The spiked reading is linked to the badly damaged Fukushima-Daiichi Nuclear Power Plant in Japan that was rocked March 11 by a devastating 9.0 earthquake.
The earthquake and tsunami severely impacted much of the South Pacific. Since the initial quake, which has been followed by additional aftershocks of varying magnitudes, leaking radiation has drifted in the air across the Pacific Ocean and into the U.S. jet stream.
Although the Chattanooga area water samples detected traces of iodine-131 measured at 1.6 picocuries per liter, it is considered well within safe limits, according to EPA sources. A reading of 3.0 is the maximum allowable for drinking water.
On March 28, EPA conducted water samples from across the nation in response to the Japanese disaster. Of the 69 drinking water samples taken, 42 showed no sign of iodine-131, according to the federal agency’s nationwide radiation monitoring system called RadNet.
Whether the Cleveland area’s drinking water supply includes any traces of iodine-131 is unknown because the national sampling initiative is being led by EPA, according to Craig Mullinax, manager of Cleveland Utilities’ Water Division.
“The U.S. Environmental Protection Agency is taking the lead to determine the impact of the radiation which will drift to and across the U.S. through time,” Mullinax said late Thursday. “U.S. EPA has apparently taken some samples in our area.”
Mullinax said he became aware of the EPA samples earlier in the day and pointed to previous reports that the iodine-131 is below the EPA’s maximum allowable limits.
“Cleveland Utilities does not sample for iodine-131 isotopes in the drinking water,” Mullinax said. “Current drinking water sampling guidelines from the U.S. EPA and the Tennessee Department of Environment and Conservation do not require water utilities to collect and analyze for this radioactive isotope.”
According to prior reports since the initial mid-March nuclear disaster in Japan, iodine-131 is produced a couple of ways; one, through the fission of uranium atoms in nuclear power plants, and also in the detonation of nuclear weapons.
The most recognized health hazard posed by iodine-131 is that it is linked to the development of thyroid cancer.
As a preventive measure, Mullinax said Cleveland Utilities has contacted the TDEC office in Chattanooga, but pointed out he was advised the state water quality control agency has not been directed by EPA to begin any random drinking water samplings of its own.
“Cleveland Utilities does not have the equipment to analyze water samples for these types of radioactive isotopes,” Mullinax said.
He pointed to the importance of the short life span of the radioactive isotope.
“The half-life for iodine-131 is eight days,” Mullinax said. “This would imply that samples would need to be analyzed almost immediately after being collected and/or stored in special containers to prevent this rapid decay rendering the sample unusable.”
Mullinax said CU will remain in contact with TDEC.
“They (TDEC) have not received any directive from the U.S. EPA to conduct sampling for iodine-131 or to require Cleveland Utilities to sample,” he stressed.