Lead is a silent killer. WHO has identified lead as one of the leading chemicals of concern to public health, and the Institute of Health Metrics and Evaluation (IHME) estimates that lead exposure caused nearly one million global deaths and accounts for more than 20 million years of healthy life lost in 2019. The burden is, however, highest in low-and middle income countries.
Lead is a toxic metal found ubiquitously and spread due to thousands of years of use in many applications. People are exposed to lead by i) Lead paint: In the US, residential use of lead paint has been banned since 1978. Many countries enacted laws limiting the amount of lead in paints, however, at least 76 WHO member states do not have binding controls on its production, import, sale, or use as of 2020. ii) Lead recycling: The use of lead acid batteries has sharply risen in LICs due to increased demand of low-cost battery given bikes in the transport sector. Almost all lead acid batteries are manufactured by recycling batteries and scrap metals. Most lead used in batteries can typically be recovered and recycled. Lead recovered from old batteries by crude smelting process is used as a raw material to manufacture new batteries. E-waste, including vehicle batteries, from rich countries is often exported to poor countries and most of it ends up in informal sites in Southeast Asia and Africa making them prone to excessive lead exposure. iii) Pottery and cookware: High demand for aluminum cookware together with an abundant supply from the recycling market has created an entire aluminum cookware manufacturing industry in modern world. Lead glaze is often used to seal traditional pottery, iv) Spices: Lead chromate is the cheapest yellow dye available in the market, leading to contamination in the regular household diets. Farmers have raised voice about the turmeric merchants selling poor quality roots and therefore increase profit margins because of this practice of adulteration with lead long before we were aware of the global lead exposure consequences. Due to its toxicity, lead is only authorized in low-middle income countries (LMIC) for industrial applications.
Exposure to lead during pregnancy can affect a child’s growth and their ability to see, hear and learn leading to behavioral difficulties. Pooled longitudinal data indicated that children with blood lead levels (BLLs) 2.4-10 μg/dL had reduced IQ, complete less formal education, and earn less money over their lifetimes. The U.S. Center for Disease Control and Prevention (CDC) has lowered BLL of concern from 60 μg/dL to 5 μg/dL today. Whereas there is no proven “safe” lead exposure level, especially in children, it is the fact that the severity of the problem increases with the increasing levels of lead exposure and consumption.
Globally, an estimated 800 million children have elevated high lead and most of the exposures occur in lower- income countries (LMIC) because there are more sources of lead and more contaminations along with less monitoring and control than in higher income countries (HIC). Most of these children live in Africa and Asia, but a high proportion live in HICs e.g., USA and European countries. Lead poisoning mounts a multi-pronged and enduring attack on children’s health and development during their vulnerable and formative years leading to devastating lifelong effects. Increasingly, evidence also points to lead poisoning as a root cause of violence and crime as a long-term effect of brain and neurological damage to children’s brain.
Maintaining protective regulations and vigilance in the production industry is key to avoid devastating consequences, therefore, eradication is needed to combat all sources of contamination through strict safe policies. Thus, we need strict commitment in the reduction of lead exposure, where governments should take urgent action to make sure all children are being fed and educated in safe, secure and healthy environment. The rapidity of the response is crucial; the longer the lead exposure continues, the greater the likelihood of disease.
* Mahfuzar Rahman is Country Director, Pure Earth, Bangladesh ([email protected])