In general, any substance introduced by people into the atmosphere that has a damaging effect on the living organisms as well as on the environment is considered as air pollution.

The Clean Air Act authorizes the U.S. Environmental Protection Agency to protect public health by regulating the emissions of these harmful air pollutants. Air quality significantly affects people; living in pollution-free environment signifies a better quality of life.

But do we really know how air pollution affects us and which parts of our bodies are damaged by each kind polluting particle? Most often, it is caused by human activities such as mining, construction, transportation, industrial work, agriculture, smelting, etc. However, natural processes such as volcanic eruptions and wildfires may also pollute the air, but their occurrence is rare and they usually have a local effect, unlike human activities that are ubiquitous causes of air pollution and contribute to the global pollution of the air every single day.

Following are types of air pollution:

Smog and soot: These two are the most prevalent types of air pollution. Smog, or “ground-level ozone,” as it is more wonkily called, occurs when emissions from combusting fossil fuels react with sunlight. Soot, or “particulate matter,” is made up of tiny particles of chemicals, soil, smoke, dust or allergens, in the form of gas or solids that are carried in the air.

Hazardous air pollutants: These are either deadly or have severe health risks even in small amounts. Almost 200 are regulated by law; some of the most common are mercury, lead, dioxins and benzene.

These are also most often emitted during gas or coal combustion, incinerating or in the case of benzene, found in gasoline. Benzene, classified as a carcinogen by the EPA, can cause eye, skin and lung irritation in the short term and blood disorders in the long term.

Dioxins, more typically found in food but also present in small amounts in the air, can affect the liver in the short term and harm the immune, nervous, and endocrine systems, as well as reproductive functions.

Lead in large amounts can damage children’s brains and kidneys and even in small amounts it can affect children’s IQ and ability to learn. Mercury affects the central nervous system. Polycyclic aromatic hydrocarbons, or PAHs, are toxic components of traffic exhaust and wildfire smoke.

Greenhouse gases: By trapping the earth’s heat in the atmosphere, greenhouse gases lead to warmer temperatures and all the hallmarks of climate change: rising sea levels, more extreme weather, heat-related deaths, and increasing transmission of infectious diseases like Lyme. According to a 2014 EPA study, carbon dioxide was responsible for 81 percent of the country’s total greenhouse gas emissions, and methane made up 11 percent. Carbon dioxide comes from combusting fossil fuels and methane comes from natural and industrial sources, including the large amounts that are released during oil and gas drilling.

Pollen and mold: Mold and allergens from trees, weeds and grass are also carried in the air, are exacerbated by climate change and can be hazardous to health. They are not regulated by the government and are less directly connected to human actions, but they can be considered air pollution.

When homes, schools or businesses get water damage, mold can grow and can produce allergenic airborne pollutants. Mold exposure can precipitate asthma attacks or an allergic response and some molds can even produce toxins that would be dangerous for anyone to inhale. Pollen allergies are worsening because of climate change. That means more people will suffer runny noses, fevers, itchy eyes, and other symptoms.

Conclusion

A very effective and promising approach to reduce air pollution is by transitioning towards renewable energy. According to a study published in the Energy and Environmental Science in 2015, switching towards 100 percent renewable energy in the United States would eliminate about 62,000 premature mortalities per year in 2050, if no biomass were used, saving about $600 billion in health costs incurred in a year.

On a larger scale, the governments of the various nation-states are taking measures to limit the emissions of carbon dioxide and other greenhouse gases. Encourage people to use more public modes of transportation to reduce pollution.

Dr. Ramamohana Reddy Appannagari works for the CHEMTEX Environmental & Industrial Hygiene Laboratory in Port Arthur.