Graduation Year
2024
Document Type
Open Access Senior Thesis
Degree Name
Bachelor of Arts
Department
Environmental Analysis
Reader 1
Kathleen Purvis-Roberts
Reader 2
Franck Fu
Terms of Use & License Information
Rights Information
© 2023 Ellen Ben Yin Hu
Abstract
Densely populated regions around the United States exhibit varying concentrations of air pollutants that can impact the health of urban populations and surrounding ecosystems. Understanding why these differences exist can be important in addressing health issues as the human population continues to increase and communities across the globe move to accommodate these trends. To investigate the impact of natural processes and anthropogenic sources on pollutant concentrations, EPA daily fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) pollutant concentrations from seven metropolitan regions across the US for 2018-2022 were used. A Spearman Rank-Order correlation test was conducted utilizing NOAA's daily weather data, including precipitation, wind speed, and average temperature. It was found that while precipitation is weakly correlated with all pollutants, a strong positive correlation between O3 and temperature in addition to a strong negative correlation between wind speed and NO2 was observed for all regions. Many outliers were observed for PM2.5 concentrations in San Francisco, possibly the result of wildfire burning in California during the fall months. Further inquiry into the impact of anthropogenic sources utilized vehicle miles traveled (VMT) data acquired from Streetlight Data LLC for a portion of 2020 in California. A Spearman Rank-Order test found a relatively strong positive correlation with NO2 for San Francisco, but generally weak or nonsignificant correlations between vehicle travel and pollutants in Los Angeles. Overall, low r-values for all correlations indicate that other factors may be contributing to differences in pollutant concentrations between metropolitan regions.
Recommended Citation
Hu, Ellen, "Investigating Factors Contributing to Differences in Air Pollutants Between Metropolitan Areas in the US" (2024). Scripps Senior Theses. 2245.
https://scholarship.claremont.edu/scripps_theses/2245
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Environmental Chemistry Commons, Environmental Health and Protection Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons