Hurricane Harvey: Texas scientists fear dangerous chemicals will leak into Houston floodwaters

Environmental Protection Agency to begin sampling sites 'as soon as possible'

A helicopter hovers above the Houston skyline as sunlight breaks through storm clouds from Tropical Storm Harvey in Texas (Adrees Latif/Reuters)

Texas scientists fear dangerous chemicals may leak from toxic repository sites into floodwaters created by tropical storm Harvey.

Harris County, where the storm-stricken Houston lies, hosts about a dozen so-called Superfund sites, where the US Environmental Protection Agency (EPA) has removed chemical stores.

The substances include chlorinated hydrocarbons and ethylbenzene, the Washington Post reported. "Yesterday as these large retention ponds filled up, 8ft deep in places, kids were swimming in them, and that’s not good," A&M University scientist Wes Highfield told the paper.

Mr Highfield attempted to sample the water at a number of sites but was forced to turn back as waves lapped at the floorboards of his car. His concerns are shared by his scientific colleagues, the Post said.

The EPA will begin sampling the floodwaters as soon as possible, said spokeswoman Liz Bowman. EPA teams will also visit water and sewage plants to offer help, she said. The agency helped secure Superfund pollution cleanup sites last week ahead of the storm and is continuing to check with site operators.

Floodwater can be dangerous for people with open wounds, particularly if they have other health conditions. After Hurricane Katrina, five people with infected wounds died and health officials believe that exposure to brackish floodwater contributed to the deaths.

The muddy floodwaters now soaking through drywall, carpeting, mattresses and furniture in Houston will pose a massive clean-up challenge with potential public health consequences.

It is not known yet what kinds or how much sewage, chemicals and waterborne germs are mixed in the water. For now, health officials are more concerned about drownings, carbon monoxide poisoning from generators and hygiene at shelters.

In the months and years to come, their worries will turn to the effects of trauma from Hurricane Harvey on mental health.

At a shelter set up inside Houston's George R Brown Convention Center, Dr David Persse was building a clinic of doctors and nurses and trying to prevent the spread of viruses or having to send people to hospitals already stretched thin.

"This is rapidly evolving," said Dr Persse, Houston Director of Emergency Medical Services. "I always worry in these large congregations of people about viral outbreaks that cause nausea, vomiting and diarrhoea. And we are just getting started."

Additional reporting by agencies