Evaluation of risk due to chronic low dose ionizing radiation exposure on the birth prevalence of congenital heart diseases (CHD) among the newborns from high-level natural radiation areas of Kerala coast, India

Background The human population residing in monazite bearing Kerala coast are exposed to chronic low dose and low dose rate external gamma radiation due to Th232 deposits in its beach sand. The radiation level in this area varies from < 1.0 to 45.0 mGy/year. This area serves as an ideal source for conducting large-scale epidemiological studies for assessing risk of low dose and low dose rate radiation exposure on human population. The areas with a dose level of ≤1.50 mGy/year are considered as normal level natural radiation areas (NLNRAs) and areas with > 1.50 mGy/year, as high level natural radiation areas (HLNRAs). HLNRAs were further stratified into three dose groups of 1.51-3.0 mGy/year, 3.01-6.00 mGy/year and > 6.0 mGy/year. The present study evaluates the effects of chronic low dose radiation (LDR) exposure on the birth prevalence of Congenital Heart Diseases (CHD) among the live newborns monitored in hospital based prospective study from NLNRAs and HLNRAs of Kerala coast, India. Methodology Consecutive newborns were monitored from two hospital units located in the study area for congenital malformations. Referred CHD cases among the newborns screened were confirmed by conducting investigations such as pulse oximetry, chest X-ray, electrocardiogram and echocardiogram etc. Results Among the newborns screened, 289 CHDs were identified with a frequency of 1.49‰ among 193,634 livebirths, which constituted 6.03% of overall malformations and 16.29% of major malformations. Multiple logistic regression analysis suggested that the risk of CHD among the newborns of mothers from HLNRAs with a dose group of 1.51-3.0 mGy/year was significantly lower as compared to NLNRA (OR = 0.72, 95% CI: 0.57-0.92), whereas it was similar in HLNRA dose groups of 3.01-6.00 mGy/year (OR = 0.55, 95% CI: 0.31-1.00) and ≥ 6.0 mGy/year (OR = 0.96, 95% CI: 0.50-1.85). The frequency of CHDs did not show any radiation dose related increasing trend. However, a significant (P = 0.005) reduction was observed in the birth prevalence of CHDs among the newborns from HLNRA (1.28‰) as compared to NLNRA (1.79‰). Conclusion Chronic LDR exposure did not show any increased risk on the birth prevalence of CHDs from high-level natural radiation areas of Kerala coast, India. No linear increasing trend was observed with respect to different background dose groups. The frequency of CHD was observed to be 1.49 per 1000 livebirths, which was similar to the frequency of severe CHD rate reported elsewhere in India and was much less than the reported frequency of 9 per thousand.

NOAA/TOVS DERIVED UPPER TROPOSPHERIC TEMPERATURE CHANGES ASSOCIATED WITH THE ONSET OF SOUTHWEST MONSOON OVER KERALA COAST

Th e NOAA· scries of pol ar urbiting meteorological JalellitC"J cany cnboent an instrumentTOYSOlROS Operational Vertical Sounder). The temperature profile da la from thi! instrument over Pakistan beatlow region and Tibetan pla teau region i5 examined in relatio n to the onset of sout h~ mnruoon OWf Kent. coast.A si,nificanl temperatu re increase in upper troposphere nead y rv.u ·~u in a.1V11ncfO of onset of monsoonh.. been observed.

Distribution and relative abundance of dominant benthic foraminifera and their palaeoecological significance from beach cores sediment in Kerala coast, India

The study on 365 sediment subsamples have been analyzed for benthic foraminifera from beach cores sediment in Kerala coast, India. The recent benthic foraminiferal faunal record that reveals the paleoecological preferences of the different benthic foraminiferal species are reported in this study. A total of 38 species belonging to 22 genera were identified from the study. For benthic foraminiferal faunal study, dry samples were sieved over 125 μm-size sieve and split into suitable aliquots to obtain ~250 specimens of benthic foraminiferal species identified and counted. The recent benthic foraminiferal faunal record assemblages were dominated by species are Ammonia beccarii followed by Ammonia gaimardii, Cancris oblongus, Discopulvinulina bertheloti, Gyroidinoides nitidula, Gyroidinoides cibaoensis and Quinqueloculina seminulum etc. The most dominant genus like Ammonia was recorded in all the samples from the study. Benthic foraminiferal species are utilized for biostratigraphy for several years and have also been confirmed very constructive in paleoceanographic and paleoclimatological modernization. This study, benthic foraminifera the major contributor to the marine biotic community is largely employed as an important tool for paleoclimatic reconstruction for high fossilization potential and a wide range of geographical distribution.