Ambient (outdoor air pollution) is a major cause of death and disease worldwide. The health effects range from augmented hospital admissions and emergency room visits, to increased hazard of early death.
An approximate 4.2 million premature deaths internationally are related to ambient air pollution, mainly from heart ailments, stroke, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections in children.
Worldwide ambient air pollution accounts for:
- 29% of all deaths and disease from lung cancer
- 17% of all deaths and disease from acute lower respiratory infection
- 24% of all deaths from stroke
- 25% of all deaths and disease from ischaemic heart disease
- 43% of all deaths and disease from chronic obstructive pulmonary disease
Pollutants with the strongest confirmation for public health problems include particulate matter (PM), ozone (O3), nitrogen dioxide (NO2) and sulphur dioxide (SO2).
The health risks associated with particulate matter of less than 10 and 2.5 microns in diameter (PM10 and PM2.5) are especially well accepted. PM is capable of piercing deep into lung passageways and entering the bloodstream causing cardiovascular, cerebro-vascular and respiratory impacts. In 2013, it was classified as a cause of lung cancer by WHO’s International Agency for Research on Cancer (IARC). It is also the most widely used indicator to measure the health effects from exposure to ambient air pollution.
In children and adults, both short- and long-term exposure to ambient air pollution can lead to reduced lung function, respiratory infections and aggravated asthma. Maternal exposure to ambient air pollution is connected with difficult birth outcomes, such as low birth weight (LBW), pre-term birth and small gestational age births. Emerging data also suggests ambient air pollution may affect diabetes and neurological growth in children. Considering the precise death and disability toll from many of the conditions mentioned are not currently quantified in current estimates, with growing evidence, the burden of disease from ambient air pollution is expected to greatly increase.
Other susceptible groups include those with pre-existing lung or heart disease, as well as elderly people and children. In children with developing lungs, air pollution exposure can cause both short- and long-term deficits in lung function, as well as long-term reductions in lung growth rate.
Improving air quality is, therefore, among the steps with the furthermost possible effect on health equity. Large health benefits would take place for lower income groups, as well as children and the elderly, who bear the brunt of contact to ambient air pollution or are most vulnerable.
Policies to reduce air pollution offer a “win-win” strategy for both health and climate. Lower levels of air pollution result in better cardiovascular and respiratory health of populations in both the long- and short-term. Decreasing outdoor air pollution can also reduce emissions of CO2 and short-lived climate pollutants, such as black carbon particles and methane, therefore contributing to the near- and long-term alleviation of climate change.
