EPA's Dioxin Review & Proposed Soil Clean-up Guidelines Provide No Defined Public Health Benefit
The EPA has been working to complete a comprehensive scientific review of the potential health risks of exposure to dioxins for more than 20 years. In February 2012, EPA released one part of its scientific review. In EPA's non-cancer assessment it set a maximum daily exposure limit of 0.7pg/kg-day for one particular dioxin compound, TCDD. Typically, EPA recommends the use of consensus Toxicity Equivalency Factors for TCDD and other dioxin-like compounds to evaluate the human health risks from environmental exposures to these compounds.
- EPA's exposure limit is three times more stringent than the World Health Organization's tolerable intake level. This difference implies that typical diets lead to unsafe consumption.
- In particular, children could easily exceed EPA's exposure limit by eating every day foods. See Attached Figure.
No Adverse Health Impacts from Current Levels of Dioxin Exposure
- EPA has stated that "known and measurable air emissions of dioxins in the United States have been reduced by 90 percent from 1987 levels."
- EPA states that "generally, over a person's lifetime, current exposure to dioxins does not pose a significant health risk."
- Approximately 95 percent of human exposure to dioxins comes from the diet. The U.S. FDA has stated that the U.S. food supply is among the safest in the world and that the EPA's analysis of dioxins does not change its opinion.
Stricter Regulations and Cleanup Levels Unwarranted
EPA has said that its dioxin assessment could be used in establishing cleanup levels at Superfund sites, reviewing the dioxin drinking water standard, or evaluating Clean Air Act limits.
- EPA has already proposed lowering preliminary remediation goals (PRGs) for dioxins by over 90% from current levels. If the EPA's RfD of 0.7pg/kg-day was used to calculate the PRGs, the proposed value would be reduced by an additional 30%.
- The proposed PRGs could necessitate unnecessary and expensive soil sampling, cause additional remediation to reclaimed brownfield sites and impede new brownfield projects.
- Even though 95% of dioxin exposure comes from food, USDA and FDA don't recommend avoiding any foods because of dioxins. EPA has not shown any public health benefit that would result from remediating soil, which accounts for less than 5% of exposure, to a level that is commensurate with dietary exposures. The PRGs assume children eat 200mg (<0.007 ounces) of contaminated soil a day.
Call to Action
The Office of Management and Budget (OMB) is currently reviewing the PRGs:
- Request that EPA require no additional clean-up when dioxin levels are within background and commensurate with dietary exposures.
- Request that OMB send the PRGs back to EPA. The EPA must:
- Justify what public health benefit the removal and disposal of dioxin containing soils provides.
- Confirm that elevated levels of dioxins in soil present a public health risk.
Comparison of EPA's RfD, Concentrations of Dioxins found in a typical 1200 Calorie Diet and EPA's Proposed PRGs
*The USDA MyPlate Diet Recommends children 2-3 years of age consume 1000 - 1400 calories per day. The quantities recommended from each food group for an average (1200 calorie) diet are 1 cup of fruit, 1 1/2 cup of vegetables, 4oz of grains, 3oz of protein and 2 1/2 cups of dairy.
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