Radioactive Particles from Fukushima Disaster Discovered in Napa Valley Wines
NAPA, CALIFORNIA — July 25, 2018
Although the radioactive level has doubled in wines, it is still far below the threshold where it would be harmful for human consumption.
The study was conducted by a team of the U.S. and French researchers, whose aim was to find evidence of the Fukushima disaster in the Bay Area in bottles of Napa Valley wine.
They tested bottles of two well-known types of California wines — rosé and Cabernet Sauvignon — that were made from 2009 and 2012.
"In January 2017, we came across a series of Californian wines from vintage 2009 to 2012. The Fukushima incident, which took place on March 11, 2011, resulted in a radioactive cloud that has crossed the Pacific Ocean to reach the west coast of the United States. And in Northern California, there is the Napa Valley. The idea was then to see if, as is the case in Europe following the Chernobyl accident, we could detect a variation in the cesium-137 level in these wines," they said in the report.
The implementation of the process required a new framework which took a few years to elaborate. Researchers looked for the radioactive particle cesium-137 in vintages from 2009 to 2012, expecting to see an increase after 2011, when the meltdown happened.
Cesium-137, or radiocaesium, is a radioactive isotope of cesium which is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. It is among the most problematic of the short-to-medium-lifespan fission products because it easily moves and spreads in nature due to the high water solubility of cesium's most common chemical compounds, which are salts. It is well known that cesium was found in higher quantities in French wines made after the Chernobyl power plant disaster of 1986.
As for Napa wines, the researchers found that after a vaporizing Napa wine at 500 degrees Celsius, they were able to discover tiny amounts of the radioactive isotope amid the residual ashes.
The final result is equal to about double the amount that was present in wines made before the meltdown. The higher levels of the particle were found in red wines than found in rosés.
"As was the case in France's white or rosé wine, Californian rosé bottles lead to significantly lower values than red wines. It seems there is an increase in activity in 2011 by a factor of 2, " said in a statement.
Researchers noted that while the elevated levels of the radioactive particle could be seen in Napa wines for decades to come, they remain well below the threshold for causing human harm.
The technique used for the study was pioneered by French pharmacologist Philippe Hubert, who originally devised the procedure to combat wine fraud. Wine fraud is the process of labeling a younger vintage as an older one in order to inflate the price.
By scanning the radioactive signature of the wine, Hubert could determine, if it was made before nuclear testing began in the 1960s — in which case, the wine would have no detectable Cesium-137 — or if it was made shortly after the Chernobyl disaster, in which case the cesium-137 levels would be elevated.
In March 2011, a 9.0-magnitude earthquake and a tsunami hit Japan. The natural disasters damaged three Fukushima Daiichi Nuclear Power Plant reactors, and radioactive materials were released into the air.
Almost 16,000 people died, and 2,500 went missing. More than 100,000 were evacuated from the area.