Fukushima fallout leaves no effect on bulls' sperm: study
By Miwa Suzuki, AFPTOKYO -- The testes and sperm of bulls abandoned in the evacuation zone around the battered Fukushima nuclear plant were not affected by chronic exposure to radiation, a Japanese academic study has found.
October 10, 2013, 12:12 am TWN
The work provides crucial data to scientists and public policy advisers on the possible impact of the reactor meltdowns on human -- and especially reproductive -- health, two-and-a-half years after the tsunami-sparked disaster.
A team of researchers examined two bulls caught in September 2011 and January 2012 within a 20-kilometer (12-mile) radius of the plant, an area that was completely evacuated because of fears over radioactive risk.
They also looked at a male fetus from the area to help determine the effects of prolonged radiation exposure associated with the disaster, the world's worst since Chernobyl in 1986.
“Since the testis is a relatively radio-sensitive organ, we considered that radiation exposure would lead to changes in the morphology or the function of this organ,” the study noted.
Researchers from Tohoku University and other schools found concentrations of cesium-134 and cesium-137, substances of concern because of their relatively slow rates of decay, were broadly similar in all organs, but were sharply higher in muscles.
“Radioactivity concentration of cesium in the testis was about more than half of that in the skeletal muscle and the level was the same as in other organs,” the study said.
Examination of the bull's sperm showed their total number and their structure and size were normal.
“Adverse radiation-induced effects were not observed in bull testes” following exposure of up to 10 months, researchers said.
“The effect of radiation on farm animals in the evacuation zone ... provides information about the health risks of livestock and can also be extrapolated to humans,” the study said.
However, they cautioned, their particular study had a small sample size and further work was required.
The Fukushima plant hurled radioactive substances into the air, soil and sea in the days and weeks after its reactors went into meltdown when their cooling systems were swamped by the Mar. 2011 tsunami.
Tens of thousands of people fled homes and farmland, many because of compulsory orders, but some because they did not trust government information that they were safe to stay where they were.