Environment Counts | Study links asthma attacks with shale gas development :

A statistical study has assessed asthma patients from 2005 through 2012 treated at a clinic in Pennsylvania. 35 508 patients with asthma aged 5 to 90 years were identified in electronic health records. Researchers identified 20 749 cases of mild, 1870 of moderate, and 4782 of severe asthma attacks were statistically compared with shale gas development activity using stage of development and distance to the patients residence as key variables.

The results showed that shale gas development activity was statistically associated with increased risk of mild, moderate, and severe asthma attacks. The researchers emphasize that statistical correlation only indicates a link but which may or may be causal. Showing the link is causal involves identifying a mechanism which will require further research.Sara G. Rasmussen et al., JAMA Intern Med. Published online July 18, 2016. doi:10.1001/jamainternmed.2016.2436