Consumers may be at risk of exceeding recommended consumption levels for methylmercury and inorganic mercury, according to evidence considered by the European Food Safety Authority (EFSA).
Unborn and young children and people eating a lot of fish are particularly at risk. The organisation has called for the development of further testing methods for foodstuffs other than fish or seafood.
Inorganic mercury has been linked to negative effects on the immune system and brain development as well as the development of cardiovascular diseases.
According to scientific data, no consumer groups exceeded recommended tolerable weekly intakes (TWIs) for the substance through diet alone.
However, considering its inhalation as mercury vapour via dental amalgam, dietary consumption could push people over the TWIs, EFSA’s Panel on Contaminants in the Food Chain claimed in a Scientific Opinion. The Opinion was issued last month.
Fish and other seafood, non-alcoholic beverages and composite food were the most important contributors to inorganic mercury dietary exposure in the European population, the panel found.
The EFSA panel also concluded that toddlers and other children in some surveys exceeded the TWIs for methylmercury. High fish consumers might exceed the TWIs by “up to approximately six-fold”, the panel stated.
“Unborn children constitute the most vulnerable group,” it continued. “Biomonitoring data from blood and hair indicate that methylmercury exposure is generally below the TWI in Europe, but higher levels are also observed. Exposure to methylmercury above the TWI is of concern.
It noted that new developments in epidemiological studies from the Seychelles Child Developmental Study Nutrition Cohort indicated n-3 long-chain polyunsaturated fatty acids in fish may counteract negative effects from methylmercury exposure.
Fish meat was the dominating contributor to methylmercury dietary exposure for all age classes, followed by fish products.
In particular tuna, swordfish, cod, whiting and pike were major contributors to methylmercury dietary exposure in the adult age groups. The same species, with the addition of hake, were the most important contributors in the child age groups.
The EFSA panel has called for an increased volume of data on inorganic mercury and methylmercury contamination of all foodstuffs.
A call for annual collection of chemical contaminant occurrence data in food and feed, including mercury, was issued by EFSA in December 2010. Subsequent data analysed from food samples covering all food types indicated that mercury levels were highest in fish and seafood.
The data was then extrapolated to deduce dietary intake of inorganic mercury and methylmercury.