Authors Dr. Joseph J. Mangano and Dr. Janette D. Sherman also said in June 2011 that there was a 35% spike in infant mortality in the US northwest after Fukushima (and refuted by Scientific American). Later that year, they published a paper that said about 14,000 babies died because of radiation from Fukushima (again countered by Scientific American).
This time, they compared the cases of congenital hypothyroid cases in infants in Alaska, California, Hawaii, Oregon, and Washington from March 17 to December 31, 2011 with those for the same period in 2010, and found the number of cases in 2011 was "16% greater", with the largest divergence of 28% occurring in the period between March 17 and June 30.
From Scientific Research Publishing, March 2013:
Elevated airborne beta levels in Pacific/West Coast US States and trends in hypothyroidism among newborns after the Fukushima nuclear meltdown
Joseph J. Mangano, Janette D. Sherman
Various reports indicate that the incidence of congenital hypothyroidism is increasing in developed nations, and that improved detection and more inclusive criteria for the disease do not explain this trend entirely. One risk factor documented in numerous studies is exposure to radioactive iodine found in nuclear weapons test fallout and nuclear reactor emissions. Large amounts of fallout disseminated worldwide from the meltdowns in four reactors at the Fukushima-Dai-ichi plant in Japan beginning March 11, 2011 included radioiodine isotopes. Just days after the meltdowns, I-131 concentrations in US precipitation was measured up to 211 times above normal. Highest levels of I-131 and airborne gross beta were documented in the five US States on the Pacific Ocean. The number of congenital hypothyroid cases in these five states from March 17-December 31, 2011 was 16% greater than for the same period in 2010, compared to a 3% decline in 36 other US States (p < 0.03). The greatest divergence in these two groups (+28%) occurred in the period March 17-June 30 (p < 0.04). Further analysis, in the US and in other nations, is needed to better understand any association between iodine exposure from Fukushima-Dai-ichi and congenital hypothyroidism risk. Link to the full paper (PDF): http://www.scirp.org/journal/PaperDownload.aspx?paperID=28599
The authors say that "All US newborns diagnosed with primary CH [Congenital Hypothyroidism] born March 17-December 31, 2011 were exposed in utero to radioactive fallout from the Fukushima meltdowns" (page 5 of the paper).
I don't know if it is scientifically valid to compare only two years, and to exclude the period from January 1 to March 16, particularly when the number of babies born with Congenital Hypothyroidism is not that large. In their previous study of infant mortality rate (which is volatile to begin with), the authors only used 4-week period prior to the accident. If the period prior to that period were used, the authors would have found out that what looked like a huge "increase" after the Fukushima accident was totally within the range for the year. In their current study on Congenital Hypothyroidism, the five states also happen to have large Hispanic and Asian populations who tend to have much higher incidence of Congenital Hypothyroidism, according to the US Centers for Disease Control and Prevention (CDC).
From the paper (click to enlarge), "Table 4. Confirmed primary congenital hypothyroid cases March 17-December 31 (2010 and 2011), 41 US States":
In Japan, the rumor of the study (as most non-scientists don't bother to or cannot read an English paper, it remains a "rumor") have already morphed into "One-third of babies born on the west coast of the United states after Fukushima have thyroid abnormalities!"
In the US, a vague headline like this, "Study: 28% Increase In Thyroid Problems In Babies Born After Fukushima in Alaska, California, Hawaii, Oregon and Washington", spreads widely. It is even quoted by some on Japanese Twitter. Thyroid problems.
About Congenital Hypothyroidism for non-experts, from wiki:
Congenital hypothyroidism (CH) is a condition of thyroid hormone deficiency present at birth. Approximately 1 in 4000 newborn infants has a severe deficiency of thyroid function, while even more have mild or partial degrees. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent mental retardation. Treatment consists of a daily dose of thyroid hormone (thyroxine) by mouth. Because the treatment is simple, effective, and inexpensive, nearly all of the developed world practices newborn screening to detect and treat congenital hypothyroidism in the first weeks of life.
Around the world, the most common cause of congenital hypothyroidism is iodine deficiency, but in most of the developed world and areas of adequate environmental iodine, cases are due to a combination of known and unknown causes. Most commonly there is a defect of development of the thyroid gland itself, resulting in an absent (athyreosis) or underdeveloped (hypoplastic) gland. A hypoplastic gland may develop higher in the neck or even in the back of the tongue. A gland in the wrong place is referred to as ectopic, and an ectopic gland at the base or back of the tongue is a lingual thyroid. Some of these cases of developmentally abnormal glands result from genetic defects, and some are "sporadic," with no identifiable cause. One Japanese study found a statistical correlation between certain organochlorine insecticides and dioxin-like chemicals in the milk of mothers who had given birth to infants with congenital hypothyroidism.
Congenital hypothyroidism can also occur due to genetic defects of thyroxine or triiodothyronine synthesis within a structurally normal gland. Among specific defects are thyrotropin (TSH) resistance, iodine trapping defect, organification defect, thyroglobulin, and iodotyrosine deiodinase deficiency. In a small proportion of cases of congenital hypothyroidism, the defect is due to a deficiency of thyroid stimulating hormone, either isolated or as part of congenital hypopituitarism.
I suppose the authors want to point to the possibility of genetic defects due to radiation from Fukushima.
Here's US ABC News San Diego Station's reporter Michael Chen quoting the authors and claiming that 39% of infants in California "were more likely to develop congenital hypothyroidism".
Never mind that it is not "likely to develop", because babies are born with it ("congenital"), and promptly treated in the first weeks of their lives. Mr. Chen doesn't ask a silly question like "What if the entire year was taken into account?" or "What is the long-term trend, not just two years?"
The authors Mangano and Sherman say in the paper that "annual data is made easily available on the internet", but I can't seem to find it so far. If readers can post links to such data, I'd much appreciate.
(Update 4/7/2013) Oh great. ABC San Diego news is being spread wide to the Twitter followers of Kouta Kinoshita...