Home / Topic / Air / What are Air Contaminants? Last Edited:
Wed Jul 15 09:52:46 PDT 2015

What are Air Contaminants?

Air contaminants are particles, liquids, and gases in the air which have harmful chemical properties that affect our health. To learn more, select from the following topics or scroll down.

How are air contaminants classified?

There are many different compounds that may pollute our air at any given time or place.  Scientists and policy makers have multiple reasons for grouping these air contaminants into specific categories. 

  • Categories may be created for pollution regulation purposes
  • Categories may be created based on how the contaminants affect health or the environment
  • Some contaminants may belong to several different categories, creating overlap
  • Some categories may include a few contaminants, while others may include hundreds

Because categories are often created from legislative or agency mandates, they may not to correspond to the health concerns for a particular group or situation.  All of this can make discussion of air quality confusing.  
 
Below are some categories of air contaminants that you may frequently encounter.  Click on the category for more details or scroll below. 

Criteria Air Pollutants

There are many different compounds that may pollute our air at any given time or place.  Scientists and policy makers have multiple reasons for grouping these air contaminants into specific categories. 

  • Categories may be created for pollution regulation purposes
  • Categories may be created based on how the contaminants affect health or the environment
  • Some contaminants may belong to several different categories, creating overlap
  • Some categories may include a few contaminants, while others may include hundreds

Because categories are often created from legislative or agency mandates, they may not to correspond to the health concerns for a particular group or situation.  All of this can make discussion of air quality confusing.  
 
Below are some categories of air contaminants that you may frequently encounter.  Click on the category for more details or scroll below. 

Toxic Air Contaminants

There are many different compounds that may pollute our air at any given time or place.  Scientists and policy makers have multiple reasons for grouping these air contaminants into specific categories. 

  • Categories may be created for pollution regulation purposes
  • Categories may be created based on how the contaminants affect health or the environment
  • Some contaminants may belong to several different categories, creating overlap
  • Some categories may include a few contaminants, while others may include hundreds

Because categories are often created from legislative or agency mandates, they may not to correspond to the health concerns for a particular group or situation.  All of this can make discussion of air quality confusing.  
 
Below are some categories of air contaminants that you may frequently encounter.  Click on the category for more details or scroll below. 

Hazardous Air Pollutants

There are many different compounds that may pollute our air at any given time or place.  Scientists and policy makers have multiple reasons for grouping these air contaminants into specific categories. 

  • Categories may be created for pollution regulation purposes
  • Categories may be created based on how the contaminants affect health or the environment
  • Some contaminants may belong to several different categories, creating overlap
  • Some categories may include a few contaminants, while others may include hundreds

Because categories are often created from legislative or agency mandates, they may not to correspond to the health concerns for a particular group or situation.  All of this can make discussion of air quality confusing.  
 
Below are some categories of air contaminants that you may frequently encounter.  Click on the category for more details or scroll below. 

Greenhouse Gases

There are many different compounds that may pollute our air at any given time or place.  Scientists and policy makers have multiple reasons for grouping these air contaminants into specific categories. 

  • Categories may be created for pollution regulation purposes
  • Categories may be created based on how the contaminants affect health or the environment
  • Some contaminants may belong to several different categories, creating overlap
  • Some categories may include a few contaminants, while others may include hundreds

Because categories are often created from legislative or agency mandates, they may not to correspond to the health concerns for a particular group or situation.  All of this can make discussion of air quality confusing.  
 
Below are some categories of air contaminants that you may frequently encounter.  Click on the category for more details or scroll below. 

Indoor Air Pollutants

There are many different compounds that may pollute our air at any given time or place.  Scientists and policy makers have multiple reasons for grouping these air contaminants into specific categories. 

  • Categories may be created for pollution regulation purposes
  • Categories may be created based on how the contaminants affect health or the environment
  • Some contaminants may belong to several different categories, creating overlap
  • Some categories may include a few contaminants, while others may include hundreds

Because categories are often created from legislative or agency mandates, they may not to correspond to the health concerns for a particular group or situation.  All of this can make discussion of air quality confusing.  
 
Below are some categories of air contaminants that you may frequently encounter.  Click on the category for more details or scroll below. 

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How does air pollution affect health?

Air pollution is a serious health threat in California.  According to the California Air Resources Board (ARB), over 90 percent of Californians breathe unhealthy levels of one or more air pollutants during some part of the year.

Exposure to air pollution during pregnancy has also been associated with reduced birthweightprematurity, and infant death.  In children, exposure to air pollution exposure has also been linked to lung function deficits, airway inflammation, asthma, and other acute respiratory diseases.  In adults, air pollution is linked to premature death and cardio-respiratory disease.

According to ARB, exposure to particulate matter and ozone results in an estimated 8,800 premature deaths and 210,000 cases of asthma and other lower respiratory symptoms annually in California.

More details about specific health effects can be found on the ozoneparticulate matter, and traffic pollutant pages.

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Who is vulnerable to air pollution?

Children, the elderly, and those suffering from respiratory disease, such as asthma, are the most vulnerable to air pollution.  Children breathe more air pound for pound than adults and spend more time outdoors.  They also have rapidly growing and maturing respiratory systems, which are susceptible to injury.  The elderly often have underlying heart or lung problems and have less adaptive capacity than younger adults.

Developing fetuses are also vulnerable to air pollution.  For example, exposure to carbon monoxide can reduce the amount of oxygen that the fetus receives.  Carbon monoxide exposure is also associated with reduced birthweight.

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What can I do to reduce my exposure to air pollution?

Potential exposure to air pollution exists in both urban and rural communities.  Air pollution from vehicles makes exposure to air pollution almost unavoidable in urban areas.  In rural areas, air pollution can be generated from agricultural applications of pesticides and off-road vehicles.  Because air is a continuous medium (air is not contained), contaminants may travel from urban areas to rural areas and vice versa.

There are several steps you can take to reduce your exposure, including:

  • Pay attention to air quality alerts and stay indoors or reduce level of physical activity during times of high pollution
  • Install a HEPA filter in your home (be sure your air filter does not generate ozone)
  • Take public transportation
  • Reduce your use of household products which are air contaminants, such as solvents, sealers, and adhesives
  • Keep car windows and vents closed when in heavy traffic
  • Donít burn wood or use cleaner wood-burning fireplaces

 You can also take steps to decrease your contribution to air pollution or to encourage pollution reduction in your community. 

  • Reduce your motor vehicle use or switch to a more fuel efficient and less polluting vehicle
  • Know the toxic air sources in your community and work for enforcement or establishment of regulations that reduce or eliminate them
  • Alert authorities to potential violations or to concerns
  • Support transportation planning and policies that encourage mass transit
  • Support policies and activities around cleaner energy sources

For further information, see these resources from the California Air Resources Board:

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