Technician writes "The meteor that crashed in Peru caused a mystery illnesses. The cause of the illness has been found. The meteor was not toxic. The ground water it contacted contains arsenic. The resulting steam cloud is what caused the mystery illness.
"The meteorite created the gases when the object's hot surface met an underground water supply tainted with arsenic, the scientists said." There is a very good photo of the impact crater in the article. The rim of the crater is lined with people for a size comparison."