Updated 2025-05-07T19:48:03Z
- Los Angeles has struggled with air pollution problems since before smog became a term.
- In 1943, smog covered the city so thickly that residents thought they were under a chemical attack.
- The creation of the Environmental Protection Agency in 1970 introduced air pollution regulations.
For much of its history, the city of stars could have been called the city of smog.
Los Angeles experienced years of thick air pollution due to a ballooning population, unregulated industry, a booming car industry, and its natural geography.
In 1943, during World War II, pollution blanketed the city so intensely residents thought Japan had launched a chemical attack, Wired reported. Over the next three decades, improvements came, but they were slow.
In 1953, the Washington Post described the conditions as "eye-burning, lung-stinging, headache-inducing smog."
The biggest victory against smog came in 1970. President Richard Nixon created the Environmental Protection Agency, which led to air pollution regulations, and allowed California to make even stricter provisions within its state.
Since its 1970 founding, the agency has been committed to protecting human health through the regulation of environmental pollutants, per its website.
In recent months, President Donald Trump has announced plans to cut the EPA's staffing and funding for its scientific research arm in efforts to promote government efficiency.
Throughout the agency's history, the Office of Research and Development has led research showing the effects of environmental pollutants on American populations. In March, The New York Times reported on the administration's intent to eliminate the agency's research wing entirely, a move that would result in thousands of agency employees being laid off.
Back when the EPA was founded, it launched the "The Documerica Project," which leveraged 100 freelance photographers to document what the US looked like in the early 1970s. By 1974, they had taken 81,000 photos. The National Archives digitized nearly 16,000 and made them available online, and we've selected 35 in the Los Angeles area.
Here's what LA looked like before the EPA regulated how pollution affected US cities.
Los Angeles' air pollution has been an issue since early in the city's history.
Los Angeles has a history of smog. The problem is exacerbated by its natural geography — the sprawling city is shaped like a bowl, which traps fumes blown by Southern California's sea breeze, and causes them to linger over the city, according to Smithsonian Magazine and the Los Angeles Times.
By the 1940s, the public became concerned about air pollution.
During the 1940s people began to notice the smog, but many thought it was clouds. They weren't.
"It was just the poor quality of the air that was a hazy, acrid, smelly, burning presence," the Los Angeles Times wrote.
In 1943, residents feared they were under foreign chemical attack thanks to what the Los Angeles Times called a "black cloud of doom."
In July 1943, a particularly bad bout of smog caused red eyes and running noses. People thought the city was under a chemical attack from the Japanese.
The newspaper once called the smog "daylight dim out."
The term "smog" eventually entered the popular vernacular, mixing the words smoke and fog.
The smog greatly affected the city's visibility.
At times, the air pollution would be so concentrated in certain areas that it looked as if the city disappeared entirely.
City residents felt the effects of the pollutants.
Here, women in 1949 dabbed their eyes and noses.
The lack of visibility due to pollutants in the air affected people's driving.
On bad days, cars would appear from out of the smog. Visibility was so bad that people had car accidents, per LAist.
As a result, crashes due to limited visibility were common on highways.
Accidents like this one in 1948 were common occurrences in the highly polluted Los Angeles roads.
Before the 1950s, open burns of garbage dumps would cover the city in trash smoke.
In 1949, smoke from a trash dump covered the city. Later, fearing the effects of smog on the city's inhabitants, Gov. Goodwin Knight restricted the open burning of garbage. It was made illegal in 1958, per the Los Angeles Times.
Despite environmental concerns, the city grew its car population rapidly.
The city had more than one million cars by 1940, according to the Smithsonian Magazine.
Before the 1950s, people didn't know of the connection between car exhaust and the air pollution in the city.
But it wasn't until the early 1950s that car exhaust was established as one of the primary causes of smog, Wired reported.
The ozone from car exhaust contributed to the health issues city residents began experiencing.
Cars contribute to ozone, which was the main cause of the smog. The ozone layer up in the atmosphere protects life on Earth from harmful UV rays. But when it's near the ground, ozone is a harmful gas that can trigger health issues like asthma.
Throughout the 1950s, there continued to be dramatic episodes of smog covering the city.
Smog continued to blanket the city in the 1950s. This is the view from the Los Angeles City Hall in 1954, after eight days of heavy smog.
It was impossible to see the mountains surrounding the city.
Lee Begovich, who moved to the city in 1953, told the Washington Post she was stunned when wind blew the smog away one day and she finally, for the first time, saw the San Gabriel Mountains to the northeast.
In the era when smoking inside was still the norm, the city's outdoors mimicked the inside of bars.
Peering at the city, the Washington Post wrote, was "like peering into the smoke-filled backrooms of the era's bars."
For residents, the effects of air pollution were just a part of daily life.
In 1954, Getty wrote that there were so many red eyes, one person said "you couldn't tell the people with hangovers from those who went to bed the night before."
Some wore masks to counter the effects of pollution.
People wore masks to counter what the Washington Post described as "eye-burning, lung-stinging, headache-inducing smog."
Others went as far as using plastic helmets to shield themselves from the pollution.
At least one woman wore a plastic helmet while relaxing at Santa Monica beach. At the time there were also bush fires, so while the helmet protected her from ash, it didn't stop smog from seeping in.
The city even tried bringing in fresh air from outside the city in air canisters.
In 1958, the city even set up a smog relief team to provide residents with "fresh air" brought from outside of Los Angeles. Whether it was effective is unclear.
Into the '60s, smog continued to define the city's landscape.
Continuing into the 1960s, parts of Los Angeles were getting 200 smoggy days each year.
By 1961, the city had begun monitoring air pollution levels.
Smog continued to cover the city as Los Angeles expanded, which meant more factories and highways. The city did have Air Pollution Control, an early pollution monitoring group.
By the late 1960s, city officials began taking the issue of air pollution into more consideration.
Here's Grand Avenue in 1967, after efforts to limit pollution began being implemented by the city.
When pollution control was introduced in Congress, California was allowed to tackle the issue with harsher restrictions than other states.
When the Clean Air Act was passed in 1970, Congress approved an amendment that allowed California to incorporate harsher pollution controls than the rest of the country, the Washington Post reported.
The city took a greater role in enforcing regulations.
Air pollution officers actively monitored the highways for emissions.
Still, the city's pollution persisted into the 1970s.
The start of regulation didn't mean the pollution just went away immediately. This is hazy Los Angeles in 1972.
As emissions began to be restricted, the city's natural landscape started to reveal itself.
Here, that same year, smog was trapped against the mountains.
Smog decreased, but it still outlined the city's landscape.
Smog still covered the San Gabriel Mountains at times in 1972.
The view of the city's rapid development was stained by its side effects.
In 1973, Los Angeles skyscrapers were blanketed in smog.
Still, a characteristic city landscape was formed by Los Angeles' skyscrapers.
At least the shape of the buildings could be made out.
The Clean Air Act helped the city transform its polluted landscape.
Over the years, the air quality in Los Angeles had improved thanks to the Clean Air Act, which helped lower emissions from cars and industry, the Washington Post reported.
Despite climate action being taken in response to the city's pollution, some issues persist.
The city's air quality future is still far from clear. Per IQAir, Los Angeles is the US city with the second-worst air quality (behind only Minneapolis) and the 72nd worst city for air quality in the world.
In fact, multiple cities in California continue to rank among the worst for air quality.
Even today, smog can be seen in the city.
The 2018 National Climate Assessment warned that "climate change will worsen existing air pollution levels," according to the Fourth National Climate Assessment and NASA.
While LA doesn't look as bad as it did before the Clean Air Act, it still gets smoggy days.
This story was originally published in January 2020 and was updated in May 2025.
