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HEALTH CONSULTATION

ABLE PEST CONTROL
SEATTLE, KING COUNTY, WASHINGTON


BACKGROUND AND STATEMENT OF ISSUES

The Washington State Department of Health (DOH) has prepared this health consultation at the request of the Washington State Department of Ecology (Ecology) in order to address the potential health hazard associated with pesticides in soil at the former Able Pest Control facility and nearby Lake Forest Park Preschool located in Seattle, King County, Washington. This consultation will consider past, current and future land use scenarios. Community health concerns collected by the Ecology site manager are also addressed. DOH prepares health consultations under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). All of the data available to DOH is presented in the background section followed by a discussion of the health implications, conclusions and recommendations.

The site is located in a residential area at 18115 62nd Avenue NE bordered by 62nd Avenue to the east, residences to the north and west and the Lake Forest Park Preschool to the south (Figure 1). Able Pest Control operated at the site from 1969 through 1985. The facility was sold in 1986 and converted into a residence in 1994. The residence consists of two units, one in the basement and one at ground level, both of which are currently occupied. Discussions with the previous owner and employees of Able Pest Control indicate that pesticides were stored on-site. Mixing is thought to have occurred primarily at the application site but some mixing of bait and pesticide did occur in the basement. Rinsate was reportedly dispensed at the application site. A shed underneath the porch and the garage have been identified as storage areas. (1) The shed was converted to a bedroom for the downstairs apartment requiring excavation of soil and pouring of a concrete slab. The soil from this excavation was piled in the southwest corner of the property. (2)

The original tenant of the basement apartment began seeking assistance for health concerns following a flood in the apartment in January 1997. The Seattle-King County Health Department (SKCHD) conducted a site visit of the residence in June 1997. Initial concerns identified at this time included indoor air quality issues related to mold, smoking, cat hair and pesticides. (3) This tenant and family moved out of the apartment in July 1997. (1)

Environmental Contamination

parts per million explanationEcology site managers and staff from the University of Washington Department of Environmental Health (UW DEH) visited the site on July 16, 1997. UW DEH staff took indoor air and wipe samples at the basement apartment and analyzed them for mold. The number of organisms found in indoor air was similar to that found outside the apartment and slightly higher than what is usually found in indoor air. (2,4) Ecology collected two soil samples at the base of the foundation near the basement bedroom (former shed area). Chlordane and dieldrin were detected at 12 and 0.4 parts per million (ppm), respectively, in one of these samples. Odors were noted during sampling at one of these locations and a reading of 1.6 ppm on a volatile organics analyzer was recorded. (2,5)

Additional samples of the interior were taken by the former resident of the basement apartment that included a photograph, carpet and furniture stuffing. A composite sample of the carpet contained up to 66 ppm chlordane, 3.8 ppm lindane and 4.2 ppm DDT. Lower levels of chlordane and DDT were found in the photograph. Analysis of a wipe sample taken from the concrete slab foundation beneath the basement carpeting detected no pesticides. (6)

In response to the detection of these pesticides, the current owner of the property contracted for the removal of soil from the south foundation of the building along the basement bedroom. Sampling and excavation from this area continued from September 1997 through February 1998. Chlordane, dieldrin and heptachlor were detected in the excavation trench at maximum levels of 4.5, 0.22 and 0.53 ppm, respectively. The trench was enlarged three times during this period until the levels of pesticides fell below state regulations established under the Model Toxic Control Act (MTCA). All soil removed during this action was disposed of off-site. As a follow-up to this soil removal action, additional soil samples were taken from underneath the concrete slab foundation of the basement bedroom and found to contain chlordane at 0.23 ppm. The soil pile located in the southwest corner of the property that resulted from the excavation of this foundation was also found to contain 8.5 ppm of chlordane and 1.1 ppm of dieldrin. (7)

Three more soil samples were taken by SKCHD in February 1998. Two of these came from the southern boundary of the property and were found to contain chlordane and dieldrin at maximum levels of 1.6 and 4.1 ppm, respectively. Lower levels of other organochlorine pesticides were also detected. A third sample taken from the play area at the adjacent Lake Forest Park Preschool had a maximum of 0.2 ppm chlordane and 0.1 ppm dieldrin. Ecology sampled the preschool grounds further in March 1998 and detected lower levels of chlordane and dieldrin. (8)

An interim removal action was initiated in May 1998 that resulted in removal of soil from both the preschool grounds and the south border of the former Able Pest Control property. Approximately 10 tons of soil were removed from the northwest corner of the preschool play area. Soil samples taken at the bottom of this excavation indicate that levels of pesticides are below MTCA standards. The area was regraded with clean soil and seeded with grass.

Soil sampling and excavation along the southern border of the former Able Pest Control property was completed in August 1998. Approximately 70 tons of soil were removed including the contaminated soil pile noted above. Sampling conducted during this excavation revealed higher contamination than was previously found including a maximum of 175 ppm chlordane and 21 ppm heptachlor. The excavated area was backfilled with clean soil and landscaped. Additional steps were taken to prevent erosion of soil onto preschool property from areas that were not cleaned up and could contain pesticides. Until Ecology can determine if further action is needed, the former Able Pest Control property will be monitored to ensure that soil is not eroding.

The maximum detected levels of the contaminants of concern are given for either property in Table 1 below. Contaminants of concern were chosen based on a comparison of levels detected in soil with the corresponding ATSDR soil screening value for each contaminant. These screening values are based on the ability of the contaminant to cause either cancerous or non-cancerous health effects. For each of the contaminants of concern given in Table 1, the screening value is based on cancer. Contaminants of concern do not necessarily represent a public health hazard, but signify the need for further evaluation.

Table 1.

Maximum levels of contaminants of concern in soil at the former Able Pest Control site given in parts per million (ppm).
Contaminant Former Able Pest Control Property Preschool Property ATSDR
Screening
Value
EPA Cancer
Class
Aldrin 0.5 ND 0.04 B2
Chlordane 175 0.21 b 0.5 B2
delta-Hexachlorocyclohexane a 1.4 ND NA D
Dieldrin 5.2 0.1 0.04 B2
Endrin Ketone 0.09 ND NA NA
Heptachlor Epoxide 0.46 ND 0.08 B2
Heptachlor 21 ND 0.2 B2

a = Also know as delta-Benzenehexachloride (-BHC)
b = Although this value does not exceed the ATSDR screening value, it was included as a contaminant of concern for the preschool property based on the high levels found along the border of the adjacent former Able Pest Control property.
ND = not detected
NA = not available
B2 = probable human carcinogen
D = not classifiable as to carcinogenicity

Biological Testing

parts per billion explanationDOH has received the results of one blood serum sample analyzed for chlordane, dieldrin and heptachlor. The sample was drawn from a student at the Lake Forest Park Preschool and indicated the presence of heptachlor at 0.4 parts per billion (ppb) which exceeded its reference range of 0.2 ppb. Trans-nonachlor, a component of the pesticide mix called technical chlordane, was also found at 0.4 ppb which is below its reference range of 1.3 ppb. The reference value is provided as a measure of what would be expected in the general population. Any result above the reference value is considered to be elevated. Reevaluation of the test data showed that the level of heptachlor should have been reported as below its detection limit of 0.2 ppb. (9) A further discussion of biological sampling and reference values for these pesticides is given in Appendix C.


DISCUSSION

Several pesticides have been found in soil at the former Able Pest Control property and the adjacent Lake Forest Park Preschool. Concentrations of these pesticides are considerably higher on the former Able Pest Control property compared with the preschool grounds. It is likely that the pesticides found at the preschool, chlordane and dieldrin only, are the result of contaminated soil migrating from the former Able Pest Control property.

The following discussion will address the exposure and potential health hazards associated with the contaminants of concern found at each property.

Former Able Pest Control Property

The primary contaminants of concern detected at the former Able Pest Control property include chlordane, dieldrin and heptachlor. Heptachlor epoxide, aldrin, endrin ketone, delta-benzenehexachloride (d-BHC) were found less frequently and at lower levels. All of these pesticides are classified as organochlorines. Some of the contaminated soil on this property has been removed.

Residents living at this property could be exposed to pesticides in soil through accidental ingestion, skin contact and dust inhalation. Exposure to these contaminants in soil is based on limited sampling of the southern border of the property. In addition to direct contact with soil during outdoor activities, contaminated soil could be brought inside and accumulate as indoor dust. No indoor dust sampling data is available for either apartment, however, and exposure via this pathway could not be quantified. A sample of carpeting from inside the basement apartment contained detectable levels of chlordane, lindane and DDT. It is important to note that ongoing cleanup of contaminated soil could increase the amount of dust migrating from excavated soil via airborne dispersion and tracking (i.e., soil brought inside through adherence to pets, shoes and clothing). If significant levels of pesticides exist in indoor dust or unsampled areas of the yard, the following evaluation of health risks could be underestimated.

oral reference dose explanationPast exposure of residents at the former Able Pest Control property to pesticides found in soil was estimated to result in a very low increased risk for non-cancerous adverse health effects. A dose was estimated for a young child exposed for several years to chlordane, dieldrin, aldrin, heptachlor and heptachlor epoxide in soil. The dose estimated for chlordane was approximately two times higher than its corresponding oral reference dose (RfD). The doses estimated for dieldrin, aldrin, heptachlor and heptachlor epoxide were all below their respective RfDs. RfDs are set by the Environmental Protection Agency (EPA) as a level below which non-cancerous adverse health effects are not anticipated. The other pesticides noted as contaminants of concern in Table 1 were not evaluated because they do not have RfDs. These contaminants are not expected to contribute substantially to the overall risk, however, because they were detected infrequently and at low levels.

For each of the contaminants evaluated, the RfD is based on liver toxicity. It is important to consider combined exposure to these pesticides since they are present together in the soil and have a similar toxic effect (liver). In order to assess the combined exposure, the estimated doses for each of the contaminants noted above were added and compared with a "combined RfD". This combined dose did not substantially add to the risk estimated from exposure to chlordane alone.

Although the estimated dose for chlordane is slightly higher than its RfD, it is 200 times below the actual toxic effect level. This is because the RfD is set many times below toxic effect levels in order to provide added public health protection. It is, therefore, unlikely that a child exposed to chlordane at this property would suffer any liver damage. A general discussion of organochlorine pesticides and their toxicity is given in the Organochlorine Pesticides and Toxicity section (page 7).

cancer risk explanationSeveral of these pesticides are classified as Group B2 probable human carcinogens by the EPA. A low increase in cancer risk was estimated for residents exposed over a 30-year period to pesticides in soil at the former Able Pest Control property. This risk would be reduced to slight or insignificant for residents who lived at the apartment for a few years or less (e.g., < 3 years).

EPA designates a chemical as a B2 probable human carcinogen when there is sufficient animal evidence but inadequate or no human evidence of its ability to cause cancer. There is sufficient evidence that aldrin, chlordane, dieldrin, heptachlor and heptachlor epoxide can cause liver tumors in mice at very high and repeated doses. Two studies of human populations have found an association between chlordane exposure and non-Hodgkins lymphoma. However, the people examined in these studies were exposed to many different types of pesticides other than the organochlorines found at the former Able Pest Control property. Several other studies have found no association between organochlorine pesticide exposure and cancer. (10)

Preschool Property

Chlordane and dieldrin are the only contaminants of concern that have been detected on the preschool grounds. The levels of these pesticides found at the preschool are much lower than what was detected on the former Able Pest Control property. The only area of contamination that exceeded Ecology cleanup levels was located along the northwest border of the property adjacent to the former Able Pest Control property and the contaminated soil pile noted previously. This area has been excavated, regraded with clean soil and seeded with grass (see Figure 1).

Exposure Pathways and Children

The potential for exposure and subsequent adverse health effects are often increased for young children as opposed to older children or adults. For example, children are far more likely to engage in activities that involve "getting dirty." Playing in dirt, combined with frequent hand to mouth activity, provides toddlers with an increased chance of exposure to soil contaminants by way of ingestion and skin contact. In addition to the potential for higher exposures of young children, the risk of adverse health effects is also increased. ATSDR and DOH recognize that children are susceptible to developmental toxicity that can occur at levels much lower than those causing other types of toxicity.

Children at the preschool could be exposed to very low levels of pesticides in soil. The area that has been cleaned up contained the highest levels of chlordane and dieldrin which were found at a maximum of 0.21 and 0.1 ppm, respectively. Children exposed to these levels of chlordane and dieldrin are not expected to suffer any adverse health effects. The estimated dose for a child exposed over a 5-year period, three days per week from September to June is well below the RfD for each of these contaminants. The estimated cancer risk from this exposure is not significant.

An adult exposure scenario was also evaluated for a teacher exposed three days per week from September to June over a 20-year period. Although a teacher is assumed to be exposed over a longer period of time than a student, the estimated dose is lower because the child is smaller and has more contact with the soil. No adverse health effects are expected to result from exposure of teachers to chlordane and dieldrin in Lake Forest Park Preschool soil.

Biological Testing

Heptachlor and trans-nonochlor were both detected in a blood sample taken from a child who attended the preschool. Heptachlor was reported above its reference value while trans-nonachlor fell below that value. No other chemicals associated with chlordane and heptachlor exposure were detected. The amounts of heptachlor and trans-nonachlor found in this blood sample were only slightly higher than what the test can detect. In fact, a reevaluation of the test result for this blood sample indicated that heptachlor should have been reported as not detected. The value of biological sampling for these pesticides in blood, and specifically this result, is discussed further in Appendix C.

No studies were found associating blood levels of heptachlor and trans-nonachlor with adverse health effects. One study found no effect on liver enzyme activity in a population of dairy farmers exposed to heptachlor epoxide, trans-nonachlor and oxychlordane in cows' milk when compared to unexposed dairy farmers. Levels of heptachlor epoxide (average of 0.84 ppb) and oxychlordane (average of 0.71 ppb) were significantly higher than those found in unexposed farmers. However, there was no significant difference in average levels of trans-nonachlor between the exposed and unexposed farmers. These data are useful in evaluating the blood sample in question because heptachlor epoxide is considered more toxic than heptachlor which was found at a lower level (0.4 ppb) in the student from the preschool. It is important to note that the levels of the these three pesticides exceeded 0.4 ppb for both exposed and unexposed farmers. (11) The toxicity of organochlorine pesticides is discussed more generally in the next section.

Organochlorine Pesticides and Toxicity

Chlordane, dieldrin and heptachlor belong to a class of pesticides called organochlorines. Agricultural use of these pesticides was phased out during the 1970s and their primary use switched to termite control. The EPA banned all uses of chlordane in 1988 although it is still prepared in the United States for export. The use of heptachlor was also banned in 1988 with an exception made for the control of fire ants in power transformers. The use of dieldrin ended in 1987 when its manufacturer voluntarily canceled its registered use for termite control.

Organochlorines are identified by the presence of chlorine in their structure and, once released, remain in the environment for very long periods of time. The ability of these pesticides to accumulate in fat tissue means that very small amounts in air, water, soil and food can result in detectable levels in fat, blood and breast milk. The main toxic effect of these pesticides is on the liver and has only been demonstrated at very high doses, primarily in laboratory animals.

Nervous system toxicity has been documented in humans receiving large doses of organochlorines through poisoning. Organochlorine poisoning can include mild symptoms such as loss of balance, headache, dizziness and tremors as well as severe effects such as convulsions, seizures and death depending upon the dose. (12) (13) (14) Other human studies have found evidence of adverse health effects in residents exposed following application of technical chlordane to their homes or workplace for termite control. Three such studies found evidence of neurotoxicity and immune system alterations in people exposed to technical chlordane applied to their homes/workplace several years prior to examination. (15) (16) (17) Although exposure in these studies was not measured by blood testing, it is considered to be substantially higher than what students at Lake Forest Park Preschool would have experienced.

There is evidence in animal testing that chlordane can affect the immune system of the developing fetus. Since organochlorines can accumulate in breast milk, exposure after birth may also be important with respect to this potential toxic endpoint. (18) Although developmental toxicity has not been demonstrated in humans, the effects on the immune system noted above support this possibility.


COMMUNITY HEALTH CONCERNS

The following community health concerns were related to the Ecology site manager during a meeting with Lake Forest Park Preschool parents on April 8, 1998.

1) What about the bark chips? Are they contaminated too?

The bark chips were not directly contaminated with pesticides. However, soil contaminated with pesticides moved onto the Lake Forest Park Preschool from the adjacent former Able Pest Control property to the north. Some of this contaminated soil will be on the bark chips that cover the preschool play area. Therefore, the amount of pesticides on the bark will be less than that found in the soil. Contact with the bark chips is not considered to be a health hazard because the amount of pesticides in the soil is below a level of health concern. Exposure to soil at the preschool and the source property is discussed above.

2) Is the play equipment contaminated (e.g., the wooden pieces and tires)?

Play equipment was not directly contaminated with pesticides. It is likely, however, that some contaminated soil is present on the equipment in the preschool play area. As noted above, however, the levels of pesticides in the soil at the preschool are below a level of concern. Exposure to soil on play equipment is, therefore, also not a health concern.

3) Are the children at risk? What do we mean by risk?

The risk to children exposed to pesticides in soil at the Lake Forest Park Preschool property is discussed previously in the Preschool Property section on page 5.

Risk is discussed here as the possibility that an adverse health effect will result from exposure to these pesticides in soil. This risk is assessed differently for cancerous and non-cancerous endpoints.

Evaluating Non-cancer Risk

In order to evaluate the potential for non-cancerous adverse health effects to result from exposure to contaminated media (i.e., air, water, soil, and sediment), a dose is estimated for each contaminant of concern. These doses are calculated for situations (scenarios) in which people might come into contact with the contaminated media. The estimated dose for each contaminant under each scenario is then compared to ATSDR's minimal risk level (MRL) or EPA's oral reference dose (RfD). MRLs and RfDs are doses below which non-cancerous adverse health effects are not expected to occur (so called "safe" doses). They are derived from toxic effect levels obtained from human population and laboratory animal studies. These toxic effect levels can be either the lowest observed adverse effect level (LOAEL) or a no-observed adverse effect level (NOAEL). In human or animal studies, the LOAEL is the lowest dose at which an adverse health effect is seen, while the NOAEL is the highest dose that did not result in any adverse health effects.

Because of the uncertainty in these data, the toxic effect level is divided by "safety factors" giving the lower and more protective MRL or RfD. If a dose exceeds the MRL or RfD, this indicates only the potential for adverse health effects. The magnitude of this potential can be inferred from the degree to which this value is exceeded. If the estimated exposure dose is only slightly above the MRL or RfD, then that dose will fall well below the toxic effect level. The higher the estimated dose is above the MRL or RfD, the closer it will be to the toxic effect level.

Evaluating Cancer Risk

Some chemicals have the ability to cause cancer. Cancer risk is estimated by calculating a dose similar to that described above and multiplying it by a cancer potency factor, also known as the cancer slope factor. Some cancer potency factors are derived from human population data. Others are derived from laboratory animal studies involving doses much higher than are encountered in the environment. Use of animal data requires extrapolation of the cancer potency obtained from these high dose studies down to real-world exposures. This process involves much uncertainty. Current thinking suggests that there is no "safe dose" of a carcinogen and that a very small dose of a carcinogen will give a very small cancer risk. Cancer risk estimates are, therefore, not yes/no answers but measures of chance (probability). Such measures, however uncertain, are useful in determining the magnitude of a cancer threat since any level of a carcinogenic contaminant carries an associated risk. The validity of the "no safe dose" assumption for cancer-causing chemicals is not clear. Some evidence suggests that certain chemicals considered to be carcinogenic must exceed a threshold of tolerance before initiating cancer.

This document describes cancer risk qualitatively using terms like low, very low, slight and no significant increase in cancer risk. These terms can be better understood by considering the population size required for such an estimate to result in a single cancer case. For example, a low increase in cancer risk indicates an estimate in the range of one cancer case per ten thousand persons exposed over a lifetime. A very low estimate might result in one cancer case per several tens of thousands exposed over a lifetime and a slight estimate would require an exposed population of several hundreds of thousands to result in a single case. DOH considers cancer risk to be not significant when the estimate results in less than one cancer per one million exposed over a lifetime.

The reader should note that these estimates are for excess cancers that might result in addition to those normally expected in an unexposed population. Cancer is a common illness that increases with age. Depending on the type of cancer, an unexposed population could be expected to have a substantial number of cancer cases. There are many different forms of cancer that result from a variety of causes. About a quarter of the people in Washington State die of cancer. Approximately one quarter to one third of people living in the United States will develop cancer at some point in their lives.

4) Should the children have blood samples taken? Is this a test that can be done by their regular doctors?

The pesticides found in preschool soil can be measured in blood. DOH is not recommending blood samples, however, because the amounts of these pesticides are below a level of health concern. There are also difficulties associated with the interpretation of blood test results. These difficulties are discussed in Appendix C.

DOH does recognize that some parents may want blood testing for their child despite the limitations of the test. Your local physician can arrange to have the blood drawn and sent to an appropriate laboratory. DOH is available to discuss and help arrange the test. Please contact Robert Duff toll-free at 1-888-5TOXICS (1-888-586-9427) or directly at 360-236-3371.

5) What about the tenants next door? Are they at risk?

The property that was the former Able Pest Control facility is now a residence with two apartments. The risk to tenants exposed to pesticides in soil at this property is discussed previously in the Former Able Pest Control Property section on page 4.

6) How long will the cleanup take? Will the site become recontaminated by the adjacent property?

The Washington State Department of Ecology (Ecology) is currently overseeing an agreed order with the responsible parties that requires excavation and removal of contaminated soil on both properties. Action has been taken to prevent further migration of pesticides from the former Able Pest Control property onto the Lake Forest Park Preschool grounds. Please contact Louise Bardy at 425-649-7209 (Ecology) for further information about the ongoing cleanup of this site.


CONCLUSIONS

No apparent public health hazard exists for children exposed to pesticides in soil at the Lake Forest Park Preschool. Past exposure did not exceed a level of health concern and the area with the highest levels of pesticides in soil has been excavated, regraded with clean soil and seeded with grass.

Levels of chlordane and heptachlor related chemicals detected in the blood of a child who attended the Lake Forest Park Preschool do not appear to be elevated above what might be expected in an unexposed population. There is no evidence associating these levels with adverse health effects.

A potential public health hazard exists for residents exposed to pesticides in soil at the former Able Pest Control property. Existing data indicates a low increased risk for both non-cancerous and cancerous adverse health effects for residents exposed to soil over a long period of time. However, DOH does not consider the available data to be sufficient to accurately assess the potential health hazard posed to residents living at the site. Specifically, soil sampling is restricted to the southern border of the property and no indoor dust sampling has been done.


RECOMMENDATIONS

1) Further soil sampling should be performed at the former Able Pest Control property. Included in the sampling plan should be samples taken from the top three inches of soil in bare soil and high use areas (e.g. walkways, doorsteps, gardens). This data should be provided to DOH for further health evalaution.

Actions

  • Ecology will require and oversee further sampling at the former Able Pest Control property.

2) Both apartments at the former Able Pest Control property should be sampled for indoor dust contamination.

Actions

  • DOH will consult with ATSDR on how best to proceed with indoor dust sanpling at these residences.

3) Tenants living in the two apartments should take precautions to reduce exposure to pesticides in soil and indoor dust.

Actions

  • DOH has provided the current tenants with specific recommendations on how to reduce exposure.


REFERENCES

  1. King County Water and Land Resources Division, Hazardous Waste Management Program. Regarding RFA #C9701845. Residential property located at 18115 62nd Avenue NE, Seattle, WA. September 8, 1998

  2. Washington State Department of Ecology. Initial investigation field report: Peggy Dennis/Schlittenhard residence. ERTS Number: N27189. July 16, 1997.

  3. Seattle-King County Department of Public Health. Letter from Jeff Ketchel to Peggy Dennis. July 7, 1997.

  4. Washington State Department of Ecology. Conversation Record between Louise Bardy (Ecology) and Dr. Mansour Samadpour (University of Washington). August 21, 1997.

  5. Manchester Environmental Laboratory. Case narrative: Peggy Dennis Residence, (soil and sediment). August 12, 1997

  6. Hart Crowser, Inc. Letter to from David E. Chawes to Mr. Scott Missal (Short, Cressman and Burgess). Re: Pesticide document review and sample analysis. Former residence of Peggy Dennis, 18115 62nd Avenue NE, Bothell, Washington. February 3, 1998.

  7. Pacific Groundwater Group. Letter from Janet N. Knox to John H. Wiegenstein (Heller Wiegenstein, P.L.L.C.). Re: Soil sample results former Able Pest Control site, Ecology I.D. No. N-17-5495-000. April 9, 1998.

  8. On-site Environmental Inc. Chain of Custody. Relinquished by Carsten Thomsen (SKCHD) to Kusten Koch. February 18, 1998.

  9. Pacific Toxicology Laboratories. Letter to Agnes Wong, MD from Linda S. Aston, Ph.D. Re: Amended heptachlor results for (NAME OMITTED). August 25, 1998.

  10. Environmental Protection Agency. Toxicological review of chlordane (Technical). December, 1997.

  11. Stehr-Green PA, Wohleb JC, Royce W, Head SL. An evaluation of serum pesticide residue levels and liver function in persons exposed to dairy products contaminated with heptachlor. JAMA. 1988;259(3):374-77.

  12. Agency for Toxic Substances and Disease Registry. Toxicological profile for chlordane. May 1994. Atlanta: U.S. Department of Health and Human Services.

  13. Agency for Toxic Substances and Disease Registry. Toxicological profile for aldrin/dieldrin. April 1993. Atlanta: U.S. Department of Health and Human Services.

  14. Agency for Toxic Substances and Disease Registry. Toxicological profile for heptachlor. April 1993. Atlanta: U.S. Department of Health and Human Services.

  15. Kilburn KH, Thornton JC. Protracted neurotoxicity from chlordane sprayed to kill termites. Environ Health Perspect. 1995;103:690-94.

  16. Menconi S, Clark JM, Langenberg P, Hryhorczuk D. A preliminary study of potential human health effects in private residences following chlordane applications for termite control. Arch Environ Health. 1988;43:349-52.

  17. McConnachie PR, Zahalsky AC. Immune alterations in humans exposed to the termiticide technical chlordane. Arch Environ Health. 1992;47:295-310

  18. Quinsey PM, Donohue DC, Ahokas JT. Persistence of organochlorines in breast milk of women in Victoria, Australia. Fd Chem Toxic 1995;33(1):49-56.

APPENDIX A: FIGURES

Former Able Pest Control Property and adjacent Lake Forest Park Preschool
Figure 1: Former Able Pest Control Property and adjacent Lake Forest Park Preschool


APPENDIX B: EXPOSURE DOSE CALCULATIONS

Exposure Dose Calculations (Part 1)
Exposure Dose Calculations (Part 1)

Exposure Dose Calculations (Part 2)
Exposure Dose Calculations (Part 2)


APPENDIX C: BIOLOGICAL SAMPLING OF ORGANOCHLORINE PESTICIDES

Biological Sampling of Organochorine Pesticides (Page 1)
Biological Sampling of Organochorine Pesticides (Page 1)

Biological Sampling of Organochorine Pesticides (Page 2)
Biological Sampling of Organochorine Pesticides (Page 2)


APPENDIX D: SITE PHOTOGRAPHS

(All photographs were taken 7/17/98)

Site Photographs (Page 1)
Page 1

Site Photographs (Page 2)
Page 2


CERTIFICATION

This Health Consultation for the Able Pest Control site was prepared by the Washington Department of Health under a cooperative agreement with the Agency for Toxic Substances amd Disease Registry (ATSDR). It is in accordance with the approved methodology and procedures existing at the time the Health Consultation was initiated.

Technical Project Officer, SPS, RPB, DHAC


The Division of Health Assessment and Consultation (DHAC), ATSDR, has reviewed this Health Consultation and concurs with its findings.

Richard Gillig
for Division Director, DHAC, ATSDR



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