Association of temporary Environmental Protection Agency regulation suspension with industrial economic viability and local air quality in California, United States

Background: This study seeks to answer two questions about the impacts of the 2020 Environmental Protection Agency's enforcement regulation rollbacks: is this suspension bolstering the economic viability of industries as oil and manufacturing executives claim they will and are these regulations upholding the agency's mission of protecting the environment?

Results: To answer the former question, we utilized 6 months of state employment level data from California, United States, as a method of gauging the economic health of agency-regulated industries. We implemented a machine learning model to predict weekly employment data and a t-test to indicate any significant changes in employment. We found that, following California's state-issued stay-at-home order and the agency's regulation suspension, oil and certain manufacturing industries had statistically significant lower employment values.To answer the latter question, we used 10 years of PM_2.5 levels in California, United States, as a metric for local air quality and treatment-control county pairs to isolate the impact of regulation rollbacks from the impacts of the state lockdown. Using the agency's data, we performed a t-test to determine whether treatment-control county pairs experienced a significant change in PM_2.5 levels. Even with the statewide lockdown-a measure we hypothesized would correlate with decreased mobility and pollution levels-in place, counties with oil refineries experienced the same air pollution levels when compared to historical data averaged from the years 2009 to 2019.

Conclusions: In contrast to the expectation that the suspension would improve the financial health of the oil and manufacturing industry, we can conclude that these industries are not witnessing economic growth with the suspension and state shutdown in place. Additionally, counties with oil refineries could be taking advantage of these rollbacks to continue emitting the same amount of PM_2.5, in spite of state lockdowns. For these reasons, we ask international policymakers to reconsider the suspension of enforcement regulations as these actions do not fulfill their initial expectations. We recommend the creation and maintenance of pollution control and prevention programs that develop emission baselines, mandate the construction of pollution databases, and update records of pollution emissions.

Supplementary information: The online version contains supplementary material available at 10.1186/s12302-021-00489-9.