If you’re wondering how Scherb et al estimated the black trend line, with its ominous upward kink, through this noisy, wavering cloud of monthly mortality data, the “change-point analysis” described in the incomprehensible statistics section probably won’t help. But even if we accept it, there are several awkward problems here for the paper’s hypothesis linking it to Fukushima fallout.

First, the alleged mortality spike didn’t kick in until ten months after the accident, in January 2012. Indeed, Scherb’s data show that perinatal mortality in his six “highly contaminated” prefectures dropped 7.9 percent in 2011, the year of the accident and of maximal radiation exposures, compared to 2010. Scherb explains this time lag by “the superposition of the periods necessary for the dispersal of the radioactivity (several weeks) and the pregnancy length;” in other words, it would take a while, perhaps ten months, for the Fukushima fallout to spread and damage pregnancies, and then for these damaged pregnancies to terminate and show up in perinatal mortality stats. But then he notes that “the duration of pregnancies at elevated risk of adverse perinatal outcome may be considerably shorter than the usual 9 months”—a point that contradicts the time-lag finding since pregnancies as short as 22 weeks should have factored into the perinatal mortality surge well before the 10-month lag.

Second, the shape of the post-Fukushima trend line doesn’t make sense if fallout is the cause. In Scherb’s graph the black-line trend after the January 2012 spike roughly parallels the dotted-line comparison. (Scherb’s 15 percent increase in mortality means that the declining black trend-line is shifted about 15 percent higher than the declining dotted comparison trend-line that he extrapolated from pre-2012 statistics.) The shape of the black line implies that the radiation effect elevated perinatal mortality rates by a constant amount for years, without wearing off over time. But that’s not how Fukushima fallout works, because that radioactivity cleared quickly from the environment and human exposures plunged accordingly. The 2014 perinatal cohort, conceived from April 2013 to July 2014, would have been exposed to much less Fukushima radiation than the 2012 and 2013 cohorts. (Ambient radiation levels from fallout in April 2013 had declined by two thirds from levels in April 2011.) [3] So the black trend line after January 2012 should slope sharply downward towards a convergence with the dotted comparison line, something like this: