Health risks related to environmental and occupational lead exposure

Lead is a ubiquitous toxic metal. This review summarizes the toxicokinetics and toxicology of lead, and the methods to measure blood lead (BL), summarizes recently published studies, and ends with an appraisal of recent regulations to protect exposed workers. Lead exposure is caused via inhalation of lead-contaminated particulate and via gastrointestinal uptake. To assess BL, inductively coupled plasma mass spectrometry and electrothermal atomic absorption spectrometry are commonly applied. BL in the general population has declined drastically, approaching pre-industrial levels, at least in developed nations. Using cardiovascular, renal, and neurological endpoints, SPHERL, a longitudinal study in a lead-exposed workers demonstrated that current regulations effectively protect against detrimental effects. FLEMENGHO, a Flemish population study, showed how BL has declined over the past 20 years and reported on the association of renal and left ventricular function with BL. A re-analysis of NHANES data representative of American adults accounted for the drastic BL fall over time (1999-2020) and produced, for cardiovascular mortality, estimates of the BL-attributable risk fraction and the number of avoidable deaths, which were, respectively, >3 and >7 times smaller than in earlier analyses, which ignored the BL decline. The worldwide GBD studies published in 2012 and 2021 were inconsistent in considering the BL-associated cardiovascular endpoints and the null-effect BL level that decreased from 2.5 to 0.016 μg/dl. In conclusion, there has been good progress in reducing occupational and environmental lead exposure, but designing and reinforcing stricter regulations should rank high on the agenda of policymakers, in particular in low- and middle-income countries.