Every day around 93 percent of the world’s children under the age of 15 years (1.8 billion children) breathe air that is so polluted it puts their health and development at serious risk.

Tragically, many of them die. The World Health Organization (WHO) estimates that in 2016, 600,000 children died from acute lower respiratory infections caused by polluted air. Children are society’s future. But they are also its most vulnerable members. The immense threat posed to their health by air pollution demands that health professionals respond with focused, urgent action.

Although more rigorous research into how air pollution affects children’s health will continue to be valuable, there is already ample evidence to justify strong, swift action to prevent the damage it clearly produces. Health professionals must come together to address this threat as a priority, through collective, coordinated efforts. For the millions of children exposed to polluted air every day, there is little time to waste and so much to be gained.

A new WHO report on Air pollution and child health: Prescribing clean air examines the heavy toll of both ambient (outside) and household air pollution on the health of the world’s children, particularly in low- and middle-income countries. The report is being launched on the eve of WHO’s first ever Global Conference on Air Pollution and Health. It reveals that when pregnant women are exposed to polluted air, they are more likely to give birth prematurely, and have small, low birth-weight children.