November 21, 2023: Lead exposure remains a significant worldwide health risk, and a study has quantified its toll on both health and economies. The study reveals that in 2019, children under 5 lost a staggering 765 million IQ points globally due to lead exposure. Additionally, 5.5 million adults aged 25 or older succumbed to cardiovascular diseases linked to lead exposure. Disturbingly, 90.2% of these deaths and 95.3% of the IQ point loss occurred in low- and middle-income countries (LMICs).
The economic fallout of lead exposure is significant, with the global cost reaching a staggering $6.0 trillion in 2019. This amounts to 6.9% of the global gross domestic product (GDP). The welfare cost of cardiovascular disease mortality constituted 77% of this, emphasizing the economic toll of premature deaths.
The scope of the study
Utilizing country blood lead level data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, the study focused on estimating IQ loss in children under 5 and cardiovascular disease mortality globally. This inclusive approach aimed to capture the true extent of lead exposure’s impact. IQ loss in children under 5 was estimated using an international pooled analysis. The cost of IQ loss was assessed in terms of lifetime income loss for those entering the workforce. Cardiovascular deaths in individuals aged 25 and older were estimated using a health impact model. The economic impact was calculated based on the present value of income loss and the welfare cost of premature mortality.
Lead exposure vs. PM2.5 air pollution
Comparisons with PM2.5 air pollution highlight the gravity of lead exposure’s impact, positioning it as a health and economic risk on par with ambient and household PM2.5 air pollution combined. This challenges previous rankings that placed lead exposure lower among environmental risk factors.
While the study underscores the substantial burden of lead exposure, it also stresses the need for improved blood lead level measurement data, especially in LMICs. The accuracy of these measurements is crucial for devising effective strategies to address the health and economic challenges posed by lead exposure.
This groundbreaking study sheds light on the pervasive and underestimated impact of lead exposure on global health and economies. The findings underscore the urgent need for heightened efforts to address lead exposure and its consequences, particularly in regions facing disproportionate health and economic burdens.
This study was supported by the Korea Green Growth Trust Fund and the World Bank’s Pollution Management and Environmental Health Program. The study is available here.