Around one-third, or 2.2 million of the world's 7 million premature deaths each year from air pollution are in the Western Pacific Region, according to new data released on Wednesday by the World Health Organization (WHO).
The Western Pacific Region is home to one-quarter of the world's population.
WHO's new estimates show that nine out of 10 people in the world breathe air containing high levels of pollutants from both household or indoor and ambient or outdoor sources.
"Polluted air penetrates deep into their lungs and cardiovascular system," WHO said in a statement.
Among the 2.2 million air pollution-related deaths in this region in 2016, WHO said 29 percent were due to heart disease, 27 percent stroke, 22 percent chronic obstructive pulmonary disease, 14 percent lung cancer and 8 percent pneumonia.
"Air pollution is the most lethal environmental health threat in our region, and it affects people in middle-income countries at a much higher rate than those in high-income countries," said Shin Young-soo, WHO regional director for the Western Pacific.
Shin said addressing air pollution and climate change are top priorities for WHO in the Western Pacific region.
"But they are not challenges that individuals or the health sector alone can solve. We need urgent action across energy, agriculture, transport, housing and beyond to ensure a healthy and sustainable future," Shin said.
Ambient air pollution is mainly made up of fine particulate matter that includes pollutants such as sulfate, nitrates and black carbon, which pose the greatest risks to human health, WHO said.
"Ambient air pollution affects urban and rural areas. Major sources include inefficient energy use in households, industry, the agriculture and transport sectors, and coal-fired power plants," WHO said.
In some areas, WHO said sand and desert dust, waste burning and deforestation are additional sources of air pollution. Air quality can also be influenced by natural elements such as geographical, meteorological and seasonal factors.
The main source of household air pollution is the use of kerosene and solid fuels such as wood in polluting stoves, open fires and lamps, WHO said.
WHO said more than 40 percent of the world's population still do not have access to clean cooking fuels and technologies in their homes. Women and children are most at risk of household air pollution, WHO said.
"Air pollution threatens us all, but the poorest and most marginalized people bear the brunt of the burden," said WHO Director-General Tedros Adhanom Ghebreyesus. "If we don't take urgent action on air pollution, we will never come close to achieving sustainable development."
While the latest data show ambient air pollution levels are still dangerously high in the WHO Western Pacific Region, WHO said the data also show some progress. "The estimated number of air pollution deaths in the region has come down from 2.8 million in 2012 to 2.2 million in 2016," WHO said.
WHO air quality recommendations call for countries to further reduce pollutants. Countries are taking measures to reduce air pollution from particulate matter, WHO said.
"The good news is that we are seeing more and more governments increasing commitments to monitor and reduce air pollution as well as more global action from the health sector and other sectors like transport, housing and energy," she said.
WHO stressed that air pollution does not recognize borders. "Improving air quality demands sustained, coordinated government action at all levels," WHO said, stressing the need for countries to work together on solutions.