Elevated Levels of Chromium-6 Discovered in Palisades and Altadena Air
By Laurel Busby
News & Information Editor
A consortium of scientists from Cedars Sinai and varied universities, such as UCLA, Stanford, Yale, Harvard, and USC, have discovered elevated levels of chromium-6 in the post-fire air of Pacific Palisades and Altadena.
The chemical, also known as hexavalent chromium, “was mostly in the form of very small particles, called nanoparticles, … [that are] less than 56 nm (nanometers),” according to the study’s data brief, which is available here. “More testing is needed to determine how much chromium-6 remains in the air, soil, and dust in the fire-impacted zones now that debris cleanup has mostly been completed. In the meantime, simple precautions are warranted to help avoid exposure to this potentially carcinogenic form of chromium.”
The average levels of chromium-6 found in the outdoor air in the Palisades and Altadena were 13.7 ng/m3 (+/- 6.2 ng/m3 ) , which is much higher than the typical background levels of 0.04 to 0.06 ng/m3, but also far lower than the 200 ng/m3 level allowed for workers during an 8-hour work day by the National Institute for Occupational Safety and Health. The levels are also less than half the amount that the EPA says could be breathed continuously for long durations “without a risk of negative health effects over a lifetime.”
Because nanoparticles can move inside homes, below are immediate steps that residents can take to reduce exposure to chromium-6.
1) Use air cleaners or purifiers with HEPA filters inside homes, offices, community spaces, and classrooms in or near the burn zones.
2) Upgrade HVAC filters to MERV 13 or higher rated filters.
3) Use HEPA vacuums to clean floors and upholstery.
4) Remove shoes before entering homes and wipe pets’ paws to avoid tracking dust into homes.
5) Wear N95 or KN95 masks while cleaning to avoid inhaling particles that may be stirred up during cleaning and debris removal activities
The consortium’s Los Angeles Fire Human Exposure and Long-Term Health Study (L.A. Fire HEALTH Study) has been evaluating the post-fire presence of pollutants in Pacific Palisades and Altadena to uncover their levels, locations and concentrations over time in order to assess potential health impacts. Hexavalent chromium, which was the pollutant featured in the movie Erin Brockovich, was detected in the air in March and April, but the contaminant’s presence was only recently uncovered due to the complicated analysis needed to assess the pollutants present in samples.
According to the study, “chromium-6 is a toxic metal that, depending on how much you’re exposed to, can impact your lungs. Chronic, long-term exposure is associated with asthma, bronchitis, and decreased lung function. Chromium-6 can also cause lung cancer. Your risk depends on how much you’re exposed to, for how long, and other factors like your overall health.”
The discovered levels were not above the 30 ng/m3 EPA standards and were not similar to the high concentrations found by Brockovich in Hinkley, California, according to the study. The levels “were below limits set for workers, but above screening levels for workers and the general public. Screening levels are used to determine when additional investigation is warranted.”
Hexavalent chromium was found on tiny nanoparticles, which are small enough to enter cells in the human body and light enough to travel up to six miles from fire-affected areas. The study, which used a truck with sophisticated air monitors to survey the burn zones, is analyzing more recent samples to see whether hexavalent chromium was also present in later months.
Resilient Palisades co-hosted a community webinar on Aug. 28 about the issue with a team of scientists and doctors from the LA Fire Health Study. The video link is available here.
