Outdoor pollution

Small particles and ozone come from exhaust from cars and factories, smoke and road dust. When inhaled, outdoor pollutants can aggravate the lungs, leading to chest pain, coughing, shortness of breath and throat irritation.

Outdoor air pollution may also worsen chronic respiratory diseases, such as asthma. On days when ozone air pollution is highest, ozone has been associated with 10-20% of all respiratory hospital visits and admissions.