Current government regulations miss key pollutants in Los Angeles region

September 29, 2008
Smog above Los Angeles, as seen from the Hollywood Hills. Credit: David Iliff

Existing regulations may not effectively target a large source of fine, organic particle pollutants that contribute to hazy skies and poor air quality over Los Angeles, according to a study scheduled for the October 15 issue of ACS' Environmental Science and Technology, a semi-monthly journal.

In the study, Ken Docherty and colleagues point out that current air quality regulations target sources of 'primary,' or directly emitted, particles. Yet their new findings indicate that "secondary" or chemically formed, particles contribute more significantly to poor air quality.

The study found that most of the organic haze above the city is not directly emitted by vehicles or industrial processes, unlike previously thought — 75 percent of organic particle pollutants form when reactive, organic gases undergo chemical transformations and condense onto existing particles in the air. "Our study suggests that regulations need to focus much more attention on the organic gases that react chemically in the atmosphere, creating the secondary particles that make up a significant portion of haze," Docherty said.

Article: "Apportionment of Primary and Secondary Organic Aerosols in Southern California during the 2005 Study of organic Aerosols in Riverside (SOAR-1)"; dx.doi.org/10.1021/es8008166

Source: ACS

Explore further: Materials made of self-spinning particles

Related Stories

Materials made of self-spinning particles

December 5, 2016

Matter is either gas, liquid or solid based on how its molecules respond to temperature and pressure. But what if the building blocks are self-spinning particles instead of ordinary molecules? Theoretical physicists found ...

How trees change the atmosphere

December 1, 2016

Rising from trees into the atmosphere, isoprene—a colorless, volatile, carbon-containing compound—smells vaguely like tires. It helped give the Blue Ridge Mountain range its name and has a profound effect upon the chemistry ...

Delhi shuts schools as smog sparks health 'emergency'

November 7, 2016

Authorities in Delhi on Monday closed schools, halted construction work and shut down a major power plant after days of choking smog led to warnings of a health "emergency" in the world's most polluted capital.

Recommended for you

Climate change will drive stronger, smaller storms in US

December 5, 2016

The effects of climate change will likely cause smaller but stronger storms in the United States, according to a new framework for modeling storm behavior developed at the University of Chicago and Argonne National Laboratory. ...

Extreme downpours could increase fivefold across parts of the US

December 5, 2016

At century's end, the number of summertime storms that produce extreme downpours could increase by more than 400 percent across parts of the United States—including sections of the Gulf Coast, Atlantic Coast, and the Southwest—according ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.