La's Air Pollution Control District: A Historical Perspective

Los Angeles, California, is known for its smog, a type of air pollution formed by PM2.5 and ozone. Despite improvements in recent years, LA's air pollution is among the worst in the United States. The Los Angeles Air Quality Index (AQI) often falls in the moderate range, and the city does not currently meet the US EPA's air quality standards. This is a significant issue, as air pollution has been linked to adverse health effects, including heart disease, respiratory illness, asthma, and premature death. To address this problem, California established the California Air Resources Board (CARB) in 1967 to work with local governments, businesses, and residents on researching and implementing effective air pollution policies. These efforts have contributed to a steady improvement in air quality, and the Clean Air Act amendments of 1990 have had a particularly positive impact on reducing air pollution in Los Angeles.

The Clean Air Act

The history of the Clean Air Act can be traced back to the 1940s, when the first recognised episodes of smog occurred in Los Angeles. In 1943, visibility was reduced to three blocks, causing burning eyes and lungs, and nausea in residents. This phenomenon was termed a "gas attack" and was blamed on a nearby butadiene plant. However, even after the plant was shut down, the smog persisted. This led to the formation of the Los Angeles County Air Pollution Control District in 1947, the first such body in the nation.

California continued to take a leading role in addressing air pollution. In 1966, the state established the first tailpipe emissions standards in the nation, followed by the creation of the California Air Resources Board (CARB) in 1967. CARB was formed by merging the Bureau of Air Sanitation and the California Motor Vehicle Pollution Control Board. The Federal Air Quality Act of 1967 further empowered California to set its own stringent air quality rules, recognising the state's unique geography, weather, and increasing population and vehicle numbers.

Air Quality Index (AQI)

The Air Quality Index (AQI) is a system used to communicate to the public how polluted the air currently is or how much it is forecasted to be. The AQI focuses on health effects that may be experienced within a few hours or days of breathing polluted air. The AQI is calculated for the five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter, including PM2.5), carbon monoxide, sulfur dioxide, and nitrogen dioxide.

Los Angeles's air quality averages a US AQI rating of "moderate". Monthly averages in 2019 varied from AQI 32 ("good") in February to AQI 64 ("moderate") in November. Despite seemingly optimistic ratings, Los Angeles's air pollution is among the worst in the United States, for both PM2.5 and ozone. PM2.5 is airborne particulate matter measuring up to 2.5 microns in size and is widely regarded as one of the most harmful pollutants to human health. Exposure to PM2.5 has been linked to health effects such as heart disease, respiratory illness, and premature death. For PM2.5, the greater Los Angeles county contains 9 of the 15 most polluted cities in the United States, according to the 2019 World Air Quality Report.

The South Coast Air Quality Management District reports that the overall risk of cancer is increased by 900 for every million people due to air pollution. The County of Los Angeles Public Health Department reports that 1 in 10 children have been diagnosed with asthma.

Los Angeles air quality has improved over the last 30 years due to the 1990 amendments to the Clean Air Act. Year-over-year trends have resulted in reductions in LA air pollution of 10.6% from 2017 to 2018 and 11.8% from 2018 to 2019. The COVID-19 lockdown measures also contributed to an 18-day stretch of exceptionally clean air in March 2020, the longest streak since at least 1995.

Weather conditions can impact air quality. For example, higher temperatures and sunlight can increase ozone levels, while temperature inversions can cause a buildup of ground-level pollution.

CARB's work with governments, businesses, and residents

California first started to address the issue of air pollution in 1967, when it established the California Air Resources Board (CARB). CARB's mission is to bring together local governments, businesses, and residents to research and implement effective air pollution policy.

CARB has worked with governments, businesses, and residents to find solutions to California's air quality problems. One of the key ways it has done this is by implementing and enforcing a wide range of air pollution controls, based on scientific evidence. For example, CARB has introduced innovative vehicle emission control strategies, such as the nation's first tailpipe emissions standards for hydrocarbons and carbon monoxide in 1966, and for oxides of nitrogen in 1971. These strategies have led to cleaner air in California, even as the population and number of cars has increased.

CARB's work with governments has been facilitated by the Clean Air Act, which was established by the federal government in 1970. This act, along with its later amendments in 1977 and 1990, created federal air quality monitoring, emission control, and enforcement. The Clean Air Act has been deemed one of the most effective federal clean air regulations, preventing an estimated 237,000 deaths from 1970 to 2020. The act has allowed California to develop and implement air pollution control strategies that have been a model for other states and countries.

CARB has also worked with businesses to implement strategies to reduce emissions across the transportation sector. For example, CARB has introduced the first tailpipe emissions standards, which have been adopted by businesses in the automotive industry. In addition, CARB has likely worked with businesses in the energy sector to reduce emissions, as California's reliance on car travel contributes to its smog problem.

Finally, CARB has also engaged with residents to improve air quality in California. For example, CARB has developed public education programs to raise awareness about the impacts of air pollution and how individuals can reduce their contributions. CARB has also worked with residents to collect data on air quality, with monitors at over a thousand locations across the country recording the concentrations of pollutants each day. This data is used to calculate the Air Quality Index (AQI), which helps residents understand the level of air pollution in their area and take appropriate precautions. For instance, when the AQI for ozone rises above 150, children and older adults, as well as people with lung disease, are advised to reduce prolonged or heavy exertion outdoors.

Strategies to reduce emissions

Los Angeles has implemented several strategies and initiatives to tackle its air pollution problem and reduce emissions. Here are some key strategies:

Clean Air Action Plan

The Clean Air Action Plan of 2006 has helped reduce particulate matter (PM) and nitrogen oxides from port operations at the Port of Los Angeles and the Port of Long Beach, the busiest container ports in the country. The San Pedro Bay Ports Clean Air Action Plan (CAAP) has achieved significant emissions reductions, and the ports continue to emphasise green development, particularly in zero-emissions technologies.

Transition to Electric Vehicles

Los Angeles is encouraging the shift to electric vehicles (EVs) to reduce emissions from transportation. The Los Angeles Metropolitan Transportation Authority (Metro) aims for an all-electric bus fleet by 2030 and already operates the nation's largest fleet of compressed natural gas (CNG) buses.

Increasing Green Spaces

The city is also focusing on increasing green spaces, such as street trees, parks, green roofs, and facades, which can reduce temperatures in cities and improve environmental sustainability and health equity.

Zero Emissions 2028 Roadmap

Los Angeles Mayor Eric Garcetti developed the Zero Emissions 2028 Roadmap, which aims to accelerate the transition of privately-owned cars and trucks to electric vehicles, improving air quality and reducing greenhouse gas emissions.

Los Angeles County 2045 Climate Action Plan

The Los Angeles County 2045 Climate Action Plan (2045 CAP) is a comprehensive strategy to reduce greenhouse gas emissions in unincorporated areas of the county. It identifies specific programs, actions, and performance goals to achieve emission reduction targets.

Clean Air Act

The Clean Air Act, along with its amendments in 1977 and 1990, has played a crucial role in reducing air pollution in Los Angeles. These regulations established federal air quality monitoring, emission control, and enforcement, contributing to the significant improvements in air quality over the last two to three decades.

Health implications of air pollution

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health and prosperity, causing more than 6.5 million deaths each year worldwide. This number has increased over the past two decades. The main pathway of exposure from air pollution is through the respiratory tract. Breathing in these pollutants can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs.

Particulate matter (PM), carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2) are among the pollutants with the most significant evidence for public health concern. Fine particulate matter, such as PM2.5, is of particular concern as it can penetrate deep into the lungs, enter the bloodstream, and travel to other organs, causing systemic damage to tissues and cells. Sources of fine particulate matter include vehicle and industrial emissions from fossil fuel combustion, cigarette smoke, and burning organic matter, such as wildfires.

Ozone, an atmospheric gas, is often referred to as smog when it is present at ground level. It is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, and other sources react chemically in the presence of sunlight. Ozone is a potent lung irritant, causing inflammation and other damage that can affect multiple body systems. High levels of ozone can lead to breathing problems such as chest tightness, coughing, and shortness of breath, even in otherwise healthy young adults.

Air pollution has been linked to a range of adverse health outcomes, including respiratory diseases such as asthma, emphysema, and chronic obstructive pulmonary disease (COPD). It is also associated with heart disease, lung cancer, and other types of cancer. Maternal exposure to air pollution has been linked to adverse birth outcomes, such as low birth weight and pre-term birth. Additionally, there is growing evidence that air pollution may impact diabetes and neurological development in children.

The health effects of air pollution are not evenly distributed among the population. Certain groups are more susceptible to the negative consequences, including pregnant women, children, older adults, and individuals with pre-existing chronic conditions, especially heart and lung diseases. Furthermore, socio-economic factors play a role, with children from low-income urban areas experiencing higher rates of asthma due to increased exposure to air pollution.

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