BACKGROUND: The National Institute for Occupational Safety and Health (NIOSH) established the Adult Blood Lead Epidemiology and Surveillance (ABLES) program in 1987. NIOSH provides guidance and technical support to state health departments to maintain blood lead surveillance programs. State ABLES programs track elevated blood lead levels and provide guidance and information to workers, employers, and physicians to reduce lead exposure. ABLES’ data are used to track national and state burden of lead, measured as prevalence rates, for the Department of Health and Human Services’ Healthy People 2020 objective to reduce the prevalence of workers with elevated blood lead levels (BLL ≥10 µ/dL).
METHODS: State ABLES programs collect adult BLL data from laboratories and health-care providers through mandatory reporting requirements. BLL reporting requirements vary among ABLES states, ranging from the reporting of all BLLs, to BLLs ≥40 µg/dL. NIOSH consolidates data from reporting state ABLES programs and calculates state and national prevalence rates, identifies industry sectors with elevated BLLs, and disseminates findings to stakeholders. The current reference blood lead level for adults (BLL ≥5 μg/dL) was adopted in 2015 (and became effective in 2016) on the basis of mounting evidence for adverse health outcomes among adults.
RESULTS: In 2014, 28 states participated in the ABLES program, providing data on 18,608 adults with BLLs ≥10 µg/dL. The national prevalence rate of BLLs ≥10 µ/dL declined to 18.6 adults/100,000 employed persons, while the national prevalence rate of BLLs ≥25 µ/dL declined to 4.4. Missouri and Alaska reported the highest prevalence rates of BLLs ≥10 µ/dL at 95.6 and 49.9 respectively. Among 4,482 adults with BLLs ≥25 µg/dL, 81% had information on exposure source. Among 3,616 adults with known exposure source, 94.3% were occupational. Individual level data were available for 1,801 occupational cases. The majority of these 1,801 workers were employed in four industry sectors: manufacturing (48%), construction (25%), services (7%), and mining (4%).
CONCLUSIONS: ABLES is the only program conducting nationwide adult lead exposure surveillance. Although prevalence rates at BLL ≥25 μg/dL and BLL ≥ 10µ/dL have continued to decrease, many U.S. adults still have BLLs that are associated with adverse health effects. Continued efforts to reduce lead exposures are needed. Moreover, the actual magnitude of adult lead burden in the United States is likely underestimated, as workers may not be tested and BLLs underreported. NIOSH continues to provide technical assistance to support state ABLES programs.