Background

Lead is a naturally occurring element in the earth's crust. Much of the lead emitted into the atmosphere is in the form of inorganic salts. Exposure to inorganic lead occurs primarily through food and drinking water, although exposure via soil, dust, air and paint chips significantly contribute to the overall exposure.

The widespread occurrence of lead in the environment is primarily a result of anthropogenic activities. With the decline in combustion of leaded fuel and the phasing out of lead in pipes and paints, industrial emissions from mining, smelting, recycling or waste incineration are the major source of environmental lead.

Lead in water may result from industrial sources, but urban runoff significantly contributes to the total burden and solid wastes such as ammunition, leaded paints as well as industrial sources all contribute to the levels of lead found in soil.

Flaking paint, paint chips and powdered paint are major sources of lead exposure in young children. Other domestic sources of exposure include the contamination of food and drink from contact with utensils such as earth-glazed pottery.

Occupational exposure to lead and inorganic lead compounds may occur in a variety of occupations, including steel welding and spray coating, battery manufacturing or plumbing.

Most people are exposed to lead or lead compounds by eating or drinking contaminated food or drink, or breathing it in the air, such as from exhaust fumes, although the use of leaded fuel is declining. Children are mainly exposed to lead from eating soil.

The harmful effects that may occur from lead largely depend on how much people have been exposed to and for how long, therefore the amount of lead in the blood is often measured.

Eating food or drink or breathing in air contaminated with lead or lead compounds for a short period usually does not cause any ill effects. In rare cases nausea, vomiting, diarrhoea or kidney damage may occur.

If exposure continues for a long time people may become anaemic, lethargic and irritable or show other symptoms such as headache, muscle tremors, kidney or liver damage, nausea, vomiting or high blood pressure. Being exposed to lead for a long time can also affect both male and female reproduction, leading to miscarriage, stillbirths or premature births.

Children exposed to lead when in the womb or during the first few years of life due to eating paint chips containing lead, may have a lower IQ, behavioural problems or nerve damage. Children with high amounts of lead in their bones may have delayed growth.

Lead and its compounds are classified as probable carcinogens by the International Agency for Research on Cancer as lung, bladder and kidney cancer was seen in workers occupationally exposed to lead.

 

Key Points       Production and Uses

• Lead - Production and Uses
  Added/updated: 8 October 2008