Difficulty breathing, coughing, nasal stuffiness and sinus problems are common symptoms. Problems stemming from chronic respiratory disease such asthma and emphysema are exacerbated by air pollution. Pollutants also irritate mucous membranes in the nose, throat and eyes. Subtle neurotoxic effects including confusion, delayed reactions and blunting of memory have also been linked to air pollution. Koenig notes that combustion of fossil fuels is responsible for most outdoor air pollution.
Vehicles emit carbon monoxide, a pollutant that robs the body of oxygen, which is hard on the heart.
Nitrogen oxides and volatile organic compounds, other components of vehicle exhaust, combine with sunlight to produce ozone, a gas that causes chest pain and cough when deeply inhaled. Home heating with wood stoves and fireplaces causes fine particulate matter air pollution. Studies done by Koenig and others have shown decreased lung function in children living in areas with high volumes of wood smoke. Stepping inside doesn't necessarily lessen your chances of breathing polluted air. Koenig points out that in many cases indoor air contains more pollutants than outdoor air.