EFSA lowers intake levels of dioxins and dioxin-like PCBs in food

Following a risk assessment by the European Food Safety Authority’s expert Panel on Contaminants in the Food Chain (CONTAM), EFSA has set a new tolerable weekly intake (TWI) for dioxins and dioxin-like PCBs in food of 2 picograms per kilogram of body weight. The new TWI is seven times lower than the previous EU tolerable intake set by the European Commission’s former Scientific Committee on Food in 2001. A picogram is one trillionth (or 10⁻¹²)of a gram.

“The main reasons for the decrease were the availability of new epidemiological and experimental animal data on the toxicity of these substances and more refined modeling techniques for predicting levels in the human body over time,” said Ron Hoogenboom of the CONTAM Panel and chair of the dioxins working group. “The new TWI is protective against effects on semen quality, the adverse health effect seen at the lowest levels of these contaminants in human blood.” The TWI is also protective against other effects observed in studies with human subjects: lower sex ratio of sons to daughters, higher levels of thyroid-stimulating hormone in newborns and developmental enamel defects on teeth.

Dioxins and dioxin-like PCBs are toxic chemicals that persist in the environment for years and accumulate at low levels in the food chain, usually in the fatty tissues of animals. Their presence in food and feed has declined in the past 30 years thanks to the efforts of public authorities and industry. The main contributors to average dietary exposure for most age groups in European countries are fish (in particular fatty fish), cheese, and livestock meat.

“Average and high exposures were, respectively, up to five and 15 times the new TWI in adolescents, adults and the elderly,” noted Hoogenboom. Toddlers and other children up to 10 years of age had a similar range of exceedance of the TWI. These exceedances are a health concern, but the toxicity of the most harmful dioxin-like PCB may be overestimated. When calculating the toxicity of substances like these, we use internationally-agreed values known as ‘toxicity equivalency factors’ [TEFs]. The panel would support a review of the TEFs for both dioxins and dioxin-like PCBs in light of new scientific data. If confirmed to be less toxic, this would reduce the concern for consumers.”