III. Hazard Risk Assessment and Impact Analysis
A. Hurricane
Because of its close proximity to the Caribbean Sea and the Gulf of Mexico, Houston and Galveston have a significant probability of exposure to hurricanes and tropical storms. In 1837, the Racer's Storm passed just south of Houston, raising water levels by four feet. The Great Hurricane of 1900 razed nearby Galveston but weakened to a tropical storm before it reached Houston. Hurricane Carla hit the city directly in 1961, causing major damage. In 1983, the city experienced a direct hit from Hurricane Alicia, causing one billion dollars of damage to the city. The most destructive and costly natural disaster in city history was Tropical Storm Allison of 2001, with 37 inches of rain which completely overwhelmed the area's flood control system and caused $6.05 billion of damage and incapacitated a large part of the medical center. In 2005, Hurricane Rita, a category 5 storm threatened the city, prompting mass evacuation. While an eastward change in landfall avoided damage in Greater Houston, Hurricanes Katrina and Rita caused the destruction of the urban and medical infrastructure along the Gulf Coast and produced a mass population evacuation to Houston. Tropical Storm Erin made landfall on the Texas coast in August 2007 causing many roads and neighborhoods to be flooded. METRO halted its light rail and bus services, and four deaths were reported. The Houston Fire Department reported 72 rescue operations.
Eye Care Needs, Hurricane: The most prevalent eye problems among evacuees of Hurricanes Katrina and Rita were loss of glasses, loss of needed eye medications to manage glaucoma, flood-related infection, blunt trauma, and need for re-establishing ongoing care of chronic eye disease such as cataract, glaucoma, and diabetic retinopathy in the evacuee population. There was also need for diagnosis and management of acute eye problems such as new retinal breaks, and a limited number of penetrating globe injuries and orbital fractures. Treatment of the evacuated population was hindered by lack of medical records; lack of transportation and contact information for continuity of care; and lack of funds to purchase glasses and medication. It is also anticipated that transportation of evacuees and aid workers will be disrupted by the storm.
B. Flooding
Flooding is a major threat in Houston, particularly in fall and winter. The marshland around Houston easily floods due to extensive building and the low land elevation. Many of the bayous in the city are close to flat land, so in the event of an overflow, many homes and business are vulnerable. Many of the city's older suburbs have outdated sewer systems, which provide inadequate drainage in the event of flash floods.
Eye Care Needs, Flooding: It is anticipated that flooding would cause loss of glasses, contact lenses, medications, and medical records. Infection exposure to flood-contaminated water may occur, as well as blunt or penetrating eye and orbital trauma. Patients may miss scheduled eye care appointments. Road access for evacuation and transport of eye care workers may be limited. The use of the Eye Vans may be limited by flooded roads.
C. Tornados
Unlike much of Texas, Houston is not considered a part of Tornado Alley, but smaller tornadoes are common during severe weather. They are most likely to be found along frontal boundaries of air mass during the spring months. The most common tornadoes in Houston measure F1 on the Fujita scale, which can destroy or damage one or two buildings. The strongest recorded tornado in Houston history was an F4 on November 21, 1992.
D. Fire, Explosion, Chemical Spills, Terrorist Attack
Beyond the single family dwelling or apartment fire, Houston is at risk from fires and explosions from one of the many oil refineries or chemical plants located in Houston and the surrounding areas. Relatively high population density and the presence of major industrial complexes present the possibility of Houston becoming a terrorist target. The Houston Metropolitan Statistical Area has nearly 40.5% of the nation's base petrochemical capacity.
Oil Refineries
Baytown Refinery (Exxon Mobil)
Deer Park Refinery (Shell Oil)
(Spring)Erickson Refining Corporation (Renexus International Corp)
Houston Refinery (Lyondell)
Houston Refinery (Valero)
Pasadena Refinery (Crown Central Petroleum)
Texas City Refinery (BP)
Texas City Refinery (Marathon Petroleum Company)
Texas City Refinery (Valero)
Chemical Plants
The Houston area is also the home to 412 chemical plants with approximately
37,500 employees:
Air Liquide USA LLC
BASF Corporation
Bayer Corporation
Celanese Clear Lake
Chevron Phillips Chemical
Equistar Chemical
ExxonMobil Chemical Company
Huntsman Corporation
Innovene
Lyondell Chemical Company
OxyVinyls, LP
Resolution Performance Products LLC
Rohm and Haas Texas Inc.
Shell Chemical, LP
Solutia, Inc.
Solvay America, Inc.
The Dow Chemical Co.
The Goodyear Tire & Rubber Company
The Lubrizol Corporation
Total Petrochemicals USA, Inc.
Examples of Explosions, Texas
Texas City Refinery Blast, 1947: The Texas City Disaster is generally considered the worst industrial accident in American history. On April 16, 1947, detonation of approximately 2,300 tons of ammonium nitrate on board the SS Grandcamp in the port at Texas City killed 581 people and injured over 5,000. More than 500 homes were destroyed, leaving 2,000 homeless. The seaport was destroyed and many businesses were burned. Burning wreckage ignited dozens of oil storage and chemical tanks at several chemical plants including Monsanto and Union Carbide.
Texas City British Petroleum Refinery Blast, 2005: On March 23, 2005, a massive explosion and fire at the third largest US petroleum refinery resulted in 14 deaths and more than 100 injuries, including eye injuries and burns.
Examples of Terrorist Attacks, USA
While Houston has not experienced a terrorist attack, there are many potential targets, including NASA, petrochemical, manufacturing, business, entertainment venues and other social gathering sites. Experiences reported from other cities may be extrapolated for eye care disaster planning.
9-11 New York City Terrorist Attack: Hundreds of survivors of the 9/11 attack and emergency response personnel suffered eye injuries from falling debris, smoke, dust and direct trauma. Within 12 hours of the first building crash, emergency care was sought by 511 (71%) of the 723 survivors. Rescue workers accounted for 59 (51%) of 115 survivors presenting to emergency departments during the first 24--48 hours after the attack. Among 790 survivors with injuries, 386 (49%) had inhalation injuries and 204 (26%) had ocular injuries. A total of 443 (56%) survivors were treated for inhalation injury, ocular injury, or a combination of both without additional injuries. Among survivors hospitalized with injuries, 52 (37%) sustained inhalation injuries and 27 (19%) sustained burns. Most survivors with fractures (59%), burns (69%), closed head injuries (57%), or crush injuries (75%) were hospitalized for additional treatment. The injury pattern among rescue workers differed from the pattern among other survivors. A significantly higher percentage of rescue workers sustained ocular injuries (39% versus 19%), and a significantly lower percentage of rescue workers sustained burns.
Oklahoma City Bombing: Eye injuries occurred in concert with severe neurological and orthopedic injury, requiring coordination and triage of eye treatment with general trauma care. Open globe was the most serious type of eye injury reported.
Eye Care Needs: Explosion, Fire, and Airborne Chemical/Toxin Release
Smoke, airborne chemical irritants (such as chlorine gas), acid or alkali exposure, burns, blunt or penetrating trauma, and airborne debris can affect both disaster victims and the health of emergency responders. Chemical injuries of the eye require immediate treatment, with delay in treatment resulting in potential blindness. Airborne irritants may rapidly affect a large segment of the population distant from the primary disaster site, which will require victims to travel to emergency centers. Treatment of both victims and first responder healthcare workers must be planned. Victims often sustain multiple injuries, including orthopedic, vascular, and neurological injury. Eye care requires triage with other medical and surgical specialists, and the patient may be medically unstable for transport.
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