Health effects of air pollution, according to WHO

Exposure to poor air quality leads to increased premature mortality from cardiovascular and respiratory diseases. Air pollution is a grave risk to human health that affects nearly everyone in the world and nearly every organ in the body. Ambient air pollution is by far the most important environmental risk factor for morbidity and mortality, and household air pollution follows closely Air pollution affects nearly every organ in the body, causing or contributing to many illnesses.

Health effects of air pollution

Indoor air pollution

• In the year 2004, indoor air pollution from solid fuel use was responsible for almost 2 million deaths (3% of all deaths) and 2.7% of the global burden of disease (expressed in disability-adjusted life years, or DALYs*). This risk factor is the second largest environmental contributor to ill-health, behind the combination of unsafe water with poor sanitation. In low- and middle-income countries, 3.9% of all deaths are due to indoor air pollution. Worldwide, indoor smoke from solid fuel combustion causes about 21% of deaths from lower respiratory infections, 35% of deaths from chronic obstructive pulmonary disease and about 3% of deaths from lung cancer.
• Carbon monoxide reduces the capacity of blood to carry oxygen. Symptoms associated with exposure to carbon monoxide include dizziness, nausea, headache, loss of consciousness and death. Persons with coronary artery disease and fetuses are particularly susceptible.6
• Exposure to biological contaminants of indoor air that are related to dampness and mould increases the risk of acute and chronic respiratory diseases, including asthma.
• Radon is the second leading cause of lung cancer after smoking. Most cases of radoninduced lung cancer occur among smokers owing to the strong combined effect of smoking and radon.

Outdoor air pollution

• In the year 2004, outdoor air pollution in urban areas was responsible for almost 1.2 million deaths (2% of all deaths) and 0.6% of the global burden of disease. Transportation-related air pollution, which is a significant contributor to total urban air pollution, increases the risks of cardiopulmonary-related deaths and non-allergic respiratory disease. Some evidence supports an association of transportation-related air pollution with increased risks of lung cancer, myocardial infarction, increased inflammatory response and adverse pregnancy outcomes (e.g. premature birth and low birth weight)
•  Exposure to particulate matter, including metals, has been linked to a range of adverse health outcomes, including modest transient changes in the respiratory tract and impaired pulmonary function, increased risk of symptoms requiring emergency room or hospital treatment, and increased risk of death from cardiovascular and respiratory diseases or lung cancer. Particulate matter is estimated to cause about 8% of deaths from lung cancer, 5% of deaths from cardiopulmonary disease and about 3% of deaths from respiratory infections
• Short-term exposures to ozone are linked with effects on pulmonary function and the respiratory system, lung inflammation, increased medication usage, hospitalization and mortality. Reduced lung function has been associated with long-term ozone
  exposure.
•  Short-term exposures to nitrogen dioxide, an indicator for a complex mixture of mainly traffic-related chemicals, have been associated with effects on pulmonary function, increased allergic airway inflammation reactions, hospital admissions and mortality. Reduced lung function and increased probability of respiratory symptoms are associated with long-term exposure to nitrogen dioxide.