Numerous studies have linked PM to aggravated heart and lung diseases such as asthma, bronchitis and emphysema. Ground-level Ozone is a colorless and highly irritating gas that forms in the atmosphere when sunlight reacts with air pollutants often found over urban areas on hot summer days. Near the ground, ozone is a serious pollutant. While airborne, these pollutants form sulphuric and nitric acid and can stay in the air for days, sometimes travelling thousands of kilometres. Airborne sulphur dioxide and nitrogen oxides can also be converted to fine particles, which can remain suspended in the atmosphere, forming a key component of smog.
POPs bioaccumulate in living organisms, persist in the environment and have long-term toxic effects.
POPs can move through the food chain to humans, and can be passed from mother to child across the placenta and through breast milk. Mercury is found in many lakes, streams, forests and fields. It can convert to a very toxic and bioaccumulative form known as methylmercury, that affects both humans and wildlife. Atmospheric environmental issues that are related to clean air also include climate change and ozone layer depletion. Many of the actions we take for cleaner air also have a benefit in addressing climate change, particularly those with transportation and energy production.