Twin Impacts of the Chernobyl Disaster: Birth Defects and Mental Health

Impact on Birth Defects:

Much of the fetal damage caused by the Chernobyl disaster involved neural tube defects. In the fetus, the neural tube is an embryonic precursor to the central nervous system. In other words, the baby’s brain, and spinal cord— two of the most important parts of the human body—are formed from the neural tube. Unsurprisingly, any harm to the neural tube can have severe consequences. For instance, anencephaly is a type of neural tube defect in which major portions of the brain and skull are missing in children. Such children typically die right after birth (Akar,2015). Microcephaly is a condition in which the baby’s head is much smaller than it ought to be because the brain remains underdeveloped. Microphthalmia is an abnormality of the eye which develops before birth. Both eyeballs are abnormally small in this condition. In some children the eyeball may appear to be missing completely.

While many cases of neural tube defects were observed in the area surrounding the Chernobyl plant, cases were also found as far out as Turkey, Belarus and Croatia. The Chernobyl Forum predicted that 15 children died of thyroid cancer while a total of 3935 people died in and around Chernobyl due to radiation-induced cancer and leukemia. At the same time, the Chernobyl Forum reported that there were 10,000-200,000 deaths in Belarus, Ukraine and Russia due to radiation exposure. Since 2000, in select regions of Ukraine, birth defects have been monitored (Wertelecki, 2017). According to researchers on this project, significantly higher rates of microcephaly, neural tube defects, and microphthalmia were observed in selected regions of Ukraine (collectively known as Polissia), as compared to adjacent regions (collectively termed non-Polissia). These significantly higher rates were evident particularly in the years 2000–2009 – 14+ years after the disaster occurred.

Although there were no firm conclusions, the scientists answered a lot of questions and helped spur new research. An article published in the British Medical Journal reported that Italy had 100 reported cases of abortion due to radiation-induced birth defects. Similar research on abortion has proceeded in other countries, although data is limited in some places where abortion rates are not well-tracked (e.g. Ukraine, Russia, and Belarus).

Another interesting topic of study was the impact of the disaster on biological sex. Data seems to show that there is a negative relationship between the level of radiation and the number of newborn boys in the Czech Republic (Parazzini, F, et al.,1998). The number of newborn males was fewer in the six eastern regions where radiation levels were strongly increased due to higher rain levels which helped carry the radioactive cloud. In contrast, the number of newborn boys was not reduced in the two western regions where radioactivity levels were much lower. In support of the results mentioned earlier, Peterka, a famous scientist at the Institute of Experimental Medicine, found that no other significant harmful environmental events occurred during 1986 that would cause this effect other than the radiation from the Chernobyl explosion (Peterka, 2017).

The study in question looked at males born in November 1986, who would have been in the third month of prenatal development during the time of increased radiation at the end April 1986 caused by the accident. The third month of prenatal development is very critical because the fetal brain is extremely vulnerable to any damage. Essentially, neurons (the basic cellular units of the brain) need to mature before they migrate to the main area of brain, called the cortex. Because of the effect of radiation during prenatal development, the immature neurons migrated to the wrong parts of the brain, leading to various kinds of disorders.

The effect was so strong in the Czech Republic, a unique and significant decrease in the male birth ratio was found in November 1986 (Peterka, 2017). This is the only time there was a reverse in the sex ratio observed at the whole population level in the Czech Republic (more females than males). The absence of other environment variables along with a missing biological hypothesis led to the conclusion that this mystery can only be explained by the harmful environment caused by the radiation from the Chernobyl accident.

Unfortunately, there were more genetic and birth defects than just neural tube defects. After the Chernobyl accident, there was a reported increase in spontaneous abortions not only in countries directly adjacent to the Ukraine, but also in Finland and Norway. It was also found that Perinatal mortality and trisomy 21 increased in Germany. Presence of Down Syndrome and childhood leukemia were detected in Sweden at the time of the accident (Peterka, 2017).  Also, in Hungary, there was an increased incidence of thyroid diseases in children. 

Trisomy 21, also known as Down Syndrome, is a genetic disorder which occurs due to a third copy of the 21^st chromosome. It results in delayed physical and mental growth in children. In 1987, an elevated number of trisomy 21 cases were reported in Berlin, Germany (Sperling, et. al., 1994). An x-ray of the chest, teeth, and bones were performed on the mothers of these children. It was found that all of the mothers were exposed to the radiation from the radioactive clouds that passed through Berlin nine months after the Chernobyl fallout. Based on the women’s menstrual cycles and ovulating period, it was found that 4 women had conceived during the time of highest exposure in Berlin.

The incidence of Leukemia, a form of blood cancer commonly found in children, was also elevated for children present near the Chernobyl plant during the accident. Studies have shown that there was an increased risk of leukemia along with the presence of leukemia in children who were residents of Pripyat in 1986 (Noshchenko, et. al., 2001)