Particulate Matter (PM2.5)

What is Particulate Matter (PM2.5)?

Particulate matter (PM) is defined as a mixture of solid particles and liquid particles in the air. Some particulate matter is visible to the naked eye while others are not. PM measuring 10 micrometers tend to be filtered by our body’s natural defenses while PM measuring 2.5 micrometers or smaller are capable of entering the body’s respiratory and cardiovascular systems.

What are the Sources of PM2.5?

PM2.5 comes from direct sources (such as particles from construction sites, unpaved roads, or fires) and indirect sources (usually from complex chemical reactions in the atmosphere such as sulfur dioxide and nitrogen oxides, pollutants from power plants, industrial sources and vehicles).1

How are People Exposed to PM2.5?

Exposure to PM2.5 varies in severity and composition throughout the year and is as simple as breathing in. Because this size of particulate matter is so small, it can be inhaled into the lungs and can enter into the bloodstream.2

What are the Health Impacts of PM2.5?

Those who are at greatest risk to the health impacts of breathing in PM2.5 include infants, young children, adolescents, seniors aged 65 and older, those with current chronic lung or heart diseases, diabetics, low-income individuals, and those working outdoors.3

The following are short- and long-term health impacts associated with PM2.5 Exposure:

  • Short-term: These include premature death , decline in lung function, negative cardiovascular effects, increase in absences from school, hospitalization, etc.
  • Long-term: These include shortening of life (by approx. 3 years), lung cancer, hospitalization due to asthma attacks, decreased lung function in younger age groups and/or development of asthma at a young age, damage to the airways of the lungs, increased infant mortality, increased risk of developing diabetes, increase in negative effects on the nervous system. 4

Protect Yourself!

Utilizing tools that alert you when PM2.5 levels rise is helpful in knowing when to stay indoors or adjust outdoor exposure as needed. The San Joaquin Valley Air Pollution Control District (SJVAPCD) has developed a Real-Time Air Quality Advisory Network (RAAN) which provides daily air quality information for the San Joaquin Valley.


What is Ozone?

Ground level ozone (not to be confused with Stratospheric ozone)  is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react chemically with sunlight and heat. Ground level ozone is also commonly referred to as “smog” and is considered a form of pollution.

What are the Sources of Ozone?

Emissions from cars, power plants, industrial sources, refineries, chemical plants, and other mechanical and natural sources create nitrogen oxides and volatile organic compounds.However, ozone is capable of being transported to other locations by wind. 1 Ozone levels tend to reach unhealthy levels in urban places during hot, sunny days.

How Are People Exposed to Ozone?

Exposure to ozone is a simple as breathing the air, especially on days when temperature are high- ozone levels rise as temperatures rise . Those who are most vulnerable to the health impacts of breathing in ozone are those with asthma, children, elderly people, those who are heavily active outdoors, and those with other existing respiratory or cardiovascular diseases.

What are the Health Impacts of Ozone?

The following are short- and long-term health impacts associated with ozone Exposure:

  • Short-term: These include immediate breathing problems (such as wheezing, coughing, asthma attacks, and increased susceptibility to respiratory infections), cardiovascular impacts.
  • Long-term: These include an increase the risk of premature death from respiratory diseases, the development of respiratory diseases in children, and potential damage to other systems in the body (such as the central nervous system), especially among infants and children who are still developing. 2

Protect Yourself!

Learning about the air you breathe and when it is at its worst ozone levels can help you in decreasing your exposure to ozone. The San Joaquin Valley Air Pollution Control District (SJVAPCD) has developed a Real-Time Air Quality Advisory Network (RAAN) which provides daily air quality information for the San Joaquin Valley.

Toxic Air Contaminants (TACs)

What are Toxic Air Contaminants (TACs) ?

Toxic Air Contaminants (TACs) have been proven to cause cancer and/or serious health effects. There are 187 toxic air pollutants identified by the US Environmental Protection Agency (EPA). Examples of these pollutants include benzene, commonly found in gasoline, perchloroethylene, commonly emitted from some dry cleaning facilities, and methylene chloride, a common solvent and paint stripper.

What are the Sources of Toxic Air Contaminants?

Most TACs are not naturally occuring and are created which include mobile sources (cars, trucks, buses), stationary sources (factories, power plants), and indoor sources (building materials, cleaning supplies). Additionally, other TACs are also released from natural sources (volcanic eruptions, forest fires).

  • There are two types of TACs most commonly emitted from stationary sources :
    • “Major Sources”: These sources emit more than 10 tons per year of any one toxic on the EPA list, or 25 tons per year of a mixture of toxics. This type of sources commonly emit toxins from equipment leaks, through the transfer of materials from one location to another, and emissions from the general operation of a facility.
    • “Area Sources”: These sources are commonly associated with smaller facilities and emit less than 10 tons per year of any one toxic on the EPA list or less than 25 tons per year of a mixture of toxics. Area sources are of concern when they are located near heavily populated areas and when there are numerous of these smaller facilities located in one area.

How are people exposed to Toxic Air Contaminants?

People can be exposed to Hazardous Air Pollutants (aka Air Toxins) through a variety of methods. Potential exposure can occur while breathing contaminated air, eating contaminated food products that have been exposed to contaminated soil where toxins have been deposited, and drinking contaminated water, and ingesting contaminated soil.

What are the Health Impacts of Toxic Air Contaminants?

The health impacts associated with the exposure of TACs include a higher potential for developing cancer, damage to the body’s immunes, neurological, reproductive and respiratory systems. Exposure can also lead to birth defects and nerve damage.

  • The most persistent TACs can accumulate when they enter the body and magnify as they move up the food chain.
  • Exposure to air toxins at sufficient concentrations and/or sufficient periods of time can increase the chance of experiencing the health effects listed above.

Protect yourself! 

The Environmental Protection Agency (EPA) is working with partners at the state and local levels to reduce the emissions of  TACS through various programs; see the list of standing programs below!

  • Industrial Source Program
    • Technology-Based”: Standards created by the EPA for industry sources to use Maximum Achievable Control Technology (MACT) which are based on emission levels.
    • “Risk-Based”: EPA must go beyond MACT standards and determine is more health-protective measures are needed. Every 8 years, the EPA is required under the Clean Air Act (CAA) to review and revise the standards if necessary.
  • Mobile Source Program
    • 2014 Tier 3 Truck vehicle and fuel standards
    • 2007 mobile source toxics rule to control benzene in gasoline and vehicle emissions at cold temperatures and emissions from portable fuel containers.
    • Low sulfur gasoline and diesel requirements
  • Indoor Air Program
    • Improving the air in homes
      • Best practices for remodeling, reducing radon, adequate and proper ventilation, effective non-chemical strategies for pest control
    • Improving the air in schools
      • Alternatives for art, science, and cleaning supplies and controlling asthma triggers such as dust, mold, and diesel exhaust from school buses.

Identifying Violations Affecting Neighborhoods (IVAN)  Network

IVAN is a user friendly, community based monitoring system that puts community voices and concerns in front of environmental agencies. For those in Fresno, Imperial Valley, Kern County, Coachella, Wilmington, BayView Hunters Point, and Kings County, suspected violations of the pollutants listed here can be reported to an Environmental Justice Task Force consisting of residents, representatives from environmental agencies, and local organizations who are working together to solve community identified environmental problems. Reports regarding violations take less than five minutes to complete and are are available online and through the IVAN mobile app.

For more information visit https://ivanonline.org/