ABSTRACT
Evaluation of genetic alterations in inhabitants of an area of Tamil Nadu, India, chronically exposed to high background radiation (HBRA), was the major purpose of the present study. A total of 216 samples (exposed inhabitants, 108; control subjects, 108) were selected based on the confirmation of radiation dose level using thermoluminescence dosimetry (TLD). After signing a consent form, volunteers provided blood samples (5 ml each) to establish cell cultures at 52 h. One hundred complete metaphase cells from each subject were evaluated for karyotyping. The frequencies of chromosomal alterations (CA) were found to be higher in the exposed groups and the aberrations predominately observed were of chromatid-type. Smoking was found to have considerable effect on the frequency of CA in exposed subjects. With the comet assay for DNA damage, a significant increase in comet tail frequency was also observed in exposed subjects compared to controls. At present there are no radioepidemiological data regarding the cytogenetic studies in these areas. Furthermore, the Kudankulam nuclear power plant nuclear power plant is being constructed in the same area. The study gives potentially important information on the general health effects due to radiation exposure and increases people's understanding of the hazardous nature of chronic low level natural radiation exposure. However, we may conclude that the HBRA by itself does not pose any significant risk of genetic damage as measured by conventional cytogenetic analysis.
Subject(s)
Background Radiation/adverse effects , Chromosome Aberrations/radiation effects , DNA Damage/radiation effects , Nuclear Power Plants , Adult , Cells, Cultured , Comet Assay/methods , Cytogenetic Analysis/methods , Environmental Exposure/adverse effects , Female , Humans , India , Karyotyping/methods , Male , Middle Aged , Occupational Exposure/adverse effects , Radiation Dosage , Young AdultABSTRACT
We screened urinary iodine (UI) concentrations in high background radiation areas of the Kanyakumari district of Tamilnadu, India. We collected 331 urine samples from three villages in the district: Chinna-Villai, Kadiyapatinam, and Pallam-Annai nagar. The median UI concentrations were 257, 262, and 454 microg/L in Chinna-Villai, Kadiyapatinam, and Pallam-Annai nagar, respectively. Only 27 samples showed mild or moderate iodine deficiency (<100 microg/L) and none showed severe deficiency (<20 microg/L). These findings indicate that iodine supplementation in the villages is sufficient, probably as a result of appropriate fortification of iodized salt in the region. Further screening, including morphological and functional analysis of the thyroid gland, will be needed to clarify the health effects of chronic low-dose radiation exposure attributable to residing in a high background radiation area.
