Eighty-three of the 100 most polluted cities are in India, but a lack of monitoring affects global rankings

Bangladesh is the most polluted country in the world and Delhi is the most polluted capital city. But India has the most air quality monitors in South Asia — and some of the wealthiest Petro-states have almost nothing.

Global ranking of cities' air quality for 2023 Published IQAir, a Swiss company, has been reporting this annually for more than six years.

No country has ever dominated air quality as badly as India, but the report also exposes massive gaps in pollution monitoring in the Global South that stem from a lack of funding, political will or both. Air pollution is highly correlated Eight million 16 deaths per year or per minute, and is considered a major health risk.

Nine of the top 10 most polluted cities are in India, up from six the previous year. Meanwhile, 42 cities in the top 50 are in India, up from 39; And 83 of the top 100 cities are Indian cities (compared to 63 and 65 in the previous two years).

Delhi has returned as the world's most polluted capital for the fifth time in the last six years. Its PM 2.5 level averaged 102 micrograms per cubic metre, 10 units higher than the previous year. The WHO's safe guideline is just 5 micrograms.

IQAir's report summarizes PM2.5 air quality data from 7,812 cities in 134 countries, regions and territories. It sources data from over 30,000 air quality monitoring stations operated by research institutions, government agencies, universities and educational facilities, non-profit organizations, private companies and citizen scientists.

Report exposes gaps in air quality monitoring

However, the data cuts both ways. While this shows how bad the crisis is in India, it also exposes huge gaps in monitoring. Take South Asia for a start. The top three most polluted countries in the world are all here: Bangladesh, Pakistan and India, in that order. But in Bangladesh, only two sites monitor air quality, while Pakistan has 10 sites. India monitors 256 cities.

“In Southeast Asia as a whole, India has 74% of the cities in the region. This increase in monitoring shows the Indian government's awareness of the country's pollution problem and the way to address it is to have a robust monitoring network, which India is actively working on,” said a spokesperson for IQAir. Health Policy Monitoring.

In other areas the lack of monitoring is glaring. In Africa and South America, this raises questions about inequality and funding. The report only includes data from 79 locations in Africa and 219 locations across Latin America and the Caribbean. In contrast, the United Kingdom alone has 219 monitoring sites, Europe has 2,004 and the United States has 3,242.

In West Asia, where some countries have the highest per capita incomes and GHG emissions globally, the lack of more widespread monitoring may raise questions about political will or priorities. For example, Iraq has only two locations with data, Saudi Arabia has three and the seven-member UAE has only three.

How data is collected

Although some countries may have more monitors than reflected in the report, IQAir says it only uses data that meets its limit. Chad, for example, was the most polluted country in 2022, but it did not meet the data inclusion criteria of the latest report, and cities such as Hotan in China and Peshawar in Pakistan, although still polluted, were not included in the top 10 most polluted cities this year.

Over the years, the report has been widely cited — last year it was cited 4,000 times, according to a spokesperson.

The report acknowledges the increasing trend to use a major shift in surveillance technology and that is low-cost sensors. In India, for example, official, regulatory standards are costly when they are more precise 10 times More than the lowest price.

Officers Hundreds of them are now being released in some of the most polluted areas, including Bihar, the #1 most polluted place in the world. Most (61%) of the approximately 30,000 monitors used for the 2023 World Air Quality Report were low-cost monitors. A spokesperson said the margin of error is approximately 10%.

World's worst polluted city and country

The world's most polluted city is Begusarai in the eastern Indian state of Bihar. Its pollution level averaged 118.9 micrograms/cubic meter, 24 times the WHO's safe limit. The most polluted country is Bangladesh, with 79.9 micrograms, 15 times the safe limit. Although the two are hundreds of kilometers apart, air pollution connects them.

„Due to its geographical location, Begusarai experiences a flow of pollution from different parts of India. This also explains why Bangladesh is the most polluted country in the world. Pollution from North and South India is carried by wind and affects the whole of East India and Bangladesh. This is called transboundary pollution.

The Begusarai-Bangladesh link clearly illustrates a great deal of hope for tackling air pollution. The concept of transboundary pollution or common air mass – a formulation Ventilation – Considered the least expensive and most impactful option for reducing pollution across political or administrative boundaries.

Climate change, pollution and pollen allergies

The report warns that climate change could increase air pollution. Fossil fuel emissions account for 65% of global CO2 emissions and are the primary cause of most PM2.5-related deaths, highlighting the interconnected relationship between air quality and climate change.

Because extreme heat events are more severe and frequent, in many regions, severe pollution events coincide with extreme heat, where winds are weak.Floor ventilation allows pollutants to accumulate through it. The frequency of such events is expected to increase.

Changing climate patterns are also extending pollen seasons and exacerbating these by increasing the amount of grass and tree pollen emissions due to changing climate patterns.

Tackling climate change and air pollution jointly is inevitable for policy makers. The question is, can they deliver quickly?

Image Credit: Wikipedia, Sumitmpsd , IQAir.