The distribution of lead in the environment varies from place to place. Each of the following sources of lead is discussed further below.
The most widespread source of lead today for U.S. children is in lead paint that remains in older buildings.
Lead may be found in and around workplaces that involve lead.
Lead may contaminate water, food, and beverages, but the contaminant cannot be seen, tasted, or smelled.
Lead may still be found in some commercial products.
Some imported home remedies and cosmetics contain lead.
Lead concentrations in soil, air, and water can be especially high near the sites of historic or ongoing mining operations or smelters.
While blood lead levels over time are consistently declining, it is still a serious health problem for many, particularly children in urban areas.
Landrigan (2002) estimates that the U.S. incurs $43.4 billion annually in the costs of all pediatric environmental disease , with childhood lead poisoning alone accounting for the vast majority of it. This is a very high cost to our society, which include medical costs, disability, education and parental lost work time.
Lead was banned from consumer use paint in the U.S. in 1977. Even though leaded paint may be covered with non-leaded paint, lead may still be released into the home environment by peeling, chipping, chalking, friction, or impact. Lead may also be released through past or ongoing home renovation. Lead-contaminated household dust is the major course of lead exposure to children in the U.S. (Lanphear et al. 2002)
Between 83% and 86% of all homes built before 1978 in the U.S. have lead-based paint in them. (CDC 1997a)
The older the house, the more likely it is to contain lead-based paint and to have a higher concentration of lead in the paint.
The number of existing U.S. housing units built before 1950, when paint had high lead content, decreased from 27.5 million in 1990 to 25.8 million in 2000 (CDC 2003); despite the gradual decline in the number of houses containing lead paint, however, it still poses a risk.
Before 1955, a significant amount of white house paint sold and used was 50% lead and 50% linseed oil. In 1955, manufacturers adopted a voluntary house paint lead-content standard of 1%, but house paint with higher levels of lead continued to be manufactured. (Rabin 1989 as cited in AAP 1993)
The amount of lead allowable in paint was lowered by federal law to 1% in 1971 and then to 0.06% in 1977.
Workers renovating highway overpasses and bridges are frequently exposed to lead paint applied to these structures over many years before current regulations were in place.
In addition to degradation of interior paint, lead may be tracked into homes in significant quantities from exterior soil that was contaminated by historical use of lead in paint, gasoline, or industries.
Lead occurs in drinking water through leaching from lead-containing pipes, faucets, and solder, which in turn can be found in plumbing of older buildings.
Homes built before 1986 are more likely to have lead pipes, fixtures and solder, although newer homes may also be at risk.
Boiling water will not get rid of lead.
Other potential sources of lead contamination include brass fixtures, older drinking water coolers, and older coffee urns (Mushak et al. 1989 as cited in AAP 1993).
While lead is prohibited from many products in the U.S., imported or pre-regulation products may still pose a risk. Consumer products are not routinely tested for lead.
Using certain imported home remedies or cosmetics. Several examples are listed below.
The Mexican folk remedies azarcon and greta used to treat the colic-like illness "empacho" contain lead. These remedies are also known as
alarcon
coral
liga
Maria Luisa
rueda
Lead-containing remedies used by some Asian communities are
ba-baw-san
bali goli
chuifong
ghasard
kandu
tokuwan
Middle Eastern remedies and cosmetics include
alkohl
cebagin
saoott
For more information on these products, see the Centers for Disease Control web site, especially Appendix 1 of the document “Managing Elevated Blood Lead Levels Among Young Children” (CDC 2002) at http://www.cdc.gov/nceh/lead/CaseManagement/caseManage_main.htm or Saper et al. 2004.
Because of widespread human use of lead, lead is ubiquitous in the environment. These background levels vary depending on historic and ongoing uses in the area.
Even abandoned industrial lead sites, such as old mines or lead smelters, may continue to pose a potential public health hazard.
Industrial sources range in size from large mines and hazardous waste sites (e.g., Superfund sites) to small garages working with old car batteries.
Industries such as mining and lead smelting contribute to high levels of lead in the environment around such facilities.
Local community members may be exposed to lead from these sources through ingestion (or inhalation) of lead-contaminated dust or soils.
Old leaded paint may also contaminate soil, especially in areas immediately adjacent to pre-1978 houses.
People may be exposed to lead in soils directly or by eating foods grown on lead-contaminated soils.
The past use of lead in gasoline has contaminated soils, especially along roadways. Tetraethyl lead was phased out of gasoline in the U.S. between 1976 and 1996.
The major exposure pathways for workers are inhalation and ingestion of lead-bearing dust and fumes.
Workers in the lead smelting, refining, and manufacturing industries experience the highest and most prolonged occupational exposures to lead (ATSDR 2005).
Increased risk for occupational lead exposure occurs among
battery manufacturing plants
construction workers especially renovation/rehabilitation
It is important to note that occupational exposures can also result in secondary exposure for workers’ families if workers bring home lead-contaminated dust on their skin, clothes, or shoes.
Children may also be exposed to occupational lead sources if parents work in these industries and allow their children to visit them at work.
Many small businesses and cottage industries are actually located in the home.
Prior to the 1970s, lead was widely used in paint and gasoline.
Lead paint is a primary source of environmental exposure to lead. Lead may be released from old paint in home environments if the paint is disturbed (e.g., renovation), deteriorated (peeling, chipping, and chalking), or subject to friction or impact (doors, windows, porches, etc…).
The past use of lead in gasoline and paint can result in high lead levels in soil.
Some commercial products still contain lead.
Workers in many industries (and secondary exposure to their families) may have occupational exposure to lead.
Contaminated drinking water, food, alcohol, and home remedies are sources of environmental exposure to lead.
Historic or ongoing lead-related industries (including mining and smelting) can result in high lead levels in surrounding soil.