01 · The problem
What is happening
Los Angeles gave its name to photochemical smog. Since the mid-twentieth century, California's regulations — from vehicle emission standards to the creation of the California Air Resources Board — have significantly reduced pollution. The South Coast Air Basin still frequently exceeds federal ozone standards because of its geography, sunshine and large emissions from vehicles, ports and goods movement.
High severity. Serious, widespread effects requiring sustained action. Severity is descriptive editorial metadata summarising documented effects. It is not a measured index or a score.
02 · Causes
Why it is happening
- 01
Vehicles and goods movement
Cars, trucks and the ports emit ozone precursors and particulates.
- 02
Geography and sunshine
Mountains trap air, and strong sunlight drives ozone formation.
- 03
Wildfire smoke
Fires add episodic particulate pollution.
03 · Impacts
Who and what it affects
- 01
Health effects
Ozone and particulate matter aggravate respiratory and cardiovascular disease.
- 02
Environmental justice concerns
Communities near freeways and ports face higher exposure.
04 · Solutions
Documented approaches
Vehicle emission standards
California's stringent standards and zero-emission vehicle requirements.
Expected effectReduces emissions as the fleet turns over.
Port clean air programmes
Cleaner trucks, shore power and equipment electrification at the ports.
Expected effectReduces emissions in nearby communities.
Community air monitoring
Community-focused monitoring and emission reduction plans.
Expected effectTargets the most affected neighbourhoods.
05 · Key indicators
What can be measured
No reliable quantitative indicator is included for this issue. TerraLens shows figures only where a credible source supports them — consult the sources below for current data.
06 · Sources
Where this comes from
- [1]California Air Resources BoardState of Californiaww2.arb.ca.gov(opens in a new tab)
- [2]South Coast Air Quality Management DistrictSouth Coast AQMDaqmd.gov(opens in a new tab)
- [3]U.S. Environmental Protection AgencyU.S. EPAepa.gov(opens in a new tab)
Links open the publishing organisation's site. Some point to the publisher's main page, where the named report or dataset can be found.