Air Quality Monitoring

SPATIOTEMPORAL VARIATION OF PM2.5 CONCENTRATIONS AND ITS RELATIONSHIP TO URBANIZATION PROCESS AND OTHER FACTORS IN CALIFORNIA STATE, U.S.

Urbanization is one of the major concerns in terms of air pollution. Rapid urbanization process leads to population growth and migration rate in major states and counties of the U.S. The consequence of the urbanization process gives rise to the concentration level of PM2.5 day by day in California. It has adverse health effects on the inhabitants of counties with high concentrations of PM2.5. This study was conducted to assess the average maximum concentration level of PM2.5 from 2001 to 2020 at five-year intervals. The results showed that the concentration level of PM2.5 had been increasing among all counties in California during the study period. It was evident that the growing concentration of PM2.5 had been becoming a concern in a few counties with poor air quality and unhealthy environments for children and adults, especially Inyo County, Mono County, Madera County, Fresno County, and Colusa County.  On the other hand, Del Norte County, San Francisco County, San Mateo County, and Santa Cruz County were found to have a comparatively healthy environment with good air quality, as population exposure was lower compared to other counties with high concentrations of PM2.5. However, if urban and population growth rates increase in the coming decades, their impact on the concentration of PM2.5 could be a serious threat to California.