How do man-made changes to the environment affect human health? That’s not an easy question to answer. There are so many complicating factors, not to mention that the human body is a rather complex piece of work.

Unfortunately, this complexity opens the door for a lot of bad science and opportunists who are not so much interested in good health and good policy as they are in pushing their own political agenda or gaining publicity.

A recently published study on the possible health effects of fracking is the latest in a pantheon of irresponsible conclusions that appear to be either motivated by a bias against the natural gas industry or just attention-seeking by a set of researchers. (Note: fracking is the use of high pressure water and chemical solutions to extract natural gas and other hydrocarbons from deep within the earth’s crust.)

In a study of data from three Pennsylvania counties from 2007 to 2011 (two counties where fracking occurred and a “control” county where no fracking was conducted), the authors found increased hospitalization rates for a series of ailments that were greater in the fracking counties than in the non-fracking control county. That finding is fact. The problem comes when the authors decided that fracking was the culprit and started trying to find why that is the case.

They expound on a laundry list of medical problems and vainly try to figure out how fracking could cause it (the data also show that admissions for orthopedics fell in the study period – maybe fracking is good for your bones!). The authors suggest increased vehicle emissions, chemical spills, and broken pipes as causes. They conveniently omit one very real possibility: it’s all in the head.

For years, anti-fracking activists have engaged in fear-mongering and hysteria to conduct their own private war. Protests at public meetings, a mass media campaign and the now-debunked movie Gasland have frightened segments of the public. Given the emotionally-charged atmosphere and how we know that stress negatively affects human health, we should expect hospital admissions to rise. We know that traumatic events and imagery affect human health.

But this study has many more problems. It examines the years 2007 through 2011, yet the data show drilling only began to become significant in 2009. Any increases in hospitalization prior to 2009 should have been discounted. Furthermore, the study makes no distinction between different conditions. A rising in oncology (cancer) admissions could only be associated with fracking if such admissions occurred well after the start of drilling activity. After all, tumors just don’t start appearing overnight. Any medical condition that takes time to develop would have to be ruled out if the condition manifested itself prior to, during, or immediately after fracking occurred.

The authors also guessed that increased truck emissions could cause some of the negative health effects. However, they did not incorporate data from air pollution monitors in the region to determine if there really was a net increase in air pollution. That’s just sloppy science.

But most critically, the study ignores an entire population: fracking workers. When the fracking industry began in Pennsylvania, few local workers were trained in the necessary skills. The industry was importing workers from Texas and Oklahoma to work the wells. It is possible that it was this group of workers that were causing the spike in hospital admissions. Well-drilling, whether for oil, gas or water is a strenuous activity. It is possible that these workers, stressed from being far from home, engaged in strenuous activity, perhaps indulging in alcohol (or worse), were importing their poor health outcomes to northeastern Pennsylvania. The bottom line? Not controlling for the influx of out-of-state roustabouts renders this study worthless.

The fact is that we don’t know if vehicle emissions, chemical spills or stress is the cause of the observed health problems. And, it could just be a temporary statistical anomaly.

If people had the facts – for instance that there is no example of fracking chemicals percolating up through a mile of rock, or that deep-well injection drilling and disposal have been standard practice for decades with no ill-effects (when conducted properly) – perhaps the negative health outcomes observed would not have happened.

In other words, if Yoko Ono would stay out of public policy and instead stick to making awful music perhaps the people of Pennsylvania would be much healthier.