Staff Reporter :
The 2024 World Air Quality Report by Swiss-based IQAir has identified Bangladesh along with Chad as the most polluted countries, with Delhi, India, ranking as the most polluted capital. However, only seven nations worldwide met the WHO’s air quality standards, while pollution levels in Africa remain largely under-reported.
The report also highlighted how environmental monitoring was affected by budget cuts and policy changes under former U.S. President Donald Trump, with the shutdown of air quality monitoring at American embassies and the removal of 17 years’ worth of data from the U.S. government’s airnow.gov database.
The report, which examined nearly 9,000 cities, found that only 17 per cent adhered to the WHO’s standard of 5 micrograms per cubic metre for PM2.5. The seven nations that achieved this benchmark were Australia, New Zealand, the Bahamas, Barbados, Grenada, Estonia, and Iceland.
The report also indicated that pollution remains a major concern for the Global South, with the worst-affected areas primarily in Asia. While some African regions also experience severe pollution, data remains incomplete, with only 24 out of 54 African nations reporting figures in 2024 – an improvement from 2017, when only three African countries contributed data.
The findings were released shortly after the Trump administration’s decision to discontinue air quality monitoring at U.S. embassies worldwide. According to IQAir, this move is likely to have serious consequences, as many developing nations have relied on this data for environmental policymaking.
Dr Christi Chester Schroeder, IQAir’s Air Quality Science Manager, emphasised that U.S. embassies had previously played a key role in encouraging host nations to take action against pollution. She estimated that at least eight countries – mostly in the developing world – will lose access to real-time air quality data as a result of these policy changes.
Due to a lack of real-time data, Iran and Afghanistan were not included in the report. IQAir’s findings were based on 40,000 ground-level monitors across 138 countries, though the company does not disclose margins of error for PM2.5 readings.
The report suggested that the high pollution rankings for Bangladesh and Pakistan could be linked to the limited scope of their monitoring systems, which predominantly focus on urban areas. Chad reappeared in the rankings after being excluded in 2023 due to insufficient data.
The situation in South Asia remains critical, with Bangladesh, Pakistan, India, and Nepal ranked second, third, fifth, and seventh, respectively. Their capitals also feature among the world’s ten most polluted cities. India leads the region in air quality monitoring infrastructure, yet vast areas – particularly smaller cities and rural regions – remain under-monitored.
Despite its high number of polluted cities, India ranked fifth globally, behind Chad, Bangladesh, Pakistan, and the Democratic Republic of Congo. Cities such as Delhi and Lahore frequently experience hazardous pollution spikes, often leading to emergency measures like school closures.
Delhi’s pollution levels worsened by 6 per cent in 2024, reaching 108.3 micrograms per cubic metre – the highest since 2019, the year India launched its National Clean Air Programme (NCAP). Vehicular emissions, traffic congestion, industrial activity, construction, and seasonal crop burning have all contributed to the decline in air quality.
Conversely, China saw pollution levels drop across 320 cities, including Beijing, Shanghai, Chengdu, Guangzhou, and Shenzhen, though levels rose in nearly 130 others. Authorities have set ambitious targets to lower annual PM2.5 levels to below 28 micrograms per cubic metre by 2027 and below 25 by 2035, with a special focus on the Beijing-Tianjin-Hebei region.
Indonesia recorded a 4 per cent reduction in pollution, with an average PM2.5 level of 35.5 micrograms. However, the country faces challenges due to its expanding coal power sector, which fuels two-thirds of its electricity production.
While Vietnam saw a slight improvement in air quality, pollution remains a major economic concern, costing an estimated 4 per cent of the nation’s GDP. Efforts are underway to improve awareness, promote sustainable agricultural practices, and expand monitoring networks.
The world’s cleanest air was found in Honaka’a, Hawaii, which recorded an annual PM2.5 level of just one microgram per cubic metre, ranking 8,954th globally.
