Lead is a toxic heavy metal that occurs naturally in the environment, but also enters the environment through emissions from industry. Much of the lead emissions come from anthropogenic activities such as mining and smelting of metals, manufacturing of batteries, munitions and metal water pipes. In the past, lead was also used in paints and gasoline. The ban on leaded gasoline eliminated a major source of lead pollution to the environment.
Lead is ubiquitous in the environment due to rock erosion and volcanism. Lead occurs in both inorganic and organic forms. Organic lead compounds such as tetraalkyl lead are more toxic than inorganic forms of lead. In the environment, lead is present primarily in inorganic forms, whereas occupationally (e.g., in plants that produce, refine, use, or dispose of lead and lead compounds), organic forms in particular are ingested.
In general, lead can be ingested through food, water, air, soil, and dust. Lead gets onto the surface of fruits and leaves via dust and precipitation. For this reason, fruits and vegetables that grow above ground and that have a large surface area are especially contaminated with lead. Lead can also get into animal foods via lead-containing, plant-based feeds. Infants and children can additionally ingest significant amounts of lead through house dust and soil particles. Another source of ingestion can be drinking water containing lead, although lead pipes are increasingly being replaced in older residential buildings.
The intake of lead occurs mainly through the consumption of contaminated food. The main sources of lead intake for adults are sausages and meat products as well as vegetables and vegetable products including mushrooms. In children, fruit and vegetable juices and nectars also contribute significantly to the total intake of lead.
After ingestion of lead through food, it enters the blood through the gastrointestinal tract. In the blood, much of the lead is bound to the hemoglobin of red blood cells and is accumulated in the liver, kidneys, and brain. The absorption rate (proportion of a substance absorbed through the gastrointestinal tract that enters the blood/lymphatic tract) of soluble lead compounds appears to be higher in children than in adults.
Lead can accumulate in the body, especially in skeletal bone. It is gradually released from the skeleton back into the bloodstream, especially with changes in calcium status during pregnancy, lactation, and osteoporosis, where bone demineralization occurs. The half-life for inorganic lead in the blood is about 30 days and in bone between 10 and 30 years.
Typical signs of acute poisoning by lead are intestinal colic. These occur with a very high intake of lead, especially with high occupational exposure (e.g., in plants that produce, refine, use, or dispose of lead and lead compounds), and result in symptoms such as abdominal pain, constipation, nausea, vomiting, and loss of appetite. Because lead remains in the body for a long time, the long-term toxic effects are of greater concern.
Chronic dietary intake of inorganic lead can affect various organ systems, but especially the central nervous system. A number of studies have also identified a relationship between blood lead concentrations, elevated systolic blood pressure, and chronic kidney disease at relatively low blood lead levels.
Situation in Austria
Maximum levels for lead are regulated for various food groups in Regulation (EC) No. 1881/2006 as amended. In August 2021, Regulation (EU) 2021/1317 amending Regulation (EC) No. 1881/2006 as regards maximum levels for lead in certain foods was published. In order to reduce dietary exposure to lead in the European Union, some maximum levels for lead already in force have been reduced and additional maximum levels for food have been set.
In addition to the maximum levels regulated at the European level, action levels have also been defined in Austria for some product groups for which no maximum levels have been set. These can be seen in the decree BMSGPK-2021-0.359.197 of 5.7.2021 as amended.
As part of the official control, the regulated product groups are checked for compliance with the legal maximum lead content. In order to obtain an up-to-date overview of the contamination of products of plant and animal origin on the Austrian market, 411 samples were tested for lead in 2020 as part of an extended investigation of planned samples distributed across the entire range of goods.
Of the 411 samples in various food groups (bread/pastries, cereal products, vegetables, cheese/preparations, milk, fruit, vegetable oils, cured and smoked meat, eggs, tea, sausages and sugar), 179 samples were below the limit of determination. While 84% of sugar samples were below the limit of quantification, followed by milk (67%) and vegetable oils (64%), lead was measured above the limit of quantification in all samples of cheese/preparations and in 93% of tea samples. The highest lead concentrations were determined in tea with a mean level of 290 µg/kg (minimum 0.7 µg/kg; maximum 1300 µg/kg), followed by sausages (excluding game and poultry sausages) with a mean of 23.7 µg/kg and cheese and cheese preparations with a mean level of 12.3 µg/kg. It should be noted, however, that in the course of preparing tea, dilution occurs through the addition of water, which significantly reduces the lead concentrations contained in the ready-to-eat beverage. The lowest mean lead levels were found in milk (0.8 µg/kg) and sugar (2.9 µg/kg).
From 2007 to 2011, we analyzed a total of 2,619 food samples from Austrian retailers for lead. The highest average concentrations of 627 μg/kg lead were found in the food group "Special foods", which includes dietary supplements and dietetic foods. In all other food groups investigated, significantly lower levels of up to 169 μg/kg were found. Exceedance of the European maximum levels was found in a total of 6 samples of food supplements.
The exposure assessment showed that the average dietary exposure to lead for women is 0.11 µg/kg body weight/day, for men 0.12 µg/kg body weight/day and for children 0.14 µg/kg body weight/day. Exposure of frequent eaters is very similar for women, men, and children. Intake levels of 0.29 µg/kg body weight/day (women, children) and 0.30 µg/kg body weight/day (men) were estimated.
While sausages and meat products as well as vegetables and vegetable preparations including mushrooms are the main sources of lead intake for adults, fruit and vegetable juices as well as nectars are the main sources of lead intake for children.
The intake levels of both average consumers and high consumers were below the toxicological reference values. Based on the available data, we therefore consider the health risk for the Austrian population from dietary lead intake to be low.
- AGES Report - Intake of lead via foodstuffs.
- Austrian Food Codex | Austrian Food Codex - Action values for certain contaminants in food. BMSGPK-2021-0.359.197 of 5.7.2021.
- Commission Regulation (EC) No. 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs.
- Commission Regulation (EU) 2021/1317 of August 9, 2021, amending Regulation (EC) No. 1881/2006 as regards the maximum levels for lead in certain foodstuffs.
Last updated: 28.09.2022