nuclear-news

1. Introduction

The harmful effects of radiation exposure to chromosomes have been known for nearly a century, starting with the discovery of chromosomal deformities in irradiated fruit flies [1] . Experiments with mice [2] [3] and rats [4] confirmed this knowledge, and documented elevated risk for congenital defects, at relatively low doses of exposure. Populations exposed to pre-conception X-rays have been shown to have higher congenital anomalies [5] as were those living in areas with relatively high background radiation [6] [7] .

One form of radiation, byproducts of uranium or plutonium fission, was first introduced into the environment from weapons and reactors seven decades ago [8] -[10] . These isotopes bind with cells, tissues, and DNA of the unborn, and thus risks of congenital defects in irradiated populations have been studied. The first documented excesses of congenital anomalies were among children of survivors of the Hiroshima and Nagasaki bombings. [8] -[10] . During the 1950s, reports of various defects among newborns in the Marshall Islands, the site of 67 large-scale U.S. nuclear weapons tests, were made public. Other studies found links with between atmospheric tests and elevated birth defects, including a high rate of Down Syndrome in northwest England in 1963-1964, the peak period of global fallout from tests [11] . Another report documented elevated birth defect incidence near the Hanford nuclear weapons plant in Washington state (USA) [12] .

The 1986 meltdown at Chernobyl produced numerous reports of certain congenital anomalies among populations subject to fallout from the stricken reactor. One documented a doubling of congenital developmental anomalies among infants born to fathers who worked as liquidators to contain the meltdown [13] . Various analyses presented elevated congenital anomaly rates in various parts of the Belarus region, which received the greatest doses of radioactivity from the meltdown, in the years following Chernobyl [14] -[22] . Other research also found high birth defect rates in the Ukraine [23] [24] , Bulgaria [25] , Croatia [26] , and Germany [27] -[30] including areas with fallout levels well below those Belarussian sites closest to the reactor.

Post-Chernobyl studies also identified elevated rates of specific anomalies, the most-analyzed of which was Down syndrome (Trisomy-21), mostly in Germany [31] -[39] . Other conditions included neural tube defects in Turkey [40] -[43] , cleft lip/palate in Germany [44] [45] , and anencephaly in Turkey [46] . Meta-analyses concluded that a pattern of elevated congenital anomaly rates was associated with exposure to the Chernobyl meltdown [47] -[49] .

No published reports exist on the change in congenital defects rates in Japan after the March 2011 meltdown at Fukushima. However, at least one report examines morphological abnormality rates in aphids in the first sexual reproduction period after the meltdown, and found a 13.2% rate close to Fukushima vs. 3.8% in seven control areas [50] .

Changes in the rate of one type of birth defect, congenital hypothyroidism, have been reported. In the five U.S. states bordering on the Pacific Ocean, with the most elevated levels of environmental radiation after the meltdown, a 16% increase in incidence of the disorder was observed in the nine months following the meltdown, compared to a 3% decrease in 36 other U.S. states [51] . The gap was particularly large (28% increase vs. a 4% decrease) in the first 14 weeks after the arrival of fallout. In addition, the rate of California newborns with a Thyroid Stimulating Hormone score of 19 micro international units per milliliter of blood during initial screening, was 27% greater in the nine months after the meltdown compared to other periods in 2011-2012 [52] . The known affinity for radioactive iodine to attack cell membranes and DNA in the thyroid gland indicates a potential link between Fukushima fallout and congenital hypothyroidism.

Historical reports linking exposure to ionizing radiation with congenital anomaly risk, plus the initial reports on congenital hypothyroidism in the western U.S. suggest further analysis be conducted on other birth defects.

The U.S. Centers for Disease Control and Prevention (CDC) publishes national data collected by state health departments on incidence of five congenital anomalies in the nation. These include Anencephaly, Cleft Lip/Pa- late, Down Syndrome, Omphalocele/Gastroschisis, and Spina Bifida/Meningocele [53] . Approximately 7500 cases of these five defects occur in the U.S. each year. As of mid-2014, the CDC web site contained complete birth defect data for the years 2007 to 2012.

These five specific anomalies to be addressed in this report, merit some discussion, including their suspected link with radiation exposure………http://file.scirp.org/Html/13-1330400_54828.htm