Hà Nội's air quality was the second worst in the world on January 2, 2025. — VNA/VNS Photo Hoàng Hiếu

HÀ NỘI — Việt Nam has the 23rd worst air quality in the worldin 2024, and the second worst in Southeast Asia, according to a recent report.

The country's average PM2.5 concentration level in 2024, 28.7μg/m³, exceeds the WHO guideline by between five and seven times, with the most polluted air in Chad at 91.8μg/m³, according to the annual report from Swiss air quality technology company IQAir.

In Southeast Asia, only Indonesia has worse air than Việt Nam, with PM2.5 levels at 35.5μg/m³, placing the country in 15th place.

Most of the top entries are South Asian and African nations.

In terms of 2024 average PM2.5 concentration, Việt Nam's capital city Hà Nội was ranked 7th across 121 regional capital cities surveyed, higher than Indonesia's Jakarta (10th place).

Hà Nội, with the dirtiest air in the country overall, was noted for recording its fifth consecutive annual increase in PM2.5 levels, rising from 37.9 µg/m³ in 2020 to 45.4 µg/m³ in 2024—more than nine times the WHO recommended guidelines, the report stated.

Monthly average statistics also indicated that the city didn't have any good air quality months throughout 2024, while March, April, and October, November, and December all saw the worst levels of pollution.

India's New Delhi, Chad's N’Djamena, Bangladesh's Dakha, Congo's Kinshasa, Pakistan's Islamabad, and Tajikistan's Dushanbe make up the top six, with India's capital suffering from 91.8μg of fine dust per m³ of air.

In 2024, air quality in Southeast Asia showed slight improvement, with PM2.5 concentrations decreasing across all countries, the report noted.

Air quality monitoring in Southeast Asia remains uneven, with nearly all countries having significant gaps in government-led initiatives, IQAir said. Việt Nam saw the greatest expansion, with 15 additional cities reporting data compared to 2023, while Thailand led the region in city-level monitoring, with 214 reporting cities.

Pollution sources and impacts

Việt Nam's fine dust originates from a variety of sources, including the burning of biomass, coal, and heavy fuel oil, emissions from vehicles and industrial processes, construction dust, open burning of municipal waste and the long-range movement of airborne particles. Seasonal variations play a significant role in pollution levels — agricultural fires, especially during the dry season, significantly elevate PM2.5 concentrations, the report noted.

Meanwhile, dust from construction sites and transport emissions can accumulate under atmospheric conditions like inversion layers, which trap pollutants near the ground. Furthermore, air pollution is worsened during colder months by transboundary emissions, particularly from power plants in neighbouring countries.

According to the report, severe air pollution episodes in Việt Nam have had wide-ranging effects on everyday life, including disruptions to air traffic and the diversion of flights at several airports.

Air pollution has imposed substantial economic and social costs, with estimated damage reaching approximately four per cent of the country's GDP, the World Bank said. — VNS