Testing our waters for radiation
FEARS OF FUKUSHIMA
have scientists along the west coast searching for radioactivity from the 2011 nuclear meltdown.
Citizen scientists along the coast are preparing to take samples of sea water this spring to determine how much low- level radioactivity from the 2011 Fukushima nuclear disaster in Japan has crossed the Pacific Ocean.
All along the Pacific coast of North America and as far south as Costa Rica, people with little or no scientific background have volunteered to raise money for the program and collect the sea water samples needed to test for radiation.
The crowdsourcing, citizen- scientist program is the idea of Ken Buesseler, a research scientist at Woods Hole Oceanographic Institution, the world’s biggest private- non- profit oceanographic agency. Buesseler began his career studying the spread of radioactivity from Chernobyl in the Black Sea and has been working with Japanese scientists since mid- 2011 to understand the spread of radiation from Fukushima across the Pacific Ocean.
Buesseler said in a phone interview from Japan that he was motivated by public concern over radiation from Fukushima and his frustration at the
You can be antinuclear and you don’t have to scare people about Fukushima” KEN BUESSELER RESEARCH SCIENTIST AT WOODS HOLE OCEANOGRAPHIC INSTITUTION
reluctance of the U. S. government to fund a program to measure radiation that is expected to arrive on the West Coast this spring.
He said because the radiation levels are expected to be low, federal U. S. officials didn’t consider it a priority. As well, radiation in the oceans fell into the bureaucratic cracks: the National Oceanic and Atmospheric Administration’s responsibility extends to oceans but not radiation; the Department of Energy is responsible for monitoring radiation but not in the ocean.
“No one wanted to take responsibility,” he said.
To educate the public about Fukushima, he set up the website www. OurRadioactiveOcean.org. In November, the number of people going to his FAQ page, as he puts it, started to “go through the roof.”
It was about the same time that a YouTube video was posted claiming to have found an increase in radioactivity on a beach near San Francisco. ( The radioactivity proved not to be connected to Fukushima.)
Buesseler said he believes there is a lot of public concern over radiation because people can’t touch, smell or feel it, yet they know it causes cancer. Some groups, he said, are taking advantage of that fear to trigger false alarms.
“You can be anti- nuclear and you don’t have to scare people about Fukushima,” he said. “There have been some really awful scaremongering — showing lesions in fish and things that have never been shown to be due to Fukushima. A lot of false and misleading claims, I think, are out there.”
Buesseler said neither he nor Woods Hole has involved non- scientists in a project like this before. Already two months into it, he thinks it’s a good way to engage and educate the public. It doesn’t replace basic research, he said, but it does add to it.
So far, 22 sites along the West Coast of North America and Central America along with Hawaii have been crowd funded; another 27 are in the process of raising enough money to take at least one sample.
In B. C., the cost of taking a sample, including shipping and testing, is $ 600. So far, two B. C. sites have been fully funded: one at the Bamfield Marine Sciences Centre on the west coast of Vancouver Island and the other on Haida Gwaii. Money is needed to fund several others.
Before a site is listed on the Woods Hole website, volunteers are asked to kick- start the campaign with $ 100 to prove their commitment, said Colleen Durkin, the post- doctoral fellow in charge of the program.
Once enough money has been raised, Durkin mails the volunteer a sampling kit. Inside, along with an instruction sheet, is a 19- litre plastic container with a temperature gauge. Citizen scientists are asked to fill the container with sea water, record the time, date and location, and send it to Woods Hole.
At some sites, the entire amount has been paid for by one person; at others, it’s more of a community effort with many small donations of $ 20. Samples are being taken directly from docks and from boats offshore. A California twist is being added at Santa Cruz where samples are being collected by surfboard.
The water will be tested for cesium- 134 and cesium- 137, both of which were released at Fukushima. Cesium- 134 has a half- life of two years, so that any detectable levels in ocean water will be considered to have originated at Fukushima.
Cesium- 137 has a much longer half- life, and there is already a background level of cesium- 137 in the Pacific Ocean left over from the atmospheric nuclear weapons tests done by the U. S., French and British in the 1950s and 1960s.
If the sea water tests produce readings above the background level, then that will be considered the amount produced by Fukushima.
Ocean currents
Buesseler said Fukushima produced two radiation plumes. The first went into the atmosphere in a northeasterly direction where it travelled around the world within the first five to 10 days. Woods Hole at Cape Cod on the East Coast measured very, very low levels of cesium and short- lived iodine- 131 10 days after the earthquake, tsunami and meltdown at Fukushima.
The next plume was through the ocean in a more easterly direction. That’s what is expected to arrive this spring. It’s taken three years, Buesseler said, because that’s how long it takes for ocean currents to mix sea water on one side of the Pacific with the other side.
He compared the dispersal of radiation to coloured dye mixing with water. As the currents move the water, especially the Kuroshio that crosses the Pacific, water- soluble cesium mixes with sea water and dilutes and disperses over time and distance.
“It just takes that long for ocean currents to get across,” he said.
Reports indicate low- level radiation from Fukushima is getting closer to the West Coast. Samples taken in June 2013 by John Smith from the Canadian government’s Bedford Institute of Oceanography in Dartmouth, along with scientists from the Institute of Ocean Sciences in Sidney, found a tiny amount — 0.9 becquerels — of cesium- 134 at a location in the Pacific about 2,000 km west of Vancouver. ( A becquerel, or Bq, measures the rate at which radioactive material emits radiation and decays; one Bq = one atom disintegrating per second.)
Four samples taken in January in California and Washington as part of the citizen science initiative showed no detectable Fukushima cesium.
Standards
The testing at Woods Hole can measure as little as 0.1 or 0.2 becquerels of cesium- 134 and cesium- 137 in a cubic metre of sea water. In the U. S., the drinking water standard is 7,400 becquerels of cesium per cubic metre; in Canada, the standard is 10,000.
Buesseler said the predicted increase in levels of cesium is anywhere from one extra becquerel to 20 or 30. While he agreed that’s a big range, the upper limit is still far below the accepted levels for drinking water.
“I would not be concerned swimming in those waters or eating seafood,” he said. “I personally don’t have concerns about human health and safety from what the levels are predicted to be.
“But without measurement, we won’t be able to confirm that level of radioactivity. Since there is debate about doses, even at the lowest levels, it behooves us to get those numbers.”
Cesium levels will increase gradually over the next two or three years as the radioactive plume moves east toward the West Coast.
Unlike mercury or PCBs, cesium- 134 and cesium- 137 don’t accumulate in fish and animals and become more concentrated up the food chain. Fish near Fukushima, he said, are still being contaminated because of leaks but as they move across the Pacific, they lose cesium because it’s watersoluble. There is some concern, however, on the impact it could have on orcas on the coast because of the large amount of food they consume daily.
Buesseler is concerned about one recent development at Fukushima. Initially in 2011, the amount of strontium- 90 was a fiftieth that of cesium. But recently that changed to a one- to- one relationship following a leak from one of the 1,000 above- ground storage tanks used to store water that was contaminated when it was pumped directly into the damaged reactors to prevent a meltdown.
Strontium- 90 is a bone- seeking isotope that replaces calcium in fish bones and could become a potential hazard among people who eat small fish bones. It stays in the environment for several years.
Most of the storage tanks are made out of welded steel. The ones that are susceptible to leaks of radioactive water are believed to be 350 improvised, temporary tanks made from steel with seams sealed with plastic materials. Those heavily contaminated tanks, he said, need to be cleaned up before another earthquake and/ or tsunami strikes the area.
While strontium isn’t being tested for in the Woods Hole crowdsourcing program, all the sea water samples will be stored in a warehouse in case Buesseler does get funding in future to test them for strontium- 90.
Buesseler said radiation remains a much more continual and direct threat in Japan than anywhere on the west coast of North America.
“We shouldn’t dismiss radioactivity effects,” he said. “Radioactivity can be dangerous — but not at the levels we expect on the west coast of North America.”