Chromosomal Aberrations, Micronuclei, Blood Parameters and Received Doses in Workers Exposed to Ionizing Radiation.

BACKGROUND: The aim of this study was to analyze the impact of low doses of ionizing radiation on healthcare workers using dosimeter data and several biomarkers of effects, and to asses the suitability of those tests. METHODS: Data from the last medical examinations, obtained from the medical records of 148 employees were analysed. They were divided into three groups: nuclear medicine, interventional radiology and general radiology. The examination included hematological parameters and cytogenetical tests: unstable chromosomal aberrations (UCA) and micronucleus test (MNT). The received cumulative 5-year dose was calibrated into personal dose equivalents Hp(10). RESULTS: A statistically significant difference was found between the groups in the UCAs (c2=6.634, p=0.036) with the highest UCA frequency in nuclear medicine. The ANOVA showed a statistically significant difference in the values of erythrocytes (F(2,140)=3.715, p=0.027), monocytes (F(2,127)=3.326, p=0.039) and platelets (F(2,135)=4.209, p=0.017), with higher erythrocytes and lower platelets in interventional radiology and lower monocytes in nuclear medicine, all with small effect size. The dose was significantly different among the groups (c2 =22,191; p<0.001). The nuclear medicine workers received a higher dose compared to interventional radiology (U=458, p<0.001) and general radiology (U=510.5, p<0.001). CONCLUSIONS: Nuclear medicine employees are at a higher risk of developing neoplastic and blood-related diseases due to consistent exposure to low doses of ionizing radiation. Results suggest that UCA test might be more suitable for detecting radiation-induced damage at low doses than MNT. Compulsory monitoring of the health status at periodic examinations is required to prevent occupational diseases, esp. among the nuclear medicine workers.

ECG changes in humans exposed to 50 Hz magnetic fields.

Possible health issues of ELF EMFs include cardiovascular effects since both electrocardiogram and heart-rate changes have been reported in the literature. A non-linear relationship between field strength and biological response has been reported in some studies. In this study, a total of 59 subjects, divided into three independent magnetic field strength groups, were compared. A calculated 12-hour time weighted average (TWA) value of the fields was used as an exposure metric for each of the three locations ("low": 0.067 muT, "medium": 1.18 muT and "high": 5.2 muT) and subsequently used to estimate workers' exposure at these sites. Electrocardiograms were recorded in the resting position. Five parameters were derived from the ECG: heart rate (HR), duration of P wave and QRS wave, and duration of PR and QT intervals. The QT intervals were normalized to a heart rate of 60 (QTc). The obtained data were analyzed first by means of multivariate analysis of covariance and then oneway univariate analyses of covariances (ANCOVA) using exposure duration as a covariate. Only the ANCOVA on the QTc interval was significant. Our results suggest that the relationship between field strength and response is non-linear: the adjusted mean QTc values are similar between the "low" and the "high" group, but significantly lower in the "medium" group. One possible interpretation of our results is that a specific exposure pattern might be responsible for the non-linear effects observed, so that generally, characterizing exposure to electric and magnetic fields using simple metrics such as TWA may be insufficient.