Jennifer McDowall explains why air pollution is causing millions of premature deaths in China.
Photo by Maud Beauregard
The World Health Organisation (WHO) has described air pollution as “the greatest environmental risk to health”. Low quality air is taking a particular toll on the population in China, one of the most polluting countries in the world, where it’s estimated that 4,000 people are dying every day due to poor air quality.
Based on the measure of air quality used by the United States Environmental Protection Agency, a massive 38% of Chinese people are currently living in areas with ‘unhealthy’ air quality. Pollutants such as nitrogen oxides, sulphur oxides, ozone and particulate matter contribute to the death of seven million people around the world every year.
Particulate matter is a mixture of solid and liquid particles of varying sizes, suspended in the air. Particles less than 2.5 micrometres, known as PM2.5, are produced mainly as a bi-product of burning fossil fuels. These particles reduce air quality, are the primary cause of smog and are extremely detrimental to human health. It’s estimated these particles alone cause 4.6 million deaths a year.
Particulate Matter and Human Health
The small size of the PM2.5 particles allows them to penetrate the lungs and blood stream, damaging the respiratory and vascular systems. This damage is worsened with increased exposure, in terms of either concentration or duration, and has been linked to lung cancer, asthma and heart disease. In fact, for every 10µg/m3 increase in PM 2.5, the risk of developing lung cancer, childhood asthma or a heart attack increases by 16%, 36% and 44%, respectively.
According to WHO, the maximum daily amount of PM2.5 exposure considered safe is 25 particles per cubic metre of air. In China, this figure often exceeds 200. This is a regular occurrence during winter, when weather conditions help keep pollution at ground level and more power is generated for heating. In addition to electricity production, transportation emissions are a major source of air pollution, especially in urban areas.
To make matters worse, China also has to deal with annual sandstorms, which carry sand and dust from the Gobi Desert, which lies to the north of China. These winds have increased in frequency over the last two decades and are sometimes bad enough to turn the sky brown.
In a recent study, researchers analysed satellite imagery along with PM2.5 concentration data from several locations in China. Using this data, the researchers estimated that 30.8 million people have died prematurely as a result of PM2.5 between 2000 and 2016, that’s between 1.5 and 2.2 million deaths per year during that time period. But now, at least, China is taking action with a plan to bring back its blue skies.
Blue Skies Ahead
The aim of the Blue Skies Project was to reduce sulphur dioxide and nitrogen oxide levels by 15%, relative to 2015 levels, and reduce PM2.5 concentrations by 18%. To reach these goals, the major causes of air pollution were targeted.
Transport systems were upgraded to be more eco-friendly and fuel efficient. This involved heavy investment and uptake of electric vehicles and a reduction, including bans in certain areas and sectors, of vehicles running on fossil fuels. In addition, a national pricing system was introduced for carbon emissions as well as charges for polluters. Over the last few years China has also shifted away from coal towards natural gas for electricity generation in an effort to improve air quality.
Although it has already made an impact, the programme has not been without controversy. In 2017, officials from seven different cities were charged for manipulating official Chinese PM2.5 air pollution data on high-pollution days to bring them within acceptable levels. Despite this setback, the concentrations of PM2.5 have shown a significant drop over the last few years, though many areas remain heavily polluted where infrastructure upgrading has not been completed.
Following China's first Covid lockdown, greenhouse gas emissions plummeted by 40% as polluting industries such as coal-fired power generation closed down. Once the country re-opened, however, emissions quickly rose above pre-pandemic levels, proving that a quick green recovery wasn’t on the cards for China. Although an effort is being made, it’s clear China still has a way to go to prove its commitment to improving air quality. It may take a little longer before the Chinese see blue skies again.
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