The air is still bad everywhere2 min read . Updated: 06 Mar 2020, 01:23 PM IST
The 2019 World Air Quality Report throws light on air pollution in different regions of the world by putting particulate matter under the lens
In terms of air pollution, 2019 was a mix of good and bad for India. According to the recently released 2019 World Air Quality Report, Ghaziabad was the most polluted city in the world last year, based on average PM 2.5 levels. But there were air quality improvements across the country. The report says that every city in India where PM 2.5 data was recorded in 2018 and 2019, except Nagpur, saw a decrease in PM 2.5 levels last year. “As a weighted average based on the available data, national air pollution decreased by a remarkable 20% from 2018 to 2019", the report adds. It was, however, unclear if this was due to the implementation of the government’s National Clean Air Programme and the introduction of BS (Bharat Stage) VI emission norms. The report cited “slowing of the marketplace" as the reason behind the reduced PM 2.5 levels.
Air quality agency IQ AirVisual surveyed 4,682 cities globally for this annual report. Twenty-one of the 30 most polluted cities in the world were in India. The data worldwide was collected from a range of ground-based PM 2.5 monitoring stations. Data sources for the report also included real-time hourly data from government monitoring stations and validated PM 2.5 monitors operated by private organizations. Governmental historical data sets of hourly PM 2.5 measurements for certain locations were also used. The report focused on PM 2.5 concentrations as the pollutant is considered the most harmful to human health—owing to its microscopic size, it can enter the bloodstream through the respiratory system.
The findings also indicate the scale of the air pollution problem facing us today. For instance, Delhi topped the rankings in the list of most polluted capital cities in the world for the second consecutive year, with an average annual PM 2.5 concentration (measured in micrograms per cubic metre, or µg/m3) of 98.6. The least polluted capital city was Nassau, Bahamas (3.3). In the Central and South Asia region, which includes India, only 0.7% of the cities met the World Health Organization’s PM 2.5 target (10µg/m3) in 2019. In India, the report adds, none of the cities met the target.
Further, what makes the situation tougher to assess is that the country still lacks a proper air quality monitoring network, with many of the highly populated cities lacking access to real-time information on air quality. This trend was noticed across the globe. Regions in the African and South American continents still lack monitoring data, which reflects in limited awareness of the health impact of air pollution.
On the other hand, as China continues to tackle the Covid-19 epidemic, its cities achieved a 9% average decrease in PM 2.5 levels last year, but 98% of Chinese cities exceeded WHO guidelines. Surprisingly enough, Beijing, often in the news for its extremely polluted air, managed to stay out of the rankings of the top 200 most polluted cities.
Report after report is now highlighting the direct health effects of air pollution. A January report by the British Heart Foundation, a UK-based charity working on heart and circulatory disease, warned that more than heart attacks and strokes, air pollution from particulate matter could kill more than 160,000 in the UK within the next decade. Research funded by the foundation showed that high levels of air pollution could make existing heart conditions worse and increase the risk of heart attacks or strokes. The report urged the UK government to adopt WHO guidelines on particulate matter and meet them by 2030.