India, Pakistan among key global hotspots for particulate matter pollution

Air pollution has emerged as the second leading risk factor for deaths worldwide, according to fourth annual Air Quality and Climate Bulletin of the World Meteorological Organization's (WMO). 

The report released on September 7,  the International Day of Clean Air for Blue Skies, reveals that around 8.1 million premature deaths annually are linked to conditions such as stroke, heart disease, lung cancer, and acute respiratory infections.

It describes Central Africa, Pakistan, India, China, and Southeast Asia as key global hotspots for particulate matter (PM) pollution.

Agriculture itself significantly contributes to PM levels through activities such as stubble burning, fertilizer and pesticide application, tillage, and manure management, the report highlights

The practices release particles into the air, which can adversely affect nearby crops or be carried over long distances, impacting agriculture in regions far from the original source.

High levels of PM can lead to significant reductions in crop yields, the report says, citing experimental evidence from countries like India and China. 

“Statistics help us grasp the magnitude of the issue: 99% of people worldwide breathe polluted air; air pollution was responsible for 8.1 million deaths in 2021, with over 90% associated with noncommunicable diseases; and more than 700,000 children under five deaths were from causes related to household and outdoor air pollution,” the report explains.

In heavily polluted areas, dry deposition of PM has been shown to decrease yields by up to 15%.

PM affects crop growth indirectly by altering the amount and characteristics of solar radiation reaching the Earth’s surface, the report says. 

The concentrations, according to the report, remain alarmingly high in key agricultural zones like the Indo-Gangetic Plain of Pakistan, India, and Bangladesh, as well as in northeastern China. The air pollution has reduced in regions such as Europe, North America, and China, the report notes.

The WMO argues for enhanced ground- and satellite-based PM monitoring in vulnerable crop-growing areas and called for new research to refine models predicting future crop yields.

“If we act now, we can halve global crop losses from air pollutants by 2050. Reducing emissions of methane, an important greenhouse gas and air pollutant, could save between $4 billion to $33 billion,” the report says. “The cost of inaction is staggering, with air pollution estimated to cost the global economy $8.1 trillion per year, equivalent to 6.1% of the global GDP due to increased healthcare costs.”