A new study published this week in Nature has reported that 3.3 million people will die around the world this year as a result of exposure to outdoor air pollution, and if emissions aren’t reduced, the annual death toll could double (6.6 million people) by 2050.

Michael Jerrett, Professor and Chair of the UCLA Department of Environmental Health Sciences stated that such an announcement should ring alarm bells in public health agencies worldwide. The highest death rates in the study were reported in China and India, which are the world’s highest and third highest greenhouse gas emitters respectively.

In China, approximately 1.4 million people die each year from pollution so bad that closes schools

In China, approximately 1.4 million people die each year from pollution so bad that closes schools and virtually forces people to remain indoors. New Dehli in India is reported to have the most toxic air quality of any city in the world, and approximately 645,000 people die each year as a result.

In terms of deaths related to air pollution, the study reported that cerebrovascular disease (which affects blood flow to the brain), some forms of heart disease and chronic obstructive pulmonary disease (COPD) are the predominant causes. Of all the sources of air pollution, residential and commercial energy use were the main contributors, arising from activities such as burning coal and wood on a small scale and using diesel for fuel.

Agriculture was the second largest contributor, resulting from ammonia being emitted from fertiliser and animal excreta reacting with vehicle traffic and power plant exhaust which creates particulate matter. Although the focus of the study was outdoor air pollution, the research group estimated that approximately 3.5 million people die annually from emissions related to indoor cooking and heating.

air pollution kills 7 million people each year

While other studies have also quantified the health impacts and deaths, the UCLA study is the most extensive to date. Last year the World Health Organisation (WHO) reported that air pollution kills 7 million people each year. If the number of deaths from the study published in Nature are added, the total (~6.8 million) is close to that of the WHO.

The WHO regards air pollution as the greatest environmental health risk and one that contributes to one out of every eight deaths worldwide. In addition, the WHO has linked long term exposure to air pollution to health effects such as asthma, kidney damage and autism. In 2013, the WHO officially listed air pollution as a human carcinogen, which is significant given that such a classification is usually reserved for specific chemicals rather than a mixture such as air pollution.

See more on the WHO assessment of air pollution here

A study in China by Berkeley Earth which was published in August this year reported that nearly 1 in every 5 deaths in China are related to air pollution. Hourly measurements of particulate matter smaller than 2.5 microns in diameter or smaller (known as PM2.5) from 1500 locations across China were analysed over 4 months, and the results of the study showed a link between sources of PM2.5 and sulfur. Given that link, the authors suggested that coal was the most likely source.

See more on the Berkeley Earth study here

As someone who has worked in air pollution control and management for 15 years, I continue to be amazed that many people seem oblivious to the serious threat that air pollution poses. Technology is advancing rapidly and more and more specialist equipment is available on the market which can identify what chemicals are in the air and how much of that chemical there is, however technology is only one part of the solution.

I suggest that education is (and will continue to be) a very important factor, given that unless people are aware of how their habits and lifestyles perpetuate air pollution around the world, and that changing these habits can change the way people relate to the earth and therefore reduce the health and economic costs associated with air pollution, the death toll will continue to mount.

Technology has given us huge amounts of data on air pollution around the world, however only education will give us the power to interpret that data and to decide once and for all whether we can live with millions of people dying every year.

See more on the UCLA study here