Air quality officials are investigating what has caused a spike in a toxic air pollutant in Paramount. They detected hexavalent chromium at 350 times the typical background level in a mostly industrial section of the south Los Angeles city last week.
More than a dozen field inspectors are trying to determine the business or industrial process causing the emissions, according to Sam Atwood, spokesman for the South Coast Air Quality Management District. He said they have narrowed the source to a two- or three-block radius and are investigating every business in the area.
"This is our number one priority and we're working every day on this," Atwood said. The district held a town hall meeting in Paramount Wednesday night to brief the community on the investigation.
Atwood said levels of the pollutant in the residential part of Paramount are five to ten times higher than typically seen in Southern California, although they have not increased in the past week.
That provides little comfort to Jane Williams, executive director of the group California Communities Against Toxics.
"We all need to do a lot more to both do more monitoring and do more enforcement, and seriously think about if it's a good idea to have so many plating and metal fabrication and forging operations in the same geographic area, so close to residents," Williams said.
The district started monitoring the air in Paramount in 2013, after community members complained about metallic odors. Residents believed the source of the odors was Carleton Forge Works.
Since then, Carleton Forge voluntarily implemented new measures to reduce emissions and odors. The district said the changes reduced the levels of nickel in the air.
But monitoring shows that hexavalent chromium levels have been increasing over the past year. The U.S. Department of Health and Human Services' National Toxicology Program has determined that hexavalent chromium, also known as chromium 6, is a human carcinogen.
The AQMD deployed eight additional monitors in Paramount in mid-October; they first registered the extremely high chromium 6 levels on Oct. 27.
There is not enough data to determine if the elevated levels pose a health risk to nearby workers or to residents, officials said.
"Once we have a good representative estimate of what the public is being exposed to, then we can actually answer the question, 'how significant is the risk?'" said Angelo Bellomo, deputy director for health protection for the Los Angeles County Department of Public Health.
Chromium 6 is used in processes such as steel making and chrome plating. Breathing it over a period of years increases the risk of lung cancer, according to the AQMD. It has also been linked to reproductive and developmental problems in lab animals.
During the course of the Paramount investigation, inspectors issued a violation to one business, Procast Industries, for operating two pieces of equipment without the required AQMD permits, Atwood said.
Paramount is "a classic environmental justice issue," said California Communities Against Toxics' Williams. She said she's pressing for the creation of a joint federal, state and local effort to study the sources of pollution in the city.
The AQMD plans to update Paramount residents on its investigation at another town hall meeting next month, said Atwood.
Chromium 6 is best known for the so-called Erin Brockovich case. Brockovich was a legal clerk who helped win a massive lawsuit against Pacific Gas & Electric in the 1990s over the alleged contamination of drinking water in the southern California town of Hinkley. PG&E had used chromium 6 in the cooling system of a compressor station.