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Metals as contaminants in food

Metals as contaminants in food

Metals such as arsenic, cadmium, lead and mercury are natural occurring chemical compounds. They can be present at various levels in the environment, e.g. soil, water and atmosphere. Metals can also occur as residues in food because of their presence in the environment, as a result of human activities such as farming, industry or car exhausts or from contamination during food processing and storage. People can be exposed to these metals from the environment or by ingesting contaminated food or water. Their accumulation in the body can lead to harmful effects over time.

EU regulatory framework

Commission Regulation 1881/2006 lays down maximum levels for certain contaminants in foodstuff, including lead, cadmium, mercury and inorganic tin. This Regulation does not cover radioactive substances. Commission Regulation 333/2007 covers the methods of sampling and analysis for the official control of the maximum levels of these metals. Surveillance for residues of chemical elements in foods of animal origin is specified in Council Directive 96/23/EC.

EFSA’s role and activities

EFSA provides scientific support and advice to risk managers based on risk assessments. The European Commission and EU Member States make decisions on regulatory issues including the setting of maximum levels for metals in food – EFSA’s scientific advice helps inform such decisions.

EFSA has been requested by the European Commission or Member States to provide risk assessments on uranium, cadmium, mercury, lead and arsenic in food. This work is carried out by the Panel on contaminants in the food chain (CONTAM Panel).

Arsenic in food

Arsenic is a widely-occuring contaminant which occurs both naturally and as a result of human activity. Foodstuffs are the main source of exposure for the general population in Europe.

In October 2009, the CONTAM Panel adopted an opinion on arsenic in food. This opinion mainly focuses on inorganic arsenic, which is the more toxic form in which arsenic can appear. The Panel compared amounts of arsenic that people could consume through food and drink to levels which may cause certain health problems. As there was little or no difference between the two, the Panel recommended that exposure to inorganic arsenic should be reduced. However, the Panel also highlighted considerable uncertainties in relation to its risk assessment. It stressed the need for more data on levels of organic and inorganic arsenic in different foodstuffs, as well as on the relationship between arsenic intake levels and possible health effects.

The main sources of inorganic arsenic intake are cereal grains and cereal based products, food for special dietary uses (e.g. algae), bottled water, coffee and beer, rice and rice-based products, fish and vegetables.

Uranium in foodstuffs

Uranium is a naturally occurring radioactive metal, which can be found in varying concentrations in the environment, water and foodstuffs. In March 2009 the CONTAM Panel conducted a risk assessment on dietary exposure to uranium in foodstuffs, in particular mineral water, and advised on the Tolerable Daily Intake (TDI) for uranium. The opinion focused on the chemical toxicity of uranium, while the radiological risk will be addressed by an expert group of the European Commission during 2009.

The Panel did not identify any new data which would have called for a revision of the TDI for uranium of 0.6 µg/kg b.w. per day established by the World Health Organisation (WHO), and therefore it endorsed this TDI.

The Panel concluded that average dietary exposure to uranium for the general population and high consumers across Europe is currently below the TDI. In specific areas where uranium concentrations in drinking water are high, the exposure estimates are close, but still below the TDI. For infants fed with infant formula made up with water containing uranium, the Panel noted that exposure in relation to body weight may be up to three times higher than for adults, and concluded that such exposure should be avoided.

Cadmium in food

In January 2009 the Panel adopted an opinion on cadmium in food providing an updated European exposure assessment and establishing a new Tolerable Weekly Intake level (TWI). Foodstuffs are usually the main source of cadmium intake for the non-smoking general population. The Panel reduced the TWI for cadmium to 2.5 micrograms per kilogram of body weight (µg/kg b.w.), based on analysis of new data. The current average dietary exposure to cadmium for adults is around this level and exposure for certain subgroups, such as vegetarians and smokers, may be higher. However, the risk of adverse effects even for groups that have exposure at levels above the TWI is very low because the TWI is not based on actual kidney damage, but on an early indicator of changes in kidney function suggesting possible kidney damage later in life.

Mercury in food

In 2004 the CONTAM Panel adopted an opinion on mercury and methylmercury, the latter being the main mercury compound present in fish and seafood products. The opinion looked at the contribution of different foods towards overall human exposure and the risks to vulnerable groups, in particular pregnant women and children. The Panel concluded that methylmercury toxicity has been demonstrated at low exposure levels, and therefore exposure to this compound should be minimised. However, it also noted that fish constitutes an important part of a balanced diet.

EFSA has also provided advice on the safety and nutritional contribution of wild and farmed fish in 2005. The CONTAM Panel assessed the health risks related to human consumption of wild and farmed fish, including an overall risk assessment related to the consumption of Baltic herring. EFSA’s advice concentrated on the most relevant metals and persistent organic contaminants, namely methylmercury, dioxins and dioxin-like PCBs. It also reviewed the nutritional value and benefits from consuming fish.

Work in progress

A scientific opinion on lead is due to be published in early 2010.