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.

Kenya's Siaya Air Pollution Report

Overview

Air Pollution in Siaya

Siaya faces significant air pollution challenges. 100% of districts exceed the WHO guideline for clean air. This is putting 1.2 million across 6 districts at risk.

The average PM2.5 over 2023 was 22µg/m³. That's 4.4 times the WHO guideline for clean air of 5µg/m³.

This is equivalent of everybody, including children, smoking about 365 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 Siaya met the WHO guideline of 5 µg/m³, the average person would live 1.67 years longer.

That's 2.0M years of life stolen from 1.2 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 6 most polluted districts in Siaya. These areas face the greatest health burden from air pollution.

1.Rarieda
1.7 years lost
2.Bondo
1.7 years lost
3.Ugunja
1.7 years lost
4.Alego Usonga
1.7 years lost
5.Gem
1.6 years lost
6.Ugenya
1.6 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

100%

1.2M

25-35 µg/m³

> 35 µg/m³

Districts

All 6 Districts in Siaya

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

District	Population	PM2.5 µg/m³	Years Lost
Alego Usonga	275K	21.9	1.7 years
Gem	223K	21.6	1.6 years
Bondo	219K	22.4	1.7 years
Rarieda	197K	22.4	1.7 years
Ugenya	146K	21.4	1.6 years
Ugunja	142K	22.1	1.7 years

Showing 6 districts, sorted by population (largest first). PM2.5 values are for 2023. Years lost calculated against WHO guideline of 5 µg/m³.

Breathing in Siaya is Injurious to Health.