Depends on how you define "Once", above.
Might be next week, next year, next century, or never.
We'll just have to wait, and see.
And in the meantime...
New Study Finds Worrisome Pattern of Birth Defects in Fracking Communities.
Science has long known that the developing fetus is sensitive to experiences of the mother – alcohol consumption, dietary factors, and mercury exposure are some of the more well-known examples. This sensitivity makes newborn babies an early indicator of something going wrong in the environment of the mother. Unfortunately, a team of researchers found preliminary evidence of something gone wrong when they looked at the patterns of birth defects in newborn babies in Colorado. The researchers found that babies whose mothers lived in close proximity to multiple oil and gas wells were 30% more likely to be born with defects in their heart than babies born to mothers who did not live close to oil and gas wells.
And here we go in circles again, citing American studies, where the cause is lack of environmental regulation.
But then that's all the environmentalists can do, cite the same biased statements again and again until it becomes wrote memory.
But then it is an effective way to win an argument, simply keep repeating yourself until the opponents can't be assed to keep refuting you.