UPDATE (11/16/2015; 10:20 am ET): The Heartland Institute recently interviewed Dr. Gilbert Ross, senior director of medicine and public health at the American Council on Science and Health on this Johns-Hopkins’ study on birth outcomes near fracking. Similar to EID’s analysis of the study, Ross said in the interview that “although these methods sound sophisticated, they tell us very little about whether fracking had any impact on the pregnancies.” He went on to explain:
“There is no possible way this retrospective study could have accounted for key issues, such as genetic factors, history of prior pregnancy issues, [or] drug or alcohol use in the parents, all of which have a large influence on birth weights and the duration of pregnancy,” Ross said.
“Realistically, there is no way hydraulic fracturing could have had an impact on pregnancy outcomes,” said Ross. “Fracking occurs two miles below the surface, and the Environmental Protection Agency found no evidence that hydraulic fracturing is causing widespread water contamination. There is no plausible mechanism to explain how pregnant women might have been exposed to anything related to fracking to cause attenuated gestation duration. Indeed, the authors didn’t measure any levels of possible toxicant exposure,” said Ross. “How could they, of course, in a retrospective analysis such as this?”
“If living close to fracking activity were truly influencing premature births, we would expect to see the highest incidences of early deliveries in the areas nearest fracking wells,” Ross said. “One of the key criteria in assessing whether a possible factor is causally related to an outcome is called ‘dose-response,’ meaning if A causes B, then more of A should cause more of B.”
— Original Post October 9, 2015 —
A new study released this week by researchers affiliated with the Post Carbon Institute (and Johns Hopkins Univ.) attempts to link fracking with premature births. But as we’ve seen with similar studies in the past, the actual data don’t support that conclusion. In this case, the authors are forced to acknowledge right up top that they cannot credibly link oil and gas activity to premature births. But, with that business taken care of, they proceed to imply that a connection probably does exist:
From the press release:
“While the study can’t pinpoint why the pregnant women had worse outcomes near the most active wells, Schwartz says that every step of the drilling process has an environmental impact.”
Despite claiming “no conflicting interests,” one of the study’s authors, Brian Schwartz, is a fellow at the Post Carbon Institute, a group known for espousing discredited “peak-oil” views that, it just so happens, has called fracking a “virus” and states as its mission to eliminate fossil fuels altogether. The study authors also received funding from the Robert Wood Johnson Foundation: at least three of its board members are also on the board of World Wildlife Fund, which has made it clear that it is, “against the use of fracking to extract shale gas – or any other ‘unconventional’ fuels – from the ground.”
So there’s that. But let’s take a look at the study itself and see what we can find in there.
Fact #1: Premature birth rate recorded in the areas closest to where wells exist is below the national premature birth rate.
According to the Centers for Disease Control and Prevention (CDC), roughly one in every nine babies is born prematurely in the United States – that’s about 11 percent of babies. According to the Quint Boenker Foundation, an organization dedicated to increasing survival rates for premature babies, “preterm births occur in about 12 percent of all pregnancies in the U.S.”
In this study, the researchers claim that women living in the fourth quartile (the area closest to gas wells) were far more likely to give birth prematurely than women in the first quartile, who were farther away. But as the chart below demonstrates, the percentage of babies born prematurely in the quartile closest to the wells is at or below the national rate at 11 percent.
The researchers’ claim that merely living closer to wells increases premature birth risk doesn’t really square with the data in each of the respective quartiles, either. As the chart shows, preterm births in each quartile did not differ substantially — going from 10 percent in the first and second quartiles, to 12 percent in the third and then declining again to 11 percent in the fourth, which, again, is closest to the gas wells.
Fact #2: Researchers don’t take into account the many factors that can cause premature birth, including genetics and socio-economic factors
Instead of drawing actual environmental samples and analyzing those, the researchers engaged in complex modeling exercises, but failed to take into account the many factors that can contribute to premature birth. That’s really important because, according to the March of Dimes,
“Family studies suggest that genetic factors may contribute to about 40 percent of preterm births. However, we do not know which genes may be involved.” (emphasis added)
On that note, a study by researchers at the University of Aberdeen (Scotland) found that premature births “tend to run in families” and that “women born prematurely or who have brothers or sisters who were born too early are 50-60 percent more likely to have a premature baby themselves.” Further, a new study by researchers that the University of Alabama has found that “variants in the DNA of the fetus – not the mother – may be the trigger for some early births.”
In addition to genetics, the Mayo Clinic explains some of the other risk factors associated with early labor:
“Often, the specific cause of premature birth isn’t clear. Many factors may increase the risk of premature birth, however, including:
Having a previous premature birth
Pregnancy with twins, triplets or other multiples
An interval of less than six months between pregnancies
Conceiving through in vitro fertilization
Problems with the uterus, cervix or placenta
Smoking cigarettes or using illicit drugs
Not gaining enough weight during pregnancy
Some infections, particularly of the amniotic fluid and lower genital tract
Some chronic conditions, such as high blood pressure and diabetes
Being underweight or overweight before pregnancy
Stressful life events, such as the death of a loved one or domestic violence
Multiple miscarriages or abortions
Physical injury or trauma
And yet, the authors chose not to include many of these risk factors in their analysis. From the report:
“Alcohol use was not a confounder, so was not included in adjusted models. We also did not adjust for blood pressure or the number of prenatal healthcare visits because we considered them potential mediators.” (page 3)
Interestingly, in a recent radio interview, Dr. Theodore Them, the Chief of Occupational and Environmental Medicine for Guthrie Health Systems in Bradford County, Pa. noted that studies on shale often leave out the very crucial element of “confounders” as the authors here have done. As Dr. Them put it,
“And there can be confounders such as smoking habits, drinking habits, drug use that never get accounted for in these studies and cause people to come to the wrong conclusions.” (28:36-30:09)
Fact #3: Baseline data were available to analyze — but the researchers decided to exclude it
If you were honestly trying to determine whether oil and gas development had any connection to preterm births, you’d probably want to take a look at some of the data that was collected prior to any oil and gas development taking place, right? You’d want to see what the rates of preterm births were prior to any wells being sunk. You’d want to take a look at disease and hospitalization rates – and lots of other environmental factors that could have an impact on the questions being studied. RIGHT?
But, according to the report:
“Due to strong collinearity between the unconventional natural gas development exposure metric and calendar year, we also excluded births before 2009 when little such activity had taken place in the study region” (page 2, emphasis added).
In other words, the researchers had all sorts of data available on preterm births before significant oil and gas development came to the study area, prior to 2009, but decided it wasn’t relevant. Even though it’s obviously relevant.
Fact #4: Researchers conducted zero environmental sampling, and the assumptions built into their computer model are contradicted by actual, real-world empirical data
As the study states:
“We were not able to take environmental samples, which may have led to exposure misclassification and prevented us from determining if a specific pollutant was responsible for our associations.”
Yet the study goes on to speculate that “expectant mothers could also be exposed to water pollution from unconventional natural gas development” (page 2).
But nowhere in the study will you find even a single mention of what has been called the most comprehensive study ever to be done on hydraulic fracturing and groundwater, which was completed by the Environmental Protection Agency’s (EPA) earlier this year. EPA’s five year study determined that fracking does not provide a credible threat for water pollution – or as the agency put it, fracking has “not led to widespread, systemic impacts to drinking water resources.”
EPA didn’t just look at the small window in which actual hydraulic fracturing work occurs to come to this conclusion, either. As Thomas Burke of EPA’s Office of Research and Development explained:
“‘The focus of our study was on wells that were fracked, but there is a narrow window in time where that fracking takes place. We looked far beyond that to look at the entire water cycle,’ Burke said, noting that there are instances where the process of fracking itself compromised well construction, which in turn led to surface water contamination.” (emphasis added)
After making claims about water contamination, the researchers go on to state,
“Truck traffic, drilling, hydraulic fracturing, and production can generate diesel particulate matter, fine particulate matter (PM2.5), methane, NOx, and volatile organic compounds, which are also ozone precursors. Some of these pollutants, most consistently PM2.5, NOx, SOx, and ozone, have been associated with adverse birth outcomes including low or reduced birth weight and preterm birth. PM2.5 and ozone are regional air pollutants, so women living long distances from unconventional natural gas development could experience effects.” (page 1-2)
The researchers cite a number of studies (several of which were written by anti-fracking activists, such as Macey et al., a study where activists literally collected air samples in buckets lined with plastic bags to suggest that air quality is being impaired by the oil and gas industry), but they fail to consult data from Pa. Department of Environmental Protection (DEP), which has actually done real, honest-to-goodness monitoring via air and soil monitors on well pads. DEP’s recent air monitoring in northeast Pennsylvania concluded that the state “did not identify concentrations of any compound that would likely trigger air-related health issues associated with Marcellus Shale drilling activities.”
A study from Drexel University from earlier this year also found that:
“Most notably, we did not observe elevated levels of any of the light aromatic compounds (benzene, toluene, etc.) that have previously been observed in oil and NG operations. With the exception of CH43OH, which was observed at one compressor station and has been observed at NG well pads, all of the other VOCs detected have been attributed to on-road engine exhaust.” (page E; emphasis added)
“Additionally we have shown that in contrast to other unconventional NG resources there are few emissions of nonalkane VOCs (as measured by PTR-MS) from Marcellus Shale development.” (page H; emphasis added)
But that’s not the only research these researchers could have looked at. A study by Professional Service Industries, Inc., commissioned by Union Township in Pennsylvania, found,
“Airborne gas and TVOC levels appear to have been at or near background levels for the entire monitoring periods in the three locations monitored.”
And also in southwest Pennsylvania, a report commissioned by Fort Cherry School District examined air emissions at a nearby well site and,
“did not show anything remarkable with respect to chemicals detected in the ambient air. When volatile compounds were detected, they were consistent with background levels measured at the school and in other areas in Washington County. Furthermore, a basic yet conservative screening level evaluation shows that the detected volatile compounds were below health-protective levels.”
And there’s more. Thanks to our increased use of natural gas, made possible by the use of hydraulic fracturing, air emissions in Pennsylvania has dropped precipitously. DEP noted earlier this year when it released the annual Marcellus air emissions inventory that natural gas is significantly improving air quality:
“While we are experiencing some increases in emissions from the natural gas sector, overall, our air quality continues to improve due to emissions reductions from other point sources such as electric generating units,” Quigley said. “We remain committed to developing and implementing the most effective ways to control and reduce emissions from Pennsylvania’s natural gas sites.” (emphasis added)
The past director for DEP, Chris Abruzzo, also noted in 2014 that,
“It is important to note that across-the-board emission reductions … can be attributed to the steady rise in the production and development of natural gas, the greater use of natural gas, lower allowable emissions limits, installation of control technology and the deactivation of certain sources.” (emphasis added)
That’s something that we’ve seen replicated across the country. Data from the EPA and the Energy Information Administration (EIA) show that while shale development has increased, from 2005 to 2013 emissions of PM 2.5 have decreased by 60 percent; emissions of SO2 decreased by 68 percent; and emissions of NO2 decreased by 52 percent. As EPA Administrator Gina McCarthy recently explained,
“Natural gas has been a game changer with our ability to really move forward with pollution reductions that have been very hard to get our arms around for many decades.”
Anyone who has had a complicated or high risk pregnancy knows that there are a multitude of factors that could contribute to the situation. EID’s own co-founder, a native of northeast Pa. himself, was born two months premature – and even though there wasn’t a single oil or gas well to be found in the area back then, one imagines his condition would have been blamed on fracking too if these researchers could have figured out a way to do it.
Health studies are important to get to the bottom of what may be causing premature births, and as mothers, we want to know what these risks are so that we can protect our children. But when a study finds rates at or below the national average closest to natural gas wells, yet garners headlines proclaiming harm, it’s worth asking some questions. Thankfully, one doesn’t need to dig too deep into this latest study to find the answers. In this case, the answer you find is that the study is poorly done.