Global health burden and cost of lead exposure in children and adults: a health impact and economic modelling analysis.
Level 4 - case-series / case-control
Health impact and economic modeling study based on secondary observational and epidemiological data (design analogy).
PubMed 37714172 · doi:10.1016/S2542-5196(23)00166-3
What was done
Using country-level blood lead estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, researchers modeled the global health and economic burdens of lead exposure for 2019. Intelligence quotient (IQ) point loss in children under 5 years was calculated using an international pooled blood lead-IQ response function, with economic costs estimated as the present value of lost lifetime earnings among projected labor force entrants. Cardiovascular disease (CVD) mortality in adults aged 25 and older was estimated using a model accounting for lead-mediated CVD pathways beyond hypertension alone, with economic impact quantified as welfare costs using the value of statistical life. Outcomes were aggregated globally and by World Bank income levels and regions.
What was found
Globally in 2019, lead exposure caused an estimated loss of 765 million (95% CI 443–1,098) IQ points in children younger than 5 years and 5,545,000 (95% CI 2,305,000–8,271,000) cardiovascular deaths in adults. Low- and middle-income countries (LMICs) bore 95.3% of total IQ loss (729 million points) and 90.2% of CVD deaths (5,004,000 deaths). The modeled cardiovascular death toll was six times higher than the GBD 2019 estimate, and LMIC IQ loss was nearly 80% higher than prior estimates. Total global costs were estimated at US$6.0 trillion (range 2.6–9.0 trillion), or 6.9% (range 3.1–10.4%) of global GDP, with 77% attributable to adult CVD mortality welfare costs and 23% to future income losses from childhood IQ reduction.
Why it matters
The findings indicate that the global disease and economic burden of lead exposure is on par with PM2.5 ambient air pollution, with the overwhelming majority of mortality and cognitive losses concentrated in LMICs.
Limits
The study is a mathematical modeling analysis reliant on underlying GBD estimates rather than direct global biomonitoring, and primary blood lead level measurements remain sparse and of variable quality in LMICs. Wide uncertainty ranges exist across both health and economic metrics (e.g., global costs spanning $2.6 to $9.0 trillion). IQ cost evaluations were restricted strictly to anticipated future labor force participants.
Cited by
- supports A 2019 study showed that lead exposure caused children under five globally to lose 780 million IQ points in that single year.