TABLE 2. Potential Health Effects of Air Pollutants Associated with Shale Gas Development.

Pollutant	Potential health effects
Methane	• Explosion and fire
	• Asphyxiation in confined space
	• Global climate change
Nonmethane volatile organic compounds including BTEXa	• Ozone precursors
	• Leukemia and other hematological effects (benzene, formaldehyde)
	• Upper respiratory tract inflammation
	• Central nervous system effects in confined spaces
Oxides of nitrogen	• Ozone precursors
	• Asthma and other acute respiratory effects
Ozone including photochemical oxidants	• Asthma and other acute respiratory effects
	• Loss of lung function
	• Premature mortality
Particulates including diesel exhaust	• Asthma and other acute and chronic respiratory effects
	• Premature mortality
	• Cancer
Silica dust	• Chronic lung disease (silicosis; particularly among workers)

^aBTEX: benzene, toluene, ethyl benzene, and xylenes.