Mesothelioma News

      A Department of Health study found no increased rate of asbestos-associated cancer among those living within a two-mile radius of two former vermiculite plants in downtown Salt Lake City. And although the study found significantly increased rates of respiratory and lung cancers there, they doubt the processing plants caused the cancers.

      People who worked at the plants and their household members, though, were likely exposed to asbestos at levels that could cause concern, health officials say. Now they’re hoping that former employees of the two vermiculite facilities will contact them so they can see whether working directly with the material had adverse health effects.

      Vermiculite is the fluffy, shiny material in ceiling insulations and potting soils, although it starts life as an ore that only becomes fluffy when it expands and pops, somewhat like popcorn.

      Concern about the vermiculite processed in Utah arose because much of it came from a mine in Libby, Mont., which was contaminated with asbestos, said Wayne Ball, a Utah Department of Health toxicologist. When the vermiculite pops, a process called “exfoliation,” asbestos can be released. The Libby mine was closed in 1990.

      With help from the Agency for Toxic Substances and Disease Registry, state health departments nationwide have been looking at cancer rates near facilities that processed asbestos-contaminated vermiculite. Salt Lake had two of them: Vermiculite Intermountain, 333 W. 100 South, operated from 1941-86. Intermountain Products Inc., 733 W. 800 South, had a short run, from 1985-87.

      But the Utah Department of Health study of cancer data between 1973 and 2000 found that within a two-mile radius of the VI facility, rates of the two primary cancers related to asbestos exposure, mesothelioma and asbestosis, were no higher than in other parts of the state. Conversely, lung and respiratory cancers were 50 percent higher, “and we don’t know why,” Ball said.

      When an environmental agent is the cause, he said, trends can be spotted. There was no upward or downward trend on respiratory cancer rates over the 28-year time period studied, from 1973-2000. “It was elevated, but consistent. We don’t know what was happening, but because mesothelioma was not increased, we don’t feel these facilities contributed to lung cancer rates in the area,” he said.

      The report, available online at www.health.utah.gov/enviroepi, said that the former VI site, now a Utah Power and Light substation, commercial parking lot and small businesses, poses no public health risk now. Most of the site had been cleaned up when the researchers were writing their report and the last remaining contaminated soil beneath asphalt was to be remediated by the end of 2006. The Environmental Protection Agency finished cleanup of the IP site in December 2004.

      They estimate that 14,000 children 15 and younger lived within two miles of the area while the facilities were operating, and put the total population at about 70,400. How many, if any, were actually exposed is unknown.

      The state’s study, Ball noted, had limitations. Health officials have no exposure data to know if asbestos was ever released as the vermiculite was processed. They don’t know who worked at the plant at the time and so have been unable to track workers — who would have had the highest exposure — to see whether they suffered harm from asbestos exposure. As for the lung cancers, they know that about 85 percent of cases are caused by smoking, Ball said, but researchers had no information on the smoking rates in that area and whether that could account for the elevated rate.

      They also couldn’t account for migration in and out of the area but had to rely on addresses at the time of a cancer diagnosis. Other personal information, such as occupation, that might shed light on lung cancer causes was not available, he said.

      They used cancer data from the Utah Cancer Registry and looked at Census tracts within the two-mile radius for the study. They also used mortality data from the Office of Vital Records and Statistics for the same population groups, breaking the data into five-year periods. They used data from the rest of the state as their study “control.”

      If they can find former workers, health officials would like to alert them to potential risks and learn more about the facilities. “We have no information on the safety precautions taken in these facilities.” They know one plant employed about 10 people at a time; they don’t know about the other. Anyone who worked there can call 538-6191.

      They plan to reanalyze the data when another five years’ worth becomes available and comb through mesothelioma case records to see if an occupation was listed for patients. The department would like to do additional research, as well, to see if it can pinpoint a likely cause of the increased lung and respiratory cancer rates, he said.

E-mail: lois@desnews.com