PM2.5 stands for particulate matter 2.5 microns or smaller. These particles are 30 times thinner than a human hair and come from car exhaust, power plants, wildfires, and burning fuel. They are small enough to bypass your body's natural defenses and enter your bloodstream.

How does air pollution affect the body?

Air pollution affects virtually every organ in the body. PM2.5 particles enter your lungs, pass into your bloodstream, and travel to your heart, brain, kidneys, liver, and other organs. This causes chronic inflammation, increasing risks of heart disease, stroke, lung cancer, dementia, and many other conditions.

How many people are affected by air pollution?

99% of the global population breathes air that exceeds WHO safety guidelines. Air pollution kills approximately 8 million people every year—more than AIDS, malaria, and tuberculosis combined.

Nepal's Koshi Air Pollution Report

Overview

Air Pollution in Koshi

Koshi faces significant air pollution challenges. 100% of districts exceed the WHO guideline for clean air. This is putting 5.3 million across 14 districts at risk.

The average PM2.5 over 2023 was 41.3µg/m³. That's 8.3 times the WHO guideline for clean air of 5µg/m³.

This is equivalent of everybody, including children, smoking about 685 cigarettes in a year.

Trends

Air Quality Trend

Annual PM2.5 levels from 2014 to 2023. The WHO guideline for safe air is 5 µg/m³.

Health Impact

Life Expectancy Impact

If Koshi met the WHO guideline of 5 µg/m³, the average person would live 3.57 years longer.

That's 18.9M years of life stolen from 5.3 million people. Years of watching children grow up. Years of building a career. Years of quiet mornings and celebrations.

Lives cut short. Breathing kills.

Most Polluted

Districts with Highest Pollution

The top 10 most polluted districts in Koshi. These areas face the greatest health burden from air pollution.

1.Sunsari
4.5 years lost
2.Morang
4.4 years lost
3.Jhapa
4.1 years lost
4.Udayapur
3.5 years lost
5.Sankhuwasabha
2.8 years lost
6.Taplejung
2.8 years lost
7.Ilam
2.5 years lost
8.Solukhumbu
2.4 years lost
9.Okhaldhunga
2.4 years lost
10.Bhojpur
2.4 years lost

Exposure

Population Exposure by Pollution Level

Distribution of population across different PM2.5 pollution levels. The WHO guideline is 5 µg/m³—only populations below this threshold are breathing safe air.

< 5 µg/m³

5-10 µg/m³

10-15 µg/m³

15-25 µg/m³

25-35 µg/m³

37%

2.0M

> 35 µg/m³

63%

3.3M

Districts

All 14 Districts in Koshi

Complete air quality data for every district in Koshi, sorted by population.

District	Population	PM2.5 µg/m³	Years Lost
Morang	1.1M	50.2	4.4 years
Jhapa	951K	46.5	4.1 years
Sunsari	871K	50.4	4.5 years
Udayapur	372K	40.5	3.5 years
Ilam	343K	30.2	2.5 years
Khotang	242K	28.4	2.3 years
Panchthar	223K	27.9	2.2 years
Bhojpur	213K	29.2	2.4 years
Dhankuta	190K	28.4	2.3 years
Sankhuwasabha	186K	33.9	2.8 years
Okhaldhunga	174K	29.8	2.4 years
Taplejung	149K	33.4	2.8 years
Solukhumbu	124K	29.9	2.4 years
Terhathum	119K	27.8	2.2 years

Showing 14 districts, sorted by population (largest first). PM2.5 values are for 2023. Years lost calculated against WHO guideline of 5 µg/m³.

Breathing in Koshi is Injurious to Health.