After a huge earthquake caused severe damage to the Fukushima 1 Nuclear Power Plant in 2011, Japanese plant scientists have been working to determine the impact of radioactive contamination on wild and cultivated plants.
In a special issue of Springer’s Journal of Plant Research, these experts examine the potential adverse effects of radioactivity on nature and society.
Of particular interest is an article focusing on the efforts of a research group led by Yoshihiro Shiraiwa of the University of Tsukuba. Seventeen microalgae, aquatic plants and algae that are able to efficiently remove radioactive cesium, iodine and strontium from the environment were identified. The findings add to existing bioremedial options which could help to decrease radiopollution in the Fukushima area.
Such measures are of utmost importance, because a large quantity of radioactivity has been released into the atmosphere. At the same time, the volume of radio-polluted water is increasing daily because of the continuous injection of cool water and the incurrent of underground water into the still defective reactor.
Because the plant strains identified are easy to harvest and dry, they could be potentially useful to recover radioactive cesium from a huge volume of radio-polluted water if cesium is dissolved in water.
Notably, a eustigmatophycean unicellular algal strain, nak 9, was found to be the most efficient in eliminating up to 90 percent of cesium without any special treatment needed. The researchers suspect the alga is able to do this by accumulating cesium on its cell surface. Potentially, nak 9 could be used to decontaminate highly radio-polluted water stored in Fukushima’s nuclear reactor building, or to reduce the volume of the radio-polluted water. The researchers noted, however, that further studies are needed on the mass cultivation and efficient coagulation and sedimentation of these algal strains before their findings can be put into practice.
“Biological concentration of radionuclides is an essential technology for bioremediation of radio-polluted soils and water,” said lead researcher Yoshihiro Shiraiwa. “Therefore our results provide an important strategy for decreasing radiopollution in the Fukushima area.”
Other articles in the special issue discuss, for example, radioactive pollution and radionuclides in wild plants, soil-to-plant transfer factors, and decontamination from farmlands by plants. The Journal of Plant Research is the official journal of the Botanical Society of Japan.
Reference:
Fukuda, S., Shiraiwa, Y., et al. (2013). Global searches for microalgae and aquatic plants that can eliminate radioactive cesium, iodine and strontium from the radio-polluted aquatic environment: a bioremediation strategy. Journal of Plant Research. DOI 10.1007/s10265-013-0596-9
Adapted from a news release by Springer
Fukushima cowboy fights Japanese Government orders to kill contaminated cattle
4 Jan 2014 Australian Broadcasting Corporation
The Fukushima cowboy’s property is just 14 kilometres from the shattered reactors at the Fukushima nuclear plant and his cattle have already been found to be contaminated with elevated levels of radioactive caesium.
Some of his cattle have even developed white spots.
The Fukushima cowboy is resisting Japanese Government attempts to have his herd slaughtered, saying the beasts should be studied to better understand the health effects of long-term radiation exposure.
Instead of slaughtering his cattle, his cattle should be used to study the long-term effects of radiation. Killing his cattle is destroying evidence.
Obviously there needs to be a study to identify the maximum radiation these algae can tolerate. Alpha and beta emitters are relatively harmless as external radiation sources. But are very damaging when ingested. The water at Fukushima is very contaminated and may have to be diluted to allow algae to grow. It would also be important in assessing the effect on the ocean food chain. Algae are the base for ocean ecosystems. The collapse of herring and anchovy stocks in north Pacific are likely related to algae exposed to too much radiation. But there is little data to go by beyond the symptoms noted.
Also of interest is that potassium poor soils result in cesium uptake by plants, filling in for the missing potassium. Bikini Atoll coconuts are classic example. The bio concentration by plants is another way of decontaminating soil and water. Domestic crop uptake of cesium cesium can be reduced by providing adequate potassium through fertilizers.