Air toxics: sources and monitoring in Texas.

Since the late 1980s, federal legislation has required industries to publicly report their annual emissions of toxic compounds. Industry reports show the largest contributor to toxic emission levels in Texas is the massive concentration of petrochemical industries along the Gulf Coast. It is interesting to note that although Texas produces over 50% of the nation's synthetic chemicals, it discharges less than 8% of the nation's toxic emissions. However, in response to growing concerns about the effects of these toxic emissions, the Texas Natural Resource Conservation Commission (TNRCC) initiated a long-term program for monitoring toxic chemicals in the air. This article provides details of this monitoring program as well as industry-funded toxic monitoring networks in Texas. This includes information on the technology currently being used for sample collection and analysis as well as plans for implementing methods that are on the technological horizon. Finally, details of some key measurements from the state's air toxics monitoring network will be provided along with an explanation of how they impact current air quality trends in Texas.