1. Managing risks of noncancer health effects at hazardous waste sites: A case study using the Reference Concentration (RfC) of trichloroethylene (TCE)
- Author
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John Lowe, Michael L. Dourson, Rod B. Thompson, Bernard Gadagbui, and Edward J. Pfau
- Subjects
Hazardous Waste ,Safety Management ,Time Factors ,Trichloroethylene ,Indoor air ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Risk Assessment ,Decision Support Techniques ,chemistry.chemical_compound ,Hazardous waste ,Reference Values ,Uncertainty factor ,Toxicity Tests ,Fetal growth ,Short-term exposure ,Animals ,Humans ,Non-cancer hazard ,Reference dose/concentration ,0105 earth and related environmental sciences ,Inhalation exposure ,021110 strategic, defence & security studies ,Reference dose ,Inhalation Exposure ,Dose-Response Relationship, Drug ,Vapor intrusion ,Safety range ,Hazardous waste sites ,General Medicine ,Sensitive subpopulation ,chemistry ,Risk management ,Environmental chemistry ,Hazardous Waste Sites ,Environmental science ,Environmental Pollutants ,Environmental Monitoring - Abstract
A method for determining a safety range for non-cancer risks is proposed, similar in concept to the range used for cancer in the management of waste sites. This safety range brings transparency to the chemical specific Reference Dose or Concentration by replacing their “order of magnitude” definitions with a scientifically-based range. EPA’s multiple RfCs for trichloroethylene (TCE) were evaluated as a case study. For TCE, a multi-endpoint safety range was judged to be 3 μg/m3 to 30 μg/m,3 based on a review of kidney effects found in NTP (1988), thymus effects found in Keil et al. (2009) and cardiac effects found in the Johnson et al. (2003) study. This multi-endpoint safety range is derived from studies for which the appropriate averaging time corresponds to different exposure durations, and, therefore, can be applied to both long- and short-term exposures with appropriate consideration of exposure averaging times. For shorter-term exposures, averaging time should be based on the time of cardiac development in humans during fetal growth, an average of approximately 20–25 days.
- Published
- 2016