China has significantly tightened its national air quality standards, affirming its unwavering commitment to sustaining air quality improvements.

While remarkably improving people's health, the new standards are also expected to substantially contribute to the country's endeavor to go carbon neutral, the Ministry of Ecology and Environment said on Tuesday.

The tighter thresholds specifically target four major air pollutants — PM2.5 and PM10 particulate matter, sulfur dioxide and nitrogen dioxide, according to the Ambient Air Quality Standards GB 3095 — 2026, which was jointly released by the ministry and the State Administration for Market Regulation.

Under the new secondary standards, the annual average concentration of PM2.5 — the air pollutant that poses the greatest threat to human health — is lowered from 35 to 25 micrograms per cubic meter, and its daily average from 75 to 50.

For PM10, the annual limit will be reduced from 70 to 50 mcg/cubic m, and the daily limit from 150 to 100.

These new standards are broadly in line with the Phase 2 interim targets of the latest World Health Organization Global Air Quality Guidelines, which were updated in September 2021.

The new standards will be implemented in two phases, with transitional limits applied from March 1, 2026, to 2030. During the period, the annual and daily limits under the secondary standard would be set at 30 and 60 mcg/cubic m for PM2.5, and 60 and 120 mcg/cubic m for PM10.

"The revision of the standards reflects the country's determination to drive continuous environmental improvement under the guidance of higher benchmarks," the ministry stressed in a media release.

Issued in 2012, the previous edition of the standards has served as a crucial driver in China's consistent efforts to safeguard blue skies and protect public health, it said.

From 2013 to 2025, it said, the country's annual average concentration of PM2.5 dropped from 68 mcg/cubic m to 28 mcg/cubic m, positioning China as the world's top nation in terms of the speed of air quality improvement.

It cited the further protection of public health as a primary reason for the revision, noting that research from both China and abroad has identified PM2.5 as the single largest contributor to the global disease burden caused by air pollution.

When factoring in both the costs of pollution control and the anticipated long-term health benefits, the new standards are expected to generate health returns nearly ten times greater than the investment required, according to the ministry.

The revision of the standards is also aimed at progressively aligning with internationally advanced levels, the release continued.

In recent years, many countries, regions, and international organizations have revised their PM2.5 concentration limits or guidelines, it stated. By comparison, the limits in the previous edition of the standards were relatively lenient.

"Further tightening the standards is therefore necessary to drive continuous air quality improvement nationwide, inject green momentum into economic development, and promote high-quality economic and social progress," the ministry said.

From 2026 to 2035, pollution control measures implemented under the new standards are projected to cut carbon emissions by more than 7 billion metric tons as a co-benefit, it said.