Calidad del aire en Shanghai

What is the air quality index of Shanghai?

Shanghai is located in China on the southern estuary of the Yangtze River. In 2019 the population was estimated to be around 25 million. This figure reflects the people who are registered as living there but does not take into account the transient workers. It is the largest populous urban area in China, surpassing the capital, Beijing. It is a very busy city because of its location and the Port of Shanghai is the busiest container port in the world. In 2018 the port handled 42 million 20 foot long containers, 259 cruise vessels and 1.89 million passengers.

According to the reputable air quality monitoring site, IQAir.com the quality of air towards the end of 2020 was recorded as being “Moderate” with a US AQI figure of 84. This classification is based on the guidelines published by the World Health Organisation (WHO).

The concentration of the main pollutants suspended in the air was as follows: - PM2.5 = 28 µg/m³, PM10 = 42.5 µg/m³, ozone (O₃) = 16 µg/m³, nitrogen dioxide (NO₂) = 59 µg/m³, sulphur dioxide (SO₂) = 8 µg/m³ and carbon monoxide (CO) = 800 µg/m³. All these figures are quoted as being micrograms per cubic metre.

Looking back over the annual figures for the past three years, it can be seen that the air quality is slightly improving. In 2019, Shanghai recorded a “Moderate” level for 7 months of the year from May through to November. During the winter period of December to April, the figure was slightly worse with an “Unhealthy for Sensitive Groups” classification. Overall, the mean figure was 35.4 µg/m³, which was an improvement on 2018 and 2017 with figures of 36 and 38.9 µg/m³, respectively.

What are the main sources of air pollution in Shanghai?

Air pollution in Shanghai is mainly caused by coal combustion, motor vehicles, industrial dust, chemical conversion in the atmosphere in urban centres, and unfavourable meteorological conditions, all of which are linked to rapid socio-economic development. To be more precise, vehicle and factory emissions account for at least 50 per cent of Shanghai’s polluted air. 10.5 per cent comes from the demolition and reconstruction sites. Power stations account for a further 7.3 per cent and rural straw-burning accounts for another 10 per cent. Pollutants carried into the city by the wind makes up the balance.

Is the air quality in Shanghai getting better or worse?

In September 2014, the local authorities introduced the strictest air pollution law in all of China which became enforceable from 1^st October. Personal penalties for company bosses were introduced with fines of RMB 100,000 and maximum fines for the company rose to RMB 500,000. The prohibition of burning straw was extended to cover the whole of the province and no just central Shanghai. However, the fines levied against farmer’s who are caught breaking this law is a relatively small sum of RMB 200 which does not, therefore, act as a deterrent.

Real-time AQI readings are now made available to all residents who can decide on their own course of action having seen the figures.

A new emissions standard was adopted for all vehicles registered after May 2014. This standard enforces lower emissions of hydrocarbons, carbon monoxide and nitrogen oxide.

Vehicles which produce a large number of pollutants are known as “Yellow Label” vehicles and are becoming the subject of ongoing tighter controls. It was estimated that in 2015 there were still 120,000 yellow label vehicles using the roads in Shanghai. In July 2014, they were banned from using the outer ring roads, having already been banned from using the inner ones. A complete ban came into force in 2015 which prevented them from entering the Shanghai suburbs.

The central government issued a directive stating that at least 30 per cent of all government operated vehicles must be fuelled by renewable energy. Subsidies have also been introduced to encourage residents to make a “green” choice when choosing their new vehicle. Each new buyer will receive RMB 40,000 and be given a Shanghai licence plate worth RMB 70.000. They can also apply for an RMB 60,000 government subsidy.

In May 2014, plans were introduced to reduce the emissions of volatile organic compounds (VOC)s from Shanghai factories.

Other measures will be that 15 major state-owned enterprises will be required to upgrade their equipment to reduce carbon emissions. Large coal-fired power plants will be forced to install equipment which will remove nitrogen (denitrification) from their chimneys.

Taxi drivers in Shanghai were given an RMB 1,300 subsidy to install the latest catalytic converters to ensure their exhaust gases are as clean as is possible.

In October 2015 it was announced that out of the remaining 8,000 diesel-powered buses in the city, 5,000 would be fitted with air filters by the end of the year and the remaining 3,000 older vehicles will be taken out of service altogether.

From 1^st January 2016, large trucks which do not meet the new standards will be prohibited from entering the city centre between the hours of 7 am and 8 pm. Unfortunately, they will be allowed entry at other times.

The port will also be governed by new restrictive measures. Vessels which use the berths at Shanghai, Ningbo-Zhoushan, Nantong and Suzhou will be required to use low sulphur content fuel whilst in the dock. Emissions from ships account for between 8-10 per cent of Shanghai’s PM2.5 pollutants. Through this new legislature, it is hoped to reduce the content of sulphur oxide (SO) in the air by at least 10 per cent.

What are the health effects of Shanghai’s polluted air?

A recent study found that a 10 µg/m³ increase in particulate matter (PM10) reduced life expectancy in China by 0.64 years and that PM2.5 accounted for 1.7 million of all-cause deaths in China in 2015. A recent study, however, estimated that the number of deaths caused by exposure to high levels of PM2.5 has decreased by 12.6 per cent from 1.2 million in 2013 to 1.05 million in 2017.

In the first six months of 2020, it was reported that around 49 thousand people died from diseases related to air pollution. The report from the Centre for Research on Energy and Clean Air (CREA) revealed that Shanghai has worse concentrations of the pollutant PM2.5, sulphur dioxide (SO₂) and nitrogen dioxide (NO₂), than Beijing. On a global scale, CREA estimates that damage to health attributed to air pollution cost between 0.4 and 6 per cent of the annual GDP in the world’s leading cities.

Shanghainese are all too familiar with the hazards of PM2.5 and are coming to terms with the problems associated with ground-level ozone (O₃). The problem gets worse in the sunny, summer months when volatile organic compounds (VOC) react to the increased sunlight and produce ozone. Levels are recorded in the Yangtze River Delta region and an annual increase of around 12.8 per cent was noted.

According to the World Health Organisation (WHO) Ambient Air Pollution fact sheet, ozone (O₃) is a major factor in asthma morbidity and mortality. It can cause breathing problems, trigger asthma, reduce lung function and cause lung diseases.

What can be done to improve Shanghai’s air quality?

Air pollution has become a major issue in China but it is not being ignored, on the contrary, since 2013 the average PM2.5 concentrations fell by 33% in 74 cities. In the following year, the overall pollution in China fell further 10 per cent. Another study shows that China reduced the concentration level of PM2.5 by 47% between 2005 and 2015.

There is a growing awareness of the environment among the public who can see the improvements which are being made. The Suzhou Creek is a waterway which runs through the city. A comprehensive clean-up campaign was launched to bring this dead river back to life. All moored barges and factories who discharged their effluence into the river were moved to the outskirts of the city. The riverbed was dredged and 1.3 million cubic metres of accumulated sludge were removed. The river is now able to support wildlife, once more.

Any remaining factories have been relocated away from the city centre and incentives are offered to transportation companies to replace their older polluting vehicles with LPG buses and taxis or electric ones.

Can the smog in Shanghai be controlled?

It is generally considered that the air pollution in Shanghai is not as high as in other Chinese cities, but is substantially polluted when compared to world standards. A record level of smog enveloped the city in December 2013 and became known as the “2013 Eastern China Smog”. At this time air pollution rates were recoded as being between 23 and 31 times higher than international standards. Levels of the microscopic PM2.5 particulate matter rose above 600 micrograms per cubic metre, and for the surrounding area, the figure was even higher at 700 µg/m³. In the Putuo District, PM2.5 levels reached a staggering 726 µg/m³. Because of this, the Shanghai Municipal Education Commission declared a suspension of all outdoor activities for all students. Nearly 33 per cent of government-operated vehicles were taken off the road and construction sites were ordered to suspend their operations. The visibility was so poor at Pudong International Airport that 50 flights had to be diverted.

It is thought that this occurrence prompted the government to introduce a “Clean Air Policy”.

In early 2014, the mayor of Shanghai announced the implementation of three measures aimed at combating the poor air quality. The first was an air-cleaning program, secondly, was a linkage mechanism with the 3 surrounding providences and thirdly was the improvement to the early warning system. The equivalent of $US 1.7 billion was allocated to help companies attain the new standards. Over the course of the next 5 years, more than 3,000 treatment facilities had been inaugurated for the treatment of industrial gas emissions. The effect was considerable with a reduction of annual smoke, sulphur dioxide and nitrogen oxide emission dropping by 65%, 95% and 54% respectively.

Did COVID-19 affect the air quality in Shanghai?

COVID-2019 (COrona VIrus Disease 2019) was discovered at the end of 2019 in the city of Wuhan in Hubei province in China. In order to prevent the spread of this virus, many local authorities introduced what became known as “lockdown”. This included the closure of factories and imposed travel restrictions. Because of the decrease in human activity, the release of polluted air was also reduced. It was soon realised that this phenomenon was having a remarkable effect on the ambient air quality. Records show that during the lockdown period, daily concentrations of PM2.5, PM10, sulphur dioxide (SO₂), nitrogen dioxide (NO₂) and carbon monoxide (CO) were reduced by 9%, 77%, 31.3%, 60.4%, and 3% respectively, compared to the same period in the previous year. But even with these decreasing values of PM2.5 and PM10, the overall figures are still over four times higher than the levels suggested by the World Health Organisation (WHO) of 10 µg/m³ for PM2.5 and 20 µg/m³ for PM10. This indicates that even with the noticeable lack of human movement and the closed factories etc. significant contributions to air pollution are coming from elsewhere.

As the largest city in the country, the Shanghai Municipal Government took proactive measures against COVID-19 and suspended all activities normally carried out by trade, catering, services, culture, education, sports, and other similar industries. At first, public transport was allowed to continue but this too was suspended towards the end of January 2020. These measures created a tremendous impact on the city which lead to lower economic growth. However, it also created a unique opportunity to study the anthropogenic activities on air pollution in the country’s largest city.

At the end of March when the lockdown was lifted, the number of pollutants in the air began to increase again due to the movement of vehicles and the start-up of factories again. The country’s largest coal-fired power station began to operate at full capacity once more which produced a spike in the levels of sulphur dioxide (SO₂).