Environment

Mutations, DNA damage seen in Fukushima forests

The March 11, 2011 magnitude 9.0 undersea earthquake off Japan's northeastern coast sparked a massive tsunami that swamped cooling systems and triggered reactor meltdowns at the Fukushima Daiichi nuclear plant.

Radiation spread over a wide area and forced tens of thousands of people from their homes -- many of whom will likely never return -- in the worst nuclear accident since Chernobyl in 1986.

As the fifth anniversary of the disaster approaches, Greenpeace said signs of mutations in trees and DNA-damaged worms were beginning to appear, while "vast stocks of radiation" mean that forests cannot be decontaminated.

In a report, Greenpeace cited "apparent increases in growth mutations of fir trees... heritable mutations in pale blue grass butterfly populations" as well as "DNA-damaged worms in highly contaminated areas", it said.

The report came as the government intends to lift many evacuation orders in villages around the Fukushima plant by March 2017, if its massive decontamination effort progresses as it hopes.

For now, only residential areas are being cleaned in the short-term, and the worst-hit parts of the countryside are being omitted, a recommendation made by the International Atomic Energy Agency.

But such selective efforts will confine returnees to a relatively small area of their old hometowns, while the strategy could lead to re-contamination as woodlands will act as a radiation reservoir, with pollutants washed out by rains, Greenpeace warned.

Environment

Radiation from Fukushima nuclear disaster spreads off U.S. shores

Radiation from Japan's 2011 nuclear disaster has spread off North American shores and contamination is increasing at previously identified sites, although levels are still too low to threaten human or ocean life, scientists said on Thursday.

Tests of hundreds of samples of Pacific Ocean water confirmed that Japan's Fukushima nuclear power plant continues to leak radioactive isotopes more than four years after its meltdown, said Ken Buesseler, marine radiochemist with the Woods Hole Oceanographic Institution.

Trace amounts of cesium-134 have been detected within several hundred miles (km) of the Oregon, Washington and California coasts in recent months, as well as offshore from Canada's Vancouver Island.

Another isotope, cesium-137, a radioactive legacy of nuclear weapons tests conducted from the 1950s through the 1970s, was found at low levels in nearly every seawater sample tested by Woods Hole, a nonprofit research institution.

"Despite the fact that the levels of contamination off our shores remain well below government-established safety limits for human health or to marine life, the changing values underscore the need to more closely monitor contamination levels across the Pacific," Buesseler said in an email.

Environment

Intense Radiation in Fish Caught Near Japan Nuclear Facility

A fish contaminated in waters off Japan’s crippled Fukushima Daiichi nuclear power plant was found to have levels of radiation over 2,500 times the legal safe limit for seafood. Scientists from plant operator Tokyo Electric Power (TEPCO) say the murasoi fish had 10 times higher radiation than that measured last August in a scorpion fish caught near the crippled reactor complex.

TEPCO says massive nets are being installed about 15 miles offshore to try to prevent contaminated fish from migrating.

The plant was pummeled by a titanic tsunami in 2011 that was generated by a massive undersea earthquake. It resulted in reactor meltdowns that caused radioactive contamination that will linger for decades to come.

Fishing around Fukushima has since been halted and the government has also banned farming, dairy and livestock production indefinitely.

Top: Murasoi fish captured by TEPCO appeared to have no mutations despite carrying 2,500 times the safe level of radiation. Bottom: Cleanup crews removing contaminated material from the crippled Fukushima Daiichi nuclear power plant.