Archive · 25 Aug 2026
Global Study Links Air Pollution to Millions of Cancer Cases
Scientists studied cancer and air pollution data from many places around the world.
They looked at tiny particles called PM2.5, as well as ozone and nitrogen dioxide.
PM2.5 was linked to the largest number of cancer cases in the study.
These particles can travel deep into the lungs and may enter the bloodstream.
The study found links with some cancers outside the lungs too.
Women had higher estimated pollution-related risks for most cancers examined.
This does not mean that polluted air causes every cancer case or that every exposed person will get cancer.
It means that pollution may contribute to a large number of cancer cases across whole populations.
The researchers said cleaner air policies could help reduce this burden.
Researchers linked PM2.5 exposure to an estimated 8.82 million cancer cases worldwide from 2000 to 2020.
The study examined 109 million cancer cases across 952 locations and assessed PM2.5, ozone, and nitrogen dioxide.
A 10-microgram-per-cubic-metre increase in long-term PM2.5 exposure was associated with a 16% higher risk of all cancers.
PM2.5 was associated with cancers beyond the lungs, including kidney, bladder, thyroid, breast, and colorectal cancers.
Researchers said the findings support stronger air-quality policies, while cautioning that the study estimates population-level associations rather than individual certainty.
- Who
- Researchers studying global cancer and air-pollution data.
- What
- A study estimated associations between long-term exposure to PM2.5, ozone, and nitrogen dioxide and cancer cases.
- When
- The data covered 2000 through 2020.
- Where
- The study covered 952 locations worldwide, including low-, middle-, and high-income countries.
- Why
- Researchers aimed to measure the global cancer burden associated with air pollution and inform air-quality policies.
- PM2.5-associated cases
- Approximately 8.82 million cancer cases from 2000 to 2020.
- Study size
- 109 million cancer cases across 952 locations.
- Other pollutants
- Nitrogen dioxide was associated with approximately 6.67 million cases, and ozone with about 2.59 million.
- PM2.5 risk increase
- Each 10-microgram-per-cubic-metre increase in long-term exposure was associated with a 16% higher risk of all cancers.
- Respiratory cancers
- Researchers estimated that 17.9% of tracheal, bronchial, and lung cancer cases could potentially be prevented if PM2.5 exposure were removed or addressed.
- Specific cancer risks
- The same PM2.5 increase was associated with a 17.9% higher kidney-cancer risk and a 21.1% higher bladder-cancer risk.
- Global exposure
- The researchers noted that 99% of the global population breathes air exceeding World Health Organization air-quality guidelines.