EPA to Develop Interim Preliminary Remediation Goals for Dioxin in Soil
October 26, 2009 // Published as a news service by IHS
The U.S. Environmental Protection Agency (EPA) will develop interim preliminary remediation goals (PRGs) for dioxin in soil at contaminated sites.
The plan includes a review of current dioxin cleanup guidance that was established by the EPA, states and other countries, including updated peer-reviewed dioxin toxicity assessments.
In developing these PRGs, EPA's Office of Solid Waste and Emergency Response (OSWER) and EPA's Office of Research and Development will review current soil cleanup levels and dioxin toxicity values used by the states, the Agency for Toxic Substances and Disease Registry and other countries.
Based on this evaluation, OSWER may reconsider EPA's currently recommended PRGs for Superfund, federal facilities, Brownfields and Resource Conservation and Recovery Act sites.
Those PRGs are 1 parts per billion (ppb) or 1,000 parts per trillion (ppt) for dioxin toxicity equivalents in residential soil and a level within the range of 5 ppb (or 5,000 ppt) and 20 ppb (or 20,000 ppt) in commercial/industrial soil, where exposure is due to direct contact.
Three key components of EPA's current recommended PRGs will be re-evaluated:
- The EPA dioxin toxicity value adopted in 1985.
- Generic exposure assumptions.
- Cancer risk level.
OSWER intends to recommend interim PRGs informed by the latest science and the work of state and other agencies.
EPA will release the draft interim PRGs for public comment in December 2009 and anticipates issuing the final interim PRGs in June 2010.
The EPA is undertaking a reassessment of dioxin, the results of which are expected to be released by the end of 2010.
Source: U.S. Environmental Protection Agency (EPA).