The officers were taken to the hospital Tuesday night and by Wednesday morning they had all been released.
Crinoid fossils from 350 million years ago have been found to contain intact biological chemicals.
The bug was recently found on the ISU campus, but university officials say they have a plan combat the ash borer.
Administering progesterone may help reduce swelling and improve memory in people who have suffered traumatic brain injuries.
Four people were hospitalized Thursday, but tests for several toxic chemicals that could have been the cause came back negative.
Butyl-benzyl-phthalate (BBP) is common in everything from vinyl flooring to fake leather.
About 1,000 gallons of the highly corrosive acid leaked from the pipe and came dangerously close to a storm water drain.
The Newport location housed the nerve agent VX, known as one of the most toxic chemical warfare agents.
Environment America says Indiana releases 27 million pounds of toxic chemicals into its waterways in 2010.
"It doesn't take them a lot of time," says one state health representative, "to get from eggs to hatching."