UN committee reduces safety limits for mercury

Experts convened by the UN Food and Agriculture Organisation (FAO) and the World Health Organisation (WHO) are to reduce their recommended safe intake level for methylmercury, the most toxic form of mercury, in foods, after studying new data.

The Joint Expert Committee for Food Additives and Contaminants (JECFA), meeting last week at FAO's Rome headquarters, said that after looking at new data for methylmercury and, crucially, in order to sufficiently protect the developing foetus, the PTWI has been reduced to 1.6 µg per kg body weight per week.

The foetus is exposed to methylmercury through contaminated food eaten by pregnant mothers. This new recommendation changes the prior recommendation for a dietary limit of 3.3 µg per kg body weight per week. Fish species such as swordfish and sharks are the most significant source of methylmercury in food.

However, not wishing to steer consumers away from real health benefits found in the large majority of fish species, the committee stressed that when providing advice to consumers and setting limits for methylmercury concentrations, public health authorities should keep in mind that fish play a key role in meeting nutritional needs in many countries.

JECFA meets regularly to provide safety and risk assessment advice to countries and to the Codex Alimentarius Commission. Codex - meeting this week in Rome to discuss world food trade and food safety - recommends international standards for food safety and quality, as well as codes of practice and guidelines.