Retrospective Evaluation of 131i Deposition Density and Thyroid Dose in Poland After the Chernobyl Accident

Abstract

The 131I deposition in Poland after the Chernobyl accident on 26 April 1986 was evaluated from the determined 129I deposition and the estimated 129I/131I ratio at the time of the arrival of fallout. Concentrations of 129I and 127I were determined by neutron activation analysis in uncultivated soils from 16 locations in Poland. Determination of 137Cs in soils was carried out by gamma spectrometry. The atomic ratio of 129I/131I at the time of fallout arrival was estimated using the 129I/131I ratio at the time of the accident, which, on the basis of the core inventory data, was assumed to be 22.8. It was estimated from the time of fallout arrival and from the weighed mean atomic ratio that the 129I/131I ratio for Poland was 32.8. The calculated 131I deposition ranged from 63.2 to 729 kBq m(-2). High deposition of 131I occurred in the locations with rainfall but occasionally also in locations without rainfall. Committed equivalent doses from 131I were evaluated for 5-y-old children, 10-y-old children, and adults using the computer model CLRP for the situations with and without countermeasures including iodine prophylaxis. The highest thyroid doses from inhalation and ingestion without countermeasures were 178 mSv, 120 mSv, and 45 mSv for 5-y-old children, 10-y-old children, and adults, respectively. The countermeasures reduced these doses by about 30%.

Iodine-129 in soils from Northern Ukraine and the retrospective dosimetry of the iodine-131 exposure after the Chernobyl accident

“…There are several earlier publications dealing with the retrospective dosimetry of I exposures us ing 129I (Straume et al, 1996;Robl et al, 1997;Mironov et al, 1999Mironov et al, , 2002Reithmeier et al, 2002;Pietrzak-Flis et al, 2003). Most of the earlier work aimed at evaluating the feasibility of I retro spective dosimetry and on determining some o f the input quantities of equation 1.…”

“…Most of the earlier work aimed at evaluating the feasibility of I retro spective dosimetry and on determining some o f the input quantities of equation 1. Only Robl et al (1997) and Pietrzak-Flis et al (2003) did complete evaluations ending up with thyroid dose esti mates.…”

“…Up to now, Pietrzak-Flis et al (2003) were the only authors reporting actual I dose estimates on the basis of a retrospective dosimetry using I. They used the CLRP model (Krajewski, 1996) in the form of a computer code by Krajewski (1999) to derive the required dose coefficients.…”

?to: Zalutskaya A, Bornstein SR, Mokhort T, Garmaev D (2003) Did the Chernobyl incident cause an increase in type 1 diabetes mellitus incidence in children and adolescents? Diabetologia 47:147?148 (Letter)

“…To date, no studies have shown a relationship between the radioactive pollution from Chernobyl and levels of islet cell antibodies, antibodies to insulin, GAD, or protein tyrosine phosphatase IA-2, or genetic risk markers for type 1 diabetes. The nuclear material released by the reactor explosion between 26 April and 5 May 1986 reached the Warmia and Mazury Region in the north of Poland [4,5]. In this study we analysed the influence of the Chernobyl disaster on the incidence of type 1 diabetes in this region.…”

“…Table 1 compares the incidence rates for the two groups according to age at diagnosis; none of the relative risks are significantly different from 1.00. There is evidence that, in Poland and Finland, high levels of radioactive isotopes were only present in food over a short period (1 month in the case of iodine or several months in the case of caesium), apart from in wood mushrooms, which contain high levels of caesium and strontium even now [2,4,5]. Thus, it is doubtful that radiation from the Chernobyl incident still affects the incidence of type 1 diabetes.…”