Hesperian Health Guides

Air Pollution

In this chapter:

Air is polluted when it becomes contaminated with poisonous gases and small dust particles. Most air pollution is caused by burning fossil fuels (oil, coal, diesel, gasoline) to run engines, factories, and power plants. Wind and rain can carry air pollution far from where the pollution was made. This causes health problems for people everywhere. Air pollution is usually worse in cities, industrial areas, low-lying areas or those circled by mountains, and places where air gets trapped and does not move well.

Air pollution may contain heavy metals such as mercury and lead, POPs, and other toxic chemicals such as sulfur dioxide.

If you are doing community air pollution monitoring, it is useful to know which chemicals are in the air. But keep in mind that it is usually more useful to know how to protect yourself and your community from harm from air pollution than it is to know exactly what is in the air.

Air pollution causes serious health problems, including many cancers and respiratory illnesses. Air pollution causes acid rain that damages forests, water sources, and buldings, as well as our lungs. Also, air pollution is one of the main causes of global warming.

People cover their noses and mouths as they walk on an overpass over a busy highway.

Air pollution monitoring

Air pollution monitoring is a method used by a community during a campaign against a polluting business or industry. The monitoring allows many people to participate in the campaign as well as building a base of evidence that can be used to pressure the companies or industries to stop polluting.

Monitoring or checking for air pollution begins with your senses and your common sense. To know what effect air pollution is having in your community, ask people to keep a record of what they smell, see, hear, taste, or feel. The more people that do this, the better chance the community will have to identify and stop the pollution.

The bucket brigade method

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Some communities monitor the air using a simple, low-cost method called the “bucket brigade.” A 5-gallon plastic bucket with a valve and a special bag are used to take air samples. By opening the valve when there is a toxic release, or any time the air seems especially polluted, a small amount of air is sucked into the bag. The bag is then removed from the bucket and sent to a laboratory to find out what chemicals it contains. (See Other Environmental Health Resources.)

Having the air sample tested in a laboratory is the most costly part of the bucket brigade. Most countries do not have laboratories that can — or will — test the air sample properly, so it may need to be sent to Europe or the United States. Some communities raise money for a bucket brigade by collecting door-to-door, or by holding dances, parties, or house meetings.

Many communities use the bucket brigade along with other community organizing activities such as interviews and surveys. They also report toxic releases to the media and government, and try to force refineries and other polluting industries to use safer equipment and reduce emissions.

GroundWork’s bucket brigade

Durban, South Africa, is a city surrounded by oil refineries and pipelines, a large chemical storage area, chemical plants, textile and paper factories, and toxic landfills. Every day, people in Durban are exposed to high levels of air pollution, water pollution, and all of the health problems that come with constant exposure to toxic chemicals. Industrial accidents, leaking storage tanks, and broken pipelines are common, causing fires and destruction of nearby wetlands and groundwater resources.

In 1999, a group called GroundWork formed to help people in Durban monitor air pollution. Using the bucket brigade method, the community began testing the air for toxics whenever there was a gas flare, an explosion, or a toxic release. Then they sent the bags full of air pollution to a laboratory in the United States for testing.

The lab tests found high levels of toxics, including sulfur dioxide, nitrogen oxide, and benzene. Test results from air samples collected near a school showed that children were exposed to levels of pollution as high as if they had stood all day, every day, on a busy highway.

A newspaper with the headlines "300th Toxic Release Reported at Chemical Plant" and "Residents for Cleaner Air."


The activists showed the test results to the government and the polluting industries, and also announced them on the radio, newspapers, and around the community. The state-run oil company said the tests were not accurate and took their own air samples. But when their samples were tested, they found even higher levels of poisons!

The bucket brigade method helped build a nationwide movement against pollution in South Africa. Under pressure from the growing environmental justice movement, the government passed the Air Quality Act in 2004. The city of Durban also set up its own air monitoring system. Since then, there has been a noticeable decrease in air pollution.

The bucket brigade helped community members feel stronger, braver, and more able to challenge polluting industries. With this increased confidence, they forced the government to listen to them.

There is still a serious pollution problem in South Africa. As chemical plants, refineries, and pipelines get older, the danger of accidents increases. But by combining strong community organization with a tool for collecting samples of toxic pollution, the people of Durban have made themselves safer. And they have shown the rest of their country and the world that people can make industry and government take responsibility for their pollution.

When there is a toxic release

Chemical plants, oil refineries, and other factories can have accidents that release large amounts of toxic chemicals very suddenly. Refineries also release toxic gases as part of ‘regular maintenance.’ A toxic release may look like a cloud of smoke or a large fire, or it simply may be a sudden strong smell. This can be frightening. It can also be deadly.

In the short term, there are steps people can take during and after every toxic release and chemical spill to reduce harm (see Appendix A: Safety and Emergencies). In the long term, it takes community organizing to pressure industries and governments to enforce better safety regulations.

During a toxic release:

  • Depending on the situation and how quickly you can respond, sometimes it is safest to just stay indoors. In other situations, it is safer to leave the area as quickly as possible. Training and a good community emergency plan will help you know when to stay and when to leave.
  • Make some kind of record. Mark the time of day the release happened, and how long it lasted. Also note any strange smells, sights, sounds, physical reactions (feelings in your body), and reactions of other people and animals nearby. This information may be useful later for taking community action.
  • Take photos and video if it is safe to do so. These can be used later in court or campaigns.

After a toxic release:

  • If people have been exposed to chemicals, help them go to a clinic or hospital right away.
  • Contact local government and media to report what happened.
  • Call a meeting to let everyone in the community know about what happened, and to organize a response.
  • Encourage community members to share their experiences and feelings. This will help people to recover from the event and build solidarity in the community.
Making notes directly onto a calendar is a good way to keep a record of toxic releases.
A calendar with the notation "2:25pm. White smoke from factory. Smell of rotten eggs."
This page was updated:05 Jan 2024