Article by Sudharsan Gopalakrishnan

To many in Claremont, the smog that usually obscures Mount Baldy is a mere consequence of excess air pollution in Southern California. Today, we mainly observe photochemical smog, which forms when sunlight reacts with pollution released from human activities (EPA, 2004). Given that Los Angeles is among the most polluted regions in the United States, it is important to better understand what pollutants specifically are in the air, their sources, and how we can mitigate pollution.

In Los Angeles, smog consists of high levels of two pollutants in particular: PM2.5 (airborne particulate matter with a diameter up to 2.5 microns) and ground-level (or tropospheric) ozone (IQAir, 2023). PM2.5 particles have been linked to heart diseases and respiratory illnesses (IQAir, 2023), and inhaling ozone can trigger chest pain, shortness of breath, and more. Note that there are two types of ozone: while stratospheric ozone forms naturally higher in the atmosphere and helps shield us from UV radiation, tropospheric ozone forms closer to Earth’s surface as a result of reactions with pollution from human activities. Specifically, tropospheric ozone forms when sunlight reacts with nitrogen oxides — found in car exhaust, factory emissions, etc. — and volatile organic compounds (VOCs) — from gasoline, paints, etc. (EPA, 2004). In the Los Angeles area, the heavy traffic congestion, shipping industry, and geography (where surrounding mountains can trap pollution) all contribute to the persistent poor air quality. As a result of these factors, Los Angeles does not meet Environmental Protection Agency (EPA) national air quality standards for both PM2.5 and ozone (IQAir, 2023).

Given Los Angeles’ air quality status, several efforts to mitigate pollution have been made for a couple decades and are continuing to be made via governmental regulations on emissions from transportation and industries. For example, the Clean Air Act was passed in 1970 which increased air quality and emission monitoring (IQAir, 2023). In more recent years, the California Air Resources Board (CARB) has also helped promote awareness of air pollution and its harmful effects on public health, and devise new approaches to address air pollution issues (California Air Resources Board, n.d.). The government has also encouraged increased use of electric vehicles to address that motor vehicles are currently the main culprits behind the PM2.5 and ozone pollutants. Overall, legislation to reduce emissions holds promise for the future. On a smaller scale, I encourage everyone to make simple, cost-effective actions when possible to help reduce the accumulation of pollutants. For example, people can use natural airflow by opening their windows instead of turning on the AC. Also, gardening is beneficial for the environment because plants can sequester carbon dioxide from the atmosphere, improving air quality on a smaller scale. 

If the use of motor vehicles, ACs, and other nitrogen oxide / VOC emitting devices continues to increase, the air quality of Southern California will continue to dwindle. This can set the stage for respiratory illnesses, increased acid rain, and holes in the stratospheric ozone layer –– thereby increasing exposure to harmful UV radiation from the Sun. As such, to ultimately combat SoCal pollution and the increasing rate at which pollutants accumulate in the air, I strongly recommend that we continue to work toward a much healthier environment, through both governmental and individual contributions.

References

California Air Resources Board. (n.d.). Rulemaking | California Air Resources Board. California Air Resources Board. Retrieved November 19, 2023, from https://ww2.arb.ca.gov/rulemaking

Environmental Protection Agency. (2023, June 27). Ozone Generators that are Sold as Air Cleaners | US EPA. Environmental Protection Agency. Retrieved November 11, 2023, from https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-are-sold-air-cleaners

EPA. (2004, March). EPA Information – Photochemical smog — what it means for us. epa.sa.gov.a. Retrieved October 1, 2023, from https://www.epa.sa.gov.au/files/8238_info_photosmog.pdf

IQAir. (2023, September 11). Los Angeles Air Quality Index (AQI) and California Air Pollution. IQAir. Retrieved October 1, 2023, from https://www.iqair.com/us/usa/california/los-angeles

Smog and air pollution at Pasadena Highway, Los Angeles. Retrieved from: https://commons.wikimedia.org/w/index.php?curid=3703917

Swinn, N., & Fuentes, C. (2022, November 22). Smog. National Geographic Society. Retrieved October 1, 2023, from https://education.nationalgeographic.org/resource/smog/#