Heavy metal exposure causes countless deaths and disabilities. The diverse range of sources and adverse health effects of heavy metals – including lead, arsenic, mercury, and cadmium – pose a complicated challenge for the world. We know that human activities are the primary driver of heavy metal production and pollution, contributing to disease and poverty on a global scale. Among heavy metals, lead is one of the most significant environmental health threats to children and pregnant women. The World Health Organization states that there is no known level of lead exposure that is considered safe, and lead poisoning in childhood is linked to cognitive impairment, violent crime in adulthood, and loss of economic productivity (Landrigan et al., 2017, p. 17).
Heavy metals have been used by humans for thousands of years. Their toxicity and tendency to accumulate in biological systems make them a significant health hazard. Some heavy metals such as copper and zinc have essential biological functions in miniscule amounts, but others – like lead, arsenic, mercury, and cadmium – can be life-threatening. Human exposure to toxic heavy metals persists globally, but the prevalence of heavy metal pollution is most notable in low- and middle-income countries (Järup, 2003, p. 167).
Lead exposure: lead is a major environmental threat because of its severe human health effects, and because of its global prevalence in air, water, dust and soil, and various manmade products. We measure lead exposure using the number of age-standardized disability-adjusted life-years (DALYs) lost per 100,000 persons due to this risk.