A three-year study on fracking well emissions could help researchers figure out if there are any harmful health effects on humans. The study measured methane, a greenhouse gas, and ozone-causing compounds that were released from wells in western Colorado. Officials are planning to hire outside researchers within the next six weeks to use the data in a model about health risks. That should be completed by January 2018. This is the first time that researchers can say they were entirely focused on pollution from fracking wells and not other sources, according to a state health department spokesman.