Several days ago Ontario Wind Resistance posted a study from Poland on the effects of raising geese close to a wind turbine. Their posting included several quotes from the study, which indicated the nearby geese suffered from both elevated cortisol levels and less-rapid weight gain. I was intrigued enough to take a closer look. The OWR posting and the excepts didn’t really do justice to what the Polish researchers found. While the study is properly cautious with its conclusions, the data itself shows the extent of the problem.
The study used two 20-member gaggles of geese, one of which was located 50 m from a single 2mw turbine and the second one was 500 m away. They started the study when the geese were 5 weeks old and followed them through week 17, taking 3 measurements of cortisol and weight during that time. For those into statistics, the differences between the groups were significant.
Most (if not all) higher animals produce cortisol as a response to stress. Certainly humans do, and cortisol levels are widely used as an indicator of how much stress a person is going through. The Health Canada study, for example, is collecting cortisol levels from the human neighbors as a physiological indicator of stress. In the chart below, the blue line is from the “control” 500-m group and the red line is from the “test” 50-m group. The purple line at the bottom shows a representative “normal” level of cortisol in presumably unstressed geese.
While the dramatic rise in the nearby group between week 5 (when they were tested a few days after moving into their new location) and week 10 is the most obvious feature of this chart, the most interesting to me is the levels in the “control” group. It seems apparent that (a) the stress is cumulative, and (b) exists even at this distance. I have “control” in quotes because their cortisol levels are still far above normals levels, which run in the below 2 ng/mL range, where the dashed purple line is.
Perhaps of more interest to a farmer growing geese for meat, does this stress have any effect on weight gain. Not so surprisingly, it does. Below is a chart showing the weight gain for the two groups during the study, with the control group ending up 10% heavier than the test group. The purple line shows the weight gain in a normal intensive meat-producing facility, but should only be used as a rough indicator (I could only find data for a different breed of geese).
I’m guessing the wind industry will try to ignore the implications of this study. If pressed, here’s what I’d expect them to say.
- These are geese, not humans, so the results can not be applied. It is true, these results are not the last word in human health impacts. But all higher animals have surprisingly similar biological processes, and the presence of cortisol is universally regarded as a stress indicator in all animals. What part of precaution is not understood by proponents?
- So there’s stress – that doesn’t necessarily mean there’s health effects. Medical journals are full of studies where stress, especially over time, leads to any number of health issues. Perhaps that’s why the industry’s health reviews use the word “direct” a lot.
- There could be some other problem between the gaggles. I suspect that, for wind energy proponents, there will always be some other problem.
- The geese just must not like the looks of wind turbines. Right.
- The geese must be jealous. Yep, must be.
- The geese have been listening to opponents like me and are just imagining things. I’m sure that’s it. Must be anglophones.
Proponents will say this study proves nothing, and that only a full epidemiological study on humans will work. A study that they are doing everything in their power to delay, or if inevitable, to control. In the meantime, people are being harmed by wind turbines and this study is important in showing that there are physiological processes at work. A mine owner would be culpable if he ignored his canary, and so should the wind industry be for ignoring the stressed geese.