Los Angeles, or LA, may be among the U.S. cities with the dirtiest air, but it’s breathing much more easily than it did a few decades ago, when cars, refineries and backyard incinerators spewed greenhouse gases and particulate matter unchecked. Technology and today’s strict controls on automobile and industrial emissions accomplished this change.

LA’s sister cities, Mexico City and Mumbai, India, face similar challenges. Los Angeles and Mexico City both have geography that traps emissions, and all three cities have populations numbering in the tens of millions in their “greater” metropolitan areas. Motor vehicles are used for private, public and commercial transport, with added pollution from planes, trains and — in the port cities — ships.

Localities with similar air quality problems are natural collaborators on solutions. A 2014 study by the India-California Air Pollution Mitigation Program, a joint initiative of The Energy and Resources Institute (TERI) India, the University of California at San Diego and the California Air Resources Board, finds that technologies and fuels that have dramatically improved air quality in LA could be implemented in India and immediately improve health as well as food and water supplies.

Technology and strict regulations cleaned up LA’s air, but more can be done. (© AP Images)

“California has demonstrated that these pollutants can be mitigated drastically without slowing down economic development,” the report says.

Regulation and innovation

Air pollution became a problem in Los Angeles after World War II. Effective remedies took time and required coordination of government, businesses and residents. Federal laws, such as the Clean Air Act, and national emissions standards for cars, plus California’s own strict regulatory measures, kick-started antipollution efforts during the 1970s.

But smog continued to hang in the air. Real progress came after the adoption of catalytic converters to cut vehicle emissions.

A recent University of Southern California (USC) study shows that LA residents are healthier than they were 20 years ago, thanks to dramatic declines in nitrogen dioxide and particulate matter. The study’s authors say their findings support a correlation between “broad-based efforts to improve general air quality” and “substantial and measurable public health benefits.”

Ambitious goals

Like other cities around the world, LA must redouble efforts to maintain healthy air. As population grows, the number of vehicles and other pollution sources grows too.

Infographic on Los Angeles air quality (State Dept.)
(State Dept.)

Tackling air pollution and climate change through legislation, innovation and conservation is a priority for LA Mayor Eric Garcetti, who serves on the C40 Steering Committee and President Obama’s Climate Task Force.  The C40 is an international network of mayors working to solve urban environmental problems.

Strategies in LA’s Sustainable Cities Plan, launched in April, are bold.

Ambitious air quality targets include cutting unhealthy air pollution days from 40 recorded in 2013 to none in 2025, and a drastic decrease in polluting emissions through alternative fuel use and sustainable power generation.

Conserving parks and surrounding forests, which store carbon dioxide, is another strategy. A stretch of the Los Angeles River and adjoining green spaces will be restored after six decades during which the river has been a concrete sluice for flood control and runoff.

A new sustainability plan includes restoring the concrete-lined Los Angeles River to a natural green area. (© AP Images)

All this means healthier citizens, and as lead USC study author W. James Gauderman told USC News, “We expect that our results are relevant for areas outside Southern California, since the pollutants we found most strongly linked to improved health — nitrogen dioxide and particulate matter — are elevated in any urban environment.”