Ocular lens opacity in residents of areas with high natural radiation background in Yangjiang City, China / 中国职业医学

OBJECTIVE: To investigate the effects of long-term and low dose ionizing radiation on ocular lens opacities of residents living in areas with high natural radiation background(HNRB) in Yangjiang City, China. METHODS: A total of 483 Han residents from Yangjiang City(HNRB area) and 517 from Enping City(control area) were selected as study subjects using a cluster random sampling method. Questionnaire survey and lens examination were carried out. The risk factors of lens opacity and its severity were analyzed by logistic regression analysis. RESULTS: The prevalence rates of lens opacity, cortical opacity and posterior subcapsular opacity in HNRB area were higher than those in control area(60.7% vs 51.6%, 53.4% vs 46.8%, 21.9% vs 9.3%, all P<0.05). There was no significant difference in karyotype turbidity between HNRB area and control area(52.4% vs 47.6%, P>0.05). After adjusting for confounding factors including age, gender, cardiovascular/metabolic diseases, smoking, alcohol drinking and tea drinking, the unconditional logistic regression analysis results showed that the risk of ocular opacity, cortical opacity and posterior subcapsular opacity in residents of HNRB area was higher than that in control area(all P<0.05). Multivariate disordered logistic regression analysis results showed that residents in the HNRB area had a higher risk of grade two karyotype turbidity than grade one karyotype turbidity(P<0.01). Ordered logistic regression analysis results showed that residents in HNRB area had an increased risk of developing severe cortical turbidity(P<0.01). CONCLUSION: Long-term and low dose ionizing radiation exposure may increase the risk of ocular lens opacity, especially cortical and posterior subcapsular cataract, and affect the severity of the disease.

Radiation Exposure during Percutaneous Endoscopic Lumbar Discectomy: Interlaminar versus Transforaminal

Objective Percutaneous endoscopic lumbar discectomy (PELD) relies heavily on fluoroscopy guidance; therefore, medical staff exposure to radiation has become an important issue. The purpose of this study was to determine the radiation dose and the amount of time to which the surgeons are exposed during PELD and to compare both parameters in the transforaminal (TF) and interlaminar (IL) approaches. Although they are considerably different, they may be wrongly considered together. Methods A retrospective evaluation of the last 20 PELD performed by the authors is presented. Patients were distributed in 2 groups. Six (1F, 5M) patients were submitted to IL-PELD and 14 (6F, 8M) to TF-PELD. Fluoroscopy reports were obtained from patients' records, all performed with the same C-Arm device and software mode. Groups were compared using unpaired t-test. Results The IL group showed an average radiation exposure of 8.37 4.21 mGy and duration of 11.1 5.45 seconds, while the TF group showed an average radiation exposure of 28.92 7.56 mGy and duration of 42 16.64 seconds. The p-value for radiation was 0.0000036, and for time it was 0.00027. Conclusions Interlaminar PELD requires a lower radiation dose and a shorter amount of exposure than TF-PELD. Studies that concern radiation required for minimallyinvasive spine surgeries should consider the PELD approaches separately.

Preliminary research on telomere length of residents in high level natural background radiation area Yangjiang of China / 中华放射医学与防护杂志

Objective To explore the effect of long-term low dose ionizing radiation on telomere length in adults. Methods Forty female residents aged more than 55 years old from high level natural background radiation area in Yangjiang city and forty age-matched female residents from control area in Enping city were selected by quota sampling as high background group and control group, respectively. Genomic DNA was isolated from their peripheral blood. Telomere length was determined using real time q-PCR. The t-test was used to compare the square roots of the means of two groups. The individuals were divided into four groups based on ages ( 55 -, 60 -, 65 - and ≥70 ) and four groups based on BMI ( <18. 5, 18. 5-23. 99, 24. 0 -27. 99 and ≥28. 0). After adjusting age and BMI, multivariate linear regression analysis was performed to study the relationship between telomere length and cumulative exposure dose. The individuals were divided into longer telomere length group (≥2 ) and shorter telomere length group ( <2). Logistic regression analysis was performed to study the relationship between telomere length and cumulative exposure dose. Results The average cumulative dose was(169. 52 ± 27. 43)mSv for high background group and(47. 52 ± 6. 50)mSv for control group. The telomere length of high background group was( 1. 98 ± 1. 25 ) , shorter than that of control group ( 2. 69 ± 1. 44 ) with statis-tically significant difference(t=2. 24, P <0. 05). The multivariate linear regression analysis revealed that the effect of cumulative dose on telomere length was not significant ( P>0. 05 ) . Association between telomere length and cumulative dose was explored through Logistic regression, and odds ratio was taken as 0. 992(95% CI, 0. 985-0. 999 ) . There was a weak inverse association between telomere length and cumulative dose, because the odds ratio ( OR) was very close to 1. Conclusions No obvious dose-effect relationship between telomere length of residents and cumulative radiation doses was found. But the long-term low dose ionizing radiation may lead to the shortening of the telomere length in adults.

A study on cancer mortality of the residents in the high background radiation area in Yangjiang,China (1979-2002) / 中华放射医学与防护杂志

Objective To increase the statistic power to estimate radiation-induced cancer risk on the basis of analysis of the 1999-2002 follow-up data from high background radiation areas (HBRA), in combination with those in the period 1979-1998, and further to estimate radiation-induced cancer risk at low dose after adjustment of individual smoking factor.Methods Cohort studies were conducted of cancer mortality for the residents in both HBRA and control area (CA), with follow-up made in phases.The present study was first focused on the collection of cancer mortality data during 1999-2002, with preliminary analysis of the risks of cancer mortality.And then, the effort was dedicated to analysis of both the risks of cancer mortality and the smoker-adjusted risks of radiation-induced cancer mortality from for the residents in HBRA in period 1999-2002 based on the pooled data during 1999-2002 and 1979-1998 through ID record linkage.Person-years were estimated using Epicure/DATAB model.The relative risk (RR), the excess relative risk coefficient (ERR/Sv) and confidence interval (CI) of cancer mortality from 1979 to 2002 were estimated using Poisson regress model in AMFIT mode.Results A total of 76 264 persons in HBRA and CA was followed up during 1999-2002, covering 300 523 person-years and 2 267 deaths identified, including 239 cancer deaths.Based on pooled data, 125 079 persons were followed up during 1979-2002, which covered 2 293 463 person-years and 14 711 deaths identified, including 1 441 died of cancer.The sex-and age-adjusted RR of all cancers in the HBRA during 1979-2002 was 0.99 (95％ CI: 0.89 to 1.11), showing no statistically significant differences between HBRA and CA (P ＞ 0.05).The value of ERR/Sv of all cancer mortality during 1979-2002 was-0.01 (95％ CI:-0.50 to 0.64).Smoker-adjusted RR of all cancer mortality in HBRA during 1987-2002 was 1.00 (95％ CI:0.87 to 1.15), with no statistically significant difference (P ＞ 0.05).The value of ERR/Sv for all cancers during 1987-2002 was 0.01 (95％ CI:-0.56 to 0.81) after adjustment of smoking.Conclusions Increased risk was not found in relation to radiation exposure at low dose in HBRA.After adjustment of smoking, the statistical difference has not been shown in all cancer mortality between HBRA and CA, but excess relative risk increased slightly.

Effects of high natural background radiation on chromosome aberration frequency of peripheral blood lymphocytes of long-term exposed inhabitants: a Meta analysis / 中华放射医学与防护杂志

Objective To quantitatively analyze the effects of high background radiation area (HBRA) on the frequencies of translocation and unstable chromosome aberrations in human peripheral blood lymphocytes.Methods Based on the data from 9 published articles retrieved from 7 electronic databases,the Meta-analysis was performed to evaluate the effects of high natural background radiation (HNBR) on the frequencies of chromosome aberrations in the peripheral blood lymphocytes in 17 777 persons from HBRA and 10 386 from the control area (CA).Cochrane's Q and I2 statistics were used to evaluate heterogeneity among studies and pooling odds ratio (OR) with 95％ confidence intervals (95％ CI) were calculated using random-effect models.Publication bias was also calculated by funnel plot,Egger linear regression test and Begg rank correlation test.Results The pooling OR of translocation [OR(95％ CI) =1.57(1.10-2.24)] and unstable chromosome aberration [OR(95％ CI) =2.04(1.32-3.14)] of long-term exposed inhabitants living in HBRA were higher than control.The subgroup analysis showed that,fortranslocation,the OR (95％ CI) were 1.24 (1.09-1.42,I2 =0.00) for male,1.37 (1.17-1.60,I2 =0.00) for female,1.17 (1.05-1.30,I2 =69.50％) for adults,and 1.38 (1.25-1.51,I2 =0.00) for Chinese.For unstable chromosome aberration,the OR (95％ CI) were 3.78 (2.40-5.97,I2 =0.00) for female,2.60 (2.25-3.00,I2 =69.60％) for adults,1.03(0.85-1.24,I2 =0.00) for children,3.19 (2.46-4.13,I2 =21.60％) for Iranian,and 1.64 (1.33-2.02,I2 =0.00) for Chinese.HBRA,age and sex differences were the reasons of above heterogeneity.Conclusions To the inhabitants living in HBRA,the frequencies of translocation and unstable chromosome aberration of peripheral blood lymphocytes are higher than those in control area.More comprehensive analysis should be performed to assess the health risk in HBRA inhabitants,which may arise new stragety in radiation protection.

Characterization of the InSTEC’s low-background gamma spectrometer for environmental radioactivity studies / Caracterización del espectrómetro gamma de bajo fondo del INSTEC para estudios de radioactividad ambiental

ABSTRACT The capabilities of the LowBackground Gamma Spectrometer (LBGS) at InSTEC were studied for environmental purposes. Fifty three glines were identified in the LBGS background spectrum. The Minimum Detectable Activity for , , , , and were calculated using the detector’s volumetric efficiency simulated by Monte Carlo method. Validation was performed by absolute and relative analysis of radionuclide activities present in a marine sediment certified material.

RESUMEN Se determinan las potencialidades del Espectrómetro Gamma de Bajo Fondo del InSTEC con fines ambientales. Se identificaron 53 líneas gamma en el espectro de fondo natural del espectrómetro. Se calculan las actividades mínimas detectables para los radionucleidos , , , , and empleando la eficiencia volumétrica del detector simulada por Monte Carlo. Como validación se determinan, por vía absoluta y relativa, las actividades de los radionucleidos presentes en un estándar de sedimento marino.

Estimation of glomerular filtration rate with different background region of interest for renography in severe renal insufficiency patients / 中华肾脏病杂志

Objective To evaluate the improvement of diagnostic accuracy with background region of interest(ROI)rectification for 99mTc-DTPA renography in patients with GFR≤plasma sampling method). Methods Thirty-three patients(age＞20 years,male/female=13/20)dose of 111 MBq/0.5 ml of 99mTc-DTPA was injected into an antecubital vein.The background ROI was selected below the kidney(Gates method,method a)or around the kidney(method b),then these two different GFR(GFRa,GFRb)were automatically estimated by computer.Meanwhile,3 ml blood samples were collected 2 h and 4 h after injection respectively,and radioactivity of 1 ml plasma was measured.GFR was calculated by dual plasma sampling method(GFRp)and the results were all standardized with the body surface area.The accuracies and correlations of GFRa and GFRb were compared to GFRp respectively. Results The correlation coefficients were ra=0.602 and rb=0.834.The median of difference of GFRa and GFRb was 8.33,-4.41.The median of absolute difference of GFRa and GFRb was 8.33,4.49.The accuracies within±15%,±30%and±50%of GFRa were 24.2%,30.3%and 48.5%,and those of GFRb were 33.3%,51.5%and 81.8%.Conclusion The background ROI around kidney can obviously improve the diagnostic accuracy of 99mTc-DTPA renography in patients with severe renal insufficiency.

Establishment of immortalized B lymphoblastoid cell lines of old residents in high background radiation area in Guangdong,China / 中华放射医学与防护杂志

Objective To establish the immortalized cell lines of peripheral blood lymphocytes for old male residents in high background radiation area(HBRA)in Guangdong,China,in order to preserve the specific genomic resources of residents in HBRA for the further genetic and molecular biological study on HBRA.Methods The peripheral blood samples of 20 old male residents in HBRA were collected after informed consent.The immortalized B lymphoblastoid cell lines,2 for each resident,were established with Epstein-Barr virus.After being frozen and recovered,the cell viability,the contamination of bacterium and mycoplaama were analyzed.The stabilization of cell lines was decided by comparing the karyotypes of the peripheral blood lymphocytes and the cell lines.Results 40 cell lines for 20 residents in HBRA were successfully established.The recovery rate of cell lines after being frozen was 100%.All the cell viablity after recovery was higher than 90%.and no contamination of bacteria and mycoplasma occurred.The karyotypes of the 20th generation cell lines were not change.Conclusion The immortalized cell lines established in this study could provide biological resources for further study on genetics and molecular biology in HBRA.

Aplicação de uma metodologia de screening para avaliar a mortalidade por câncer em municípios selecionados do Estado de Minas Gerais, Brasil / Screening methodology application to evaluate cancer mortality in selected cities in the State of Minas Gerais, Brazil

Iniciou-se uma investigação epidemiológica em municípios do sul de Minas Gerais, Brasil, considerando a possibilidade de aumento na incidência de câncer devido a maior exposição à radiação natural em alguns deles. Buscou-se, preliminarmente, conhecer o padrão de mortalidade por câncer, avaliar se existe excesso de óbitos e discutir os possíveis fatores de risco associados a esse aumento. Propõe-se uma metodologia de screening com base na razão de mortalidade padronizada (RMP) para classificar os municípios prioritários em estudos futuros. Os municípios considerados de altíssima prioridade para investigação foram: Andradas - câncer de pulmão em homens [RMP = 208 (106-310)] e fígado em mulheres [RMP = 403 (104-701)]; Poços de Caldas - leucemia em homens e mulheres (RMP = 284 (156-412) e RMP = 211 (111-312), respectivamente); Pouso Alegre - leucemia em homens [RMP = 333 (127-540)] e cânceres hematológicos em mulheres [RMP = 257 (188-396)].Estudos epidemiológicos devem ser conduzidos para avaliar a contribuição da radiação e outros fatores de riscos relacionados ao câncer e assim subsidiar futuras medidas de prevenção e controle.

An epidemiological investigation was launched in several cities in southern Minas Gerais State, Brazil, considering the possibility of increased cancer incidence due to high exposure to natural radiation. First, the cancer mortality patterns were assessed to determine whether there was an increase in cancer deaths and to discuss the possible risk factors related to such an increase. The study proposed the use of a screening methodology based on standardized mortality ratio (SMR) in order to classify priority areas for future studies. Cities considered high priority for further investigation were: Andradas, for lung cancer in men (SMR = 208 (106-310)) and liver cancer in women (SMR = 403 (104-701)); Poços de Caldas, leukemia in men and women (SMR = 284 (156-412)) and SMR = 211 (111-312), respectively); Pouso Alegre, leukemia in men (SMR = 333 (127-540)) and hematological cancers in women (SMR = 257 (188-396)). Epidemiological studies are necessary to evaluate the role of radiation and other risk factors in these cancers and thus to support future preventive and control measures.