Safeguarding children's health in a changing global environment

Children are exquisitely vulnerable to environmental hazards.1 This sensitivity reflects children's unique exposures, their immaturity, and the great complexity of early human development. Exposures during prenatal windows of susceptibility can increase risk for disease in childhood and impair health across the lifespan. WHO estimates that one death in four among children worldwide could be averted by reducing hazardous environmental exposures.2
Three hazards of particular concern today are air pollution, toxic chemicals, and climate change. Air pollution harms children's health by increasing risks of premature birth, low birthweight, stillbirth, and asthma.3 Air pollution is linked also to IQ loss and increased risks of autism and attention deficit hyperactivity disorder.4 More than 90% of air-pollution-related deaths occur in low-income and middle-income countries (LMICs).5 Chemical pollution is a growing threat.5 The health hazards of chemical pollution have been recognised since the publication of Rachel Carson's Silent Spring in 1962,6 but the problem has worsened since then. Children today are surrounded by an estimated 350 000 manufactured chemicals,7 many of which pollute the planet and harm human health. Polychlorinated biphenyls (PCBs), methyl mercury, lead, brominated flame retardants, and organophosphate insecticides impair cognitive function and increase risks of neurodevelopmental disorders.4 Phthalates are linked to male reproductive birth defects and neurodevelopmental delays.8 In-utero exposure to bis(4-chlorophenyl)-1,1,1-trichloroethane (DDT) increases risk of adult breast cancer.6 Prenatal exposures to perfluorinated substances (PFAS) are linked to immune dysfunction and impaired fetal growth.9 Climate change increases risks of adverse pregnancy outcomes, heat-related illness, allergic diseases, famine, and migration.10 The burden of these climate-related hazards is only beginning to be measured.