By: Jessica Hefes
A certain amount of physical exercise is generally known to be good for the health and necessary to the development of children. However in highly polluted areas pollution may in fact make exercise dangerous for children. In low pollution districts exercise is associated a higher maximal oxygen uptake but not in the high-pollution district. Similarly physical exercise normally increases the fitness of the heart and lungs in children but but not those who live in the more polluted districts. The benefits of physical exercise thus seem to be cancelled out by pollution!
Whilst there is no definite relationship between exercising in polluted conditions and lack of cardiopulmonary fitness, it is considered prudent to refrain from strenuous physical activity in highly polluted environments, such as jogging on roads with moderate or heavy traffic.
The possible relationship between exercising in polluted conditions and lack of cardiopulmonary fitness should lead to an urgent assessment of the potential harm to children playing in school grounds exposed to heavy traffic fumes. 
- ↑ Impact of air pollution on cardiopulmonary fitness in schoolchildren, Yu IT, Wong TW, Liu HJ, 2004, J Occup Environ Med 46:946–952