Dioxins Could Interfere With Lactation
July 2, 2009 -- A recent study in the journal Toxicological Sciences reports that exposure of mice to dioxins during pregnancy can affect the development of mammary cells, which under normal conditions proliferate rapidly beginning early in pregnancy. The inhibition of growth has been reported to result in reduced breast-milk production.
Dioxins are a natural byproduct of volcanic eruptions and forest fires, but they are most commonly produced by industrial processes and municipal and medical waste incineration, particularly certain plastics. Once these toxic chemicals are released into the atmosphere, they are absorbed by water, soil, plants, and animals. Human and animal systems have a hard time eliminating the compounds, which accumulate in fatty tissues and persist there for years. This means dairy, meat, fish, and shellfish all accumulate dioxins. According to the World Health Organization, more than 90 percent of human exposure to dioxins is through the food chain.
Because of public concern over a likely carcinogen in the food supply, the Institute of Medicine issued in 2003 Dioxins and Dioxin-like Compounds in the Food Supply: Strategies to Decrease Exposure, which recommended that the government encourage people to minimize their consumption of animal fat and thereby reduce their dioxin exposure while more information is gathered on the health effects of levels found in foods. In addition, the government and food producers should collaborate to stem accumulation of the compounds in food animals. The government should make it a priority to work with food producers on ways to curtail the recycling of rendered animal fats and contaminated grasses into feeds and to develop voluntary guidelines for practices that would minimize animals' exposure.
In 2004, the Environmental Protection Agency asked the National Research Council to evaluate its 2003 draft reassessment of the risks of dioxins. In Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment, the Research Council said the agency did not adequately quantify the sources of uncertainty and variability associated with estimating the risks from dioxin exposure, nor did it sufficiently justify the assumptions used to estimate them. It recommended that EPA re-estimate the cancer risks using several different assumptions and better communicate the uncertainties in those estimates. They also recommended the agency explain more clearly how it selects both the key data sets upon which its reassessment is based and the methods used to analyze them. Based on the recommendations in this report, EPA is currently revising the 2003 risk assessment.Additional Resources