PUBLIC HEALTH ASSESSMENT
POOLS PRAIRIE SITE
(a/k/a Neosho Wells)
NEOSHO, NEWTON COUNTY, MISSOURI
Water Ingestion Exposure Calculations
IDw = C x IR x EF
IDw = ingestion exposure dose (milligram/Kilogram/day or mg/Kg/day);
C = contaminant concentration (milligram/Liter or ppm);
IR = ingestion rate (Liter/day or L/day);
EF = exposure factor
BW = body weight (Kilogram or Kg)
This calculation assumes that an adult weights 70 Kg (approximately 155 pounds), drinks 2 liters oftap water per day, the exposure factor is 100%, and is exposed to the maximum detected level ofTCE at 310 ppb or 0.310 parts per million (ppm).
This calculation assumes that a child weights 10 Kg (approximately 22 pounds), drinks 1 liter of tap water per day, the exposure factor is 100%, and is exposed to the maximum detected level of TCE at 310 ppb or 0.310 ppm.
This calculation assumes that an adult weights 70 Kg, drinks 2 liters of tap water per day, theexposure factor is 100%, and is exposed to the maximum detected level of carbon tetrachloride at 8.4 ppb or 0.0084 ppm.
This calculation assumes that a child weights 10 Kg, drinks 1 liter of tap water per day, the exposure factor is 100%, and is exposed to the maximum detected level of carbon tetrachloride at 8.4 ppb or 0.0084 ppm.
Inhalation exposure from TCE and carbon tetrachloride in drinking water
In order to estimate the inhalation exposure residents of the Pools Prairie site experienced, we needto make some assumptions. These are: A person breathes in approximately 15 cubic meters of airper day, that they live in a 2,000 square foot house with three bedrooms, that there is 100% TCEand carbon tetrachloride volatilization from water, and that water usage in a home is approximately120 gallons/bedroom.
TCE inhalation exposure:
Cancer Risk = Exposure dose x risk factor x years of exposure
Using the assumption that TCE is carcinogenic, even though it is under review as to itscarcinogenicity, the following calculation is used to approximate its risk if it would be determined tobe carcinogenic.
|Comments and Responses on the public comment version of the Pools Prairie Public Health Assessment. |
|1. Page 7.||The Draft Decision Document for the Engine Test Area (ETA) is used as a reference and being a draft document is subject to revision and not intended for public distribution when there are other sources for the information. |
|The reference for this information has been revised.|
|2. Page 7.||The last two sentences in the first paragraph are inconsistent with the referenced document and appear to be derived from some other document. |
|The document has been revised.|
|3. Page 7.||In the second paragraph, the results of the 1996 EPA sampling event are incorrectly ascribed to a 1993 report by RUST (reference 17). Also, the 4,000 ppb TCE in groundwater was actually 4,200 ppb. The information on this sampling event is in the Ecology and Environment, 1997, Removal Assessment of the Neosho Well Site. |
|The RUST document was incorrectly referenced. The public health assessment has been revised to reflect the proper document and the proper value of TCE.|
|4. Page 18.||The conclusion regarding source areas exposure (both current and future) is not quantitatively supported (Conclusion 4). |
|The Public Health Assessment is not intended to be a quantitative document. It is assumed that as long as contamination remains at the source areas, the chance of exposure is possible.|
|5. Page 26.||The exposure and cancer calculations are not adequately explained. The numeric results are not quantitatively interpreted. |
|Additional information about the exposure and cancer calculations were added to better understand why and how they were completed. The public health assessment is not intended to be a quantitative document.|