Over the past several decades there has been a remarkable reduction in environmental sources of lead, improved protection from occupational lead exposure, and an overall decreasing trend in the prevalence of elevated blood lead levels (BLLs) in U.S. adults. As a result, the U.S. national BLL geometric mean among adults was 1.2 µg/dL during 2009–2010 (1).
Nonetheless, lead exposures continue to occur at unacceptable levels (2). Current research continues to find that BLLs previously considered harmless can have harmful effects in adults, such as decreased renal function and increased risk for hypertension and essential tremor at BLLs µg/dL (3–5). CDC has designated 10 µg/dL as the reference BLL for adults; levels ≥10 µg/dL are considered elevated (2).
CDC's Adult Blood Lead Epidemiology and Surveillance (ABLES) program tracks elevated BLLs among adults in the United States (2).
In contrast to the CDC reference level, prevailing Occupational Safety and Health Administration (OSHA) lead standards allow workers removed from lead exposure to return to lead work when their BLL falls below 40 µg/dL (6). During 2002–2011, ABLES identified 11,536 adults with very high BLLs (≥40 µg/dL).
Persistent very high BLLs (≥40 µg/dL in ≥2 years) were found among 2,210 (19%) of these adults. Occupational exposures accounted for 7,076 adults with very high BLLs (91% of adults with known exposure source) and 1,496...