In the wake of the accident at Japan's Fukushima nuclear power plant, radioactive isotopes were blown over Japan and its coastal waters. Fears that agricultural land would be contaminated spurred research into whether Japanese vegetables and meat were safe to eat. An early study suggested that harvests contained levels of radiation well under the safety limit for human consumption. Now, an international team of researchers suggests this result deserves a second look.
Caesium-137 lingers in the environment for decades, and so is more of a concern than other radioactive elements released in the cloud of steam when the reactors' cooling systems failed, leading to explosions. The team found that the area of eastern Fukushima had levels of the radioactive element that exceeded official government limits for arable land. The researchers estimate that caesium-137 levels close to the nuclear plant were eight times the safety limit, while neighbouring regions were just under this limit. The study showed that most of Japan was well below the safety limit. Relatively low contamination levels in western Japan could be explained by mountain ranges sheltering those regions from the dispersal of radioactive material.
Food production in the most contaminated regions is likely to be "severely impaired", and Fukishima's neighbouring regions, such as Iwate, Miyagi, Yamagata, Niigata, Tochigi, Ibaraki, and Chiba are likely to also be affected. They urge the Japanese government to carry out a more thorough assessment of radioactive contamination across Japan before considering future decontamination plans. A second study found similarly high caesium-137 levels across the Fukishima prefecture, and its neighbouring regions.
Once in soil, caesium will become bound to mineral components, which limits its uptake into plants. However, this process depends on the soil type. "Caesium stays mobile for longer in organic soils, hence why England and Wales still have some post-Chernobyl restrictions in upland areas." Ploughing, and some fertilisers can help farmers reduce plants' uptake of the dangerous elements, and binding agents can be added to animal feed to reduce their uptake from the gut.
and the blind can see.**
Mark Twain
LARGEST QUAKES -
This morning -
None 5.0 or higher.
Yesterday -
11/14/11 -
5.2 EASTERN TURKEY
6.3 MOLUCCA SEA
EASTERN TURKEY has been struck by a strong earthquake for the third time in a month.
VOLCANOES -
Congo's Nyamuragira VOLCANO ERUPTION IS THE BIGGEST IN A CENTURY - The Nyamuragira volcano, in a remote area of the Democratic Republic of Congo's Virunga national park, is producing lava fountains reaching up to 400 metres. Park officials say the eruption does not pose any immediate threat to the local population. The volcano began erupting Nov. 6 and has several lava fountains spewing up to 650 feet (200 meters) into the air. A Monday statement from the park says rivers of incandescent lava are flowing slowly north. (video)
HAWAII - Lava lake sinks, spurring quakes. Eight small earthquakes rocked Kilauea Volcano after the lava lake at the summit caldera dropped in elevation Sunday. But the seismic shaking was actually below normal levels. The strongest quake was a magnitude 3.3.
TROPICAL STORMS -
No current tropical storms.
PHILIPPINES - A low-pressure area that state weather forecasters consider a potential cyclone threatened to trigger flash floods and landslides in parts of Luzon and the Visayas as it moved closer to Leyte province before noon Tuesday.
EXTREME HEAT & DROUGHT / WILDFIRES / CLIMATE CHANGE -
UK trees' fruit ripening '18 days earlier' - Britain's native trees are producing ripe fruit, on average, 18 days earlier than a decade ago, probably as a result of climatic shifts, a study reveals. It shows that acorns are ripening 13 days earlier, while rowan berries are ready to eat nearly a month earlier. Experts warn that one consequence could be that animals' food reserves would become depleted earlier in the winter.
"Some of the changes are really quite big and quite surprising. This caused me to go back and look at the data again to make sure it was valid because even I did not believe it initially." Nature's Calendar, formerly known as the UK Phenology Network, was established in 1998 to collect spring-time information. "But the gap in data was in the autumn So, since about 2000, the scheme has also been collecting data on things such as fruit ripening dates, leaf colour change and fall dates, and the last birds seen. We now have 10 years worth of data that can look at and identify changes. In terms of looking at the fruit-ripening dates and the thing that came out was that they all seem to have steadily advanced over the past decade."
It is still uncertain what the ecological consequences of the advances would mean. "Anything that changes out of synchronicity is likely to cause disruption. What the actual consequences will be is slightly harder to work out. In this particular case, if all of this fruit is ripe earlier, and if all the mammals and birds are eating it earlier, what are they going to be feeding on during the rest of the winter? In terms of feeding birds, you have big flocks of thrushes coming down from Scandinavia and feeding on berry crops in Britain, and they tend to do that after they have exhausted the supply of berries in Scandinavia. You get these periods when hedges are being stripped bare, but the birds are going to have to do that earlier because that is when the fruit is ripe."
Although phenological records have shown that the arrival of spring is also advancing, it was "still a bit of a mystery" why the ripe-fruit dates had advanced over the past decade. "There is a very strong correlation between these ripening dates and April temperatures, and that might be a result of flowering dates - it might just be that warmer springs result in earlier flowering dates, and subsequently result in earlier ripening. But it might be a result of more sunshine; longer, warmer summers and therefore earlier ripening. So the exact mechanisms really are still a bit of a mystery. We know it is happening, but we are uncertain why."
