PUBLIC HEALTH ASSESSMENT
POOLS PRAIRIE SITE
(a/k/a Neosho Wells)
NEOSHO, NEWTON COUNTY, MISSOURI
Figure 1: Pools Prairie Site Map
Exposure Calculations
Water Ingestion Exposure Calculations
IDw = C x IR x EF
BW
where,
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)
Trichloroethylene (TCE)
Adult:
This calculation assumes that an adult weights 70 Kg (approximately 155 pounds), drinks 2 liters 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 parts per million (ppm).
Child:
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.
Carbon Tetrachloride
Adult:
This calculation assumes that an adult weights 70 Kg, drinks 2 liters 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.
Child:
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 need to make some assumptions. These are: A person breathes in approximately 15 cubic meters of air per day, that they live in a 2,000 square foot house with three bedrooms, that there is 100% TCE and carbon tetrachloride volatilization from water, and that water usage in a home is approximately 120 gallons/bedroom.
TCE inhalation exposure:
Cancer Calculations
Formula:
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 its carcinogenicity, the following calculation is used to approximate its risk if it would be determined to be carcinogenic.
Ingestion Exposure:
| 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. | |
