Tuesday, December 30, 2014

Fukushima "fallout": issues in reporting scientific research in the popular media

I had other articles planned but a news report just popped up on my twitter feed that just begs to  discussed in the context of issues in reporting scientific research in the popular media. The article appeared in our local paper under the title: Fallout from radioactive Fukushima rising in west coast waters. The article represents an attempt to describe the results from an original research paper in the Proceedings of the National Academy of Sciences by Smith et al. but suffers from the writer's difficulties relating (or issues with) the scientific data; the inability to get the paper's author on the record to clarify the science and a poor headline.

In order to really understand the issues, you have to read the original paper. Happily for you, I have done that for you and will summarize: the Smith (et al.) paper presents the results of a survey. Surveys form the most basic research reports. They allow for the collection of baseline data to either test hypotheses or to get enough information to develop hypotheses. Most importantly, in this age of research needing to show a "purpose" or a "link to a private sector partner" they are notoriously hard to get funded. Yet surveys are absolutely necessary if we want to build our understanding of our world. In this case the research hook was the Fukushima reactor release. The research involved sampling seawater at various locations, depths and times across the Pacific in order to establish cesium isotope concentrations in the seawater. Cesium isotopes are used because, thanks to the half-life of the isotope, 134 Cs represent a clear human "fingerprint" of contamination from the nuclear release at Fukushima. The article then takes the results from the survey and uses it for global circulation model calibration. To explain, after the release, various modeling exercises were carried out and estimates of rates of movement of the plume were generated. The results presented in the paper help demonstrate that most of the models were insufficiently conservative and also uncovered some interesting features of global circulation patterns in the Pacific. The article represents a technical success and its only downside is that in order to justify its hook it included an attempt to relate the results of the survey to levels of radioisotopes in food fish, specifically the Bluefin Tuna.

Relating radiation risks to the public is an inherently challenging task as most non-scientists have been trained to fear radiation and few have a sense of naturally occurring background radiation levels. The classic xkcd radiation dose chart is a useful tool to relay this information, in doing so it helped introduce the "Banana Equivalent Dose". For those of you not familiar with the unit, bananas are rich in potassium which has a radioactive isotope 40K. Thus bananas are mildly (and I mean really mildly) radioactive. This level of radioactivity has been calculated at being about 14 - 15 Becquerels (Bq) per banana.If you assume that an average banana weighs about 125 g, bananas have a level of approximately 115 Bq/kg (wet weight). Since we feed bananas to babies it provides a clear "safe" level of radioisotopes for discussions. After saying all this I can get back to the Smith (et al.) paper, which in an attempt to relate their findings to human health spend their final paragraph establishing that Bluefin tuna exposed to the plume are expected to reach a whopping 6 Bq/kg from 134 Cs from Fukushima. That is to say about a 5% banana equivalent dose?

Let us return to the newspaper item. Let's start by saying that the article is very poorly served by whoever wrote the headline. I have been told many times that writers do not get to write the headlines for their articles but someone has to take responsibility when a headline writer does such an egregious job. The headline starts by misusing a term from the report: "fallout". The word has a lot of baggage and the Smith (et al.) paper explicitly distinguishes between the Fukushima plume and radioactive fallout, but don't tell that to the headline writer. This headline immediately sets the reader in the wrong direction. This misdirection is continued in the first paragraph which manages to frighten the reader by (accidentally?) conflating nuclear reactors (scary) with a "nuclear plume". The plume being "nuclear" in that radioactive  134 Cs in seawater marginally exceeds the detection limit (and historic background levels) while not being at all risky. The concentrations of 134 Cs are so low that in order to get readings for the survey, methods more detailed than those used in Health Canada testing methodologies were required (which means not just safe but incredibly safe).

The article itself is a real mish-mash. The writer repeatedly assures readers that the plume does not represent a risk to human health but does so in a less than convincing manner. In particular there is a  liberal, but inconsistent, use of quotation marks throughout the article. Sometimes quotation marks are used around a somewhat technical terms like "Fukushima signal" sometimes they are used correctly around direct quotations from the paper “an unequivocal fingerprint indicator of contamination from Fukushima,” but they are also used around common words like "are critical" and "background" which I view as classic scare quote mode. Consider the following line from the article:

The level of Cesium-137 in the water is far below levels seen in the 1960s and 1970s from nuclear weapons testing and “well below Canadian guidelines for drinking water quality,” they say. 

I may be wrong but the quotation followed by the "they say" essentially tells me that the writer does not believe what she is writing. The report continues this way until the end which reassures readers one more time, but since research indicates that a large proportion of people reading an article don't get to the end, the extra reassurances were likely missed by many/most readers.

I cannot say for sure whether the writer does or does not believe the paper (or possibly the press release) but access to Dr. Smith would have helped the article tremendously. I have read that the federal government is restricting reporter access to researchers. If they did so in this case then it certainly backfired. Instead of providing an informed researcher who could provide helpful analysis, press-friendly quotes and less technically analogies, the writer had to rely on a dry paper designed to appeal to a technical audience. Science of this quality deserves to be supported by a measure to ensure it is explained to the public effectively and not mistranslated because the one person best able to explain it to the public is not available to do so. Instead, for the next couple weeks people will be discussing the "not dangerous" "nuclear plume" that definitely does not threaten our seafood supply or the health of West Coast residents.

In reading the research paper and the ensuing newspaper article it is easy to see the pitfalls associated with informing the public about useful science. The journal put out a press release because the paper is of clear interest to the technical audience and even readers like myself might have missed it (the journal is a general interest one not on my reading list). Unfortunately, by not providing someone to speak to the paper, the reporter tasked with reporting the paper was left on her own. At that point it falls to the luck of the draw. If the reporter covering the beat has the knowledge to translate the research then the public may be well served. Unfortunately, due to the nature of modern journalism, very few journalists have the knowledge-base to effectively translate scientific papers in numerous disciplines to the public. At that point we get articles like this one that appear to honestly attempt to inform the public but don't always get the job done right.


  1. OK, fine. The dose of cesium-134 from Fukushima is small. But surely there are other radioactive isotopes that are also contributing to the total level. Is there a survey or an estimate of the total dose that we can expect to see accumulating in fish?

  2. Howard, the total safe dose of radioisotopes in fish has been established by Health Canada, but fear not, the concentrations in fish available to us seldom come within three orders of magnitude of that number. The concern for long-lived, high trophic-level fish (like Bluefin) tends to be mercury. The levels of which tend to increase in the vicinity of areas where a lot of coal is burned.