A cement factory near Riverside is emitting high levels of hexavalent chromium, a toxic carcinogen, from enormous outdoor dust piles blowing downwind across an industrial area and a residential community, the region’s top air regulator told The Times on Monday.
Barry Wallerstein, chief executive of the South Coast Air Quality Management District, said months of sampling and lab work showed that so-called clinker dust piles at TXI Riverside Cement in the Rubidoux area near the Riverside-San Bernardino County line were the source of high levels of airborne hexavalent chromium detected at sites in the area, including a uniform factory directly across the street.
“We’re not aware of any previous reports that a cement factory would have this level of hexavalent chromium-related risk, but the fact of the matter is we have sampled downwind of the facility, we’ve sampled upwind of the facility, we cross-checked and did backward calculations using air quality modeling, and it’s our best professional opinion that this is coming from the Riverside cement plant,” said Wallerstein.
“They have very large piles of cement material . . . and we believe that the dust from these piles is causing a downwind hexavalent chromium condition.”
A company official said TXI had been talking with air quality officials about the readings, but maintained that the company’s plant had not officially been identified as the source of the emissions.
“We’re obviously just as concerned as the district is,” said Frank Sheets, a spokesman for TXI Riverside Cement. “I think the key here is verification . . . They’re making an assumption, we believe at this point in time, that we’re the source of that high concentration, and we need to go through a verification process, to verify their findings.”
Wallerstein said that under California’s toxic hot-spots law, the facility’s owners would be required to notify the public of the emissions and take steps to mitigate them. He added that AQMD attorneys had advised him that the agency was not required to notify the public of the readings until the source of emissions had been confirmed.
The district had been in contact with TXI about the readings for about a month, according to the company.
Long-term exposure to airborne hexavalent chromium, also known as chromium 6, has been repeatedly linked in studies to terminal nasal and lung cancer. Recent studies, including one by the National Toxicological Program last year, have linked it to cancer in every major organ of the body in laboratory animals that drank contaminated water.
The toxic metal is widely used in metal plating, the aerospace industry, stainless steel processing and dye manufacture. It also can be found in rocks and other raw material used in cement production. Chromium 6 was at the center of a drinking-water contamination case in Hinkley, Calif., made famous by the movie “Erin Brockovich.”
Wallerstein said he did not know how long the carcinogenic dust had been blowing from the factory’s outdoor areas, but that his staff had first become aware of a potential problem in November when they noticed slightly elevated levels of hexavalent chromium at a regional monitoring station. That data was collected in 2005 and 2006 but not compiled and studied until late last year, he said.
The levels found across the street from the plant are 10 times higher than typical amounts found in air, according to Wallerstein. A state health official said long-term exposure to those levels could lead to an additional 480 cases of cancer in 1 million people. That is far higher than the 10-per-million level that triggers the state’s toxic hot-spots law.
Sheets, the TXI spokesman, said the clinker dust piles were part of a recycling operation that may have been in place since the 1960s. He thought it was possible that such dust piles could be covered or cleaned up, if they were proved to be a risk.
Sheets said officials at the 100-year-old plant previously had notified potentially affected neighbors of possible hazardous emissions, as required by the toxic hot-spots law. But in an e-mail, he said the levels that they calculated would come from the factory and its operations were below the reporting threshold set by the state. Records show the factory has complied with federal environmental reporting standards. In 2006, the most recent year for which data were available, they reported 7 pounds of hexavalent chromium emissions.
Dr. Robert Blaisdell, chief of exposure modeling for the air toxicology and epidemiology branch of the California Office of Environmental Health Hazard Assessment, cautioned that it would take years of continuous exposure to cause illness.
But he said the local air district “should follow up on it . . . hexavalent chromium is a potent carcinogen, and the concern here would be with long-term exposure.”
Some questioned why it took so long to figure out the source of the chromium and notify the public. In a March 14 letter, Wallerstein informed Riverside County officials that the tests taken directly across the street from the TXI cement factory in February and March showed levels of the carcinogen were on average 10 times higher than typical amounts in the region’s air. But in the same letter, citing an ongoing investigation, Wallerstein asked them to “please maintain the confidentiality of this information to the extent possible.”
Documents obtained by The Times show that AQMD tests in January also found elevated levels of the carcinogen at a dozen sites near the cement plant, including a park, two water facilities, a self-storage business and other factories.
Under one state law, any government official who learns that hazardous waste is being released must notify county officials within 72 hours or face up to three years in prison and stiff fines. Those officials must in turn notify the public “without delay.”
Wallerstein said it would have been wrong to alarm members of the public without positively identifying a source of the emissions. That source was not sufficiently determined until he ordered additional tests over the weekend, after The Times contacted him about reports of high chromium readings near the plant.
Riverside County Health Officer Eric Frykman said Friday that when the county received the March letter and a one-page report, he checked with his internal agency expert, who said that based on the levels reported, there was insufficient risk to warrant notifying the public.
Richard Drury, an attorney who has successfully sued polluters over hexavalent chromium emissions, said he was less troubled by the lack of public notification than by evidence that high levels were detected in 2005 but not further investigated.
“That’s absurd,” he said. “The air district should have investigated immediately. If you have a peak of hexavalent chromium, you want to find out where it’s coming from. It should not take three or four years. . . . It seems like someone’s been asleep at the switch over at the air district.”