Asthma sufferers could be adversely affected by fracking – the controversial method for mining natural gas.
Pennsylvania doctors found a patient’s asthma was harder to control if they lived near a fracking site, compared with asthma patients who did not. The findings were based on a study of more than 25,000 people.
Fracking involves drilling miles underground and blasting the shale rock with high-pressure water to release the natural gas trapped inside.
There are proponents who say it has the potential to be greener and critics who worry about the impact on the planet caused by pollution to the water table and earth tremors.
The authors, writing in the journal JAMA, say more studies to understand the impact of fracking are needed.