Title


California PM 2.5 Concentration Comparison 1999 and 2022

Author


Joseph Jimenez, American River College, Geography 350, Fall 2022

Abstract

Over the last few decades, The California Air Resources Board (CARB) and the local Air Districts have taken measures to reduce the PM 2.5 concentration in California. The purpose of this study is to conduct a comparison of the PM 2.5 concentration in California in 1999 to 2022.

Introduction

Particulate matter (PM) are fine particles in the atmospheric air that causes pollution. These particles can be made up of smoke, dust, soil, or other fine gaseous, solid and liquid chemicals. The main culprit of air pollution is the burning of fossil fuels for production, mobility, and energy. The PM concentration is measured by mass/volume. Microgram/Cubic Meter (ug/m3) will be used for this study. The most hazardous category of particulate matter suspended in our air is PM 2.5. PM 2.5 are very fine air pollutant particles with a diameter of 2.5 micrometers (microns) or less. To give you an idea of how small 2.5 micrometers is. The diameter of an average hair strand is about 70 micrometers, which is about the minimum size the average human eye can see. PM 2.5 can easily be absorbed in the lungs and bloodstream. There are long and short-term health effects that can result form PM 2.5 exposure. The short-term health effects include irritation of the eyes, nose, throat and skin. The long-term effects are a decrease in lung function, respiratory and cardiovascular diseases, cancer and premature death.

Data Download and Processing

Daily PM 2.5 and air quality data was downloaded as excel spreadsheets from the United States Environmental Protection Agency (USEPA) Download Daily Data Portal for 1999 and 2022. The data was collected from air monitoring stations throughout California.


Here's one of the spreadsheets of daily air monitoring data from all of the air monitoring stations in california for 1999. There were over 10,000 values in this spreadsheet.


A series of mathematical and statistical applications were conducted in excel to break down the data to average PM 2.5 per monitoring station for both the 1999 and 2022 spreadsheets. The data was first sorted by site name from lowest to highest. The subtotal function in excel was used to classify the data to the yearly average of PM 2.5 and AQI values for 1999 and 2022. The data was than filtered based on the blanks in the units of measure field to only select the average fields. The unit of measure field was eliminated. The word "Average" was removed from each site name by writing a query in the site names field in excel. The query formula was Left(C2,LEN(C2)-8). Data was saved as a CVS (Comma dellimted)(*.CVS) file.





Map Development in ArcGIS Pro

Both CSV data for 1999 and 2022 was uploaded to ArcGIS Pro. I used the display XY data function to derive the air monitoring station locations as point feature classes. I downloaded US states boundries data from ArcGIS Online Living Atlas Portal. I conducted a definition query in ArcGIS Pro to only display the state of California. Maps of the air monitoring stations in California in 1999 and 2022 were created. There were 86 stations in 1999 and 145 stations in 2022. I converted the 1999 and 2022 air monitoring station location point features into continues surface rasters by using the Interpolation, IDW geoprocessing tool in ArcGIS Pro. This displayed the PM 2.5 concentration surface maps for California. I changed the symbology to classify, natural breaks with 5 classes. I changed the color scheme to the condition number color ramp for both maps. I downloaded the US county boundries data from the ArcGIS Online Living Atlas Data Portal. I conducted a definition query to display counties that cover the LA Basin. I used the clip geoprocessing tool in ArcGIS Pro to clip the raster to display PM 2.5 concentrations in the LA Basin for 1999 and 2022.

PM 2.5 Comparison

The PM 2.5 concentration in California for 1999 was very high in the Central Valley and LA Basin, which was between 20.275 to 31.161 ug/m3. The PM 2.5 concentration in California for 2022 has improved signicantly. The highest concentration levels decreased to 11.163 to 15.201 ug/m3. The highest concentration for 2022 is in the Southern Central Valley around Bakersfield and parts of Fresno. As you can see, the LA Basin shows a significant improvement in 2022. This study showed a 53.48 % improvement for California and a 47.96% improvement for the LA Basin.

Historical Success in Cleaner Air and The Future

The Clean Air Act was passed in 1970. This gave the Environmental Protection Agency (EPA) the legal authority to regulate pollution from transportation sources. This allowed the adoption of stringent standards. Since then, vehicle pollution control has been a major success. Since the Clean Air Act was implemented in 1960, vehicles have become 98% to 99% cleaner, cleaner fuels have been developed, we improved the Air quality in US cities despite increasing population and vehicle mileage traveled, we've gain technology innovation from the vehicle industry, we've developed stringent regulations on stationary sources, we've developed technology innovation in reducing Hydrocarbon emissions from stationary sources and we have more air monitoring programs on stationary and mobile sources. To better improve our air quality for our future, the Governor signed the zero emissions by 2035 Executive Order. On behalf of the new executive order, The California Air Resources Board (CARB) approved a rule that requires new car sales in California to be Zero Emission Vehicles (ZEV) by 2035. This goal will further help improve California’s air quality and reduce the PM 2.5 concentration if this goal is met.

Conclusion

As you can see, the comparison of the PM 2.5 concentrations in 1999 and 2022 in California and in the LA Basin shows a significant improvement. California must continue to work towards reducing air pollution, improving air quality and achieving carbon neutrality. These goals are important for the health of current and future generations.

References

California Air Resources Board. “Governor Newsome's Zero-Emissions by 2035 Executive Order (N-79-20). Executive Order calls for elimination of new internal combustion passenger vehicles by 2035." January 19, 2021.

https://ww2.arb.ca.gov/resources/fact-sheets/governor-newsoms-zero-emission-2035-executive-order-n-79-20

United States Environmental Protection Agency (USEPA)."History of Reducing Air Pollution from Transportation in the United States." May 16, 2022.

https://www.epa.gov/transportation-air-pollution-and-climate-change/history-reducing-air-pollution-transportation

United States Environmental Protection Agency (USEPA)."Outdoor Air Quality Data. Download Daily Data." July 6, 2022.

https://www.epa.gov/outdoor-air-quality-data/download-daily-data

Youtube, LLC."Making Air Pollution Maps from Scratch". October 7, 2019.

https://www.youtube.com/watch?v=-2FCzJa1SuQ

United States Environmental Protection Agency (USEPA)."Air Trends. Particulate Matter (PM2.5) Trends" August 1, 2022.

https://www.epa.gov/air-trends/particulate-matter-pm25-trends

New York State Department of Health."Fine Particles (PM 2.5) Questions and Answers" February 2018.

https://www.health.ny.gov/environmental/indoors/air/pmq_a.htm#:~:text=
%20Fine%20particulate%20matter%20%28PM%202
.5%29%20is%20an,with%20little%20or%20no%20wind%20or%20air%20mixing

Dr. Asha Jyoti. Food Thesis. Healthy Living."What is PM 2.5? It’s Health effects and remedies" June 15, 2018.

https://foodthesis.com/what-is-pm-2-5/#:~:text=How%20PM%202.5%20impacts%20our%20health%3F%201%201.,
of%20the%20throat%20...%205%205.%20Skin%20irritation

Puraka."PM 2.5 - What does it mean, and why does it matter?" September 1, 2020.

https://www.cleanairresources.com/resources/what-is-pm-2-point-5-and-why-does-it-matter

ArcGIS Online."Brouse Living Atlas Layers". December, 2022.

https://arc-gis.maps.arcgis.com/home/index.html