Starting with the COVID-19 update, there is little change with 192 Coloradans hospitalized last week and with case numbers and test positivity trending upwards somewhat. As for variants, the Omicron subvariant XBB.1.5 now accounts for the majority of isolates in Colorado, as it does nationally
, with a falling proportion of BQ1.1. Winter continues with ferocity in Colorado, but it has not driven a COVID-19 surge.
Of course, events affecting public health continue. For more than two weeks, the train derailment and toxic spill in East Palestine, Ohio, have been in the news. Per the New York Times
, more than 1,000 trains derail each year, many carrying toxic and flammable substances
. Of the 38 cars that derailed in East Palestine, five were carrying vinyl chloride and two benzene, both well-established human carcinogens. The vinyl chloride was destroyed in a controlled burn while the cars with benzene remained intact. Other chemicals and materials burned as well, likely generating a mix of toxins. Cars 66-74 containing beer were undamaged, sparing the populace. For those in the field of environmental carcinogenesis, vinyl chloride and benzene are particularly infamous.
I have long used the discovery of the carcinogenicity of vinyl chloride as exemplifying the critical role of clinicians in identifying sentinel disease events. Dr. John Creech, a Louisville, Kentucky, surgeon, called attention to vinyl chloride as a cause of angiosarcoma of the liver after treating a number of patients with this rare form of liver cancer
. Four employees at a B.F. Goodrich production plant, all working in the production of polyvinyl chloride, died from this cancer as the sentinel event, i.e., “the canary in the coalmine.” Quoting Dr. Creech, “But had the cancer been a more common one, such as lung cancer, I probably would not have realized that there was any problem in the first place.” Ironically, a century ago, rising lung cancer cases, a rarity at the time, were the sentinel for the start of the smoking-caused lung cancer epidemic.
Benzene causes acute myelogenous leukemia through a genotoxic mechanism
. The early epidemiological evidence on benzene exposure and risk for acute myelogenous leukemia in workers led the Occupational Safety and Health Administration (OSHA) to tighten the occupational exposure standard for benzene across the 1970s. The American Petroleum Institute, a trade association, sued and the resulting case, Industrial Union Department v. American Petroleum Institute
, went to the Supreme Court and was decided in 1980. The decision in the case, generally known as “The Benzene Case,” offered that “the burden was on the Agency to show, on the basis of substantial evidence, that it is at least more likely than not that long-term exposure to 10 ppm of benzene presents a significant risk of material health impairment.” This “material health impairment” criterion remains in-play, placing a risk assessment burden on OSHA. There were other aspects of the case around its administrative elements that have also had lasting impact on regulation.
The spill reminded me of White Noise
, a 1985 National Book Award winner written by Don DeLillo. Its second section, “The Airborne Toxic Event,” involves a chemical spill from a rail accident and exposure of the protagonist to a toxin. There is a recent film adaptation
, which I watched with the impetus of the East Palestine disaster. The movie is disjointed, but it does feature a very ominous black cloud spreading from a train derailment. Photos of the East Palestine plume are remarkably similar.
Perhaps the most tragic industrial accident involving chemicals occurred in Bhopal, India, in 1984
with the release of methyl isocyanate from the Union Carbide India Limited pesticide plant. The plant was located in a densely populated area and thousands were killed and hundreds of thousands injured. This disaster should not be forgotten.
Sorting out the health consequences of disasters like the East Palestine derailment is challenging. The documented presence of toxins and carcinogens is alarming, but the path from air and water contamination to exposure of people is complicated. Environmental measurements are typically made in such disaster setting. The findings may signal unacceptable levels or may fall within established exposure limits. However, measurements of contaminant levels may not be reassuring or trusted, particularly if there is detectable evidence of ongoing contamination, such as odors. Health consequences may be immediate and perhaps lasting, or only emerge over the long-term. For example, the syndrome of Multiple Chemical Sensitivity is typically triggered by a chemical exposure and then reignited by further exposures. Increments in any potential increase in risk for cancer can be estimated, but an excess beyond expectation cannot generally be detected at the population level, absent some signature characteristic.
One recent example of such research is the study launched by the University of California Los Angeles (UCLA) on the health consequences of the release of massive quantities of methane from the underground storage facility at Aliso Canyon
. Between October 2015 and February 2016, 109,000 metric tons of methane were released adjacent to a residential area. The UCLA team is charged with understanding the short- and long-term health consequences of the release
. Study funding is at $21 million over five years, reflecting the scope of the research needed, which will likely involve reconstruction of exposure and a comprehensive assessment of health effects. Results may not be considered as sufficiently timely for those affected, likely not available until more than a decade after the event.
Friday is the annual Public Health Advocacy Day at the Capitol
, organized by the Colorado Public Health Association. The event starts at 8:20 a.m. after a breakfast and networking session. This year, there is an emphasis on climate and health. This is an always well attended event and an opportunity to network with colleagues in public health.
Jonathan Samet, MD, MS
Dean, Colorado School of Public Health