1 million pounds of air pollutants released after storm,

Chemical, oil firms’ emissions exceed permitted levels.

Oil refineries and chemical plants across the Texas Gulf Coast released more than 1 million pounds of dangerous air pollutants in the week after Harvey struck, according to public regulatory filings aggregated by the Center for Biological Diversity.

While attention has zeroed in on the crisis at the Arkema chemical plant in Crosby, Texas, other facilities — oil refineries, chemical plants and shale drilling sites — have been reporting flaring, leaks and chemical discharges triggered by Harvey.

Emissions have already exceeded permitted levels, after floating rooftops sank on oil storage tanks, chemical storage tanks overflowed with rainwater, and broken valves and shutdown procedures triggered flaring at refineries.

The chemicals released in the week after Harvey made landfall include benzene, 1,3-butadiene, hexane, hydrogen sulfide, sulfur dioxide, toluene and xylene.

All seven chemicals are toxic air pollutants documented to harm human health; several cause cancer. Other emissions would bring the total to more than 5 million pounds, the Center for Biological Diversity said.

“Our general concern is the fact that these are relatively unseen environmental threats that don’t normally get recognized,” said Elena Craft, a toxicologist at the Environmental Defense Fund.

Further damage and emissions across the region could be uncovered in the coming weeks as flood waters recede, and chemical safety experts warned that restarting plants could carry as many dangers as the shutdowns.

“We are not out of the woods yet, not the entire industry,” said M. Sam Mannan, a professor of chemical engineering at Texas A&M University and director of an institute that studies safety procedures in chemical factories.

In addition, winding rivers overflowed and washed over some of the waste pits and drilling pads at shale gas and shale oil drilling sites in the Eagle Ford play in central Texas, according to satellite imagery collected by Sky Truth, a nonprofit group. The extent of the damage was not clear.