Environmental Health Program

The Environmental Health Program is committed to improving the quality of the environment in the Fresno area. The Program is guided by the principle of Environmental Justice throughout its work.

The San Joaquin Valley has the most polluted air in the country. The toxic air in the Valley endangers the health of its residents, retards the growth of its crops, and threatens the overall quality of life in the region.

Recognizing that there are a variety of factors which are needed to support a healthy environment, the Program is increasingly becoming involved in land use planning issues.

The Program has also developed a 10 week curriculum which informs professional gardeners and landscapers on environmentally healthy ways to operate including reducing the use of toxics, improved water conservation practices, and ways to improve the health, appearance, and value of the landscape.

The Program also provides homemakers with information which allows them to reduce and eliminate the need for toxic cleaners in the home.

map of san joaquin valley basin

What is air pollution?

In the San Joaquin Valley, air pollution comes from two main sources: ozone and particulate matter (PM).

Ozone is a colorless, odorless gas comprised of three oxygen atoms. Ozone is found naturally in the earth's stratosphere (the Ozone layer) where it absorbs the sun's harmful rays. But ozone closer to the earth's surface is dangerous, and more commonly referred to as smog.

Particulate Matter (PM) is a generic term used to describe a mixture of fine airborne solid particles and liquid droplets that are present in the air. These tiny particles are invisible to the naked eye, but can cause serious health problems.

Where does air pollution come from?

Ozone (or smog) is created by chemical reactions and sunlight. Pollutants like nitrogen oxides (NOx) and volatile organic compounds (VOCs) are called "ozone precursors." They combine in the presence of hot, stagnant, sunny weather to create ozone (or smog). Ozone precursors in the San Joaquin Valley come from cars, trucks, buses, agricultural equipment, dairies, and consumer products such as paint and even hair spray.

PM comes from agricultural operations, industrial processes, combustion of wood and fossil fuels, construction and demolition activities, and road dust kicked into the air. Windblown dust and wildfires also contribute to the problem. Diesel soot is of particular concern in the Valley, due to the high volume of trucks that use Highway 99.

The geography of the San Joaquin Valley acts as a trap for these pollutants. Surrounding mountains trap airborne pollutants near the Valley floor where people live and breathe. Population growth also contributes to the problem, as more people bring more activities that contribute to poor air quality.

Contrary to popular belief, the majority of pollution in the San Joaquin Valley does not come from outside the area. Air pollution transported from the San Francisco Bay and Sacramento areas account for approximately 27% of the total emissions in the Northern portion of the Valley (San Joaquin, Stanislaus, and Merced Counties). In the Central region (Fresno, Madera and Kings Counties), the percentage drops to 11%, and in the south valley (Kern and Tulare Counties), transported air pollution accounts for only 7% of the total problem.

How does air pollution harm us?

Air pollution kills more people in the San Joaquin Valley than homicide. More than 2,200 people have died prematurely over the past two years because of our dirty air. One in six children in Fresno County has asthma—that's twice the national average and the highest rate in the state.

Air pollution harms our economy as well, decreasing crop yields and increasing public health expenditures.

diesel health chart

Who monitors air pollution?

The San Joaquin Valley Air Pollution Control District regulates stationary sources of pollution in the region. The California Air Resources Board is in charge of setting State standards. The Environmental Protection Agency is in charge of monitoring national standards.

air quality standards chart

Where can I go for more information?

Central Valley Air Quality Coalition (CVAQ)

Steven and Michele Kirsch Foundation

San Joaquin Valley Air Pollution Control District

Daily Air Quality Status (SJVAPCD/CARB data)

California Air Resources Board

air quality and environmental health resources

Air Quality and Environmental Health Resources

Air Pollution 101 presentation, in PDF format (Copyright 2005 Fresno Metro Ministry) Download this file

Air Pollution 101 presentation (Spanish), in PDF format (Copyright 2005 Fresno Metro Ministry) Download this file

Diesel Pollution in the San Joaquin Valley, in PDF format (Copyright 2005 Fresno Metro Ministry) Download this file