Summary - Pb
Lead is a metal that exists both in inorganic and organic forms. In the environment, inorganic lead predominates over organic lead and the former is also the only type found in food [1-link]. Although it is a natural environmental contaminant, its ubiquitous occurrence is the result of anthropogenic activities like mining and smelting, soldering, battery manufacturing and the use of lead ammunition for hunting, but particularly the use in the past of lead in paint and petrol and for soldering or making of water pipes (ATDSR, 2007)[2-Link].
Lead in the environment can easily contaminate food through water or through atmospheric lead deposition on agricultural crops. Control measures have been taken to regulate lead in paint, food cans, water pipes and petrol in Europe since the 1970s. Leaded petrol was banned from use in the European Union in 2000 with exemptions possible until 2005 and continued use only allowed in vintage cars.
The general population is exposed to lead via food, water, air, soil and dust. Food is the major source of exposure to lead, although for children ingestion of soil and dust can also be an important contributor (EFSA, 2010)[3-Link]. Absorption of ingested soluble lead compounds appears to be higher in children than in adults. Lead can accumulate in the body, primarily in the skeleton and most seriously affects the developing central nervous system in young children. From the skeleton, it is released gradually back into the blood stream, particularly during physiological or pathological periods of bone demineralisation such as pregnancy, lactation and osteoporosis, even if lead exposure has already ceased. Maternal transfer of lead occurs through the placenta and subsequently during breast feeding. Half-life for inorganic lead in blood is approximately 30 days and for bone it is between 10 and 30 years (Rabinowitz, 1991)[4-Link]. The International Agency for Research on Cancer (IARC) classified inorganic lead as probably carcinogenic to humans (Group 2A) in 2006 (IARC, 2006)[5-Link].
In the lead dietary exposure study of the the European population by the EFSA Panel on Contaminants in the Food Chain (CONTAM), 144206 analytical results were examined for lead in food collected during a nine-year period. More than half of the foods tested had levels of lead at less than detection or quantification limits. The mean lead levels varied between 0.3 µg/kg for infant follow-on formulae to 4300 µg/kg for dietetic products with an overall median across all categories of 21.4 µg/kg. Food lead levels decreased by about 23 % between 2003 and 2010, although this should be interpreted cautiously. Mean lifetime dietary exposure was estimated at 0.68 µg/kg b.w. per day in the European population based on middle bound mean lead occurrence. Exposure was highest for toddlers and other children with 1.32 and 1.03 µg/kg b.w. per day, respectively, while the two infant surveys ranged between 0.83 and 0.91 µg/kg b.w. per day. Adult exposure was estimated at 0.50 µg/kg b.w. per day. The elderly and very elderly population groups had similar profiles to the adult age group, while adolescents had slightly higher estimated dietary exposure. Important food category contributors include bread and rolls (8.5 %), tea (6.2 %), tap water (6.1 %), potatoes and potato products (4.9 %), fermented milk products (4.2%) and beer and beer-like beverages (4.1 %), although this will vary between age groups and surveys.