Environmental Hazards and Global Child Health: The Need for Evidence-Based Advocacy

Abstract

Children in today’s ever-smaller, more densely populated, tightly interconnected world are surrounded by a complex array of environmental threats to health.1 Because of their unique patterns of exposure and exquisite biological sensitivities, especially during windows of vulnerability in prenatal and early postnatal development, children are extremely vulnerable to environmental hazards.2,3 Even brief, low-level exposures during critical early periods can cause permanent alterations in organ function and result in acute and chronic disease and dysfunction in childhood and across the life span.4 The World Health Organization estimates that 24% of all deaths and 36% of deaths in children are attributable to environmental exposures,5 more deaths than are caused by HIV/AIDS, malaria, and tuberculosis combined.6–8 In the Americas, the Pan American Health Organization estimates that nearly 100,000 children younger than 5 years die annually from physical, chemical, and biological hazards in the environment.9 Children in all countries are exposed to environmental health threats, but the nature and severity of these hazards vary greatly across countries, depending on national income, income distribution, level of development, and national governance.10 More than 90% of the deaths caused by environmental exposures occur in the world’s poorest countries6–8—environmental injustice on a global scale.11 In low-income countries, the predominant environmental threats are household air pollution from burning biomass and contaminated drinking water. These hazards are strongly linked to pneumonia, diarrhea, and a wide range of parasitic infestations in children.9,10 In high-income countries that have switched to cleaner fuels and developed safe drinking water supplies, the major environmental threats are ambient air pollution from motor vehicles and factories, toxic chemicals, and pesticides.10,12,13 These exposures are linked to noncommunicable diseases—asthma, birth defects, cancer, and neurodevelopmental disorders.9,10 Toxic chemicals are increasingly important environmental health threats, especially in previously low-income countries now experiencing rapid economic growth and industrialization.10 A major driver is the relocation of chemical manufacturing, recycling, shipbreaking, and other heavy industries to so-called “pollution havens” in low-income countries that largely lack environmental controls and public health infrastructure. Environmental degradation and disease result. The 1984 Bhopal, India, disaster was an early example.14 Other examples include the export to low-income countries of 2 million tons per year of newly mined asbestos15; lead exposure from backyard battery recycling16; mercury contamination from artisanal gold mining17; the global trade in banned pesticides18; and shipment to the world’s lowest-income countries of vast quantities of hazardous and electronic waste (e-waste).19 Climate change is yet another global environmental threat.20 Its effects will magnify in the years ahead as the world becomes warmer, sea levels rise, insect vector ranges expand, and changing weather patterns cause increasingly severe storms, droughts, and malnutrition. Children are the most vulnerable. Diseases of environmental origin in children can be prevented. Pediatricians are trusted advisors, uniquely well qualified to address environmental threats to children’s health. Prevention requires a combination of research to discover the environmental causes of disease coupled with evidence-based advocacy that translates research findings to policies and programs of prevention. Past successful prevention efforts, many of them led by pediatricians, include the removal of lead from paint and gasoline, the banning of highly hazardous pesticides, and reductions in urban air pollution. Future, more effective prevention will require mandatory safety testing of all chemicals in children’s environments, continuing education of pediatricians and health professionals, and enhanced programs for chemical tracking and disease prevention.