Last month, the Colorado Department of Public Health and Environment (CDPHE) released a landmark health assessment finding that “the risk of harmful health effects is low for residents living [near] oil and gas operations,” and that “results from exposure and health effect studies do not indicate the need for immediate public health action.” 

CDPHE collected over 10,000 air samples in parts of the state with “substantial” oil and gas operations. “This isn’t cherry-picked air sampling data,” said CDPHE’s head of environmental epidemiology Dr. Mike Van Dyke at an oil and gas forum in Broomfield, Colorado. “This is all air sampling data.”

Here are the main conclusions of the assessment:

  • “All measured air concentrations were below short- and long-term ‘safe’ levels of exposure for non-cancer health effects, even for sensitive populations.”
  • “Overall, available air monitoring data suggest low risk of harmful health effects from combined exposure to all substances.”
  • “All four cancer-causing substances (benzene, ethylbenzene, formaldehyde and acetaldehyde) were within acceptable risk range, even for combined exposures.”
  • “Two substances, ethane and methane, do not produce any health effects except at extremely high exposures.”
  • “All other 56 substances were 5-10,000 times below standard health-based reference values and considered in the negligible risk range.”

Needless to say, these findings are a huge blow to the anti-fracking movement, and particularly to the research of Lisa McKenzie, who has become a hero to the movement for her reports attempting to link fracking to cancer.

Van Dyke (who has a PhD in environmental health from Colorado State University) recently sat down for an interview that addressed a number of important points, including McKenzie’s research.  As he said,

“[McKenzie’s research] is just research that suggests more research needs to be done, not research that definitively links oil and gas exposure to cancers in this age group […]

It could also be due to living near a road, there could also be unmeasured factors in terms of things like agricultural exposures, there could be family exposures like people smoking indoors. None of those things were really accounted for in the design of the study, nor should they have been. That kind of research requires a much more detailed and expensive study. I don’t want this to come across as if I’m bashing this study, but I do want to come across as saying that this study has significant limitations.” (emphasis added)

He also further explained the far more rigorious methods used in the CDPHE study, noting,

Our current report has two pieces. The first part is essentially all the air samples that we could find that were taken in areas near oil and gas, and we really, in a conservative way, took the max concentration and the max average concentration from those datasets, and compared them to what would be called “safe” levels by the U.S. EPA, or by other states if the EPA did not have a value.

Those values are really based on all the studies that have been done on those particular chemicals, and safety factors have been applied to the levels in those studies. The way people interpret those results are that they are conservative estimates to protect nearly all people from health effects.

What we found was that based on these data, there were no chemicals or substances that exceeded those safe levels. (emphasis added)

At the Bloomfield meeting, Van Dyke elaborated on this point noting that the level of exposure is key, especially considering how many of the substances examined in the assessment are also emitted by sources other than oil and natural gas development – including vehicle traffic and consumer products such as nail polish, detergents, sealants, aerosol antiperspirants and deodorants. “Each can be a health concern at some level of exposure,” Dr. Van Dyke said.

To illustrate why the level of exposure is critical, Dr. Van Dyke offered the example of saccharin, an artificial sweetener that prompted a health scare in the 1980s when researchers discovered that it caused bladder tumors in laboratory animals. Later, however, researchers found that humans would have to consume the equivalent of a hundred cans of Diet Coke in a single day in order to experience those same health effects – “and, I mean, I don’t know anyone who drinks quite that much Diet Coke,” Dr. Van Dyke said. Saccharin was then removed from the carcinogen list altogether. “What’s important in terms of exposure to these hazardous substances is how much you’re exposed to,” Dr. Van Dyke concluded.

These findings are right line with CDPHE’s previous work. Remember the agency’s Chief Medical Officer and Executive Director Dr. Wolk told the Greeley Tribune recently “we don’t see anything to be concerned with” with regard to oil and natural gas development and public health:

“I’m not going to tell anybody to go drink a pint of liquid petroleum or stand over an active well site and wave the fumes in to breath[e] them in. … Nobody would argue that this stuff isn’t toxic, but it’s all about exposure to toxins, and we don’t see anything to be concerned with at this point in time.” (emphasis added)