The Chernobyl accident, the male to female ratio at birth and birth rates

Human fertility after a disaster: a systematic literature review

Fertility is a key demographic parameter influenced by disaster. With the growing risk of disasters, interest in the fertility response to a disaster is increasing among the public, policy makers and researchers alike. However, a systematic literature review on how disaster affects live birth counts does not yet exist. We reviewed 50 studies retrieved from a systematic search based on a pre-registered protocol. We found an overall negative impact of disasters on fertility. If any, increases in fertility were mostly linked with weather-related physical disasters. We also identified 13 distinct mechanisms which researchers have considered as underlying the fertility effects of disaster. By contrast to the common belief that disasters are more likely to increase fertility in contexts with already high fertility, we found little evidence to suggest that the total fertility rate of the studied populations was an important predictor of the direction, timing or size of fertility impacts. While this may be because no relationship exists, it may also be due to biases we observed in the literature towards studying high-income countries or high-cost disasters. We summarize the methodological limitations identified from the reviewed studies into six practical recommendations for future research. Our findings inform both the theories behind the fertility effects of disasters and the methods for studying them.

Response to the "letter to the editor" by Sani Rachman Soleman et al., "spatiotemporal association of low birth weight with Cs-137 deposition at the prefecture level in Japan after the Fukushima nuclear power plant accidents"

We thank Sani Rachman Soleman et al. for three specific points of criticism concerning our investigation of the ecological association between low birth weight (LBW) and radioactive contamination in Japan after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accidents: 1. Ecological variables are not justified enough to adjust potential confounding. 2. The spatiotemporal regression model does not consider temporal reduction in radiation dose rate. 3. Dose-response plot between dose rates and odds ratios overestimates R² and underestimates p-value. This criticism is a good starting point to explain some of the technical backgrounds of our approach in more detail.

Trends in births and the birth sex ratio in the vicinity of the Mainz research reactor in Germany

INTRODUCTION

The human sex ratio or sex odds at birth (M/F) are influenced by many factors. Radiation is the only stressor known to elevate the ratio while dropping total births. The Mainz research nuclear reactor (FRMZ) underwent extensive refurbishment commencing in 1992 and with further upgrading in 2011. This study was carried out in order to investigate any possible effects of these events on M/F.

METHODS

Annual municipality-specific births by sex were obtained from official government sources. Statistical methods used included ordinary linear logistic regression and Poisson regression.

RESULTS

M/F rose significantly in 1993 only close to the FRMZ (<10 km) with sex odds ratio (SOR) 1.023 (p = 0.0074) and this rise was associated with numerically equivalent drops in male births of 4.01% (p = 0.0251) and female births of 6.17% (p = 0.0005). No such effects were seen beyond 10 km.

DISCUSSION

These findings add to the corpus of evidence that man-made radiation may have significant effects on total births and on M/F with a skew toward male births. While the authors are certain that suitable precautions were taken when the reactor in Mainz was handled, the findings imply that these may not have been sufficient. Perhaps even greater care and even more stringent precautions need to be employed when dealing with radioactive elements. It clearly behoves humanity to exercise extreme caution when handling, processing, and storing radioactive materials and waste.

Guest Edited Collection: Radioisotopes and radiochemistry in health science

Radioisotopes can be produced artificially from stable nuclei through the interaction with particles or highly energetic photons. In combination with modern detection and counting techniques, radioisotopes and radiochemical methods uniquely contribute to the health sciences. This Collection showcases salient aspects of medical radioisotope science ranging from the production, recovery and purification of radioisotopes to the methods used to attach them to biomolecules. The Collection also presents studies that highlight the importance of radiochemistry in the assessment of environmental radioactivity.

A Glance at the Errors of Some Studies on the Health Effects of High Background Natural Radiation Areas

There is no place on the Earth, the planet we live on, where the natural background radiation level is zero. Since the birth and even in our fetal stage, we have been exposed to different sources of natural radiation. Life, in fact, evolved in a radiation environment that was much more harsh than today. Earth serves as a source of terrestrial radiation. Uranium, thorium, and radium are among the radioactive materials that naturally exist in soil and rock. Moreover, the air, we breathe, contains radon, a colorless, odorless, radioactive gas that is created naturally by the radioactive decay of uranium and radium. The crucial importance of the studies on the health effects of living in areas with high levels of background radiation for understanding the biological impact of exposure to low doses of ionizing radiation is well documented. Despite the undeniable need for accurate information about the health effects of exposure to high levels of background radiation, many published papers suffer from methodological and other common types of errors. In this paper, we review three articles published on high background radiation areas. The first paper has addressed the frequencies of unstable (dicentrics& rings), stable (translocations & inversions), and other types of chromosome aberration in adult men from both high background radiation areas of Kerala and areas with normal background radiation. The second paper has addressed different aspects of the world’s high background natural radiation areas. Finally, the third paper has tried to address the role of background radiation on males to females’ ratio at birth. The author has mainly referred to the studies performed on the impact of radiation exposures from nuclear testing (worldwide) and Chernobyl fallout (in Europe).The major shortcomings of these three papers, especially methodological errors, which affected the accuracy of their findings and conclusions are discussed.

Demographic and onco-epidemiological situation in radioactive contaminated territory of Zhytomyr Oblast

We performed an assessment of demographic parameters of occurrence of malignant tumours and mortality of the population which lives in the radioactive contaminated territory of Zhytomyr Oblast (Yemilchynskyi, Luhynskyi, Narodytskyi, Korostenskyi, Olevskyi, and Ovrutskyi districts) over a 32-year period (1985–2017). The source material for the study of the demographic situation and malignant tumours in the population of the radioactive contaminated administrative districts of Zhytomyr Oblast during 1985–2017 was the statistical data of the Management of Healthcare of Zhytomyr Oblast State Administration, Central Department of Statistics in Zhytomyr Oblasts, reports on occurrences of malignant tumours of the state institution Center of Medical Statistics of the Ministry of Healthcare of Ukraine, data of the Radiological Control Service in Zhytomyr Oblast. It was determined that over 1985–2017 in the radioactive contaminated territory of Zhytomyr Oblast, a natural decline of population was observed, maximum values of which occurred in 2005 (except Narodnytsky district – 2000). The highest levels of occurrence of tumours and mortality caused by them among the adult population were observed 14 years after the Chornobyl nuclear power plant disaster. The peak of the occurrence of malignant tumours among children in the radioactive contaminated territory of Zhytomyr Oblast was observed 9 years after the explosion. A relationship was determined between doses of irradiation of the population and the risk of occurrence of malignant tumours in the radioactive contaminated regions of Zhytomyr Oblast. Taking into account that the method of calculation of passport dose (average annual effective dose of irradiation) was developed 23 years ago, nowadays it can lead to errors. This is related to change in amounts of consumption of different products by the population, which needs to be considered when determining radiological risks. The obtained data indicate that analysis of demographic and onco-epidemiological consequences of the Chornobyl catastrophe remains a relevant issue nowadays and will remain so in the near future.

Human sex ratio at birth and residential proximity to nuclear facilities in France

The possible detrimental genetic impact on humans living in the vicinity of nuclear facilities has been previously studied. We found evidence for an increase in the human secondary sex ratio (sex odds) within distances of up to 35km from nuclear facilities in Germany and Switzerland. Here, we extend our pilot investigations using new comprehensive data from France. The French data (1968-2011) account for 36,565 municipalities with 16,968,701 male and 16,145,925 female births. The overall sex ratio was 1.0510. Using linear and nonlinear logistic regression models with dummy variables coding for appropriately grouped municipalities, operation time periods, and corresponding spatiotemporal interactions, we consider the association between annual municipality-level birth sex ratios and minimum distances of municipalities from nuclear facilities. Within 35km from 28 nuclear sites in France, the sex ratio is increased relative to the rest of France with a sex odds ratio (SOR) of 1.0028, (95% CI: 1.0007, 1.0049). The detected association between municipalities' minimum distances from nuclear facilities and the sex ratio in France corroborates our findings for Germany and Switzerland.

Ionizing radiation and the human gender proportion at birth--A concise review of the literature and complementary analyses of historical and recent data

It has long been known that ionizing radiation causes genetic mutations and that nuclear bomb testing, nuclear accidents, and the regular and incidental emissions of nuclear facilities enhance environmental radioactivity. For this reason, the carcinogenic and genetic impact of ionizing radiation has been an escalating issue for environmental health and human health studies in the past decades. The Windscale fire (1957) and the Chernobyl accident (1986) caused alterations to the human birth sex ratio at national levels across Europe, and childhood cancer and childhood leukemia are consistently elevated near nuclear power plants. These findings are generalized and corroborated by the observation of increased sex ratios near nuclear facilities in Austria, France, Germany, Luxembourg, Switzerland, and The Netherlands. We present a concise review of the pertinent literature and we complement our review by spatiotemporal analyses of historical and most recent data. Evidence of genetic damage by elevated environmental radioactivity is provided.

Secular trends in newborn sex ratios

A wide variety of factors have been shown to influence the male to female ratio at birth, which invariably displays a male excess. This paper will review and amplify recent work by the author, with specific references to individual countries, regions and entire continents in order to provide a global overview of this subject. It will be shown that stress, including stress related to political events, influences this ratio. Man-made radiation is also shown to have played a significant role in relation to the Windscale fire (1957) and Chernobyl (1986).