Results of the study further suggest that age at exposure, history of thyroid diseases, and location of residence do not modify its risk. This is the first epidemiologic study of the association between radiation exposure from radioactive iodine fallout from the Chernobyl accident and subsequent risk of follicular adenoma in those exposed at 18 years old or younger. The paper is published in the February 2008 issue of the American Journal of Epidemiology.
The Chernobyl accident in 1986 was the largest nuclear accident ever and exposed many individuals to radioactive iodines. Thyroid cancer is one of the most radiosensitive tumors when exposure occurs at young ages. Previous studies showed that the risk of thyroid cancer increased with radiation dose from radioactive iodines, but the effects of radiation on benign thyroid diseases has been largely unknown.
Researchers selected a random sample of 32,385 persons from a database of more than 75,000 records of thyroid radioactivity measurements taken within two months after the incident in those under the age of 18 who resided in three heavily contaminated areas in Ukraine. Various methods were used to trace these subjects and invite them for screening which consisted of an examination of the thyroid gland and sonogram, blood and urine tests, a detailed questionnaire, and an independent clinical examination by an endocrinologist. Those with suspicious findings were further referred for fine-needle biopsy and surgery as needed. The scientists reported a significant three-fold increase in risk for those exposed to the standard measure of 1 gray of radiation compared to those with zero dose. The study further indicates that women had a notably higher risk of follicular adenoma compared with men.
“The Chernobyl accident presented an unparalleled opportunity to study the association between radioactive iodines and a spectrum of thyroid diseases,” said Lydia B. Zablotska, MD, PhD, principal investigator of the project and assistant professor of Epidemiology at the Mailman School of Public Health. “While there have been several analytical epidemiologic studies of thyroid cancer following the Chernobyl accident, none had evaluated follicular adenoma in particular. This paper presents risk estimates of follicular adenoma in relation to individual thyroid doses as well as the effects of gender, age at exposure, iodine deficiency, and other possible effect-modifying factors.”
The researchers note that the radioactive iodines accumulated in the human thyroid gland via the consumption of contaminated milk and other food items. Various earlier studies have shown that the populations of Ukraine, Belarus, and the Russian Federation experienced large increases of thyroid cancer in those exposed to the fallout before the age of 18 years. This increase became apparent 4–5 years after the accident and confirmed previous suggestions.
Also among the major strengths of the Mailman School study are the availability of individual thyroid doses based on thyroid radioactivity measurements made within two months after the accident and the data collected during screening. While the researchers caution that these results are based on a small number of cases, “our findings are further strengthened by the high fine-needle biopsy compliance rate of 93 percent. Because all those referred for surgery following fine-needle aspiration biopsy have been operated upon, it is unlikely that follicular adenoma was underdiagnosed,” Dr. Zablotska said.
Ukraine is known to have a mild to moderate iodine deficiency previously shown to affect radiation-related risks of thyroid cancer. In this study several indicators of iodine deficiency such as place of residence, history of thyroid diseases, and current urinary iodine excretion did not modify the risk of follicular adenoma.
“Our findings confirm that follicular adenoma is strongly related to exposure from radioactive iodines, and while we found that the risk is modified by gender, age at exposure, place of residence, and personal history of thyroid diseases do not affect its subsequent development,” said Dr. Zablotska.
Stephanie Berger | EurekAlert!
The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences