Although lead occurs naturally in small quantities in the earth’s crust, by far the greatest risk of exposure to lead that people face comes from man-made processes and products. The use of large quantities of lead over many years has resulted in extensive environmental contamination.
Currently, the principal industrial use of lead is in the manufacture of electrical storage batteries. Other uses include the production of ammunition, various chemicals, and sinkers for fishing. Although the use of lead in paint additives, gasoline additives, solder, and pipes has been reduced or eliminated, the old products and their remains can still be found in the environment.
The major exposure to lead for most adults comes from the work place. Surface dust and soil contaminated with lead are the major sources of lead exposure for infants and young children. Young children frequently play on floors and in outside areas and they may put lead-contaminated fingers, toys, and other objects in their mouths. Lead also can be found in airborne dust during refinishing or renovation activities or because of windblown surface dust, but air is a less important source of lead exposure for children. Children are also often exposed to lead that is brought into the house on their parents’ work clothes.
A person may become poisoned through exposure to a single high-level source of lead or through the cumulative effect of repeated exposure to several low-level sources of lead. High-level exposure can occur on the job or from the environment, such as from deteriorating paint in the home. High-level or acute lead exposures can result in severe health problems, including convulsions, coma, and even death. Although deaths are now rare, a young boy in Wisconsin died in the early 1990s from lead-based paint poisoning.
Experts agree childhood lead poisoning can be attributed to
- Lead-based paint in housing;
- Lead in interior and exterior surface dust (through hand-to-mouth transmission);
- Urban soil (contaminated from lead-based paint, gasoline, and industrial sources);
- Drinking water (primarily from leaded solder; brass fittings and fixtures; and service lines).
These sources are considered major sources of lead exposure because they generally expose many people. Other sources can result in high exposures to lead in individual cases. Contributions from these other sources add to the problem and are, therefore, of potential concern.
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