05/04/2012 11:46 am ET

Pennsylvania Drilling Settlement: Doctors, Environmentalists Call On Gas Companies To Release Details

The pressure is mounting on gas companies to reveal what they know about the possible health side effects of their activities.

More voices are calling upon a group of gas companies to release a sealed court settlement that last year capped a long-running legal battle. The sealed records concern a Pennsylvania family -- Stephanie and Chris Hallowich and their children, of Mount Pleasant Township -- who say they developed health problems, including headaches, earaches and nosebleeds, after gas developers began drilling on their property.

The Hallowich family reached a settlement with the gas companies, including Range Resources and MarkWest Energy Group, in 2011, according to the Pittsburgh Post-Gazette. Details of the settlement were ordered sealed by the court. But the PPG and another Pennsylvania newspaper have since been trying to get those details made public.

This week, they were joined by a group of doctors, scientists and environmental advocates, according to the PPG, all of whom argue that whatever the gas companies know about the possible health side effects of drilling shouldn't be kept confidential.

The case is just the latest example of critics expressing concern over the opaque practices of the oil and gas industries, which have made an aggressive push in recent years to mine what they say is a wealth of natural energy resources on American soil.

One of the most contentious issues involves fracking, or hydraulic fracturing, the process of blasting chemically treated water into underground layers of rock in order to free quantities of oil or natural gas.

When it comes to actually disclosing which chemicals are being injected into the ground, laws vary from state to state. In Wyoming, companies have reportedly been allowed to keep secret more than 100 chemicals, saying the information is sensitive and could put energy companies at a commercial disadvantage if it were publicized. That provision has drawn sharp protests from environmental groups.

Meanwhile, in Pennsylvania, health professionals are going head-to-head with energy companies over a law that doctors say could tie their hands when interacting with patients. The law requires doctors to sign a confidentiality agreement when requesting information about drilling chemicals.

Pennsylvania doctors say they're concerned the law would prevent them from talking to co-workers and even patients about industry-sensitive information. Sam Smith, the Republican speaker of the state House of Representatives, has claimed the law would have no such effect.