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.

Iran's Semnan Air Pollution Report

Overview

Air Pollution in Semnan

Semnan faces significant air pollution challenges. 100% of districts exceed the WHO guideline for clean air. This is putting 821 thousand across 4 districts at risk.

The average PM2.5 over 2023 was 16µg/m³. That's 3.2 times the WHO guideline for clean air of 5µg/m³.

This is equivalent of everybody, including children, smoking about 265 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 Semnan met the WHO guideline of 5 µg/m³, the average person would live 1.08 years longer.

That's 887K years of life stolen from 821 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 4 most polluted districts in Semnan. These areas face the greatest health burden from air pollution.

1.Garmsar
1.5 years lost
2.Semnan
1.2 years lost
3.Damghan
1 years lost
4.Shahrud
0.8 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

35.5%

292K

15-25 µg/m³

64.5%

529K

25-35 µg/m³

> 35 µg/m³

Districts

All 4 Districts in Semnan

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

District	Population	PM2.5 µg/m³	Years Lost
Shahrud	292K	13.0	0.8 years
Semnan	286K	17.4	1.2 years
Garmsar	138K	20.2	1.5 years
Damghan	105K	15.3	1.0 years

Showing 4 districts, sorted by population (largest first). PM2.5 values are for 2023. Years lost calculated against WHO guideline of 5 µg/m³.

Breathing in Semnan is Injurious to Health.