Tourists wear masks in Chiang Mai province, Thailand, Tuesday, April 2, 2019. The air hanging over Thailand's far north has become so polluted, the prime minister went Tuesday to see in person what's been called a severe health crisis.
Tourists wear masks in Chiang Mai province, Thailand, Tuesday, April 2, 2019. The air hanging over Thailand's far north has become so polluted, the prime minister went Tuesday to see in person what's been called a severe health crisis.

GENEVA - Activists marking World Environment day are calling for action to tackle air pollution, which researchers say kills millions of people every year and impoverishes societies struggling to reduce its harmful effects.

"We are walking on" is a World Environment Day song inspired by childhood memories of a Japanese town fighting air pollution — and winning. The young, enthusiastic performers express their love for the environment.  Through their artistry, they hope to raise awareness of the dangers threatening the planet and to promote action to preserve its natural beauty.

Smog blankets the sky in Mexico City, May 17, 2019. Both lower schools and universities were closed for a third straight day.

​​The World Health Organization considers air pollution the world's largest single environmental health risk, killing about seven million people every year. Millions more suffer long term health problems, such as asthma, stroke, lung cancer, and heart disease.

The World Bank estimates the global economic cost of breathing in dirty air at more than five trillion dollars every year. Executive Secretary of the UN Economic Commission for Europe, Olga Algayerova called the human and economic costs arising from air pollution staggering.

But she said her agency has shown that effective action can be taken to combat this scourge. She noted that in 1979, 51 countries in Europe and North America signed the Convention on Long-range Transboundary Air Pollution, familiarly known as the Air Convention or CLRTAP.

The convention was reached under the auspices of the United Nations Economic Commission for Europe (UNECE.)

"For instance, emissions of harmful substances including particulate matters and sulfur have been cut by 30 to 80 percent since 1990 in Europe and 30 to 40 percent in North America," she added. "... People in Europe live 12 months longer due to our Air Convention."

FILE - A man wears a face mask as he walks near the Han river at a park in a smog-covered Seoul, South Korea, Jan. 14, 2019.

​​She said the one additional year of life expectancy gained by reducing air pollution is preventing 600,000 premature deaths annually in the European region.

Algayerova noted that the Air Convention is the only regional policy solution of this kind. Thanks to its success, she said other regions are looking to UNECE for advice on how they too can act to reduce air pollution.