Occurrence in food
Lead is a toxic heavy metal occurring naturally in the environment. Lead is also released into the environment as a result of human activities in, for example, metal smelters, the battery industry, waste treatment and shooting ranges. The amount of lead released into the environment as a result of human activity is limited by environmental. In the past, leaded petrol was commonly used. In Finland, use of leaded petrol was discontinued in the 1990s and this has resulted in a significant decrease in lead levels in foods.
Plants can become contaminated with lead when they absorb it from the soil during growth and especially through lead in dust from atmospheric deposition. Old paints and inks and joints in old plumbing pipes may contain lead. Game shot with lead bullets contains lead in and around the gunshot wound.
Lead can also migrate to food from food contact materials. High amounts of lead, especially from old ceramic containers with lead glazing, can migrate to food. Lead content can also be high in crystal glasses imported from abroad. In addition, lead is also present as an impurity in tin containers, food processing equipment and in printing inks for food contact materials.
Adverse health effects
Exposure to high levels of lead has a detrimental effect on the central nervous system, causing, among other things, behavioural disorders and IQ impairment. In addition, lead has been shown to damage the kidneys and the cardiovascular system. Lead accumulates in the bone but also to some extent in the liver and kidneys.
The European Food Safety Authority (EFSA) has set the toxicological reference value (BMDL01, benchmark dose limit) for lead at 0.5 µg/kg bw/d. The BMDL01 value is defined as the average long-term exposure level at which the risk of the studied health hazard at the population level increases by one per cent of the risk level that the unexposed population would have. In the long term, 0.5 µg of lead/kg bw/d increases the risk of developmental nervous system damage in children presenting as IQ impairment by one per cent compared to the risk level of the unexposed population. BMDL01 values are higher for other side effects of lead, such as cardiovascular and kidney damage.
Maximum levels in food
EU legislation ((EU) 2023/915 as amended) sets maximum levels for lead in milk, infant formulae and follow-on formulae, processed cereal-based foods and foods for infants and young children, dietary foods for special medical purposes for infants and young children, in beverages for infants and young children, meat, certain by-products, muscle meat of fish, crustaceans, bivalve molluscs, cereals, legumes and pulses, vegetables, fruit and berries, fats and oils, fruit juices and nectars, wines, food supplements and honey.
The EU Ceramics Directive, which has been implemented in Finland by Decree 165/2006 of the Ministry of Trade and Industry (KTM), sets a limit value for lead migrating from ceramics to food of 0.8 mg/dm2, 1.5 mg/dm2 or 4.0 mg/dm2 depending on the size of the container and the intended use. In addition, Finland has a national decision 268/1992 (KTM), which sets a migration limit value of 0.5 mg/dm2 for all food contact materials. Migration from food contact materials intended for young children should only be 1/10 of this amount. The same regulation also sets limit values for cadmium, chromium and nickel migrating from food contact materials.