Difference between revisions of "TCA in groundwater"
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In text: 6 Exposure & 7 Determination of dose | In text: 6 Exposure & 7 Determination of dose | ||
| + | |||
| + | * Domestic wells | ||
| + | * Routes | ||
| + | * Ingestion | ||
| + | * Toilet bowl | ||
| + | * Shower | ||
| + | * Bath | ||
| + | * Total dose | ||
| + | |||
| + | Worst case bathroom exposure: 1 bath per day + staying bathroom for 1 hour + ingestion of 2 litres | ||
| + | |||
| + | * 0,0286 ug/kg day + 0,0478 ug/kg day = '''0,0764 ug/kg day''' (Water containing 1 ppb TCA) | ||
== Risk Characterization == | == Risk Characterization == | ||
In text: 10 Conclusions & 9 Estimation of nontoxic dose | In text: 10 Conclusions & 9 Estimation of nontoxic dose | ||
Revision as of 11:00, 13 September 2006
Introduction to Environmental risk analysis - course
Groupwork
Mikko Pohjola
Juha Villman
James L. Byard: Hazard Assessment of 1,1,1-Trichloroethane in Groundwater
Contents
Identification of Hazard
In text: chapters 8 Toxicology & 9 Estimation of nontoxic dose
- TCA has been used as an industrial degreasing solvent
- TCA is absorbed from the gastrointestinal tract and 30 % from the lungs
- Chemical is rapidly distributed to all tissues via bloodstream
- Chronic toxicity
- Reported in several studies for no toxicity, no excess cancers, no marked oncogenic effect, no effect on mortality or body weight
- One study reported excess of leukemias in rats exposed to TCA
- Only few weakly positive results for mutagenicity of TCA
- These results can be explained by butylene oxide present in some commercial formulations of TCA
- No teratogenic effects in rodents exposed to TCA
- TCA is relatively nontoxic chemical
- High dose of TCA can cause:
- Narcosis
- Mild organ pathology
- Irritation of respiratory tract
Dose-Response assessment
In text: 8 Toxicology & 9 Estimation of nontoxic dose
- 15 minutes of vapor concentrations of TCA increasing from 0 to 2650 ppm
- Mild eye irritation at 1000 - 1100 ppm
- Throat irritation at 1900 - 2000 pm
- Lightheadedness at 2600 ppm
- Inability to stand at 2650 ppm
Exposure assessment
In text: 6 Exposure & 7 Determination of dose
- Domestic wells
- Routes
- Ingestion
- Toilet bowl
- Shower
- Bath
- Total dose
Worst case bathroom exposure: 1 bath per day + staying bathroom for 1 hour + ingestion of 2 litres
- 0,0286 ug/kg day + 0,0478 ug/kg day = 0,0764 ug/kg day (Water containing 1 ppb TCA)
Risk Characterization
In text: 10 Conclusions & 9 Estimation of nontoxic dose
