Running - Breathing in polluted air can cause long term damage to lungs. Swimming - Pollution is one of the many hosts of bacteria, and if someone was to accidentally drink the pool water, it could lead to them being extremely ill.
In general, all outdoor activities can be harmed by pollution, running and walking are no exception.
Air pollution can impair running and walking. This is because in addition to making it difficult for people to breathe, it ends up unmotivating to complete the activity as air pollution can bring several breathing problems. With pollution, a physical activity that should do good to the body ends up doing harm, so people end up abandoning some healthy and exciting activities.
