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.

Switzerland's Valais Air Pollution Report

Overview

Air Pollution in Valais

Valais faces significant air pollution challenges. 100% of districts exceed the WHO guideline for clean air. This is putting 354 thousand across 14 districts at risk.

The average PM2.5 over 2023 was 9.8µg/m³. That's 2.0 times the WHO guideline for clean air of 5µg/m³.

This is equivalent of everybody, including children, smoking about 163 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 Valais met the WHO guideline of 5 µg/m³, the average person would live 0.48 years longer.

That's 170K years of life stolen from 354 thousand 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 Valais. These areas face the greatest health burden from air pollution.

1.Sion
0.5 years lost
2.Brig
0.5 years lost
3.Entremont
0.5 years lost
4.Visp
0.5 years lost
5.Goms
0.5 years lost
6.Martigny
0.5 years lost
7.Raron
0.5 years lost
8.Conthey
0.5 years lost
9.Leuk
0.5 years lost
10.Sierre
0.5 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

69.2%

245K

10-15 µg/m³

30.8%

109K

15-25 µg/m³

25-35 µg/m³

> 35 µg/m³

Districts

All 14 Districts in Valais

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

District	Population	PM2.5 µg/m³	Years Lost
Sierre	46K	9.7	0.5 years
Monthey	37K	8.9	0.4 years
Martigny	37K	9.9	0.5 years
Conthey	31K	9.8	0.5 years
Sion	29K	10.1	0.5 years
Visp	29K	10.0	0.5 years
Entremont	26K	10.1	0.5 years
Brig	25K	10.1	0.5 years
Hérens	25K	9.6	0.5 years
Leuk	17K	9.8	0.5 years
Goms	16K	10.0	0.5 years
West Raron	15K	9.6	0.4 years
Saint-Maurice	13K	9.4	0.4 years
Raron	8K	9.9	0.5 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 Valais is Injurious to Health.