Global health and environmental pollution.

Environmental pollution—contamination of air, water and soil by human activity—is the largest cause of disease and death in lowand middle-income countries (LMICs). The World Health Organization (WHO) estimates that 8.9 million persons die each year of diseases caused by pollution, 8.4 million (94 %) of them in poor countries (WHO 2014a, b). By comparison, HIV/AIDS causes 1.5 million deaths per year (WHO 2014c), and malaria and tuberculosis cause fewer than 1 million deaths each (WHO 2014d). In the world’s poorest countries, the predominant forms of pollution have been indoor air pollution and contaminated drinking water (PAHO 2012). Pneumonia and diarrhea are their principal consequences. By contrast, ambient air pollution, toxic chemicals, pesticides and hazardous wastes are the predominant environmental hazards in richer countries. They are linked to noncommunicable diseases—to asthma, neurodevelopmental disorders and birth defects in children, and to heart disease, stroke, and cancer among adults (PAHO (Pan American Health Organization) 2012). Toxic chemicals are increasingly important causes of pollution worldwide. Many thousands of new chemicals have been invented in the past 50 years. They are used in a vast array of products, are widely disseminated in the global environment and are detectable today in the bodies of most people. Many have never been adequately tested for safety (Landrigan and Goldman 2011). Toxic chemicals are linked to a wide range of diseases. Chemical contamination in LMICs is increasing rapidly (Laborde et al. 2015). Globalization of the chemical manufacturing industry, the recycling industry and other polluting industries is a powerful driver of this trend. These industries are relocating to poor countries where production costs are low and environmental regulations and public health infrastructure often absent. Workers and communities in LMICs are increasingly exposed to toxic chemicals, often under highly uncontrolled conditions. Examples include the Bhopal disaster in India (Mishra et al. 2009); the continuing global trade of 2 million tons per year of newly produced asbestos (Frank and Joshi 2014); the shipment into poor countries of 45 million tons per year of e-waste (Perkins et al. 2014); informal recycling of car batteries for lead scrap in third world mega-cities; and enormous releases of mercury to the environment from artisanal gold mining. The diseases caused by pollution impose great economic costs on countries around the world—direct medical costs, opportunity costs reflecting the diminished productivity of populations damaged by pollution, and costs to health care systems (Landrigan and Fuller 2015). In the United States, the annual cost of diseases in children caused by environmental pollution is estimated to be US$ 76.6 billion (Trasande and Liu 2011) and the cost of occupational diseases and injuries is US$ 250 billion (Leigh 2011). Pollution can be controlled. High-income countries have identified and controlled many of their worst problems of environmental pollution. They have developed feasible, cost-effective and replicable strategies that have reduced incidence and prevalence of the diseases caused by pollution. The most effective of these strategies, such as the This Editorial is part of the special issue ‘‘Driving the Best Science to Meet Global Health Challenges’’ edited on the occasion of the 9th European Congress on Tropical Medicine and International Health 2015.