HEALTH CONSULTATION
CHEMICAL COMMODITIES, INCORPORATED SITE
(a/k/a CHEMICAL COMMODITIES, INCORPORATED)
OLATHE, JOHNSON COUNTY, KANSAS
The former Chemical Commodities Inc. facility in Olathe, Kansas, engaged in the resale of
chemicals that were surplus, off-specification, recycled, or had exceeded their specified shelf
life. The facility, in operation from 1951 until 1989, stored chemicals on site in both above
ground and underground storage tanks as well as drums, boxes, barrels and other miscellaneous
containers (1). Significant surface soils, subsurface soil and groundwater contamination has
been identified on site, primarily due to spills and leaks of chlorinated solvents over the years.
The Environmental Protection Agency (EPA) 
placed the site on the National Priorities List
(NPL) in May 1994. The EPA Project Manager for the Chemical Commodities, Inc. (CCI) site
requested that the Agency for Toxic Substances and Disease Registry (ATSDR) review recent
indoor air sampling results for several homes next to the CCI site and determine if these levels
are of public health concern (2).
Several chemicals were found in the indoor air of each of the five homes located adjacent to this site including chemicals which may be related to groundwater contamination at the CCI site. However, many of the chemicals detected in the indoor air are not believed to be related to the CCI site. Regardless of the source of these chemicals, no adverse health effects are expected at the levels found in the indoor air. Outdoor air samples contained three chemicals whose source is unknown (methylene chloride, pentane and acetone). The source(s) of detected chemicals in the outdoor air samples is(are) unknown. We recommend the source(s) of these chemicals be identified and evaluated.
The levels of chemicals reported in indoor air are not a public health concern. However, we recommend that these homes be checked for seasonal variations for those chemicals that may be linked to soil gas movement. Additionally, as the extent of groundwater contamination in the area is better defined, we recommend evaluating other homes to determine if indoor air sampling is warranted.
The Chemical Commodities Inc. site, which occupies about 1½ acres, is in a largely residential area of Olathe, Kansas (Figure 1). The shallow groundwater contamination includes a plume of dissolved chlorinated solvents such as tetrachloroethylene (PCE), trichloroethylene (TCE), chloroform, carbon tetrachloride 1,1,1 trichloromethane (TCA) and 1,1,2,2, perchloroethane (PCA) (1). A dense non-aqueous phase liquid (DNAPL) has been found below the shallow groundwater in the areas of highest contamination. A recovery trench was constructed in 1991 to remove this DNAPL, primarily TCE, from the shallow aquifer. Additionally, a groundwater extraction and treatment system was installed to address the dissolved phase groundwater plume (1 ).
Residences border the property to the north and across Keeler Street to the west. The shallow groundwater plumes, approximately 15-20 ft below the surface extends to the north and west of the site below homes adjacent to CCI. Past soil vapor and crawl space sampling indicate a potential for volatile compounds in the soil and groundwater to transport through soil vapor into indoor air (1,3,4).
The potential for health hazards due to chemical releases at the CCI at the Olathe site was reviewed by the Centers for Environmental Health at the Centers for Disease Control (CDC) in 1983 at the request of the EPA (5). This CDC evaluation concurred with existing EPA recommendations to address on- site chemical hazards, which included removal of contaminated surface soils. The CDC recommended these actions be taken as soon as possible to prevent further releases. When considering the impact of this site on public health, CDC evaluation notes the elevated levels of chemicals in the surface soil on site; but that the data were not sufficient to evaluate the impact on the surrounding homes. Therefore, CDC agreed that site "investigation is needed to quantify the extent of contamination both on and off the site" in order to assess any potential impact on the surrounding community due to contaminated soils or airborne contamination (5).
ATSDR evaluated results from ambient air, and residential air monitoring conducted in 1989 by the EPA. Levels of site contaminants, most notably PCE and TCE, were elevated downwind of CCI facility (6). Additionally, these compounds were found in the three residences sampled. PCE and cis-1,2-DCE were found in two of the residences. However, the levels found both in ambient and residential air, were not considered either an imminent or long term health hazard (7). At that time, ATSDR recommended reducing ambient air emissions from the site, and to continue periodic monitoring of indoor air. Specifically, ATSDR recommended sampling across different seasons as weather conditions can effect contaminant migration and build-up in buildings (7).
In 1996, the EPA requested that ATSDR review environmental data collected at CCI in Olathe, Kansas, specifically soil vapor and flux measurements from the ground into the air. A review of data available at that time indicated measurable chlorinated solvents in soil gas and flux of some of these chemicals into the ambient air including TCE, PCE, PCA, TCA and cis-1,2-dichloroethene (DCE) (1). Additionally, groundwater isopleth maps indicated that contaminants have migrated off-site and the plumes were currently underlying residences adjacent to the CCI site to the north and west (1). Although these data indicated the potential for movement of these volatile compounds into ambient air and indoor air, the flux data alone were not considered sufficient to assess human health threats at the site (4). ATSDR recommended additional sampling in basements, crawl spaces and other confined spaces in the vicinity of the plumes (4). Concurrent ambient air monitoring was also recommended. ATSDR also noted that soil gas may also migrate through underground utility lines which "may result in VOC intrusion into homes not located directly over the contaminated plume."(4) ATSDR's site review and update in December of 1996 reiterated these recommendations. (8)
ATSDR completed a public health assessment, as mandated by CERCLA, on the CCI site in April of 2000 (9). This report summarizes site conditions and past ATSDR work on CCI. In addition, the author reviewed air sampling conducted in 1997 in the crawl space below four homes adjacent to the CCI site (10), concluding the levels of VOCs found at that time "did not pose a health concern for crawl space air."(9) ATSDR's earlier recommendations to sample ambient air at the site and indoor air in homes above the groundwater contamination were reiterated. Additionally, the author concurred with EPA's current actions to prevent public access to the site and to continue treating contaminated groundwater in the area.
Indoor air samples were collected by the EPA in five homes near the CCI site in October and November of 2000 (11) (Figure 1). These samples were collected in response to earlier data which indicated some plume related chemicals were found in the soil gas, and in crawl space below homes in the area. The five homes were chosen due to their proximity to the groundwater contamination associated with the CCI site (11). Although there is some overlap, all of the homes previously sampled for volatile chemicals in crawl space air are not included here. The homes (labeled A,B,C,D and E in Figure 1) are adjacent to CCI, lying north and east of the facility.
It is possible for chemicals which evaporate easily into the air, which are called volatile chemicals, to travel through the air spaces in soil above groundwater and enter buildings. Crawl spaces below buildings, basements and storage areas not often opened, are particularly susceptible to collecting these volatile chemicals. Many variables can influence if the conditions are right for chemicals to enter the home and to accumulate. If the chemicals are present in the the living spaces within a home, residents will be exposed to these chemicals in the air.
The major volatile contaminants in the CCI plume are TCE, PCE, TCA cis-1,2-dichloroethene, carbon tetrachloride and 1,1,2,2-perchloroethane (PCA) (1). Chloroform, methylene chloride, benzene, toluene, xylene and other chlorinated solvents are found in the groundwater at lower levels (1). Of the major plume contaminants, PCE, TCE and DCE were found in soil-gas samples in the vicinity of the sampled homes in 1996 (1). The presence of these chemicals in the soil gas above the plume indicates a potential for them to migrate into buildings over the plume.
Historical air sampling of the crawl spaces below the homes indicate these chemicals and others are found in crawl space below the homes (3,10). Crawl spaces are not occupied as often as the living spaces within the home and these chemicals were not present at levels that would be a hazard for the occasional entry into the crawl space(7,9). Sampling studies conducted by the EPA in 1989 in three homes, one of which is included in the present study, found PCE, TCE, TCA, cis-1,2-DCE hexane, toluene and methylene chloride in crawl space air (3). Additional sampling of the crawl space below four homes in 1997, two of which were included in the present study, found low levels of TCE, TCA, DCE, benzene, ethylbenzene, toluene, xylene, chloroform and 1,3-dichlorobenzene in some of the homes (10). The presence of these chemicals in the crawl space below the home does indicate they may also be present in the living space within the home. Therefore, air samples from the living areas of these homes were taken to determine if volatiles from the plume may be in the indoor air.
Each of the homes were sampled for 24 consecutive hours on three different days (13). The samples were collected in a metal cylinder (SUMMA© canister) and sent to a laboratory for chemical analysis (11). Additionally, four background samples were taken outside in order to understand what ambient levels of these chemicals may be in the neighborhood. The air samples were collected during October and November 2000 (11). Each air sample was analyzed for a group of 68 volatile chemicals (Appendix A). In addition to the chemicals known to be at the site, many chemicals were checked for which may be present naturally or due to manufactured products used in the home (Table 1). Chemicals may off-gas from consumer products, such as building materials and materials used for hobbies. Other consumer products such as cosmetics and cleansers may also be sources of volatile organic chemicals in the home. It is known smoking can be a significant source of benzene. Benzene and toluene are both components of fuels, such as gasoline. These data cannot determine the source of the chemicals found in the homes. Regardless of the source of the chemicals found in these homes, the following health evaluation will look at residential exposure to all of these chemicals.
The 24 hour samples are an average air concentration for that period of time. It is likely the actual concentration of the chemicals in the indoor air fluctuated throughout the day. The three day average is the average of all three of the 24 hour samples taken within the same residence. Where no chemical was found in the air sample, the limit of detection was used for the 24 hour sample when calculating a three day average. Although it is possible that the chemical was not present at all, the limit of the detection is the greatest amount that could have been there and not seen by the laboratory. Therefore assuming the chemical was present at this level is a 'worst case' scenario, providing for a conservative assessment of any potential health effects.
The majority of chemicals found in the outdoor air samples do not seem to be related to the CCI groundwater plume. TCE, TCA, chloroform, DCE and DCA found in the groundwater plume are not reported in any of the outdoor air samples (Table 2). Only PCE, of the major plume contaminants was found. PCE was detected in two of the four air samples at 14 and 51 µg/m3 (micrograms of chemical per cubic meter of air). Benzene, toluene, xylene and ethylbenzene, are also site related. However, groundwater levels are low such that they are not expected to impact ambient air. Benzene, toluene, xylene and ethylbenzene have many other potential sources as they are present in gasoline. Isopropyl alcohol, pentane and acetone were found in all four outdoor air samples, but are unrelated to site contamination. Chloromethane was found in three of four samples near the detection limit.
Methylene chloride is a site related chemical and was detected in all four outdoor samples at levels higher than other chemicals (440-810 µg/m3). However, methylene chloride is a minor plume constituent in the area sampled. Methylene chloride, acetone and pentane levels were noticeably higher in outdoor air than the other compounds detected. Levels reported for methylene chloride are above what may be expected for ambient air. Potential source areas for these chemicals near these homes have not been identified.
Historically, site related contaminants were found in ambient air. The EPA conducted outdoor air monitoring in 1989 (6). The earlier sampling was limited to those chemicals expected as site contaminants. TCA, TCE and PCE, all major site contaminants, were found at higher levels downwind than they were up- wind at the CCI site (6). This indicated the CCI site was a source of airborne contamination in 1989 (6). The EPA removal of contaminated surface soils would be expected to reduce volatile emissions from the CCI site. However, since the wind direction on the sampling days is not known, one cannot determine the impact of the CCI site on ambient air quality. These samples do provide an indication of the ambient air quality outside of the sampled homes during indoor air sampling. However, it should be noted the detection limits were higher for the analysis of the four outdoor samples than for the analysis of the indoor air samples (Appendix B). For several of the chemicals found at low levels in the homes, no determination can be made as to if these chemicals were present at the same low levels in outdoor air. This is discussed further below when addressing the indoor air samples.
The indoor air samples indicate several potentially site- related as well as non-site related chemicals were present in the homes on the days sampled (Table 3). This is not alarming as there are many sources of chemicals in the home, both natural and manufactured. These data cannot distinguish the source of the chemical measured, but a discussion of potential sources is provided for perspective. Regardless of the source of the chemicals found in these homes, the following health evaluation will look at residential exposure to all of these chemicals.
Of the five residences, residence A is closest to the site, and directly over part of the plume. Residence E is the farthest from the site and may or may not lay directly over the groundwater contamination. TCE was found in all five homes with three day averages ranging from 2.7 to 5.9 µg/m3 (Table 3). PCE was found in two homes with averages of 4.7 and 8.9 µg/m3. TCA was found in three homes with averages of 2.8, 27 and 31 µg/m3. Chloroform was found in three homes with three day averages from 2.6 to 4.2 µg/m3. Methylene chloride was found in all five homes with averages ranging from 2.0 - 11.1 µg/m3. DCE was not detected in any of the homes.
Volatile chemicals reaching the homes through the soil-gas pathway would be expected to be present in the groundwater, soil gas and then would accumulate in the homes similarly, for similar chemicals. For example, TCE, PCE and TCA have similar chemical properties which define how they move through the environment. All are found in the groundwater near these homes and all were found in the soil gas sampled near the homes in 1996. However, TCE and PCE were only detected together in two homes (B and E). TCA was found in two homes well above the method detection limit (C and D) and one home at the detection limit (home E), but two of these homes did not show PCE. Therefore, even though these three chemicals occur together in the groundwater plume and in the soil gas; they do not occur together in the homes.
PCE, TCE , TCA and DCE have all been detected in past sampling events in the soil gas in the vicinity of the homes as well as in some of the crawl space air samples taken in 1989 and 1997. Chloroform was not analyzed for in the 1996 soil gas samples, and was found in one of the four crawl space samples from 1997 at the method detection limit. Although analyzed for in the 1989 sampling, the method detection limit of 42 µg/m3 for chloroform is much higher than levels currently being found in the homes; therefore, if chloroform was present at current levels, it would not have been seen in the earlier samples.
Methylene chloride is also a component of the groundwater plume near home A. However, methylene chloride has not been previously analyzed for in either soil gas or crawl space air. The levels reported in indoor air are ten to 100 fold lower than those seen in outdoor air during the same days of sampling, ranging from 2 µg/m3 to 11.1 µg/m3 in indoor air and ranging from 440 µg/m3 to 810 µg/m3 in outdoor air. This difference is especially marked since all samples were taken for 24 consecutive hours.
Although only PCE of the major plume components was found in the outdoor air samples, it should be noted that the detection limits for the outdoor air samples were higher than the indoor samples. The detection limits for TCE, PCE and chloroform were higher than most of the detected levels reported for indoor air (Appendix B). Therefore, the data allow us to draw no conclusions about the indoor levels of these chemicals and the quality of outdoor air on the day of sampling. TCA, which was found at 27 and 31.7 µg/m3 in two of the homes, was not seen in the outdoor air. These indoor TCA levels are greater than the detection limit for outdoor air (4.5-5.9 µg/m3 ) indicating levels of TCA were greater in these homes than the ambient air on those days.
The fuel components, benzene, toluene and xylenes were found in all five homes, with toluene and xylene occurring at the highest concentrations (Table 3). Ethylbenzene was found in two of the five homes. These chemicals are found in the groundwater in the vicinity of the homes, but at very low levels in the part per billion range. It is unlikely their presence in the home is due solely to the plume. Soil gas sampling in 1996 did not detect measurable quantities of these chemicals in the air below the ground. These chemicals are found in gasoline, solvents and other products which may be present in the home. Also, it should be noted that all four of the outdoor air samples contained benzene and toluene (Table 2).
Other chemicals seen in the indoor air of some of these homes includes alcohols, ketones, aldehydes, styrene, carbon disulfide and some solvents (Table 3). Many of these chemicals are used industrially, but their presence in the indoor air samples does not indicate a direct connection to an industrial site. Chemicals may be present in the home due to consumer products such as cleansers, toiletries, paints or chemicals used for hobbies. Chemicals may be used as solvents for oils, waxes, resins, varnishes, dyes, lacquers and rubber and in other industrial processes (Table 1). If left within the product, the chemical may release into the air when the product is brought within the home. So building materials, textiles, plastics and rubber materials used in the home may contribute low levels of organic chemicals to indoor air. Some of the chemicals found in indoor air may be due in part to natural sources. For example, various alcohols, ketones and aldehydes may be produced by plants and microorganisms. The types and levels of the chemicals found in these five homes are not unusual.
The presence of these chemicals in indoor air does not necessarily present a health hazard. The amount of chemical an individual is exposed to, as well as the duration of exposure, must be taken into account in order to understand if any health effects would be expected. These two factors together define the exposure conditions and the dose of the chemical. The dose is the amount of chemical that an individual takes into their body. When considering a residential exposure to indoor air, the route of exposure is by breathing and the intake into the body through the lungs.
The duration of exposure to indoor air in homes can vary greatly. In this case, the duration would be the amount of time per day, or per week an individual spent in the home. Although many individuals work, go to school or leave the home for periods of time over the week, this may not always be the case. Therefore, in an effort to protect all individuals, a full time exposure, 24 hours a day, is assumed in this evaluation. Additionally, when evaluating theoretical cancer risk, this full time exposure is taken as a lifetime exposure, a full 70 years of residency. Although it is extremely unlikely that any individual in these homes will meet these conditions, the most conservative exposure scenario is chosen here to be protective of all conditions. It should be noted that going to school or to work every day for 8 hours could reduce this assumed exposure by as much as 1/3.
There is a potential for indoor air levels to vary seasonally and over time as site conditions change. Days of heavy heating may actually pull soil gas into the homes and the closed up homes for insulation may allow it to remain in the home. Significant changes in the CCI plume over time may increase or decrease any contribution of solvents to the homes which may be coming from the plume. Additionally, changes in home usage, hobbies and new consumer products will influence indoor levels of these chemicals regardless of the impact from the CCI groundwater contamination.
ATSDR establishes minimum risk levels (MRLs) for exposures to chemicals based on the available medical, toxicological and epidemiologic data. Often these data include studies on people exposed to chemicals in the workplace, and laboratory animal studies. There are uncertainties in applying both the worker studies and animal studies to the general population. Therefore, these MRLs are often 100 to 1000 times lower than the level which may have resulted in a health effect. As such, the MRLs are conservative values below which no adverse health effects are expected.
MRLs are established for a route of exposure (e.g. breathing) and a duration (acute, intermediate or chronic). Chronic MRLs are established for a lifetime exposure. Eleven of the chemicals detected in homes near CCI have chronic MRLs. Most of the chemicals with established MRLs are chlorinated solvents and fuel components. In all cases, the amount of the chemical seen in the indoor air is well below the established MRL, indicating that no non-cancer adverse health effects are expected (Table 3). TCE, ethylbenzene and benzene do not have chronic MRLs, but the intermediate MRLs are given in Table 3. The balance of the chemicals do not have MRLs established.
A chronic MRL was not set for ethylbenzene (13). However, the intermediate MRL is believed to be protective for chronic effects. A chronic-duration study in rats defined a NOAEL of 250,000 ppb (1,090,000 µg/m3) (14). This NOAEL is greater than the NOAEL for developmental effects on which the intermediate MRL is based (97,000 ppb, 420,000 µg/m3) (15). The sensitive end point of developmental effects results in a more conservative, and in a more protective MRL, than would have been derived from the chronic-duration study. Therefore, chronic exposures below the intermediate MRL are not expected to result in adverse health effects.
As with ethylbenzene, no chronic MRL exists for benzene (16). Chronic-duration studies for benzene exposure do exist, and a human LOAEL can be defined at 3,000 ppb (9,570 µg/m3) (16). However, pancytopenia, or a decrease in red cells, white cells, and platelets in the blood , is seen at this exposure level and is considered a serious effect which cannot be used to establish an MRL. There is not a LOAEL at levels below that found in this study that is less serious. This LOAEL for noncancer health effects in humans is 2000-fold greater than benzene levels seen in these homes. These levels do not pose a healthy hazard for non-cancer health effects.
Both the acute and intermediate MRLs for TCE are based on neurological effects: headache fatigue and drowsiness in humans breathing up to 200,000 ppb (1,080,000 µg/m3) during a workday (acute exposure), and decreased wakefulness and sleeping heart rates in rats exposed to 50,000 ppb (270,000 µg/m3) for 6 weeks of forty hours a week of exposure (intermediate exposure) (Reviewed by ATSDR, 17). The only chronic duration study in animals for inhalation of TCE showed no respiratory, cardiovascular, hematological hepatic, endocrine, dermatological, occular or body weight effects at exposures as high as 600,000 ppb (3,240,000 µg/m3) for 104 weeks of exposure, 40 hours per week. Kidney effects were seen, in the male rats only, at 300,000 ppb (1,620,000 µg/m3) but not at the lower dose of 100,000ppb ( 540,000 µg/m3) (Reviewed by ATSDR, 17). However, these effects are believed to be species and sex dependent, and are not expected to occur in humans (17). Therefore, available data indicate no non-cancer health effects would be expected due to chronic exposures to the levels of TCE found in the indoor air at CCI (2.7-5.9 µg/m3).
MRLs do not exist for many of the alcohols, ketones and aldehydes. However, these compounds are generally readily metabolized by our bodies and in some case produced in our bodies during normal metabolism. The small amounts found in indoor air do not pose a health hazard.
As with non-cancer health effects, the levels of chemicals found in these homes are far below levels that are known or believed to cause cancers, either in human or animal studies. However, some of the chemicals are classified as known or suspected carcinogens. Table 4 shows the classification based on reviews by the EPA, the National Toxicology Program (NTP) and the International Agency for Research on Cancer (IARC). Of the chemicals evaluated, benzene is classified as a known human carcinogen (18,19,20). PCE and TCE are classified as probably carcinogenic to humans by the IRAC and are considered to be reasonably anticipated to be human carcinogens by the NTP, but not currently classified by EPA. Chloroform, methylene chloride and styrene are all believed to have some degree of carcinogenic potential (Table 4). The balance of the chemicals either have not been reviewed or there is not enough data to classify them in terms of their potential to cause cancer.
Benzene
Benzene is the only compound found in these air samples which can be
linked definitively in human studies with cancer. However, the levels seen in
both indoor and outdoor air are not believed to be a hazard. Studies examining
workers show benzene exposure has been associated with leukemia, but no detectable
excess of leukemia is seen in workers who are below 40,000 ppb-years (125,000
µg/m3-years), or an exposure of 1000 ppb (3190 µg/m3)
for a duration of 40 years (21). There is uncertainty in the extrapolation of
cancer incidence data from occupational studies, usually involving exposures
higher than those seen in the environment, to low-level residential exposures.
However, based on the levels of benzene in these homes, and the EPA unit risk
(18) for cancer incidence, there is no apparent increased risk of cancer due
to these exposures, even for long term residential exposure.
Trichloroethylene and Tetrachloroethylene
The chlorinated solvents TCE and PCE are classified as potential human
carcinogens (20). However, although the carcinogenicity of these compounds has
been shown in animal models, the weight of evidence for carcinogenicity in humans
is not definite (Reviewed by ATSDR, 17). Additionally, studies which explore
why these chemicals are toxic to animals indicate the same mechanisms may not
be relevant to humans, especially at the low doses seen in indoor air at this
site (Reviewed by ATSDR, 17). Considered individually, there is some doubt about
either chemical's carcinogenicity. Currently, IRIS does not provide a cancer
slope factor to provide theoretical estimates of cancer risk for exposures to
these chemicals.
One study of cardboard manufacturing workers shows a link between TCE exposure in the workplace and kidney cancer (22). However, other epidemiological studies for workers exposed to only TCE vapors show no higher incidence of cancer than controls (reviewed by ATSDR, 17). There are several studies which include TCE exposure as well as other workplace chemicals which show increased cancer rates. An association has been reported between low level exposure to TCE in drinking water supplies and leukemia and other cancers, but these studies are also confounded by the presence of other chemicals (reviewed by ATSDR, 17). Similarly, epidemiological studies examining PCE exposure are inconclusive. Epidemiologic studies of dry cleaning workers, exposed to PCE and other solvents, have shown evidence of increased mortality due to cancer including: kidney, bladder and cervical cancer (23), reviewed by ATSDR 24). Other studies of dry cleaning and laundry workers suggest a link with cancers of the lung, cervix, esophagus, kidney, skin. Therefore, workplace exposures to multiple chemicals, including PCE, TCE and other solvents,in the air, have been linked to increased cancer mortality. Although indoor air samples at the CCI site show exposures to these chemicals, along with other solvents, similar health effects are not expected. The levels of these chemicals at the CCI site are 100 to 1000 times lower than occupational exposures believed to have some link with cancer mortality.
Chloroform
There are no studies which evaluate the potential for cancer after
being exposed to chloroform in the air, either for humans or in laboratory animals.
The basis for considering chloroform a possible human carcinogen includes 1)
animal studies where animals ingested the chloroform and 2) general population
studies on human consumption of chlorinated drinking water. Both sets of data
are problematic. Results of the animal studies vary dramatically from indications
of carcinogenicity, to one study which indicated chloroform was protective against
a specific cancer in male rats (reviewed by ATSDR 25). The authors summarize
that the method of dosing the animals was influencing the outcomes of the animals
studies (25). Although studies of communities on chlorinated water may suggest
an association with cancer, these associations are weak and remain unproven.
Additionally, although chloroform is known to be in chlorinated drinking water,
many other compounds are also found as a result of chlorination. Any association
between chlorinated drinking water and cancer, if it exists, may or may not
be due to chloroform. However, the EPA has established a unit risk (or slope
factor) for human exposure based on extrapolation from the animal studies (18).
Based on the indoor air levels of chloroform and this unit risk, there is no
apparent increased risk of cancer due to these exposures, even for a long term
residential exposure.
Methylene Chloride
One study of the workers exposed to methylene chloride indicated a
significant increase in bile-duct cancers (26). The workers were exposed to
as much as 1,700,000 ppb for up to 28 years. However, other studies have shown
no link between deaths due to cancer and lower levels of methylene chloride
in the workplace (<475,000 ppb) (reviewed by ATSDR, 27). Methylene chloride
has been shown to cause tumors in animal studies at 500,000 ppb and 2,000,000
ppb (reviewed by ATSDR, 27). These studies, taken together with evidence which
indicates the same mechanism of toxic action may exist within animals and humans,
support the designation of methylene chloride as a probable/possible human carcinogen.
However, the levels of methylene chloride seen here in indoor air are well below
any cancer studies. Based on the indoor air levels of methylene chloride and
the EPA established unit risk (18), there is no apparent increased risk of cancer
due to these exposures, even for a long term residential exposure.
Styrene
The IARC has categorized styrene as possibly carcinogenic to humans.
Neither EPA nor the NTP has classified styrene at this time (18,19). The IARC
cites several epidemiological studies which indicate an association between
exposure to styrene in the workplace and lymphatic and hematopoitic cancers
(20). There is limited evidence for cancer in animal studies but not lymphatic
and hematopoitic cancers. However, a reactive metabolite of styrene can be measured
in both humans and animals exposed to high levels of styrene. This metabolite
be responsible for changes in cells consistent with the development of cancer
(20). Therefore styrene is a possible carcinogen. Although there is no available
unit risk factor for styrene, the air levels seen in these homes are well below
worker exposures which may be linked to cancer.
Summary of Cancer Health Effects
For all chemicals addressed here, the measured levels in these five
homes are far below the levels which have been seen to produce cancers in animal
and human studies. Therefore, the ability for these exposures to result in increased
cancer is highly unlikely (as represented in the unit risk factors) and essentially
unmeasurable even if it occurred at the calculated incidence. In practical terms,
there is no expectation of increased incidence of cancer due to chronic exposures
to these chemicals, taken either singly or together, at the measured levels.
Children and other sensitive populations
ATSDR recognizes that infants and children may be more vulnerable to exposures than adults in communities faced with contamination of their air, water, soil, or food. As part of its Child Health Initiative, ATSDR is committed to evaluating children's special interests. Considering exposure to indoor residential air at the CCI site, children may have an increased vulnerability due to the following factors: 1) children weigh less than adults, resulting in higher doses of chemical exposure relative to body weight, 2) the developing bodily systems of children can sustain permanent damage if toxic exposures occur during critical growth stages and 3) children have a breathing zone lower to the ground. Similarly, the elderly may be susceptible due to changes in the body's ability to detoxify chemicals and repair damage which come with aging. As a conservative screening tool, the MRL is designed to account for these factors. When considering how well the experimental data can be applied to the general population, an uncertainty factor for human variability is used in developing the MRL. This uncertainty factor addresses the application of the MRL to sensitive populations, including children and the elderly, which may not have been involved in the study population on which the MRL is based. Therefore the MRLs are considered protective of these sensitive populations. Although, there are still many unknowns about the carcinogenic process and the bodies ability to defend against it, the cancer estimates, where done, and the weight of evidence discussions above are believed to be protective of the general population by their conservative nature.
Several volatile organic chemicals were found in the indoor air of each of the five homes sampled adjacent to the CCI facility. The presence of some of these chemicals may be consistent with soil gas accumulation from the groundwater plume beneath the homes. However these data cannot establish this. Many of the chemicals found are not site related, but may be due to other sources within the home. Regardless of the source of these chemicals, there is no apparent health hazard indicated by these data. No discernable adverse health effects are expected based on exposure to these chemicals over a lifetime.
The above analysis is based on the assumption that the three 24-hour samples are representative of the residential exposures. Any changing site conditions that may cause soil vapor and indoor air levels to fluctuate such as further migration of the contaminants, seasonal effects, and changes in building use, may impact indoor air quality. This evaluation is limited to the current measured conditions.
The air samples collected in October and November 2000 only address the five homes located north of the CCI facility. Groundwater contamination also extends west of the facility underlying homes in that direction (1). The EPA is currently in the process of determining the area impacted by the groundwater plume. ATSDR concurs with these actions to better understand the extent of groundwater contamination due to the CCI facility. Differences in home construction, geology, building use, utilities and the basements can impact soil gas accumulation on a building by building basis. All buildings above the CCI plume should be identified and evaluated to determine if indoor air sampling is warranted. Similarly, the homes immediately to the east of the facility should be evaluated to determine if there is any potential for the plume to impact these homes as well.
The outdoor air samples are not sufficient at this time to make a health call. Although the chemicals detected were below levels of health concern, the representativeness of these data cannot be determined. Without knowledge of the source(s) of acetone, methylene chloride and pentane, there is no way to determine if these samples represent typical outdoor air levels due to the source(s). Additionally, the levels of these chemicals in the outdoor air may indicate a light industrial source in the vicinity of the homes. If so, other chemicals not analyzed for in this study may be released by the same site. The source (s) of these chemicals should be determined and their impact on this residential area evaluated.
1. The levels of chemicals detected in the indoor air of homes sampled near the CCI facility, are not expected to result in any observable adverse health effects, either cancer or non-cancer.
2. The shallow groundwater plume from CCI may underlie other homes in the community. The air samples reviewed here do not address indoor air in these other homes
3. The source(s) of the methylene chloride, pentane and acetone detected in the outdoor air samples are unknown. These samples cannot be used to evaluate the public health implications of those sources.
1. Resample these homes to check for seasonal variations in those chemicals which may be linked to soil gas movement.
2. Continue to identify the extent of groundwater contamination, especially in the adjacent residential areas. Identify and evaluate other homes and buildings above and adjacent to the CCI plume for the potential to accumulate soil gas within their structures. Conduct representative sampling within the living space for constituents of the groundwater plume to determine if these chemicals are present in the buildings.
3. Identify potential sources for the methylene chloride, acetone and pentane seen in the outdoor air samples. Evaluate the potential impact on the residential areas surrounding the facility.
Danielle DeVoney, Ph.D.
Toxicologist, Environmental Engineer
Petition Response Section
Exposure Investigations and Consultations Branch
Division of Health Assessment and Consultation
Reviewed by
Susan Moore
Section Chief
Health Consultations Section
Exposure Investigations and Consultations Branch
Division of Health Assessment and Consultation
Donald Joe
Section Chief
Petitions Response Section
Exposure Investigations and Consultations Branch
Division of Health Assessment and Consultation
Allan Susten, Ph.D, D.A.B.T.
Associate Director for Science
Division of Health Assessment and Consultation
Ben Puesta,
Public Health Advisor
Office of Regional Operations
Figure 1. Location of five residences near the CCI Site, Olathe, Kansas
Table 1: Potential sources of chemicals in household indoor air:
Fuel components (benzene, toluene, ethylbenzene, xylene and decane) are all found in gasoline and solvents used in the home. Benzene is also produced while smoking.
Chlorinated solvents (PCE, TCE, TCA, chloromethane, and chloroform) are used in industry primarily for degreasing and cleaning operations or in chemical manufacturing processes. TCE may be part of a solvent blend in a consumer product such as adhesives, paints/strippers, spot removers, varnishes and pesticides. PCE is used in textile processing and dry cleaning operations. TCA is found in adhesives, cleansers, paint removers, wood stain and varnishes. Chlororform, in addition to the uses of the other solvents, is produced as a byproduct of drinking water chlorination.
Alcohols (2-propanol, 1-propanol and 1-butanol) are produced naturally by plants and during microbial degradation or fermenting processes. Alcohols are also used as solvents for oils, waxes, resins varnishes and rubber and in other industrial processes. 2-propanol is the same as isopropyl alcohol, or rubbing alcohol which may be used in the home.
Ketones (acetone, 2-butanone, 4,methyl-2-pentanone and 2-hexanone) may be used in the production of adhesives, rubber cements, resins, dyes, lacquers, varnishes and even as a food and fragrance additive. Acetone is actually the major component of nail polish remover.
Aldehydes (propanal, butanal, pentanal and heptanal) may be used as disinfectants, preservatives, food flavorings, and in the manufacture of polyvinyl, plastics, rubber and resins. The aldehydes are also released from plants and microorganisms and will be byproducts of wood and fuel combustion. Aldehydes have been found in foods both raw and prepared.
Other solvents and chemical intermediates (carbon disulfide, trimethylbenzenes, and styrene) may be present in a myriad of products from food additives to pesticides and are used in the chemical manufacture of paints, dyes, plastics, resins rubber found throughout the home.
Table 2: Summary of volatile chemicals found in outdoor
air near five homes adjacent to the CCI Site, Olathe, KS. All values are shown
µg/m3. Samples were collected in metal cylinders and analyzed for
the volatile organic chemicals shown in Appendix A. Any chemical not reported
here was undetected by the laboratory.
| Sample Number Location Date of Sample |
#16 Home A 10/30/00 (ug/m3) |
#17 Home B 11/17/00 (ug/m3) |
#18 Home C 11/20/00 (ug/m3) |
#19 Home D 11/06/00 (ug/m3) |
Average of samples |
MRL a (ug/m3) |
Uncertainty Factor b |
|
| tetrachlorethene |
51.0 |
(7.3)c | (7.1) | 14.0 | 9.5 | 270 | 100 |
| methylene chloride |
670.0 |
810.0 | 580.0 | 440.0 | 610 | 1000 | 30 |
|
|
|||||||
| Benzene |
3.9 |
4.3 | 3.6 | 4.0 | 4.0 | 12 (I) | 90 |
| ethylbenzene |
5.0 |
(4.7) | (4.5) | 4.3 | 4.5 | 4300 | 100 |
| toluene |
6.2 |
(4.0) | 9.8 | 120.0 | 44.6 | 1500 | 30 |
| m and/or p xylene |
16.0 |
15.0 | (4.5) | 16.0 | 11.8 | 430 | 100 |
| o-xylene |
5.1 |
4.8 | (4.5) | 5.3 | 4.9 | 430 | 100 |
|
|
|||||||
| 2-propanol |
30.0 |
13.0 | 44.0 | 83.0 | 46.7 | ||
| pentane |
140.0 |
150.0 | 170.0 | 590.0 | 303 | ||
| Acetone |
220.0 |
230.0 | 200.0 | 150.0 | 193 | 31000 | 100 |
| chloromethane |
2.8 |
(2.2) | 2.7 | 2.6 | 2.5 | 100 | 1000 |
a. Minimal Risk Level. An estimate of daily human exposure--by a specified route and length of time--to a dose of a chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects. The values shown here are expressed as µg/m3 and have been converted from the MRLs established in ppm. All values shown are the Chronic MRL unless designated as the Intermediate MRL (I).
b. Uncertainty Factor: Factor used to account for uncertainties in establishing an MRL. Uncertainty factors may be used to apply data on animals to human exposure, to account for human variability if a level of no adverse effect has not been defined. This factor is the fold margin between observed adverse health effects, or the lowest no observed health effects level, and the set MRL.
c. Values shown in parentheses are the chemical detection level for that air sample. On this table, the limit of detection is given for those compounds which were not found. It is possible the chemical was present at a level below the laboratory detection limit.
Table 3: Summary of volatile chemicals found in residential
air in five homes adjacent to the CCI Site, Olathe, KS.
All values are shown µg/m3.
| Home A | Home B | Home C | Home D | Home E | MRLa (µg/m3) | Uncertainty Factor b | |
| Chlorinated solvents and others | |||||||
| trichloroethene | 4.9 | 5.9 | 2.7 | 3.0 | 3.7 | 540( I) | 300 |
| tetrachlorethene | (3.4) c | 8.9 | (3.4) | (3.7) | 4.7 | 270 | 100 |
| 1,1,1-tricholoethane | (2.8) | (2.8) | 31.7 | 27.0 | 2.8 | 3800 (I) | 100 |
| chlororform | (2.5) | 3.0 | 4.2 | (2.7) | 2.6 | 98 | 100 |
| methylene chloride | 2.0 | 2.4 | 4.6 | 11.1 | 2.2 | 1000 | 30 |
| carbon disulfide | (6.3) | (6.3) | (6.3) | 7.8 | (6.3) | 930 | 30 |
| styrene | (2.2) | (2.2) | (2.2) | (2.4) | 3.9 | 260 | 100 |
| Chloromethane | 3.4 | 4.7 | 1.3 | 2.6 | 4.4 | 100 | 1000 |
| 1,2,4-trimethylbenzene | (2.5) | (2.5) | 9.4 | 2.9 | 17.1 | ||
| 1,3,5-trimethylbenzene | (2.5) | (2.5) | 3.5 | (2.7) | 5.2 | ||
|
|
|||||||
| Fuel Components | |||||||
| Benzene | 2.6 | 4.5 | 2.1 | 3.0 | 5.5 | 12 (I) | 90 |
| ethylbenzene | (2.2) | (2.2) | (2.2) | 2.5 | 6.0 | 4300 | 100 |
| toluene | 21.0 | 11.8 | 45.7 | 31.3 | 32.7 | 1500 | 30 |
| m and/or p xylene | 4.9 | 5.4 | 3.2 | 3.9 | 42.7 | 430 | 100 |
| o-xylene | (2.2) | 2.2 | 5.6 | 2.4 | 19.3 | 430 | 100 |
| decane | (12.0) | (12.0) | (12.0) | (13.0) | 15.0 | ||
|
|
|||||||
| Alcohols | |||||||
| 1-propanol | (5.0) | (5.0) | (5.0) | (5.4) | 7.0 | ||
| 2-propanol |
5.9 |
27.2 | 8.9 | 286.7 | 210.3 | ||
| 1-butanol | 12.0 | (6.2) | 10.5 | 10.0 | 14.7 | ||
|
|
|||||||
| Ketones | |||||||
| Acetone |
97.0 |
32.3 | 50.0 | 350.0 | 54.3 | 31000 | 100 |
| 2-butanone (MEK) | 13.0 | 8.7 | 9.8 | 8.7 | 14.3 | ||
| 4-methyl-2-petanone | (8.3) | (8.3) | 9.7 | 8.9 | 55.1 | ||
| 2-hexanone | (8.3) | (8.3) | (8.3) | (8.9) | 13.0 | ||
|
|
|||||||
| Aldehydes | |||||||
| propanal | 15.0 | 5.9 | 10.1 | 11.4 | 6.3 | ||
| Butanal | 18.0 | 10.4 | 12.1 | (6.5) | 12.3 | ||
| heptanal | (9.5) | (9.5) | (9.5) | (10.3) | 12.3 | ||
| pentana |
(7.2) |
(7.2) | (7.2) | (7.8) | 7.8 | ||
a. Minimal Risk Level. An estimate of daily human exposure--by a specified route and length of time--to a dose of a chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects. The values shown here are expressed as ug/m3 and have been converted from the MRLs established in ppm. All values shown are the Chronic MRL unless designated as the Intermediate MRL (I).
b. Uncertainty Factor: Factor used to account for uncertainties in establishing an MRL. Uncertainty factors may be used to apply data on animals to human exposure, to account for human variability if a level of no adverse effect has not been defined. This factor is the fold margin between observed adverse health effects, or the lowest no observed health effects level, and the set MRL.
c. Values shown in parentheses are the chemical detection level for that air sample. On this table, the limit of detection is given for those compounds which were not found. It is possible the chemical was present at a level below the laboratory detection limit.
Table 4: Cancer classification for chemicals found in indoor
air in five residences near the CCI Site, Olathe, KS.
| Chemical | IRIS Classification a | IARC Classification b | National Toxicology Program c |
| Benzene | A -Known human carcinogen | Group 1 - Human carcinogen | Known to be a human carcinogen |
| Trichloroethylene | Withdrawn d | Group 2A - Probably carcinogenic to humans | Reasonably anticipated to be a human carcinogen |
| Tetrachloroethylene | None | Group 2A - Probably carcinogenic to humans | Reasonably anticipated to be a human carcinogen |
| Chloroform | B2 - Probable human carcinogen | Group 2B - Possibly carcinogenic to humans | Reasonably anticipated to be a human carcinogen |
| Methylene Chloride | B2 - Probable human carcinogen | Group 2B - Possibly carcinogenic to humans | Reasonably anticipated to be a human carcinogen |
| Styrene | None | Group 2B - Possibly carcinogenic to humans | Not listed |
a. Environmental Protection Agency, Integrated Risk Information
System (18).
b. International Agency for Research on Cancer (20).
c. National Toxicology Program, the U.S. Federal Department of Health and Human Services (19).
, accessed on
April 17, 2001., last revised January 2001., accessed on
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