Lead Information


Modern building with lead-coated copper sheeting on exterior wall

Lead (Pb) is a metal. Lead melts easily and quickly, and it can be molded or shaped into thin sheets and can be drawn out into wire or threads. Lead also has great resistance to different weather conditions. Unfortunately, lead and lead compounds are toxic and can present a severe hazard to those who are overexposed to them. Whether ingested or inhaled, lead is readily absorbed and distributed throughout the body.

Historically, lead has been used in a variety of applications because of its aesthetic beauty, unique properties and durability. For example, this modern building's exterior wall (the gray center portion) is lead coated copper sheeting.

How are people exposed to lead?

Lead is widespread in the environment, and people absorb lead from a variety of sources every day. Although lead has been used in numerous consumer products, the most important sources of lead exposure to the general population are:

  • Soil and Dust (which has been contaminated by air, and includes dust both inside and outside the home)
  • Food (which can be contaminated by lead in the air or in food containers, particularly lead soldered food containers)
  • Drinking Water (from corrosion of plumbing systems)
  • Lead Based Paint
  • Occupational Exposure, or Hobbies

On average, it is estimated that lead in drinking water contributes between 10-20% of total lead exposure in young children. Food is the greatest single source of lead for the average adult. In the past few years, federal controls on lead in gasoline and from industrial air emissions have significantly reduced total human exposure to lead.

How does lead affect human health?

Lead absorbed by the lungs and the digestive tract from all sources enters the bloodstream, where it distributes to all tissues of the body. Excessive levels of lead can damage the brain, kidneys, nervous system, red blood cells and reproductive system. The degree of harm is directly related to the level of lead in the blood (from all sources). Known effects of exposure to lead range from subtle changes in body chemistry and nervous system function at low levels of exposure, to severe toxic effects or even death at very high levels associated with acute poisoning. Some harmful effects are reversible if exposure is reduced, while other harmful effects can be permanent.

Does lead affect everyone equally?

Young children, infants and fetuses appear to be particularly vulnerable to harmful effects of lead. A dose of lead that would have little effect on an adult can have a significant effect on a small, developing body. Also, growing children will more rapidly absorb any lead they consume. A child's mental and physical development can be irreversibly stunted by overexposure to lead. In infants, whose diet consists of liquids made with water, such as baby formula, lead in drinking water makes up an even greater proportion of total lead exposure (40-60%).

Occupational Exposure to Lead:

Lead has been poisoning workers for thousands of years. In the construction industry, traditionally most overexposures to lead are found in the trades, such as plumbing, welding and painting. Significant lead exposures can also arise from removing paint from surfaces previously coated with lead-containing paint, such as in bridge repair, residential renovation, and demolition.

Hobbies resulting in lead exposure may include firearm practice, soldering in jewelry making or stained glass work, and ceramics.

Exposure to lead may result when lead or any product containing lead is heated, especially above 500 degrees C (932 degrees F). Lead dust exposure may result from such operations as pouring powders containing lead, sanding or sandblasting surfaces coated with lead based paints.

Very small amounts of lead that may be unintentionally ingested via eating, drinking, or smoking on the job or through hobbies can be harmful. Good personal hygiene is important where lead is present.

Worker awareness and training are important so that employees can recognize the symptoms of exposure and get prompt medical attention. Jobs involving potential lead exposure should be targeted for detailed evaluation of their potential for lead exposure.

OSHA regulates lead for employees who work in the private sector. In Wisconsin, DCOM enforces the same regulations for public sector employees. The OSHA lead regulations (29 CFR 1910.1025 and 29 CFR 1926.62) require:

  • If a worker works with lead, the employer must test the air for lead levels.
  • If the lead level in the air is 30 micrograms per cubic meter of air or greater, the employer must offer employees routine blood testing.
  • An employee must be removed from all exposure to lead if the average blood level is 50 micrograms/deciliter or more on three tests. He or she cannot return to an environment where lead is present until the blood level falls to at least 40 mcg/dl.
  • The standard also establishes requirements for medical monitoring, respiratory protection, protective clothing, engineering controls and ventilation, work practice controls, hygiene facilities, and employee education.

OSHA and DCOM require employers to reduce airborne lead exposure below the OSHA Permissible Exposure Limit (PEL). The best way to do this is to simply replace lead and products that contain lead with less toxic materials. If this is not possible, the employer must provide change rooms and lockers, showers, and a thorough cleaning of work surfaces. There can be no smoking or eating in work areas. The employer must also provide training to employees on the hazards of lead and on the OSHA lead standard. Currently, there is no OSHA standard which provides a permissible limit for lead contamination of surfaces in occupational settings.

Lead dust can settle on your clothes and if these are not changed before going home, family members can be exposed. Lead can stay on your skin, hair, and on your shoes, lunch bucket, bookbag, etc. Young children are more sensitive to lead than are adults and can have health problems from exposure to less lead. If you are concerned, you can have your child's blood lead tested. Contact your physician or local health department for additional information.

For work involving lead at UWM, please contact the Department of University Safety and Assurances for a workplace lead exposure evaluation.

Sources:

  • Lead in Drinking Water, Wisconsin Department of Natural Resources-Bureau of Water Supply, 1988.
  • Occupational Lead Fact Sheet, Wisconsin Division of Health, 1992.
  • Working with Lead in the Construction Industry (OSHA 3126), U.S. Department of Labor, Occupational Safety and Health Administration, 1991.

Updated August 8, 2007