A new China air pollution study has been sensationalized in the western press and local expat media, causing quite a stir in the expat community.
We discussed many international and China studies on the effects of air pollution in our air pollution solutions article, but here we will take a deeper look at this one study which led to to the shocking headlines.
Negative news always sells. We have a new term for this phenomenon; click-bait.
One newspaper in Russia lost two-thirds of its normal readership when it only published positive news for one day.
Air pollution is one popular topic that gets a lot of negative press these days. Studies on the serious health effects of air pollution proliferate, many of them focused on China.
These reports are beneficial if they raise our awareness and encourage us to take precautions to protect our health, but the one-sided bias does not reflect the full story in China.
Recent reports with headlines such as ‘Living in China Takes 3½ Years Off Your Life’ and ’Living in Shanghai Takes Nearly 6 Years Off Your Life’ were shared extensively by the expat community on social media.
These articles were based on a China air pollution study released by the University of Chicago’s Energy Policy Institute; “The Impact of Sustained Exposure to Particulate Matter on Life Expectancy: New Evidence from China’s Huai River Policy”.
The researchers used an in-depth analysis of mortality data to show the connection between China’s policy of installing coal-powered residential heating systems in Chinese cities North of the Huai River since the 1950’s and an increase in cardiorespiratory related deaths in those areas due to the increased particulate matter (PM) emitted. This study was a follow up to an earlier study which analyzed the same phenomenon.
The Huai river is located between China’s Northern Yellow River and Central Yangtze River and traditionally is considered the delineation line between North and South China.
Based on an analysis of the statistics the researchers calculated that life expectancy for residents North of the Huai River was on average 3.1 years less than for residents living to the South of the River where no such coal-powered heating infrastructure was installed.
The researchers further used their data to come up with a metric showing the impact of increased PM2.5 exposure on life expectancy. They estimate that for every extra 10 μg/m3 of average PM2.5 life-time exposure 1.03 life years are lost.
Based on this metric the same institute has developed an Air Quality-Life Index™ to estimate how average life expectancy around the world is impacted by local air pollution. The ALQI website (under the Data and Methodology tab) explains how they made their calculations.
The western and local expat media seized on this metric to create their sensational headlines.
The fact that air pollution has serious effects on our health is not in contention, and this China air pollution study does provide valuable evidence of the serious health impact from coal-burning emissions.
A different interpretation of the same study, however, can show us how efforts since 2013 to reduce air pollution in China are increasing life expectancy.
The average annual PM2.5 density in Shanghai dropped from 62 ug/m3 in 2013 to 45 in 2016 and in Beijing from 89.5 to 73 in the same time span.
By applying the UofC AQLI metric, therefore, we can come up with a much more sanguine interpretation; the decrease in PM2.5 air pollution between 2013 and 2016 has increased life expectancy in both Shanghai and Beijing by about 1.7 years.
Even when compared to a PM2.5 density of 0; a very unlikely level for most major cities, Shanghai’s 2016 average PM2.5 density of 45 would only result in a hit on life-expectancy of less than 5 years to long-term residents.
Considering that average PM2.5 pollution in most large North American and European cities is between 15 and 20 ug/m3, the hit on life expectancy for long-term residents in Shanghai directly related to air pollution is less than 3 years when compared to living in most Western cities, and even lower for those who only stay in Shanghai a short time.
Of course, we shouldn’t be overly positive. The figures for Shanghai and Beijing are still much higher than China’s national healthy air quality standard for annual average PM2.5 exposure of 35 ug/m3 and the World Health Organization’s recommendation of no more than 10 ug/m3.
Another conclusion of this study was that the Huai River Policy "...had disastrous consequences for human health".
Analyzing the real-world situation, however, does not support this argument.
Due to the colder weather to the North of the Huai River more winter heating is required for a livable environment.
The central heating systems use coal-fired boilers to heat water which is pumped to radiators in residences. These boilers do cause heavy emissions, but we should compare this drawback to the alternatives available.
Clean and green energy were not economically viable until recently. The more likely alternative, therefore, was coal or wood stoves inside residences which would likely create just as much outdoor air pollution and certainly more indoor air pollution.
After making a comeback in the UK in recent years, experts have warned that residential wood burning stoves are also disastrous to our health. The Mayor of London has launched a campaign to ban the practice to tackle air pollution.
In 2017 China has begun to invest heavily to switch from coal-fired heating systems to natural gas and other cleaner energies as you can read about in our air quality in China article.
In an online report by the same University to announce the launch of the China air pollution study it was acknowledged that "Since the earlier paper, China has increased its efforts to confront its air pollution challenge. China is switching its primary source of heating from coal-fired boilers to gas-fired or electric units, and it has shut down many polluting plants. The consequence is that particulate air pollution in some of China’s most polluted cities, such as Beijing, has improved significantly."
Moreover, China’s rapid increase in life expectancy in the last 40 years should also be acknowledged.
In 1980 when China began its opening up and the new phase of industrialization which would eventually lead to the heavy air pollution we have come to suffer from, average life expectancy in China was 65.5 years. By 2015 it had increased to 76.1 years; moving China from 79th place in the world up to 55th place.
Life expectancy in Shanghai reached 83 years in 2016, only slightly lower than the highest national life expectancy rate of Japan.
And life expectancy in Beijing is not far behind at about 82 years.
Great accomplishments have been achieved in the battle against air pollution in China, but the war on pollution declared by Chinese Premier Li Keqiang in 2014 continues. In the meantime be sure to read our air pollution solutions article to learn how you can protect yourself from smog.
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