An assessment of emissions events trends within the greater Houston area during 2003-2013

Cynthia A Luong, The University of Texas School of Public Health


The Greater Houston Area is home to one of the largest petrochemical complexes in the world, where the likelihood of emissions events are potentially higher than other areas in the nation. Emissions events are upsets (unavoidable breakdown in process or operation) or unscheduled maintenance, startup, or shutdown activities within industrial facilities that release unauthorized excess emissions into the atmosphere during a limited duration of time. These events can release large amounts of pollutants for several hours or days, potentially causing air quality to exceed standards established to protect the environment and human health. Because these events are unexpected, they can be difficult to control and warn people about to prevent exposure. Notable emissions events in the Greater Houston Area have caused unexpected explosions and fires, killing workers and triggering various health issues among communities nearby exposed to the excess chemicals released during these events. As such, it is important to understand how to minimize the occurrence of emissions events to protect people’s health. We analyzed emissions event data for the Greater Houston Area over 11 years during 2003-2013 for criteria pollutants and other selected pollutants to identify any annual and season trends and industrial classification patterns within the data. We merged several datasets obtained from the Texas Commission on Environmental Quality (TCEQ’s) emissions event database, and extracted the data for the Greater Houston Area. We evaluated 7,273 emissions events and found that total emissions event and event releases from nitrogen oxides (NOX), nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2) have declined over the 11 years. However, particulate matter (PM) event emissions have been increasing since 2009. Our seasonal analyses demonstrated that emissions events were more likely to occur during winter for several pollutants. Furthermore, we demonstrated that the majority of emissions events were generated from the chemical manufacturing and petroleum and coal product manufacturing industries. We reviewed these results against regulatory policy governing emissions events. Based on our review, we found potential gaps within the state regulations and TCEQ emissions event database explaining our findings, and provided suggestions on resolving these gaps. Our study could drive policy change that could help lower emissions events in the Greater Houston Area, potentially improving air quality and reducing the health impact from these events.

Subject Area

Environmental Health|Environmental Studies

Recommended Citation

Luong, Cynthia A, "An assessment of emissions events trends within the greater Houston area during 2003-2013" (2015). Texas Medical Center Dissertations (via ProQuest). AAI1603944.