HOUSTON (AP) -- Authorities on Thursday ordered people to stay indoors for several hours after high levels of benzene were detected in the air near a petrochemical storage facility outside of Houston where a fire sent a black pillar of smoke into the air for days.
Firefighters on Wednesday extinguished the blaze at the Intercontinental Terminals Company in Deer Park, which started Sunday and destroyed several large tanks that contained gasoline and chemicals used in nail polish remover, glues and paint thinner. They continued to spray foam on the site Thursday to try to prevent flare-ups.
Authorities said Wednesday that benzene levels near the facility didn't pose a health concern, but they issued the shelter-in-place order early Thursday due to "reports of benzene or other volatile organic compounds" in Deer Park, which is about 15 miles (24 kilometers) southeast of Houston. Several school districts also canceled classes for the day due to the air quality concerns.
The order was lifted at around noon on Thursday after authorities said several readings showed the air quality had improved.
At a news conference before the order was lifted, Harris County Judge Lina Hidalgo, who is the county's top administrator, said that light winds were helping to keep the vapors from spreading more broadly.
"Outside of that immediate area we're not seeing elevated levels right now," said Hidalgo.
Dr. Umair Shah, who heads the county health agency, said there was still only a minimal public health risk, but he cautioned that the elderly, pregnant women and other vulnerable groups should try to limit their exposure.
"The most important thing is that the levels that have been detected are still not high enough for the level of concern that people may be having," he said.
The county fire marshal, Laurie Christensen, said the benzene vapors may be escaping from gaps in the foam that firefighters have been spraying to try to prevent flare-ups at the site.
The Texas National Guard's 6th civil support team was assisting at the scene Thursday. The team of about a dozen was helping to contain hazardous materials and provide other assistance to local emergency responders.
Environmental groups said residents who live near the facility have experienced various symptoms, including headaches, nausea and nose bleeds. According to the Centers for Disease Control and Prevention, long-term exposure to the highly flammable chemical causes harmful effects on the blood, including bone marrow.
The Environmental Protection Agency conducted air quality tests throughout the Houston area, both on the ground and from a small airplane, and "measured no levels of hazardous concentrations," EPA official Adam Adams said Wednesday.
Some residents who live near the facility, though, said they didn't have confidence in the air quality test results.
"I do not fully trust what they say," Kristin Crump, who lives with her husband and two children less than two miles (3.2 kilometers) from ITC, said before the order was lifted. "I do believe what is in the air is very harmful and it can have long-term affects such as cancer and things like that later down the line. I don't think it's worth risking that for me or my kids to stay there and breathe in this stuff."
Crump, 31, placed damp wash cloths over her mouth and those of her 13- and 6-year-old children Thursday as they walked to their car to go stay with family elsewhere. Her husband later joined them.
The family also left the area Tuesday after the children complained of headaches, she said. They returned the next day.
Bryan Parras, an organizer in Houston with the Sierra Club, said his environmental group had concerns not just about the air quality, but about the potential impacts to the environment and the fishing industry if chemicals from the storage facility or firefighting foam get into the Houston Ship Channel, which leads to the Gulf of Mexico.
"This issue isn't over just because the fire is out. We want systems in place that will protect our communities," Parras said Wednesday.
The EPA and the Texas Commission on Environmental Quality said Wednesday that they were waiting for test results of water samples to determine any potential impacts from the foam used to fight the fire on waterways next to the storage facility, including the Houston Ship Channel.