The state already has responded with significant procedural improvements. This directive, however, will tap the best available science to determine if further policy adjustments are warranted. Engler imposed no deadline on the board but asked that it complete the evaluation as soon as possible. At higher concentrations it irritates the eyes and respiratory tract, and can be a health threat. The impacts of exposure to high levels of hydrogen sulfide are well-documented.
Opinions differ, however, regarding the effects of long-term exposure to lower levels.
In addition to oil and gas drilling, hydrogen sulfide is generated by such sources as agricultural operations, wastewater treatment plants and manufacturing processes. The DEQ conducted a public meeting on the issue last year in Mason County in response to community concerns. It also has had several meetings with citizens, emergency response agencies, representatives of the Public Service Commission and staff of the Department of Community Health. Initiating further safeguards in Michigan's hydrogen sulfide management rules, which already are among the nation's most strict. The proposed changes would set standards for certain hydrogen sulfide gas pipelines, upgrade requirements for equipment exposed to hydrogen sulfide gas, and strengthen requirements for reporting gas releases.