New research shows that more than 5.5 million people die prematurely every year due to household and outdoor air pollution. More than half of deaths occur in two of the world's fastest growing economies, China and India.
Power plants, industrial manufacturing, vehicle exhaust and burning coal and wood all release small particles into the air that are dangerous to a person's health. New research, presented 12 Feb at the 2016 annual meeting of the American Association for the Advancement of Science (AAAS), found that despite efforts to limit future emissions, the number of premature deaths linked to air pollution will climb over the next two decades unless more aggressive targets are set.
"Air pollution is the fourth highest risk factor for death globally and by far the leading environmental risk factor for disease," said Michael Brauer, a professor at the University of British Columbia's School of Population and Public Health in Vancouver, Canada. "Reducing air pollution is an incredibly efficient way to improve the health of a population."
For the AAAS meeting, researchers from Canada, the United States, China and India assembled estimates of air pollution levels in China and India and calculated the impact on health.
Their analysis shows that the two countries account for 55 per cent of the deaths caused by air pollution worldwide. About 1.6 million people died of air pollution in China and 1.4 million died in India in 2013.
In China, burning coal is the biggest contributor to poor air quality. Qiao Ma, a PhD student at the School of Environment, Tsinghua University in Beijing, China, found that outdoor air pollution from coal alone caused an estimated 366,000 deaths in China in 2013.
Ma also calculated the expected number of premature deaths in China in the future if the country meets its current targets to restrict coal combustion and emissions through a combination of energy policies and pollution controls. She found that air pollution will cause anywhere from 990,000 to 1.3 million premature deaths in 2030 unless even more ambitious targets are introduced.
"Our study highlights the urgent need for even more aggressive strategies to reduce emissions from coal and from other sectors," said Ma.
In India, a major contributor to poor air quality is the practice of burning wood, dung and similar sources of biomass for cooking and heating. Millions of families, among the poorest in India, are regularly exposed to high levels of particulate matter in their own homes.
"India needs a three-pronged mitigation approach to address industrial coal burning, open burning for agriculture, and household air pollution sources," said Chandra Venkataraman, professor of Chemical Engineering at the Indian Institute of Technology Bombay, in Mumbai, India.
In the last 50 years, North America, Western Europe and Japan have made massive strides to combat pollution by using cleaner fuels, more efficient vehicles, limiting coal burning and putting restrictions on electric power plants and factories.
"Having been in charge of designing and implementing strategies to improve air in the United States, I know how difficult it is. Developing countries have a tremendous task in front of them," said Dan Greenbaum, president of Health Effects Institute, a non-profit organization based in Boston that sponsors targeted efforts to analyze the health burden from different air pollution sources. "This research helps guide the way by identifying the actions which can best improve public health."
The research is an extension of the Global Burden of Disease study, an international collaboration led by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington that systematically measured health and its risk factors, including air pollution levels, for 188 countries between 1990 and 2013. The air pollution research is led by researchers at the University of British Columbia and the Health Effects Institute.
Additional facts about air pollution:
- World Health Organization (WHO) air quality guidelines set daily particulate matter at 25 micrograms per cubic metre.
- At this time of year, Beijing and New Delhi will see daily levels at or above 300 micrograms per cubic meter metre; 1,200 per cent higher than WHO guidelines.
- While air pollution has decreased in most high-income countries in the past 20 years, global levels are up largely because of South Asia, Southeast Asia, and China. More than 85 per cent of the world's population now lives in areas where the World Health Organization Air Quality Guideline is exceeded.
- The researchers say that strict control of particulate matter is critical because of changing demographics. Researchers predict that if air pollution levels remain constant, the number of deaths will increase because the population is aging and older people are more susceptible to illnesses caused by poor air quality.
- According to the Global Burden of Disease study, air pollution causes more deaths than other risk factors like malnutrition, obesity, alcohol and drug abuse, and unsafe sex. It is the fourth greatest risk behind high blood pressure, dietary risks and smoking.
- Cardiovascular disease accounts for the majority of deaths from air pollution with additional impacts from lung cancer, chronic obstructive pulmonary disease (COPD) and respiratory infections.