Lead Poisoning Poses Greater Global Health Threat than Previously Thought, Study Finds
A recent study has revealed that lead poisoning has a significantly higher impact on global health than previously believed. The study, conducted by two World Bank economists and published in the Lancet Planetary Health journal, estimates that lead exposure could contribute to over five million deaths per year, making it a similar threat to air pollution. Furthermore, the toxic metal is responsible for an average loss of nearly six IQ points in young children in developing countries.
Lead pollution has long been known to cause various serious health issues, particularly relating to heart disease and the brain development of young children. As a result, the use of leaded gasoline has been banned worldwide. However, exposure to the neurotoxin can still occur through sources such as food, soil, cookware, fertilizers, cosmetics, and lead-acid car batteries.
The authors of the study described their findings as a “wake-up call,” as they are the first to assess the impact of lead exposure on heart disease deaths and child IQ loss in both affluent and developing nations. The model used in the study suggests that 5.5 million adults died from heart disease in 2019 due to lead exposure, with 90 percent of these deaths occurring in low- and middle-income countries. This figure is six times higher than previous estimates and represents approximately 30 percent of all cardiovascular disease-related deaths worldwide.
Lead author Bjorn Larsen noted that the figure calculated by their model was initially so “enormous” that they hesitated to even mention it. The research also estimated that children under five lost a cumulative 765 million IQ points globally in 2019 as a result of lead poisoning, with 95 percent of these losses occurring in developing countries. This number is nearly 80 percent higher than previous estimates.
Considering the economic impact, the World Bank researchers estimated the cost of lead exposure at $6 trillion in 2019, equivalent to seven percent of global gross domestic product. The study utilized blood lead level estimates from 183 countries, which were obtained from the landmark 2019 Global Burden of Disease study.
While the study has garnered attention for shedding light on the far-reaching effects of lead exposure, some experts express caution regarding the uncertainties associated with the findings. Roy Harrison, an expert in air pollution and health at Birmingham University, highlighted the reliance on a survey conducted in the United States to establish the relationship between lead in blood and heart disease. Furthermore, the study’s use of estimations, rather than tests, of lead in blood in many developing countries raises further questions.
Richard Fuller, president of the NGO Pure Earth, emphasized that previous surveys in developing countries have generally found higher levels of lead in blood than estimated in the new study. This suggests that the impact of lead may be even worse than currently described, making the study a crucial “wake-up call.”
The authors themselves acknowledge that more research is needed to fully understand the contribution of different sources of lead to blood contamination. In this regard, a recent report by Pure Earth, which analyzed 5,000 samples of consumer goods and food in 25 developing countries, provides insights into the “missing piece of the puzzle.” The report found significant levels of lead contamination in metal pots and pans, ceramic cookware, paint, cosmetics, and toys. These findings reinforce the notion that items commonly found in kitchens are a major source of lead poisoning in poorer countries.
In conclusion, the study’s findings underscore the urgent need for increased awareness and action to address the global health threats posed by lead pollution. Efforts to eliminate lead exposure should focus not only on banning leaded gasoline but also on implementing strict regulations and measures to prevent lead contamination from various sources.