Association of low-dose ionising radiation with site-specific solid cancers: Chinese medical X-ray workers cohort study, 1950-1995.

BACKGROUND: The dose-response relationship between cancers and protracted low-dose rate exposure to ionising radiation is still uncertain. This study aims to estimate quantified relationships between low-dose radiation exposures and site-specific solid cancers among Chinese medical X-ray workers. METHODS: This cohort study included 27 011 individuals who were employed at major hospitals in 24 provinces in China from 1950 to 1980 and had been exposed to X-ray equipment, and a control group of 25 782 physicians who were not exposed to X-ray equipment. Person-years of follow-up were calculated from the year of employment to the date of the first diagnosis of cancer or the end of follow-up, whichever occurred first. All cancers were obtained from medical records during 1950-1995. This study used Poisson regression models to estimate the excess relative risk (ERR) and excess absolute risk (EAR) for incidence of site-specific solid cancers associated with cumulative dose. RESULTS: 1643 solid cancers were developed, the most common being lung, liver and stomach cancer. Among X-ray workers, the average cumulative colon dose was 0.084 Gy. We found a positive relationship between cumulative organ-specific dose and liver (ERR/Gy=1.48; 95% CI 0.40 to 2.83), oesophagus (ERR/Gy=18.1; 95% CI 6.25 to 39.1), thyroid (ERR/Gy=2.96; 95% CI 0.44 to 8.18) and non-melanoma skin cancers (ERR/Gy=7.96; 95% CI 2.13 to 23.12). We found no significant relationship between cumulative organ-specific doses and other cancers. Moreover, the results showed a statistically significant EAR for liver, stomach, breast cancer (female), thyroid and non-melanoma skin cancers. CONCLUSIONS: These findings provided more useful insights into the risks of site-specific cancers from protracted low-dose rate exposure to ionising radiation.

Exposure to low-dose radiation in occupational settings and ischaemic heart disease: a systematic review and meta-analysis.

Ionising radiation is a human carcinogen, but the evidence is less clear that exposure to low-dose ionising radiation (LDIR) increases the risk of adverse cardiovascular outcomes. We synthesised the literature of chronic occupational exposure to LDIR and cardiovascular disease, particularly for ischaemic heart disease (IHD).The literature search was conducted using three databases including studies published between 1990 and 2022. A quality assessment of the studies was completed using the Office of Health and Assessment and Translation Risk of Bias Rating Tool. We conducted meta-analyses for IHD mortality using random effects models using measures of excess relative risk per sievert (ERR/Sv) obtained from internal cohort comparisons, as well as with standardised mortality ratios (SMRs) from external cohort comparisons.We identified 2189 articles, and of these, 26 provided data on IHD and were retained. Most studies were classified as having a 'moderate' level of risk of bias. Fourteen and 10 studies reporting external radiation doses were included in meta-analyses using SMR and ERR/Sv, respectively. The meta-summary SMR was 0.81 (95% CI 0.74 to 0.89) with evidence of reduced risk but high heterogeneity across studies. For internal cohort measures, the summary ERR/Sv for a lagged exposure of 10 years was 0.10 (95% CI 0.01 to 0.20) with low heterogeneity. The subgroup analysis by lagged exposure time showed the strongest association were for the 15 and 20 years lag.Our findings suggest that occupational exposure to LDIR increases the risk IHD mortality and highlight the relevance of internal cohort comparisons.

[Research progress of irradiation injuries anti-agents].

Irradiation injuries anti-agents refer to drugs that can inhibit the initial stage of radiation injuries, or reduce the development of radiation injuries and promote the recovery of injuries when used early after irradiation exposure. According to the mechanism of action and the time of intervention, the irradiation injuries anti-agents are divided into four categories: radioprotectors, radiomitigators, radiation therapeutics for external radiation exposure, and anti-agents for internalized radionuclides. In this paper, the research progress of irradiation injuries anti-agents in recent years is reviewed.

Occupational exposure to ionizing radiation in medical staff: trends during the 2009-2019 period in a multicentric study.

OBJECTIVES: Health workers exposed to ionizing radiation account for + 50% of workers exposed to man-made radiation in France. Over the last decade, the use of radiation in medicine has increased due to the introduction of new practices. The EXposition des Professionnels de santE aux RayonnemenTs ioniSants study aims to evaluate and characterize the trends in radiation exposure of health workers in France between 2009 and 2019. METHODS: This retrospective study includes all health workers with at least one dosimetric record in the system for occupational dosimetry registration (Système d'information de la surveillance de l'exposition aux rayonnements ionisants) database for each of the years 2009, 2014, and 2019, in the hospitals included in the study. Individual external doses and socio-professional data were collected. Statistical analyses include descriptions, graphs, and logistic regressions. RESULTS: A total of 1457 workers were included (mean age: 39.8 years, 59% women). The average exposure significantly decreased between 2009 and 2019 (-0.008 mSv/year, p < 0.05). There were large discrepancies in trends according to professions, departments, hospitals, and gender. Over the 10-year study period, radiologic technologists and physicians were the most exposed (0.15 mSv (95%CI 0.14-0.16) and 0.13 mSv (0.06-0.21), respectively), but their exposure tended to decrease. Workers in nuclear medicine departments had the highest radiation exposure (0.36 mSv (0.33-0.39)), which remained stable over time. Thirty-eight percent of recorded doses were nonzero in 2009, decreasing to 20% in 2019. CONCLUSIONS: This study allowed to identify physicians and radiologic technologists in nuclear medicine departments as the most exposed medical workers in France, and to show an overall decrease trend in radiation exposure. This should be instructive for radiation monitoring and safety of exposed medical workers. KEY POINTS: • Radiation exposure of healthcare workers in most medical departments has steadily decreased between 2009 and 2019 in several French hospitals. • The number of zero doses consistently increased during the study period. • Workers in nuclear medicine departments are the most exposed, especially radiologic technologists and physicians.

Astragaloside IV plays a role in reducing radiation-induced liver inflammation in mice by inhibiting thioredoxin-interacting protein/nod-like receptor protein 3 signaling pathway.

OBJECTIVE: To investigate the efficacy of Astragaloside IV (AS-IV) on radiation-induced liver inflammation in mice. METHODS: The mice were divided into normal group, dimethyl sulfoxide solvent group, irradiation group (IR), irradiation + AS-IV (20 mg/kg) group (IR+AS-20) and irradiation + AS-IV (40 mg/kg) group (IR+AS-40). One month after intraperitoneal injection of AS-IV, the mice were irradiated with 8Gry Co60γ, the blood was collected for biochemical analysis, and the liver was collected for hematoxylin-eosin staining, immunofluorescence and electron microscopic observation, oxidative stress, and Western blot analysis. RESULTS: The AS-IV treatment significantly ameliorated the pathological morphology of liver and reduced the alanine aminotransferase and aspertate amino-transferase levels in serum induced by radiation; AS-IV treatment also significantly reduced the expression of inflammatory factors tumor necrosis factor alpha and interleukin 6 and antagonized malonaldehyde content and superoxide dismutase activity in liver caused by radiation; in addition, AS-IV treatment can significantly inhibited the positive expression of thioredoxin-interacting protein (TXNIP) and nod-like receptor protein 3 (NLRP3) inflammasome in liver tissue after radiation; The expression of TXNIP, NLRP3 inflammasome, apoptosis-associated speck-like protein containing a CARD, cysteinyl aspartate-specific proteinase 1 and interleukin 1beta in the AS-IV prevention group decreased significantly compared to the radiation group. CONCLUSIONS: These findings suggested that Co60γ radiation can cause structural and functional damage to the liver, which may be related to the NLRP3 mediated inflammatory pathway; AS-IV may play a protective role by inhibiting the TXNIP/NLRP3 inflammasome signaling pathway in the radiation-induced liver injury model.

Effect and mechanism of ionizing radiation on ferroptosis in mouse hepatocytes / 中华放射肿瘤学杂志

Objective:To investigate the effect and mechanism of ionizing radiation on ferroptosis in mouse hepatocytes.Methods:Twenty-four C57BL/6J mice were divided into two groups by random number table method: healthy control group (control group, n=6) and irradiation group (whole liver was irradiated with a single dose of 30 Gy X-ray, n=18). Mice were sacrificed at 6, 24 and 72 h (6 mice per time point) after irradiation to obtain liver tissue and plasma samples. The contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma were measured by automatic biochemical analyzer. The prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured by automatic biochemical analyzer. Pathological changes of liver tissues were observed by hematoxylin-eosin (HE) staining. The iron deposition in liver tissues was detected by Prussian blue staining. The expression levels of 4-Hydroxynonenal (4HNE) and hepcidin in the liver were determined by immunohistochemical staining, and quantitative analysis was performed. Plasma malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC) and glutathione (GSH) content were determined by microplate reader analysis according to the kit instructions. The expression levels of transferrin receptor 1 (TfR1), p53, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in the liver were measured by Western blot. Results:Compared with the control group, the plasma contents of ALT ( t=5.15, 5.47, both P<0.001) , AST at 6 and 24 h after irradiation were increased ( t=8.42, 2.50, both P<0.001), the plasma PT was prolonged ( t=3.12, P=0.011) and the APTT was shortened ( t=3.26, P=0.009) at 72 h after radiation in the irradiation group. Histopathological results showed that evident liver edema was observed at 6, 24 and 72 h after irradiation ( t=9.58, 10.09, 18.70, all P<0.001). Different degrees of iron deposition were observed ( t=8.57, 15.31, 32.11, all P<0.001). The infiltration of hepcidin positive cells was significantly increased after irradiation ( t=5.36, 13.17, 17.11, all P<0.001). The number of 4HNE positive cells was significantly increased ( t=18.86, 22.67, 9.12, all P<0.001). At the same time, ionizing radiation induced a significant increase in plasma MDA content ( t=4.36, 7.47, 8.22, all P<0.001), and a decrease in SOD ( t=4.52, 5.80, 7.60, all P<0.001), T-AOC ( t=13.24, 20.49, 24.96, all P<0.001) and GSH ( t=2.78, 6.07, 11.25, P=0.020, <0.001, <0.001), respectively. The expression level of TfR1 protein was significantly up-regulated ( t=3.46, 5.40, P=0.026, 0.006), whereas that of GPX4 protein was significantly down-regulated ( t=11.88, 30.63, both P<0.001) at 24 and 72 h after irradiation. At 6, 24 and 72 h after irradiation, the expression level of p53 protein was significantly up-regulated and maintained at a high level ( t=7.84, 4.25, 8.22, P=0.001, 0.013, 0.001), while that of SLC7A11 protein was significantly down-regulated ( t=9.29, 19.96, 9.09, all P<0.001). Conclusion:Ionizing radiation induces the ferroptosis in hepatocytes, and its mechanism may be related to the activation of p53-SLC7A11-GPX4 pathway.

Research progress of radiation protection in interventional diagnosis and treatment of pediatric heart disease / 中国基层医药

Interventional diagnosis and treatment of heart disease is the gold standard to evaluate the anatomy and physiology of children with congenital heart disease. It plays an important role in the treatment of congenital heart disease. However, ionizing radiation is inevitably harmful to the health of children and surgery operators to varying degrees. More and more attention has been paid by surgery operators to children's unique characteristics, protective awareness and skills. This paper reviews recent literature regarding the application, radiation hazards, and research status of interventional surgery in children with congenital heart disease, which hope to help people to better understand the importance of ionizing radiation protection.

Research progress of irradiation injuries anti-agents / 中华劳动卫生职业病杂志

Irradiation injuries anti-agents refer to drugs that can inhibit the initial stage of radiation injuries, or reduce the development of radiation injuries and promote the recovery of injuries when used early after irradiation exposure. According to the mechanism of action and the time of intervention, the irradiation injuries anti-agents are divided into four categories: radioprotectors, radiomitigators, radiation therapeutics for external radiation exposure, and anti-agents for internalized radionuclides. In this paper, the research progress of irradiation injuries anti-agents in recent years is reviewed.

[Analysis of lens status of 4452 medical radiation workers in a city].

Objective: To understand the lens condition of radiation workers in a city, explore the factors affecting lens opacity, and provide basis for strengthening the radiation protection management of radiation workers. Methods: In December 2020, according to the national radiation health monitoring project, the occupational health examination data of radiation workers in an occupational health examination institution in a city from December 2018 to November 2020 were collected, including the basic information of radiation workers and ophthalmic examination results. The lens conditions of radiation workers in different subgroups were analyzed, and the influencing factors of lens opacity were analyzed by multifactor logistic regression. Results: A total of 4452 radiation workers were included, of which 439 (9.9%) had lens opacity. The lens opacity rate of male radiation workers was higher than that of female radiation workers (P<0.05) . With the increase of age and length of service, the lens abnormalities of radiation workers increased (r(s)=0.269, 0.212, P<0.01) . The lens opacity rate of radiation workers engaged in nuclear medicine was high (12.7%, 9/71) . The rate of lens opacity in off-the-job medical examination radiation workers was high (18.3%, 26/142) . By multivariate logistic regression analysis, the risk of lens opacification in the age ≤30-year-old group and the >30-<50-year-old group were 0.087 times (95%CI: 0.058-0.132) and 0.076 times (95%CI: 0.054-0.107) that in the age ≥50-year-old group, respectively. The risk of lens opacification in the age ≤10-year-old group, >10-<20-year-old group and 20-30-year-old group were 0.293 (95%CI: 0.189-0.456) , 0.413 (95%CI: 0.256-0.666) and 0.318 (95%CI: 0.204-0.497) times, respectively. Conclusion: The lens opacity rate of radiation workers is related to age and working age.Attention should be paid to high-age and long-term radiation workers to ensure their health.

Perception of Orthopedics Surgeons about the Risks of Radiation Exposure in Fluoroscopy.

Objective The present study aims to understand the perceptions of orthopedists and traumatologists regarding the risk of exposure to ionizing radiation in fluoroscopy procedures. Methods An objective, structured, self-administered questionnaire with sociodemographic, professional, and occupational variables was developed, available through an invitation sent to orthopedist physicians whose contacts were made publicly available. Results A total of 141 questionnaires were answered and analyzed. Most respondents (99%) use fluoroscopy in their surgeries, and only 34.8% of the participants feel safe with the use of the equipment. It was observed that the knowledge about ionizing radiation is inadequate, because 22.6% of the participants are unaware of the type of radiation emitted in fluoroscopy and its biological effects. In addition, 52% of the participants did not know or do not understand the principles of radiological protection and their relationship with surgical practices. Conclusion We concluded that the radiological protection of most orthopedists in surgical procedures is inadequate, and initial and continued training programs of professionals are necessary, bringing health benefits to orthopedists and their patients.

Effects of Ionizing Radiation on Human Peripheral Blood Mononuclear Cells (PBMCs) in the Presence of Mentha-Pulegium Essential Oil: A Study on the Radioprotective Effect.

Background: The Mentha-Pulegium essential oil (MP-EO) contains different antioxidant compounds and reduces the indirect effects of dispersed ionizing radiation on biological systems. Objective: The current study aimed to assess a possible radio-protective effect of MP-EO on peripheral blood mononuclear cells (PBMCs). Material and Methods: In this experimental study, MP-EO was firstly prepared and PBMCs were then irradiated in various groups with doses of 25 and 200 cGy of X-rays in the presence of IC10 of MP-EO. After incubation times of 48h and 72h, the survival, apoptosis, and necrosis percentages of PBMCs were determined by MTT assay and flow cytometry analyses; the radio-protective effect of MP-EO was examined. Results: In the presence of 80 µg/ml (IC10) MP-EO, the mean survival percentage of irradiated PBMCs by radiation doses of 25 and 200 cGy was significantly increased after 48h of incubation compared with the control. At 72h of incubation, the mean survival percentage of irradiated PBMCs was significantly increased only at 25 cGy. The percentage of apoptosis and necrosis of PBMCs was significantly reduced in the presence of the MP-EO at both incubation times and radiation doses; therefore, the highest reduction was at 200 cGy and 48h incubation compared to the control. Conclusion: MP-EO as a natural, non-toxic, and cost-effective compound can exhibit a favorable in-vitro radio-protective effect by increasing the survival and decreasing the percentage of apoptosis and necrosis of irradiated PBMCs.

Effects of radiation-associated miRNA in radiotherapy for breast cancer / 国际肿瘤学杂志

Breast cancer is the most common cancer in women, and radiotherapy is an important method of its treatment. The outcome of radiotherapy greatly depends on radiosensitivity of cancer cells. The key pathways of microRNAs (miRNAs) involved in breast cancer radiotherapy response include DNA damage repair, apoptosis, cell cycle arrest, autophagy and related signaling pathways. This article reviews the role of miRNAs in regulating the response of breast cancer to radiotherapy and related signaling pathways. To explore the role of miRNAs in regulating the treatment response of breast cancer to radiotherapy and related signaling pathways, it can provide reference for miRNAs to be used as an indicator to evaluate the diagnosis, prognosis and radiotherapy efficacy of breast cancer.

Implante de marcapasos permanente. Acceso al ápex del ventrículo derecho usando radioscopia solo en el último momento

RESUMEN En Cuba, el primer implante de marcapasos se realizó el 6 de julio de 1964, mientras que en Cienfuegos se inicia esta actividad en 1979, por un grupo de profesionales liderados por el Dr. Francisco Riverón Mena, quien se mantuvo durante más de diez años al frente de la estimulación cardíaca, en el Hospital Dr. Gustavo Aldereguía Lima. El presente trabajo se propone describir el método para el implante de marcapasos permanente aplicado en dicha institución, introducido por el Dr. Riverón, como alternativa al modo convencional. Esta técnica requiere muy poca utilización de radiaciones ionizantes; resulta eficaz y más segura, tanto para el paciente como para el personal de salud, pues se emplea radioscopia solo en el último momento del procedimiento, lo cual la diferencia del método convencional. Aunque en la actualidad no se practica, durante la etapa que se aplicó en el hospital, brindó seguridad a pacientes y personal de salud, por lo que debería retomarse su uso.

ABSTRACT In Cuba, the first pacemaker implant was carried out on July 6, 1964, while in Cienfuegos this activity began in 1979, by a group of professionals led by Dr. Francisco Riverón Mena, who stayed for more than ten years in charge of cardiac stimulation, at the Dr. Gustavo Aldereguía Lima Hospital. The present work aims to describe the method for permanent pacemaker implantation applied in said institution, introduced by Dr. Riverón, as an alternative to the conventional mode. This technique requires very little use of ionizing radiation; It is effective and safer, both for the patient and for the health personnel, since fluoroscopy is used only at the last moment of the procedure, which differentiates it from the conventional method. Although it is not currently practiced, during the stage that it was applied in the hospital, it provided security to patients and health personnel, so its use should be resumed.

[A study on the correlation between occupational radiation exposure and risk of chronic metoblis disease].

Objective: To study the correlation between occupational radiation exposure and chronic metabolic diseases. Methods: The status of chronic metabolic diseases of medical workers were compared in 5 hospitals in Hangzhou. As representatives of chronic metabolic diseases, diabetes and metabolic syndrome (MS) were compared in association with duration of radiation exposure. Results: Long-term ionizing radiation (IR) exposure was led to increased blood pressure, fasting blood glucose (FBG) , dyslipidemia, gallbladder disease, and MS. The years of radiation exposure was associated with lens opacity, gallstone and MS in men and gallbladder polyps in women. Radiation working more than 10 years is one of the independent risk factors for increased FBG and MS. Moreover, the risk of FBG increase in the group of radiation working more than 10 years was 3.052 times of that the non-exposed group, and the risk of MS occurrence was 4.132 times that of the non-exposed group. Conclusion: Long-term exposure to IR increases the risk of chronic metabolic diseases.

[Analysis of occupational health status of radiation workers in Guangdong Province].

Objective: To discuss the effect of low-dose ionizing radiation on the health of radiation workers, and provide a basis for occupational health risk assessment of radiation workers. Methods: In January 2020, 3165 radiation workers who performed radiation occupational health examinations in Guangzhou Prevention and Treatment Hospital for Occupational Disease from January 2017 to December 2019 were selected as the research objects, and compared and analyzed the health status of radiation workers with different examination types (pre-job, in-job and off-job) , types of work, gender, and length of service. Results: The off-job occupational radiological health examination was rare at 2.3% (74/3165) . The abnormal detection rate of chest radiographs, renal function, thyroid function, and blood routine of the radiation workers in-job group was higher than that of the pre-job group (P<0.05) . No statistical difference was found in the abnormal detection rate of the examination items during the in-job group and the off-job group (P>0.05) . The blood routine abnormality detection rate of medical application group and industrial application group were higher than those of nuclear fuel group (P<0.05) . The abnormal detection rate of blood pressure and renal function of male radiation workers was higher than that of females, while the abnormal detection rate of blood routine of females was higher than that of males (P<0.05) . The abnormal detection rate of electrocardiogram, chest radiograph, blood pressure, renal function, thyroid function, and blood routine of radiation workers increased with increasing working age (P<0.05) . Conclusion: Occupational health status of radiation workers is not optimistic. Radiation occupational health monitoring should be strengthened, special attention should be paid to off-job radiation occupational health examination, focusing on the sensitive indicators of sensitive personnel, improving radiation protection conditions, and effectively protecting the occupational health of radiation workers.

Excessive z-axis scan coverage in body CT: frequency and causes.

OBJECTIVES: The aim of this study was to determine the frequency and causing factors of excessive z-axis coverage in body CT examinations. METHODS: A total of 2032 body CT examinations performed between 1 March and 1 April 2018 in 1531 patients were included in this study. The over-scanned length values in the z-axis for each CT examination on each patient were determined by calculating the difference between the actual scanned length and optimal scan length in the z-axis. Over-scanning and over-scanning ratios were interrogated in terms of potential underlying factors that can be affected by patient demography, time, the throughput of CT, and the experience of technologists. RESULTS: Over-scanned CTs in z-axis were 66% of all CTs performed. CT scans were over-scanned in the cranial side in 18.4% and caudal side in 48.5% of patients. Over-scanning was found to be more frequent in 55-64-year-old age group (74%), thorax CTs (89.2%), patients with consciousness change (88.9%), patients with misleading findings related to lung apex or diaphragm on the scout images (76.6%), CTs performed in day shift (66.8 %), in CT with low daily scan (72.4%), and CT scans performed by less-experienced technologists (75.9%). CONCLUSIONS: Over-scanning in z-axis in body CT examinations is not infrequently encountered in routine practice. Awareness of causes of over-scanning in z-axis can be helpful to prevent over-scanning in CT and unnecessary ionizing radiation exposure in patients. KEY POINTS: • Over-scanning in z-axis frequently occurs in body CT. • The frequency of over-scanning in caudal side is higher than cranial side. • Chest CT and any CT performed in following situation were more prone to over-scanning: older patients, patients with consciousness change, presence of misleading findings on the scout images related to lung apex or diaphragm, day shift, CT with low daily scan, less-experienced technologist.

Research progress in DNA radiation damage detection technologies / 国际生物医学工程杂志

DNA is an important biological molecule that contains genetic information. Ionizing radiation generally exists in the environment of modern uranium mining, radiological medicine and nuclear power plants. Improper protection of the human body against ionizing radiation may cause various types of DNA damage, make genome splicing unstable, and cause various biological diseases related to cancer and aging. The development of DNA radiation damage detection technology is helpful for researchers to assess the extent of biological radiation damage and to diagnose and treat patients with nuclear radiation. In this paper, the domestic and abroad research progress in DNA radiation damage detection methods was reviewed, in which the principles, functions, advantages and disadvantages of relevant detection methods were described, and the future development direction of DNA radiation damage detection methods was prospected.

Is ionizing radiation a risk factor for anxiety in employees?

SUMMARY OBJECTIVE: Workers describe many physical and mental symptoms when working in radiation areas. This study aimed to assess these symptoms in radiation workers using the Beck Anxiety Inventory (BAI). METHODS: A total of 42 radiation workers (22 males and 20 females, mean age 34±7 years) and 47 control subjects (22 males and 27 females, mean age 31± 8 years) who work in non-radiation areas in the hospital were included in the study. All participants anonymously filled out the Beck Anxiety Inventory (BAI) questionnaire. RESULTS: The demographic data of workers were not significantly different between groups. In the BAI, the dizzy or lightheaded (p =0.01), terrified (p= 0.01), unsteady (p=0.02), heart-pounding and racing (p=0.02) items were significantly higher in the radiation-exposed group compared to the control group. -The BAI score was also significantly higher in the radiation-exposed group (11.1±6.8 vs. 8.7±3.8, p =0.04) CONCLUSION: These results suggest the possibility that radiation may play a role in the psychometric properties of workers. The effects of radiation on the health of employees need to be further investigated and understood.

RESUMO OBJETIVO: Ao trabalhar em áreas de radiação, trabalhadores descrevem muitos sintomas físicos e mentais. Este estudo teve como objetivo avaliar esses sintomas em trabalhadores expostos à radiação utilizando a Escala de Ansiedade de Beck (BAI - Beck Anxiety Inventory). MÉTODOS: Um total de 42 trabalhadores expostos à radiação (22 homens e 20 mulheres, com idade média de 34±7 anos) e 47 controles (22 do sexo masculino e 27 do sexo feminino, com idade média de 31±8 anos) que trabalham em áreas do hospital sem radiação foram incluídos no estudo. Todos os participantes responderam anonimamente ao questionário da BAI. RESULTADOS: Os dados demográficos dos trabalhadores dos dois grupos não apresentaram diferenças significativas. Na BAI, os itens de tonturas ou vertigens (p =0,01), medo (p= 0,01), instabilidade (p=0,02) e batimento cardíaco mais forte e acelerado (p=0,02) foram significativamente mais elevados no grupo exposto à radiação em comparação ao grupo de controle. A pontuação da BAI também foi significativamente maior no grupo exposto à radiação (11,1 ± 6,8 versus 8,7 ± 3,8, p = 0,04). CONCLUSÃO: Esses resultados sugerem a possibilidade de que a radiação pode desempenhar um papel importante nas propriedades psicométricas dos trabalhadores. Os efeitos da radiação na saúde dos funcionários precisam ser mais bem investigados e compreendidos.

Evaluation of ionizing radiation as a risk factor for the incidence of breast cancer: long-term analysis after the cesium-137 accident in Goiânia, Brazil. An ecological study

ABSTRACT BACKGROUND: The largest radiological accident to occur in any urban area happened in Goiânia, Brazil, in 1987. OBJECTIVE: To evaluate the association between breast cancer incidence and ionizing radiation levels. DESIGN AND SETTING: Ecological study among residents of the city of Goiânia, Brazil. METHODS: The central region of Goiânia, with seven major sources of contamination from cesium-137, was defined as the study area. The addresses of women diagnosed with breast cancer were identified between 2001 and 2010. The data were geographically referenced and, using census data, the annual averages of crude incidence rates were estimated. The existence of clusters of new cases was ascertained by means of the Moran index. Correlations of radiometric measurements with the incidence were assessed using unconditional linear regression. RESULTS: A total of 4,105 new cases were identified, of which 2,233 were in the study area, and of these, 1,286 (57.59%) were georeferenced. The gross rates of total and referenced cases were 102.91 and 71.86/100,000 women, respectively. These were close to the average for Brazilian state capitals, which is 79.37/100,000 women. The cluster analysis showed slight correlations in three small sets of census tracts, but these were far from the sources of contamination. The scatter plot of points and the R2 value close to zero indicated that there was no association between the variables. CONCLUSION: This study reinforces the hypothesis that the ionizing radiation levels to which women living in Goiânia are now exposed to are not associated with the onset of new cases of breast cancer.