Where traffic fumes lead to childhood asthma

A landmark study published in the medical journal The Lancet has found that four million children develop asthma every year as a result of air pollution from traffic. That's equivalent to 11,000 new cases a day. Worryingly, most of the new cases are occurring in countries where air pollution levels are below the limits set by the World Health Organization which suggests that fumes from vehicles are even more harmful than previously thought.

Countries suffering from high levels of air pollution such as China and India are not the worst offenders for traffic-induced asthma cases among children. Kuwait actually had the highest prevalence with 550 new cases recorded per 100,000 children each year. Canada came third with 450 new annual cases. The following infographic provides an overview of the situation in a selection of countries from the research with the United States experiencing an incidence rate of 300 new asthma cases per 100,000 children.