By Whitney Akinyi

Lead exposure may have been responsible for higher cases of cardiovascular disease (CVD) deaths than previously estimated, a new study published in the Lancet Planetary Health journal reveals.

According to the study an estimated 5.5 million adults died in 2019 as a result of lead exposure, this is six times higher than the Global Burden of Disease (GBD)study estimate of 850,000 deaths. Of these, 90% were from lower and middle-income countries (LMICs).

The analysis did not include deaths from high blood pressure – and because lead exposure also increases the risk of dying from causes other than cardiovascular disease – the true number of deaths linked to lead exposure may be substantially higher.

Additionally, the study found that lead exposure resulted in a loss of 765 million IQ points in children under five years old worldwide in 2019. As a result, children in LMICs, on average, lost 5.9 IQ points during their first five years of life.

The economic implications of lead exposure are equally concerning. The study estimates that the global cost of lead exposure in 2019 reached a staggering US$6 trillion, equivalent to 7% of global GDP. In LMICs, this cost was even more staggering, equivalent to over 10% of GDP, double that of High-Income Countries (HICs).

This economic and health cost of lead exposure was found to be at par with the combined impact of PM2.5 outdoor ambient and household air pollution, and three times greater than the health effects of unsafe drinking water, sanitation, and hand washing.

Despite the global phase-out of lead-containing petrol, lead exposure remains a significant health risk, especially in LMICs. Key sources of lead exposure include lead acid battery recycling, metal mining, contaminated food, soil, and dust, leaded paint, cookware from recycled materials, lead-glazed pottery, cosmetics, electronic waste, fertilizers, and cultured fish feed. The presence and contribution of these sources vary greatly across countries, emphasizing the need for better monitoring, identification, and mitigation plans.

Lead author Bjorn Larsen emphasized the urgency of the situation: “What is concerning about our study is that it indicates these damaging health effects are much greater than we previously thought and that they come at a very high economic cost, especially in low- and middle-income countries. Efforts to address the impacts of lead exposure must reflect that these are as significant as those posed by PM2.5 outdoor ambient and household air pollution.”

This study represents the first attempt to estimate lead exposure’s global health burden and cost in terms of IQ loss in children and cardiovascular disease deaths in both LMICs and HICs. Lead exposure can have severe health consequences, including brain damage, developmental delays, and learning difficulties in children, as well as an increased risk of cardiovascular disease and other health issues in adults.

The findings underscore the urgent need for improved monitoring of exposure sources and the implementation of relevant legislative responses and public health policies, particularly in LMICs where the majority of health impacts and economic costs are concentrated.

Despite the ban on leaded petrol, the study’s findings reveal that the dangers of lead exposure continue to affect millions of lives and economies worldwide. This research serves as a stark reminder of the pressing need for global cooperation to address the crisis of lead exposure and protect the health and future of our children. The cost, both in terms of lives and economic resources, is simply too high to ignore.