Number of American Workers with Elevated Blood Lead Levels Declining

Since 1987, a growing number of states have conducted surveillance of occupational lead poisoning, coordinated by the National Institute of Occupational Safety and Health (NIOSH) under the Adult Blood Lead Epidemiology and Surveillance (ABLES) Program, to track cases of elevated blood lead levels (BLLS). This data was last published in 1999 for the years 1994 - 1997. The latest data from 25 states during 1998 - 2001 shows a declining trend in BLLs among employed adults.

During 1998 - 2001, the overall program's annual mean state prevalence rate for adults with BLLs greater than or equal to 25 µg/dL was 13.4 per 100,000 employed adults. This compares with 15.2 per 100,000 for 1994 - 1997. Yearly rates were 13.8 (1998), 12.9 (1999), 14.3 (2000), and 12.5 (2001).

For the maximum level deemed acceptable under OSHA lead standards of 40 µg/dL, the overall program's annual mean state prevalence rate during 1998 - 2001 was 2.9 per 100,000 employed adults, compared with 3.9 per 100,000 for 1994 - 1997. Yearly rates were 3.3 (1998), 2.5 (1999), 2.9 (2000), and 2.8 (2001).

Lead Exposure

Lead is ubiquitous in U.S. urban areas because of the widespread use of lead compounds in industry, gasoline, and paints during the 1900s. With the phasing out of lead in gasoline (which began in the 1970s), lead in paints and in soils and dusts have become the principal sources of exposure. Adult exposure to inorganic lead occurs when dust and fumes are inhaled and when lead from lead-contaminated hands, food, water, cigarettes, and clothing is ingested. If showers and changes of clothing are not provided, workers can bring lead dust home on their skin, shoes, and clothing, thus inadvertently exposing family members.

Lead absorbed through the respiratory and digestive systems is released into the blood, which distributes the lead throughout the body. Approximately 90% of total body lead content is accumulated in the bones, where it is stored for decades. Lead in bones continues to be released gradually back into the body after the external environmental exposure occurs. As the BLL increases in an individual, the frequency and severity of symptoms associated with lead exposure also increase (albeit with considerable variability).

The public health objective of the ABLES program is to reduce the number of persons with BLLs greater than or equal to 25 µg/dL from work exposures; the target is to reduce that number to zero by 2010. Intervention strategies implemented by ABLES-reporting states include:

• Conducting follow-up interviews with physicians, employers, and workers;
• Investigating work sites; delivering technical assistance regarding exposure reduction or prevention; providing referrals for consultation and enforcement; and
• Developing and disseminating educational materials and outreach programs.

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