Low-dose Ionizing Radiation Exposure Research Articles

Cohort Studies and Multi-omics Approaches to Low-Dose Ionizing Radiation-Induced Cardiovascular Disease: A Comprehensive Review.

The effect of low-dose ionizing radiation exposure on the risk of cardiovascular disease (CVD) represents a significant concern in the field of radiation protection. The prevailing approach to mitigating the adverse effects of low-dose or low-dose-rate radiation does not currently incorporate the potential risk of CVD, despite the possibility that such risk may be a substantial contributor to overall health hazards. Current evidence suggests a potential association between radiation exposure and CVD; however, the overall findings remain inconclusive. This is particularly due to the uncertainty surrounding the influence of significant non-radiation risk factors on the associations reported in epidemiological studies. It is difficult to discern the underlying connection in observational epidemiology when there is substantial variation in baseline risk factors. The paucity of epidemiological research in this domain is being partially offset by the advancement of multi-omics approaches. These methods assist in identifying radiosensitive targets, comprehending underlying biological processes, and pinpointing biomarkers. This, in turn, fortifies the evidence gleaned from epidemiological studies. In this review, we delve into the body of epidemiological research pertaining to CVD induced by low-dose ionizing radiation and the application of multi-omics techniques. The integration of these two methodologies holds the promise of identifying specific molecules or biological pathways that can be employed to validate endpoints related to radiation risk assessment.

Cancer mortality after low dose ionizing radiation exposure among workers in France, the United Kingdom, and the United States (INWORKS)

Cancer mortality after low dose ionizing radiation exposure among workers in France, the United Kingdom, and the United States (INWORKS)

Long-Term, Non-Invasive Detection of Low-Dose Ionizing Radiation Exposure

Ionizing radiation induces complex changes in cells and tissues. The conventional approach to biological dosimetry has been to integrate physical and clinical measurements to optimize dose assessment. Molecular biodosimetry is an effective strategy to monitor radiation exposure and hematologic, cytogenetic, protein and transcript-based approaches have been developed to increase dose estimation accuracy. However, these approaches are invasive, time-consuming, have limited effectiveness over time, and importantly do not accurately inform on low dose radiation exposures. Therefore, novel, non-invasive, biomarkers are required that can overcome these limitations. We developed a pipeline that employs Fourier transform infrared (FTIR) spectroscopy in the mid-infrared spectrum to identify a signature of low dose ionizing radiation exposure in mouse ear pinnae over time. Two cohorts of C57BL/6J and one cohort of BALB/c mice were followed for ninety days after total body X-ray exposures of 10, 50, 100 or 200 cGy. The stratum corneum layer of the ear pinnae were repeatedly measured with attenuated total reflectance - focal plane array (ATR-FPA)-FTIR at 5, 14, 21, 49 and 90 days after radiation exposure. We found statistically significant discriminative power for all doses and all tested time-points out to 90 days after exposure. Classification accuracy was maximized when testing 14 days after exposure (specificity > 0.9 with a sensitivity threshold of 0.9) and dropped by roughly 30% sensitivity at 90 days. Since only hundreds of samples were required to learn highly discriminative signatures, developing human-relevant diagnostic capabilities is likely feasible and this non-invasive procedure points toward future non-invasive biodosimetry applications at population scales.

Reparative effects after low-dose radiation exposure: Inhibition of atherosclerosis by reducing NETs release

ObjectiveThe cardiovascular system effects of environmental low-dose radiation exposure on radiation practitioners remain uncertain and require further investigation. The aim of this study was to initially investigate and explore the mechanisms by which low-dose radiation may contribute to atherosclerosis through a multi-omics joint comprehensive basic experiment. MethodsWe used WGCNA and differential analyses to identify shared genes and potential pathways between radiation injury and atherosclerosis sequencing datasets, as well as tissue transcriptome immune infiltration level extrapolation and single-cell transcriptome data correction using the CIBERSORT deconvolution algorithm. Animal models were constructed by combining a high-fat diet with 5 Gy γ-ray whole-body low-dose ionizing radiation. The detection of NETs release was validated by enzyme-linked immunosorbent assay. ResultsAnalysis reveals shared genes in both datasets of post-irradiation and atherosclerosis, suggesting that immune system neutrophils may be a key node connecting radiation to atherosclerosis. NETs released by neutrophil death can influence the development of atherosclerosis. Animal experiments showed that the number of neutrophils decreased (P < 0.05) and the concentration of NETs reduced after low-dose radiation compared with the control group, and the concentration of NETs significantly increased (P < 0.05) in the HF group. Endothelial plaques were significantly increased in the high-fat feed group and significantly decreased in the low-dose radiation group compared with the control group. ConclusionsLong-term low-dose ionizing radiation exposure stimulates neutrophils and inhibits their production of NETs, resulting in inhibition of atherosclerosis.

Low-Dose Ionizing Radiation Exposure on Human Male Gametes: Damage or Benefit.

With the improvement of medical devices for diagnosis and radiotherapy, concerns about the effects of low doses of ionizing radiation are also growing. There is no consensus among scientists on whether they might have beneficial effects on humans in certain cases or pose more risks, making the exposure unreasonable. While the damaging consequences of high-dose radiation have been known since the discovery of radioactivity, low-dose effects present a much bigger investigative challenge. They are highly specific and include radio-adaptive responses, bystander effects, and genomic instability. Current data regarding the consequences of exposure to low-dose radiation on the quality of male gametes and fertility potential are contradictory. The reports suggest two directions: indirect impact on male gametes-through spermatogenesis-or direct effects at low doses on already mature spermatozoa. Although mature gametes are used for observation in both models, they are fundamentally different, leading to varied results. Due to their unique physiological characteristics, in certain cases, exposure of spermatozoa to low-dose ionizing radiation could have positive effects. Despite the findings indicating no beneficial effects of low-dose exposure on male fertility, it is essential to research its impact on mature spermatozoa, as well.

Long-term, non-invasive FTIR detection of low-dose ionizing radiation exposure

Non-invasive methods of detecting radiation exposure show promise to improve upon current approaches to biological dosimetry in ease, speed, and accuracy. Here we developed a pipeline that employs Fourier transform infrared (FTIR) spectroscopy in the mid-infrared spectrum to identify a signature of low dose ionizing radiation exposure in mouse ear pinnae over time. Mice exposed to 0.1 to 2 Gy total body irradiation were repeatedly measured by FTIR at the stratum corneum of the ear pinnae. We found significant discriminative power for all doses and time-points out to 90 days after exposure. Classification accuracy was maximized when testing 14 days after exposure (specificity > 0.9 with a sensitivity threshold of 0.9) and dropped by roughly 30% sensitivity at 90 days. Infrared frequencies point towards biological changes in DNA conformation, lipid oxidation and accumulation and shifts in protein secondary structure. Since only hundreds of samples were used to learn the highly discriminative signature, developing human-relevant diagnostic capabilities is likely feasible and this non-invasive procedure points toward rapid, non-invasive, and reagent-free biodosimetry applications at population scales.

Multiple exposures to low-dose ionizing radiation induced the initiation and progression of pro-atherosclerotic phenotypes in mice and vascular endothelial cell damage.

This study aimed to investigate the effects of low-dose radiation on the abdominal aorta of mice and vascular endothelial cells. Wild-type and tumor-bearing mice were exposed to 15 sessions of low-dose irradiation, resulting in cumulative radiation doses of 187.5, 375, and 750 mGy. The effect on the cardiovascular system was assessed. Immunohistochemistry analyzed protein expressions of PAPP-A, CD62, P65, and COX-2 in the abdominal aorta. Microarray technology, Gene Ontology analysis, and pathway enrichment analysis evaluated gene expression changes in endothelial cells exposed to 375 mGy X-ray. Cell viability was assessed using the Cell Counting Kit 8 assay. Immunofluorescence staining measured γ-H2AX levels, and real-time polymerase chain reaction quantified mRNA levels of interleukin-6 (IL-6), ICAM-1, and Cx43. Hematoxylin and eosin staining revealed thickening of the inner membranes and irregular arrangement of smooth muscle cells in the media membrane at 375 and 750 mGy. Inflammation was observed in the inner membranes at 750 mGy, with a clear inflammatory response in the hearts of tumor-bearing mice. Immunohistochemistry indicated increased levels of PAPP-A, P65, and COX-2 post-irradiation. Microarray analysis showed 425 up-regulated and 235 down-regulated genes, associated with processes like endothelial cell-cell adhesion, IL-6, and NF-κB signaling. Cell Counting Kit 8 assay results indicated inhibited viability at 750 mGy in EA.hy926 cells. Immunofluorescence staining demonstrated a dose-dependent increase in γ-H2AX foci. Reverse transcription quantitative PCR results showed increased expression of IL6, ICAM-1, and Cx43 in EA.hy926 cells post 750 mGy X-ray exposure. Repeated low-dose ionizing radiation exposures triggered the development of pro-atherosclerotic phenotypes in mice and damage to vascular endothelial cells.

Assessment of Trace Metal Disturbances in Healthcare Workers Exposed to Low Dose Ionizing Radiations in a Tertiary Care Hospital

Objective: To determine the effects of ionizing radiations on trace metal levels in healthcare workers exposed to occupational radiation in a tertiary care health facility. Study Design: Comparative cross-sectional study. Place and Duration of Study: Department of Chemical Pathology &amp; Endocrinology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, in collaboration with the Department of Radiology, Combined Military Hospital, Rawalpindi Pakistan, from Apr to Oct 2021. Methodology: Healthcare workers (n=45) exposed to occupational radiations were compared with an equal number of Controls in a tertiary care health facility for their trace metal levels. An atomic absorption spectrophotometer (AAS) was used to measure serum zinc (Zn) and copper (Cu) levels. A calorimetric technique was used to measure serum iron (Fe) levels. Results: Mean serum Copper (9.54±2.52 µmol/l) and Zinc (11.78±1.90 µmol/l) concentrations of the Risk-Group were significantly lower than their respective Control-Groups (Copper: 14.76±3.13 µmol/l and Zinc: 14.67±3.01 µmol/l). At the same time, mean serum Iron levels in the Exposed-Group (17.55±3.88 µmol/l) were significantly (p&lt;0.001) higher than the Control-Group (14.41±4.23 µmol). The duration of radiation exposure was inversely proportional to serum Copper (p-value0.002) and serum Zinc (p&lt;0.001) concentrations, which is statistically significant. At the same time, serum iron level (p-value0.001) and TIBC (p-value 0.003) increased proportionately with increasing duration exposure, which was also statistically significant. Conclusion: Low-dose ionizing radiation exposure led to a significant decrease in serum Copper and Zinc levels, whereas an increase in serum Iron levels was no................

Epidemiology of Low-Dose Ionizing Radiation Exposure and Health Effects

Epidemiology of Low-Dose Ionizing Radiation Exposure and Health Effects

Could Hypertension in Radiographers Associated with Low Ionizing Radiation Exposure? An Evidence-Based Case Report

Low-dose ionizing radiation exposure (<0.5 Gy) may give rise to circulation disorders. Nevertheless, it is not yet known whether low-dose ionizing radiation exposure can cause hypertension. A 27-year-old male patient, who is a radiographer, consulted regarding the result of his periodic check-up with the result of hypertension. He also said that his electrocardiogram (ECG) examination in the previous year's periodic check-up suggested a poor result, but he couldn't remember what the cardiologist told him. Could hypertension in radiographers be associated with ionizing radiation exposure at work? The literature was searched via PubMed, Scopus, and Cochrane. One relevant article was found that met the inclusion criteria. A cohort study by Preetha R, et al (2015) showed no relationship between the risk of hypertension with fluoroscopically guided interventional procedures (FGIP) exposure. The selected article is quite valid but not in importance. Therefore, it did not apply to the case patient. Since research about this matter is still rare, there was only one suitable article found, so the causal relationship still cannot be proven. Further research is recommended using better exposure and outcome measures.

Computed tomography scan radiation and brain cancer incidence.

Computed tomography (CT) scans make substantial contributions to low-dose ionizing radiation exposures, raising concerns about excess cancers caused by diagnostic radiation. Deidentified medicare records for all Australians aged 0-19years between 1985-2005 were linked to national death and cancer registrations to 2012. The National Cancer Institute CT program was used to estimate radiation doses to the brain from CT exposures in 1985-2005, Poisson regression was used to model the dependence of brain cancer incidence on brain radiation dose, which lagged by 2years to minimize reverse causation bias. Of 10524842 young Australians, 611544 were CT-exposed before the age of 20years, with a mean cumulative brain dose of 44 milligrays (mGy) at an average follow-up of 13.5years after the 2-year lag period. 4472 were diagnosed with brain cancer, of whom only 237 had been CT-exposed. Brain cancer incidence increased with radiation dose to the brain, with an excess relative risk of 0.8 (95% CI 0.57-1.06) per 100 mGy. Approximately 6391 (95% CI 5255, 8155)persons would need to be exposed to cause 1 extra brain cancer. For brain tumors that follow CT exposures in childhood by more than 2years, we estimate that 40% (95% CI 29%-50%) are attributable to CT Radiation and not due to reverse causation. However, because of relatively low rates of CT exposure in Australia, only 3.7% (95% CI 2.3%-5.4%) of all brain cancers are attributable to CT scans. The population-attributable fraction will be greater in countries with higher rates of pediatric scanning.

Therapeutic potential of low dose ionizing radiation against cancer, dementia, and diabetes: evidences from epidemiological, clinical, and preclinical studies.

The growing use of ionizing radiation (IR)-based diagnostic and treatment methods has been linked to increasing chronic diseases among patients and healthcare professionals. However, multiple factors such as IR dose, dose-rate, and duration of exposure influence the IR-induced chronic effects. The predicted links between low-dose ionizing radiation (LDIR) and health risks are controversial due to the non-availability of direct human studies. The studies pertaining to LDIR effects have importance in public health as exposure to background LDIR is routine. It has been anticipated that data from epidemiological and clinical reports and results of preclinical studies can resolve this controversy and help to clarify the notion of LDIR-associated health risks. Accumulating scientific literature shows reduced cancer risk, cancer-related deaths, curtailed neuro-impairments, improved neural functions, and reduced diabetes-related complications after LDIR exposure. In addition, it was found to alter evolutionarily conserved stress response pathways. However, the picture of molecular signaling pathways in LDIR responses is unclear. Besides, there is limited/no information on biomarkers of epidemiological LDIR exposure. Therefore, the present review discusses epidemiological, clinical, and preclinical studies on LDIR-induced positive effects in three chronic diseases (cancer, dementia, and diabetes) and their associated molecular mechanisms. The knowledge of LDIR response mechanisms may help to devise LDIR-based therapeutic modalities to stop disease progression. Modulation of these pathways may be helpful in developing radiation resistance among humans. However, more clinical evidence with additional biochemical, cellular, and molecular data and exploring the side effects of LDIR are the major areas of future research.

M2 microglia activation and proNGF inhibition : Possible Mechanisms Behind Cognitive Improvements by Low‐Dose Ionizing Radiation on Alzheimer's Disease; A Literature Review

AbstractBackgroundRecent studies showed that Low‐Dose Ionizing Radiation (LDIR) may induce significant cognitive improvements on Alzheimer's disease (AD). The mechanism behind it is still remain unclear.MethodIn this review, numerous research papers and clinical studies results from the last 10 years related to LDIR exposure on AD as a treatment, immunochemistry in AD, and neurogenesis are collected. The results of the studies are then comprehensively analyzed to find any associations that could explain or give clues on how LDIR exposure may induce significant cognitive improvements in AD.ResultThere is evidence that LDIR modulates microglia phenotypes by switching phenotype M1 to M2. The anti‐inflammatory M2 microglia may associated in amyloid plaques and tau tangles reduction that showed in many studies on LDIR for AD treatment. Further study shows that LDIR also promotes proNGF inhibition that may triggers neurogenesis.ConclusionLDIR shows that it may be a promising novel treatment for AD retrospectively via immunomodulation and triggers neurogenesis.

Abstract 12585: Flexible Modeling of the Association Between Cumulative Exposure to Low-Dose Ionizing Radiation From Cardiac Procedures and Risk of Hematopoietic Cancer in Children With Congenital Heart Disease

Background: High-dose ionizing radiation is a well-established risk factor for childhood malignancies, including hematopoietic cancers (HC). However, data on the effect of low-dose ionizing radiation (LDIR) from medical imaging is conflicting and scant, especially in the pediatric population with congenital heart diseases (CHD). This study evaluated the association between cardiac LDIR exposure and hematopoietic cancers among children with CHD. Methods: A nationwide population-based cohort study was conducted using the Canadian Congenital Heart Disease (CanCHD) database. The study population included children born between 1999 and 2017 with at least one CHD diagnosis in their medical records. The cumulative dose of ionizing radiation corresponding to cardiac diagnostic and therapeutic procedures was quantified considering a 6-month exposure lag. The recency-weighted cumulative exposure (WCE) model, a flexible extension of Cox’s proportional hazards model, was used to assess the association. Results: We identified 139,975 children with CHD born between 1999 and 2017 and followed them for 1,388,681 person-years since birth. In this population, 718 hematopoietic cancer cases were observed. Children with HC were exposed to low-dose ionizing radiation earlier in life (median age at first exposure: 6 vs. 10 months; p=0.03) and had more procedures than those without cancer (mean number of procedures: 0.4 vs. 0.2; p&lt;0.001). The cases received higher cumulative LDIR doses than their counterparts (mean dose: 2.3 vs. 1.1 mSv; p&lt;0.001). We observed that cumulative LDIR doses within five years were associated with increased risk of hematopoietic cancer with the maximum association magnitude around 2 years. Conclusion: This is the first large population-based study documenting increased risk of HC associated with increased dose and recency of the LDIR exposure among children with CHD. Along with these findings, future studies focusing on detecting a threshold effect will help physicians decide the exposure point at which increased surveillance on LDIR exposure should be initiated.

An estimate assay for low-level exposure to ionizing radiation based on mass spectrometry quantification of γ-H2AX in human peripheral blood lymphocytes.

Exposure to environmental ionizing radiation (IR) is ubiquitous, and large-dose exposure to IR is known to cause DNA damage and genotoxicity which is associated with an increased risk of cancer. Whether such detrimental effects are caused by exposure to low-dose IR is still debated. Therefore, rapid and early estimation of absorbed doses of IR in individuals, especially at low levels, using radiation response markers is a pivotal step for early triage during radiological incidents to provide adequate and timely clinical interventions. However, there is currently a crucial shortage of methods capable of determining the extent of low-dose IR exposure to human beings. The phosphorylation of histone H2AX on serine 139 (designated γ-H2AX), a classic biological dosimeter, can be used to evaluate the DNA damage response. We have developed an estimation assay for low-level exposure to IR based on the mass spectrometry quantification of γ-H2AX in blood. Human peripheral blood lymphocytes sensitive to low-dose IR, maintaining low temperature (4°C) and adding enzyme inhibitor are proven to be key steps, possibly insuring that a stable and marked γ-H2AX signal in blood cells exposed to low-dose IR could be detected. For the first time, DNA damage at low dose exposures to IR as low as 0.01 Gy were observed using the sensitive variation of γ-H2AX with high throughput mass spectrometry quantification in human peripheral blood, which is more accurate than the previously reported methods by virtue of isotope-dilution mass spectrometry, and can observe the time effect of DNA damage. These in vitro cellular dynamic monitoring experiments show that DNA damage occurred rapidly and then was repaired slowly over the passage of post-irradiation time even after exposure to very low IR doses. This assay was also used to assess different radiation exposures at the in vitro cellular level. These results demonstrate the potential utility of this assay in radiation biodosimetry and environmental risk assessment.

Evaluation of natural chronic low dose radiation exposure on telomere length and transcriptional response of shelterin complex in individuals residing in Kerala coast, India

The high level natural radiation areas (HLNRA) of Kerala coast provide unique opportunity to study the biological effect of chronic low dose ionizing radiation (LDIR) on human population below 100 mSv. The radiation level in this area varies from < 1.0–45 mGy /year due to patchy distribution of monazite in the sand, which contains 232Th (8–10%), 238U (0.3%), and their decay products. Telomere length attrition has been correlated to DNA damage due to genotoxic agents. The objective of the present study is to evaluate the effect of natural chronic LDIR exposure on telomere length and transcriptional response of telomere specific and DNA damage repair genes in peripheral blood mononuclear cells (PBMCs) of individuals from normal level natural radiation areas (NLNRA) and HLNRA of Kerala coast, southwest India. Blood samples were collected from 71 random male donors (24–80 years) from NLNRA (≤1.50 mGy/year; N = 19) and two HLNRA dose groups [1.51–10 mGy/year (N = 17); > 10 mGy/year, (N = 35)]. Genomic DNA was isolated from PBMCs and relative telomere length (RTL) was determined using real time q-PCR. Radio-adaptive response (RAR) study was carried out in PBMCs of 40 random males from NLNRA (N = 20) and HLNRA (>10 mGy/year; N = 20), where PBMCs were given a challenged dose of 2.0 Gy gamma radiation at 4 h. Transcriptional profile of telomere specific (TRF1, TRF2, POT1, TIN2, TPP1, RAP1), DNA damage response (RAD17, ATM, CHEK1) and base excision repair pathway (BER) (OGG1, XRCC1, NTH1, NEIL1, MUTYH, MBD4) genes were analysed at basal level and after a challenge dose of 2.0 Gy at 4 h. Our results did not show any significant effect of chronic LDR on RTL among the individuals from NLNRA and two HLNRA groups (p = 0.195). However, influence of age on RTL was clearly evident among NLNRA and HLNRA individuals. At basal level, TRF1, TRF2, TIN2, MBD4, NEIL1 and RAD17 showed significant up-regulation, whereas XRCC1 was significantly down regulated in HLNRA individuals. After a challenge dose of 2.0 Gy, significant transcriptional up-regulation was observed at telomere specific (TRF2, POT1) and BER (MBD4, NEIL1) genes in HLNRA individuals as compared to NLNRA suggesting their role in RAR. In conclusion, elevated level of natural chronic LDR exposure did not have any adverse effect on telomere length in Kerala coast. Significant transcriptional response at TRF2, MBD4 and NEIL1 at basal level and with a challenge dose of 2.0 Gy suggested their active involvement in efficient repair and telomere maintenance in individuals from HLNRA of Kerala coast.

Low-dose ionizing radiation exposure and risk of leukemia: results from 1950–1995 Chinese medical X-ray workers’ cohort study and meta-analysis

BackgroundIt has been well-established that acute radiation exposures increase the risk of leukemia. However, it is still unknown whether these leukemia risk estimates could be extrapolated to occupational populations who receive repeated low-dose radiation exposure. The purpose of this study was to estimate quantified associations between low-dose radiation exposures and leukemia. MethodsThe Chinese medical X-ray worker study (CMXW) included 27,011 medical X-ray workers employed at major hospitals in 24 provinces in China from 1950 to 1980, and a control population of 25,782 physicians matched by hospital, who were unexposed to X-ray equipment. Poisson regression models were used to estimate the excess relative risk (ERR) and excess absolute risk (EAR) for the incidence of leukemia associated with cumulative doses. A meta-analysis of the published literature on low-dose occupational radiation exposure and leukemia risk was also conducted. ResultsThe incidence rates of leukemia in X-ray workers and the control group were 6.70 and 3.39 per 100,000 person-years, respectively. Among X-ray workers, the average cumulative red bone marrow dose was 0.046 Gy. We found a positive relationship between 2-year lagged cumulative red bone marrow dose and risk of leukemia excluding chronic lymphocytic leukemia (CLL) (ERR = 0.66 per 100 mGy, 90% CI: 0.09, 1.53; EAR = 0.29 per 104 PY-100 mGy, 90% CI: 0.07, 0.56). The excess risk was largely driven by myeloid leukemia (ERR = 1.06 per 100 mGy, 90% CI: 0.22, 2.51). Based on the meta-analysis, the pooled ERR at 100 mGy was 0.19 (95% CI: 0.08, 0.31). ConclusionThis study provides strong evidence of a positive and linear doseresponse relationship between cumulative red bone marrow dose and the incidence of non-CLL leukemia.

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

BackgroundThe 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.MethodologyConsecutive 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.ResultsAmong 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‰).ConclusionChronic 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.

Effects of Low Dose Ionizing Radiation Exposure on Memory Performances is Rats During Adulthood

Effects of Low Dose Ionizing Radiation Exposure on Memory Performances is Rats During Adulthood

Occupational Radiation Exposure Among General Surgery Residents: Should We Be Concerned?

Low-dose ionizing radiation exposure is associated with development of solid organ tumors as well as increased risk of cataract formation in a linear-dose response. While occupational radiation exposure has been studied across subspecialties with regular fluoroscopy exposure such as interventional radiology and urology, the contribution of increasing endovascular case volume to occupational radiation exposure among general surgery residents remains largely unreported. In this study, we sought to determine typical occupational radiation exposure among a pool of general surgery residents as part of a formal radiation safety curriculum. A radiation safety program was introduced to a group of 28 general surgery residents who rotate on a vascular surgery service with a high endovascular volume in a hybrid room setting. All residents received training in proper use of a radiation dosimeter and minimizing exposure during fluoroscopy times in the operating room. Data was collected from radiation film dosimetry badges distributed to general surgery residents on a bimonthly basis throughout the year, and radiation exposure in mRem was compared between residents rotating on vascular and nonvascular surgical services during 4-week rotations. A total of 14 months of data were collected. Resident compliance was 84% with regular use and return of dosimeters at the end of each bimonthly cycle. The radiation exposure among residents rotating on vascular surgery was significantly higher compared to those on nonvascular rotations (mean = 71 mRem vs 3.13 mRem, p = 0.02). Exposure among senior residents was not statistically different than that of attending vascular surgeons (mean = 212 mRem vs 164 mRem, p = 0.20). All exposures were significantly lower than institutional ALARA dose limits for radiation exposure (5000 mRem/year). General surgery residents are routinely exposed to measurable occupational radiation levels, especially while participating in endovascular procedures during their training. However, data from our study suggests that these levels are below ALARA dose limits and senior surgical residents are not at greater risk than vascular surgery attending surgeons while on their vascular rotation. The results of this study will be used to help guide resident education on radiation safety and identify institution-specific practices which can minimize exposure and improve radiation safety adherence.