But first, how does all this air pollution kill people? The WHO says that it's tough to understand the exact connection, but "the lower the levels of air pollution, the better the cardiovascular and respiratory health of the population will be, both long- and short-term." And when your cardiovascular and respiratory health suffers, cases of lung cancer and strokes rise. In 2012, the most recent year for which data is available, they rose to contribute to an estimated 3.7 million premature deaths around the world (indoor pollution added another 4.3 million). Here's the unsurprising kicker: "Some 88% of those premature deaths occurred in low- and middle-income countries, and the greatest number in the WHO Western Pacific and South-East Asia regions," the WHO says.
When it comes to solutions, the WHO makes a number of recommendations and admits that, "most sources of outdoor air pollution are well beyond the control of individuals." The real change will happen when city, national and international governments and policymakers make big changes. For example, in the transportation sector, those should include:
The WHO has warned about the negative effects of air pollution before, pointing out the awful impacts of diesel fumes and brake dust. For more, you can read the WHO's fact sheets on outdoor and indoor air pollution and see a summary of the new study below.
shifting to clean modes of power generation; prioritizing rapid urban transit, walking and cycling networks in cities as well as rail interurban freight and passenger travel; shifting to cleaner heavy duty diesel vehicles and low-emissions vehicles and fuels, including fuels with reduced sulfur content.
Summary of results
Globally, 7 million deaths were attributable to the joint effects of household (HAP) and ambient air pollution (AAP) in 2012. The Western Pacific and South East Asian regions bear most of the burden with 2.8 and 2.3 million deaths, respectively. Almost 680'000 deaths occur in Africa, about 400'000 in the Eastern Mediterranean region, 287'000 in Europe and 131'000 in the Americas. The remaining deaths occur in high-income countries of Europe (295'000), Americas (96'000), Western Pacific (68'000), and Eastern Mediterranean (14'000).
Note of caution: An approximation of the combined effects of risk factors is possible if independence and little correlation between risk factors with impacts on the same diseases can be assumed1. In the case of air pollution, however, there are some limitations to estimate the joint effects: limited knowledge on the distribution of the population exposed to both household and ambient air pollution, correlation of exposures at individual level as household air pollution is a contributor to ambient air pollution, and non-linear interactions2,3. In several regions, however, household air pollution remains mainly a rural issue, while ambient air pollution is predominantly an urban problem. Also, in some continents, many countries are relatively unaffected by household air pollution, while ambient air pollution is a major concern. If assuming independence and little correlation, a rough estimate of the total impact can be calculated, which is less than the sum of the impact of the two risk factors. The joint effects of both ambient and household air pollution would result in the impacts shown in Figure 1-4. Given the limitations, however, the estimates presented below should be interpreted with caution, and provide indicative values only.