October 29, 2014 — Scientists studying kelp beds along the coast of Southern California have detected "pervasive" amounts of a radioactive isotope known as Iodine-131 in the waters off the ports of Los Angeles and Long Beach.
Steven Manley, a marine biologist with California State University-Long Beach, says the most probable source of the contamination is the Terminal Island Water Reclamation Plant.
Iodine-131 is regularly used to diagnose and treat cancers of the thyroid gland. The material is later expelled, and it enters sewer systems and water treatment facilities.
The isotope is also used as a radioactive tracer in the hydraulic fracturing process. But Manley said the most likely source of the contamination in the ports was wastewater from medical facilities.
I-131 is not naturally occurring, and could harm fish and other marine animals if it is absorbed in large amounts.
The discovery of the iodine isotope was made as part of a project called Kelp Watch 2014, which aims to determine if nuclear material from the Fukushima disaster has reached the West Coast of North America.
Researchers across the region have been sampling kelp because the ubiquitous rubbery sea plant soaks up radioactive material like a sponge. So far no Fukushima-related material has been found, Manley said.
However, during a survey of kelp in the two ports, Iodine-131 turned up in what Manley called "low but significant" concentrations.
His team took further samples near the ports to home in on the contamination.
"Everyone of those samples has I-131 present in kelp," Manley noted.