water through showering.

If the homeowner were to drink two liters of this water a day for their entire life, the estimated dose for children (0.0005 mg/kg/day) and adults (0.0002 mg/kg/day) would be lower than the point at which health effects are likely to occur. The exposure should not cause health problems or increase the risk of developing cancer. This estimated dose does not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use.

No information is available on the health effects in humans who ate food or drank water that contained low doses of 1,1-DCE. The lowest drinking water concentrations associated with noncancer effects in animal studies, which were much higher than the levels found at MCI, resulted in effects on the liver. Animals that consumed much higher concentrations of the substance than found at this site, experienced liver and kidney effects (ATSDR, 1992).

Because 1,1-DCE is volatile, people can be exposed through breathing vapors released from the water during showering and cooking. Animal studies show that inhaled 1,1-DCE can affect the liver, kidneys, and lungs. Breathing exposure of pregnant female rats to 1,1-DCE resulted in birth defects in the offspring (ATSDR, 1992).

1,1-DCE, is a colorless manufactured liquid that evaporates quickly at room temperature and has a mild, sweet odor. It can easily enter the body through the stomach and intestines when people drink contaminated water, through the lungs when people breath contaminated air, and through the skin. Within a few hours of exposure, 1,1-DCE begins to leave the body through the lungs. The remaining 1,1-DCE breaks down in the body into other substances that leave in the urine within 2 days. Some of these breakdown products are more harmful than the original 1,1-DCE.

Trichloroethene (TCE)

There were six private wells that contained TCE. Concentrations were very low ( less than 3.0 µg/L) and did not pose a risk to those people who drank this water. By 1992, most area residents with contaminated wells were provided with public water and there are no data which indicate that people are currently being exposed to TCE. People can be exposed to TCE by drinking contaminated water, inhaling vapors released from water during household use, and coming in contact with the water through showering.

If a person were to drink two liters of this groundwater containing the highest level of TCE found on site for their entire life, the estimated dose for children (0.004 mg/kg/day) and adults (0.002 mg/kg/day) would still be lower than the point at which health effects are likely to occur. The exposure should not cause health problems. The dose estimate does not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use.

The principal target organs of TCE in both humans and animals are the bone marrow, brain, spinal cord, liver, and kidney. TCE in drinking water in combination with other VOCs has been associated with congenital mouth and nervous system defects and very low birth weight (Bove et al., 1992), and childhood leukemia, deaths around the time of birth, childhood disorders, and congenital abnormalities (Lagakos, 1986). TCE has also been associated with leukemia and recurrent infections (Byers et al., 1988), and heart disease (Goldberg, 1990). These studies, however, did not provide sufficient evidence that TCE causes these harmful health effects, because the people were exposed to more than one chemical simultaneously. It is difficult to determine which chemical or combination of chemicals would be associated with the various adverse effects. Moreover, information on other risk factors for these adverse effects was not included in this study.

1,1,1-Trichloroethane (1,1,1-TCA)

TCA has been detected in ten private wells near the site. Public water was supplied to most area residents by 1992 and there is no evidence that people are presently being exposed to 1,1,1-TCA. If the off-site homeowner with the highest level were to drink two liters of this water a day for their entire life, the estimated dose for children (0.003 mg/kg/day) and adults (0.001 mg/kg/day) would be much lower than the point at which health effects are likely to occur and should not pose a risk to the people who drank this water. The estimated dose did not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use.

If a person were to drink two liters of water containing the highest level of TCA (1,300 µg/L) found on site for their entire life, the estimated dose for children (0.08 mg/kg/day) and adults (0.04 mg/kg/day) would be slightly higher than the reference dose of 0.09 mg/kg/day. The estimated dose did not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use. If people were to drink water with this amount of TCA in it, there is a slight risk of developing adverse health effects. One must keep in mind that they would have to drink water with this amount in it every day for their entire lives which is not likely to occur.

1,1,1-TCA is a colorless manufactured liquid with a sweet, sharp odor that most people can detect when it reaches levels of 120,000 to 500,000 micrograms per cubic meter (µg/m³) in the air. People could not detect it at the levels found in the groundwater at the site. It has many household and industrial uses. It can enter your body if you breathe in air or drink water containing it. Most of it quickly leaves your body through your lungs, but a small amount is broken down into other substances. Most of these leave your body in a few days, but some may collect in your fat tissue.

If a person consumed levels much higher than this level in the drinking water, this person might experience digestive symptoms. 1,1,1-TCA in drinking water in combination with other VOCs has been associated with developmental defects of the heart (Bove et al., 1992). These studies, however, did not provide sufficient evidence that 1,1,1-TCA causes these harmful health effects, because the people were exposed to more than one chemical simultaneously. It is difficult to determine which chemical or combination of chemicals would be associated with the various adverse effects. Moreover, information on other risk factors for these adverse effects was not included in this study. The people in this study could have been exposed for ten years or longer.

Toluene

Toluene was found in only one residential well, two commercial wells, and the on-site potable water well, and in several on-site monitoring wells. Public water was supplied to most area residents by 1992 and there is no evidence that people are presently being exposed to toluene. If the homeowner were to drink two liters of this water a day for their entire life, the estimated dose for children (0.02 mg/kg/day) and adults (0.008 mg/kg/day) would be lower than the point at which health effects are likely to occur (0.2 mg/kg/day). If people working on the site were to drink two liters of water from the on-site drinking water well (18,000 µg/L) for five days a week for 25 years, the estimated dose 0.1 mg/kg/day would be slightly lower than the reference dose. Neither of these exposure scenarios should result in health problems because of exposure to contaminated drinking this water.

However, if a person were to drink on-site water for a lifetime, the doses for children (1 mg/kg/day) and adults (0.5 mg/kg/day) would be higher than the reference dose of 0.2 mg/kg/day. This reference dose is based on a laboratory study where toluene exposures caused changed in the liver and kidneys of rats (NTP, 1989). The changes included increases in the weight of the organs. The estimated dose did not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use. We can not say what significance this would be if people were to drink this water that contained toluene, but there could be a risk of adverse health effects from the exposure.

Toluene is a clear, colorless fluid with a distinctive odor. You start to smell toluene in the air at a concentration of 8000 µg/m³ and you can taste it in water at a concentration of 40-1000 µg/L. Thus, people may have been able to smell or taste the toluene found in the on-site water. Toluene evaporates easily and when it is in the air it will combine with oxygen to form other substances (such as benzaldehyde and cresol), which are harmful to people. You can absorb toluene if you drink contaminated water, or come into skin contact with it. You can also absorb it if you breathe its vapors. Most of the toluene that enters the body leaves within 12 hours.

Chief target organs of toluene exposure are the liver, kidneys and the brain. Low to moderate repeated occupational exposure to Toluene can cause tiredness, confusion, weakness, memory loss, drunken-type behavior, nausea, appetite loss, and hearing loss. These symptoms usually disappear when exposure is stopped. It is unknown if the levels of toluene that people breathe at work can cause permanent effects on the brain or body after many years (ATSDR, 1992).

Toluene may change the way your kidneys work, but they will return to normal after the exposure stops. Occupational studies, where concentrations generally are higher than those expected to occur at landfills, have suggested that exposure to toluene and ethanol may increase the potential for alcohol-induced fatty liver. Combinations of toluene and some common medicines like aspirin and acetaminophen may increase the effects of toluene on hearing. Populations that may be unusually susceptible to toluene exposure are: asthmatics, people having respiratory difficulties, those with cardiovascular or liver disease, the malnourished, the elderly, the young, cigarette smokers, and alcoholics.

Ethylbenzene

Ethylbenzene was found only in the on-site drinking water well and in on-site monitoring wells. There is no evidence that people are presently being exposed to ethylbenzene. The on-site water supply well was taken out service in 1983. If a person were to drink two liters of this water a day for their entire life, the estimated dose for children (0.07 mg/kg/day) and adults (0.03 mg/kg/day) would be lower than the point at which health effects are likely to occur and would not pose a risk to the people who drank this water. The estimated dose did not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use.

Ethylbenzene is a colorless liquid that smells like gasoline. People can smell it at concentrations as low as 2,000 µg/L, which is higher than the levels found in water at the site. It is found in gasoline, petroleum products, and manufactured goods. If spilled, it can move quickly into groundwater, because it does not bind readily to soil. Because it evaporates easily, it is often found as a vapor in the air. In the air, it breaks down into chemicals found in smog.

Vinyl Chloride

Vinyl chloride was only found in on-site monitoring wells and not in any residential wells. There is no evidence that people are presently being exposed to vinyl chloride. If a person were to drink two liters of water containing the highest level found on site (1,800 µg/L) for their entire life, the estimated doses for children (0.1 mg/kg/day) and adults (0.05 mg/kg/day) would be above the U.S.EPA reference dose of 0.00002 mg/kg/day. This RfD was calculated from results of experiments done on rats showing that exposure to 0.018 mg/kg/day resulted in cell changes in the liver (Til et al., as seen in ATSDR, 1993). The level of exposure could also increase the risk of developing cancer. The exposure would have to be over the person's lifetime and they would have to drink a lot of water every day with this amount of vinyl chloride in it throughout their life. The estimate of doses do not incorporate exposures that may occur through skin contact and inhalation of vapors released from water during household use.

Vinyl chloride can be either a liquid or a vapor. It is colorless and has a mild, sweet odor. It can enter your body when you breath air or drink water containing it. After it enters your blood, it travels throughout your body. When it reaches your liver, it is changed into several substances, most of which leave through your kidneys by a day. The liver, however, also makes some new substances that stay in your body longer. A few of these substances are even more harmful than vinyl chloride.

Some people who have breathed vinyl chloride at levels above comparison doses for several years have developed changes in their livers. People are more likely to develop these changes if they breathe levels of vinyl chloride that are much higher than the levels found at the MCI site. People who have worked with vinyl chloride sometimes develop nerve damage and immune reactions. The lowest levels that can cause liver changes, nerve damage, and immune reactions in people are unknown. Some people who have been occupationally exposed to high levels have had problems with the blood flow in their hands. Some people are more sensitive to this effect than others. Men who have had occupational exposures complained of a lack of sex drive. Results of animal studies show that long-term exposure may damage the sperm and testes. Some occupationally exposed women have experienced irregular menstrual periods and developed high blood pressure during pregnancy. Because vinyl chloride decreases the circulation in the hands and fingers of some people, people with impaired circulation may be more susceptible to its effects (ATSDR, 1996).

Barium

Elevated levels of barium were only found in on-site monitoring wells and not in any residential wells. Low levels were also present in on-site surface soil. There is no evidence that people are presently being exposed to barium. If a person were to drink two liters of water containing the highest level found on site (3,150 µg/L) for their entire life, the estimated doses for children (0.2 mg/kg/day) and adults (0.09 mg/kg/day) would be higher than the U.S.EPA reference dose of 0.007 mg/kg/day. This RfD was calculated from results of a number of different studies that have the association between exposure to barium and an increase in blood pressure (Wones et al., 1990; Brenniman and Levy, 1985).

The most sensitive health effect so-far associated with barium exposure in people (10,000 µg/L for 4 weeks in the drinking water) is blood pressure changes. The lowest level of exposure that resulted in health effects in animals was shown by rats, which were exposed to barium in their drinking water. They experienced increased blood pressure when exposed to levels above the calculated reference dose for humans. Subgroups of people that may be more susceptible to the effects of barium than others include those with cardiovascular problems, those taking certain prescription drugs (such as barbiturates), children, pregnant women, smokers, and possibly those consuming large quantities of milk, such as young children.

Barium is a natural element that is normally found combined with other chemicals. Its health effects depend on how well the specific barium compound to which you are exposed dissolves in water. Those barium compounds that dissolve the most readily cause the most health effects. Barium can enter your body when you drink water containing it and it can also enter your body if polluted water touches your skin. Almost all of the barium that enters your body is gone within 1-2 weeks. The small amount that stays goes into the bones and teeth.

Arsenic

Elevated levels of arsenic were detected in on-site surface soils and in on-site groundwater monitoring wells. Lower levels were detected in three residential wells and the on-site drinking water well. Public water was supplied to most area residents by 1992. There is no evidence that people are presently being exposed to arsenic. If a person were to drink two liters of the on-site water a day for their entire life, the estimated dose for children (0.002 mg/kg/day) and adults (0.0008 mg/kg/day) would be slightly higher than the U.S. EPA reference dose and ATSDR MRL of 0.0003 mg/kg/day. The U.S.EPA RfD is based on skin effects in people (Tseng, WP, 1977 as seen in Heast Table, 1994). The doses that could result from this exposure would be lower than the point at which health effects are known to occur from drinking contaminated water and should not pose a risk to people if they drank this water.

Long-term, low level exposure to arsenic has been associated with damage to the vascular system. The most common effect of arsenic exposure is a pattern of skin changes that include generalized hyperkeratosis and hyperpigmintation of the face, neck and back (ATSDR, 1992). Although neurological effects are also common with arsenic exposure, the estimated doses for possible exposure at the MCI site are below where symptoms are likely to occur.

Arsenic is an element that exists in two forms, organic arsenic and inorganic arsenic. The organic forms are usually less harmful than the inorganic forms. Because arsenic is a natural part of the environment, low levels will normally be found in your water, food, soil, and air. Most arsenic compounds dissolve in water; thus, it can get into lakes, rivers, or underground water. Some will stick to the sediment on the bottom of lakes or rivers and some will travel along with the water. If you swallow arsenic most of it will quickly enter into your body. Both inorganic and organic forms leave your body in your urine and most will be gone within several days, although some will stay in your body for several months or longer.

Cadmium

Elevated levels of cadmium (6.5 µg/L) were detected in on-site groundwater monitoring wells. Lower levels were detected in four residential wells. Public water was supplied to most area residents by 1992. There is no evidence that people are presently being exposed to cadmium. If a person were to drink two liters of the on-site water a day for their entire life, the estimated dose for both children and adults would be lower than the point at which health effects are likely to occur and would not pose a risk to the people if they drank this water.

In people, the kidney is the primary target organ of cadmium exposure. When people consume low levels of cadmium over a long period of time, they may experience a buildup of cadmium in their kidneys. Too much cadmium can overload your kidneys' storage system and cause health damage. Animals that consume cadmium sometimes get high blood pressure, iron poor blood, liver disease, and nerve or brain damage. It is unknown whether people who consume cadmium get any of these diseases. In animal studies, cadmium can interact with lead in producing reductions of body weights.

Cadmium is a soft metallic element that does not have any definite taste or odor. Cadmium can enter your body from drinking contaminated water. If you do not have sufficient iron or some other nutrients in your body, you are likely to take up more cadmium. Cadmium that enters your body stays in your liver and kidneys. It leaves your body slowly.

Lead

On-site surface soils contained elevated levels (2,094 mg/kg) of lead. People on site and children who regularly trespassed on the site (e.g. every day, spring through fall) could have been exposed to lead by ingesting contaminated dirt, inhaling contaminated dust, or eating food or smoking cigarettes with dirty hands (lead contaminated dirt).

Children absorb lead from their stomachs more readily than adults do. After lead gets into your body, it travels in the blood to the soft tissues such as the liver, kidney, lungs, brain, and heart. After several weeks, in adults, most of it then moves into the bones and teeth. In children, when compared to adults, more of the lead will go to their organs and blood. In both children and adults, part of the lead will stay in the bones for decades and can reenter the blood and organs. In addition, most of the lead absorbed by adults with leave their body within a couple of weeks, but a higher percentage of the lead absorbed by children will stay in their bodies. Lead absorption also depends upon one's nutritional state, if you do not have sufficient iron or some other nutrients in your body, you are likely to take up more lead.

The effects of lead in the body are the same no matter how it has entered. Exposure to lead is particularly dangerous for unborn children. It is also dangerous for young children because they swallow more lead through mouthing activity, absorb more of what they swallow, and are more sensitive to its effects. Lead exposure can decrease the intelligence quotient scores and reduce the growth of young children. These effects may last as they get older and interfere with their performance in school. In adults lead exposure can decrease reaction time and possibly memory, increase the blood pressure in middle-aged men, and cause anemia.

B. Health Outcome Data Evaluation

The only health outcome data readily available for review are cancer mortality statistics for Miami County. These data are not useful for evaluating the potential effects from MCI.

C. Community Health Concerns Evaluation

No health concerns were expressed by the community surrounding the Miami County Incinerator site. The majority of community concerns reported during the RI/FS process related to the remedial alternatives chosen for the site.

There were also concerns about the potential for additional residential wells to be impacted by site-related contamination. ODH is recommending that a well survey be performed to identify any further existing wells, and that any of these wells which could be impacted by site contaminants be sampled.

Agency for Toxic Substances and Disease Registry, 1825 Century Blvd, Atlanta, GA 30345
Contact CDC: 800-232-4636 / TTY: 888-232-6348 

Department of Health and Human Services