Fine particles of air pollution reach unhealthy levels in most of California
Residents of the southern San Joaquin Valley were the Californians most often breathing unhealthy levels of fine particles, known as PM2.5. This chart shows the average number of days per year the federal health standard was exceeded in 2021-2023. Fine particles are linked to serious health effects, including heart attacks and respiratory disease.
A choropleth map of California showing the average number of days per year that exceeded the fine particles (PM2.5) standard in each county from 2021-2023. The map shows that Kern, Tulare, Kings and Fresno counties all had an average of 25 or more days that exceeded the standard.
