Medical isotopes the likely cause of radiation in Ottawa waste
The sludge that was recently quarantined near the Canadian border tested positive for radiation because of the presence of a medical isotope, according to the Canadian Nuclear Safety Commission.
The biosolids, which were being transported from the Robert O. Pickard Environmental Centre in Ottawa for disposal in New York State, were turned away at the border last Thursday because the truckloads had registered low levels of radiation.
Since then, the sludge has been stored at Third High Farms, a waste storage facility in Iroquois, Ont., and consultants have been called in to investigate.
The culprit appears to be the isotope iodine 131.
The Canadian Nuclear Safety Commission (CNSC) has said the isotope, which is used for medical procedures, is most likely the source of the radiation detected in the sludge.
The commission also said that the presence of medical isotopes in sludge is not unusual.
"Many hospitals use radio iodine in nuclear medicine applications," said Patsy Thompson, from the CNSC. "Hospitals have a licence … to have those radio isotopes and they have protocols on how to use them."
She said that radioactivity is detected about twice a month when it comes to these types of shipments.
Hospitals will be reminded of the procedures to follow when dealing with medical isotopes, Thompson said.
"We can build radiation detectors that are extremely sensitive," said Anthony Walker, a professor at the University of Ontario Institute of Technology, in Oshawa.
Isotopes can end up in sewers because both hospitals and universities use them, he said. Those who receive treatment with medical isotopes can help them enter the sewage system by simply going to the bathroom.
"The fact that [the detectors] are triggered doesn't mean anything of importance," he said. "It's just an indicator of their overall sensitivity."
Canada's Natural Resources Minister Lisa Raitt talked about the presence of the isotopes Wednesday in question period.
She said that the CNSC had assured her that the radiation was linked to medical isotopes and had nothing to do with a Dec. 5 leak at the Chalk River nuclear plant, which is 185 kilometres northwest of Ottawa.
Meanwhile, the City of Ottawa said every shipment coming out of the Robert O. Pickard Environmental Centre is being tested.
The city said that it still hasn't been able to determine where the isotopes came from, but they're continuing their investigation.