URGENT UPDATE: A new study has revealed that levels of carcinogenic hexavalent chromium, also known as chromium-6, surged to over 200 times baseline levels in the air of Los Angeles following the devastating wildfires earlier this year. This alarming finding was confirmed by researchers in late March 2023, more than two months after the flames were extinguished.
The presence of this toxic pollutant poses a significant health risk as it has been linked to lung and nasal cancers. Although the detected levels fell below certain safety thresholds, the unusually small size of the particles raises serious concerns about their potential impact on human health.
Researchers, led by environmental engineer Michael Kleeman from the University of California Davis, sampled air from cleanup zones near the Eaton and Palisades fire regions. They recorded concentrations of hexavalent chromium ranging from 8.1 to 21.6 nanograms per cubic meter in the areas hardest hit by the fires, including Altadena and the Pacific Palisades.
The South Coast Air Quality Management District has responded, emphasizing that their data do not indicate an immediate health risk from hexavalent chromium. However, the study has raised alarms about the potential long-term effects of exposure, especially given that fire can significantly enhance the toxicity of chromium.
Kleeman stated, “It is really surprising to find all of the hexavalent chromium in the LA fire debris cleanup zones concentrated in particles smaller than 56 nanometers.” This finding is critical because nanoparticles can penetrate deeper into the respiratory system and even enter the bloodstream, potentially affecting vital organs.
While the Occupational Safety and Health Administration has established a workplace exposure limit of 200 nanograms per cubic meter, the EPA has set a stricter indoor limit at 0.1 nanograms per cubic meter. The detected levels, although below the OSHA threshold, exceed the EPA’s indoor safety limit, warranting serious consideration from public health officials.
Kleeman and his team have chosen to make their findings public through the preprint server Research Square to alert policymakers and the public as soon as possible, despite the study awaiting formal peer review. Kleeman emphasized, “The current findings warrant caution, but not panic.”
As California grapples with increasing wildfire frequency driven by climate change, understanding and mitigating this newly identified threat is more crucial than ever. Kleeman plans to return to affected areas to monitor airborne hexavalent chromium levels and identify potential sources of exposure.
With climate change reshaping the landscape of wildfires, the implications of this study extend beyond Los Angeles. “We all need to work together to adapt to this new reality,” Kleeman stated, highlighting the urgent need for community awareness and action.
Stay informed about this developing story as researchers continue to investigate the long-term consequences of hexavalent chromium exposure in urban areas affected by wildfires.
