Age at exposure to ionising radiation and cancer mortality among Hanford workers: follow up through 1994

Background: Studies of workers at the plutonium production factory in Hanford, WA have led to conflicting conclusions about the role of age at exposure as a modifier of associations between ionising radiation and cancer.

Aims: To evaluate the influence of age at exposure on radiation risk estimates in an updated follow up of Hanford workers.

Methods: A cohort of 26 389 workers hired between 1944 and 1978 was followed through 1994 to ascertain vital status and causes of death. External radiation dose estimates were derived from personal dosimeters. Poisson regression was used to estimate associations between mortality and cumulative external radiation dose at all ages, and in specific age ranges.

Results: A total of 8153 deaths were identified, 2265 of which included cancer as an underlying or contributory cause. Estimates of the excess relative risk per Sievert (ERR/Sv) for cumulative radiation doses at all ages combined were negative for all cause and leukaemia and positive for all cancer and lung cancer. Cumulative doses accrued at ages below 35, 35–44, and 45–54 showed little association with mortality. For cumulative dose accrued at ages 55 and above (10 year lag), the estimated ERR/Sv for all cancers was 3.24 (90% CI: 0.80 to 6.17), primarily due to an association with lung cancer (ERR/Sv: 9.05, 90% CI: 2.96 to 17.92).

Conclusions: Associations between radiation and cancer mortality in this cohort are primarily a function of doses at older ages and deaths from lung cancer. The association of older age radiation exposures and cancer mortality is similar to observations from several other occupational studies.

     

Occupational sunlight exposure and mortality from non-Hodgkin lymphoma among electric utility workers.

This case-control study examined occupational sunlight exposure and death from non-Hodgkin lymphoma (NHL) and NHL subtypes among 188 cases and 1880 controls selected from a cohort of 138,905 male electric utility workers. Exposure was classified according to work history linked to indices of cumulative sunlight exposure. Odds ratios and 95% confidence intervals were derived from conditional logistic regression models and were conditioned on the matching factors birth year and ethnicity. Mortality from NHL and intermediate/high-grade lymphomas was not related to cumulative sunlight exposure, with odds ratios around the null. For low-grade lymphomas, a dose-response gradient was observed for exposure in the past 12 to 21 years, but this result seemed to be sensitive to cut points for categorization of cumulative exposure. These data do not provide evidence for an association between occupational sunlight exposure and mortality from NHL or NHL subtypes.     

Occupational radiation exposure of women workers

The protection of women exposed to ionizing radiation in the workplace has been intensively examined in recent years but no data concerning women workers themselves have been used. The emphasis has been on the possible exposure of the embryo/fetus, with no concern directed to the potential radiation induction of breast and thyroid cancer in the woman nor to the effect on the woman of adverse pregnancy outcome, which can also result from irradiation of the male germ cells. The recent risk estimates developed by the United Nations Scientific Committee on the Effects of Atomic Radiation from observations of biological effects on populations with nonoccupational exposure to ionizing radiation are presented. Surveys of average annual doses for occupationally exposed populations in hospitals show marked variation in radiation exposure from one country to another and for different medical specialties. Radiation exposure in brachytherapy and nuclear technology has been considerably higher than for X-ray technology. The improvements in radiation protection are a continuous process. The employment of both men and women in hospital and industrial settings where there is radiation exposure will have to be evaluated more realistically in terms of the risk to the workers themselves and their reproductive integrity.     

Occupational exposure to magnetic fields in relation to mortality from brain cancer among electricity generation and transmission workers.

OBJECTIVE: To investigate whether the risks of mortality from brain cancer are related to occupational exposure to magnetic fields. METHODS: A total of 112 cases of primary brain cancer (1972-91) were identified from a cohort of 84,018 male and female employees of the (then) Central Electricity Generating Board and its privatised successor companies. Individual cumulative occupational exposures to magnetic fields were estimated by linking available computerised job history data with magnetic field measurements collected over 675 person-workshifts. Estimated exposure histories of the case workers were compared with those of 654 control workers drawn from the cohort (nested case-control study), by means of conditional logistic regression. RESULTS: For exposure assessments based on arithmetic means, the risk of mortality from brain cancer for subjects with an estimated cumulative exposure to magnetic fields of 5.4-13.4 microT.y v subjects with lower exposures (0.0-5.3 microT.y) was 1.04 (95% confidence interval (95% CI) 0.60 to 1.80). The corresponding relative risk in subjects with higher exposures (> or = 13.5 microT.y) was 0.95 (95% CI 0.54 to 1.69). There was no indication of a positive trend for cumulative exposure and risk of mortality from brain cancer either when the analysis used exposure assessments based on geometric means or when the analysis was restricted to exposures received within five years of the case diagnosis (or corresponding period for controls). CONCLUSIONS: Although the exposure categorisation was based solely on recent observations, the study findings do not support the hypothesis that the risk of brain cancer is associated with occupational exposure to magnetic fields.     

Occupational exposure to dust and lung disease among sheet metal workers.

A previous large medical survey of active and retired sheet metal workers with 20 or more years in the trade indicated an unexpectedly high prevalence of obstructive pulmonary disease among both smokers and non-smokers. This study utilised interviews with a cross section of the previously surveyed group to explore occupational risk factors for lung disease. Four hundred and seven workers were selected from the previously surveyed group on the basis of their potential for exposure to fibreglass and asbestos. Selection was independent of health state, and excluded welders. A detailed history of occupational exposure was obtained by telephone interview for 333 of these workers. Exposure data were analysed in relation to previously collected data on chronic bronchitis, obstructive lung disease, and personal characteristics. Assessment of the effects of exposure to fibreglass as distinct from the effects of exposure to asbestos has been difficult in previous studies of construction workers. The experienced workers studied here have performed a diversity of jobs involving exposure to many different types of materials, and this enabled exposure to each dust to be evaluated separately. The risk of chronic bronchitis increased sharply by pack-years of cigarettes smoked; current smokers had a double risk compared with those who had never smoked or had stopped smoking. The occurrence of chronic bronchitis also increased with increasing duration of exposure to asbestos. Workers with a history of high intensity exposure to fibreglass had a more than doubled risk of chronic bronchitis. Obstructive lung disease, defined by results of pulmonary function tests at the medical survey, was also related to both smoking and occupational risk factors. Number of pack years smoked was the strongest predictor of obstructive lung disease. Duration of direct and indirect exposure to welding fume was also a positive predictor of obstructive lung disease. Duration of exposure to asbestos was significantly associated with obstructive lung disease but the dose-response relation was inconsistent, especially for those with higher pack-years of smoking exposure. Exposure to fibreglass was not a risk factor for obstructive lung disease.     

Neuropsychological effects associated with exposure to mercury vapor among former chloralkali workers.

OBJECTIVES: This investigation studied possible neuropsychological effects among former chloralkali workers with past exposure to mercury vapor. METHODS: Seventy-five formerly exposed workers who had been examined with an extensive neuropsychological test battery were compared with 52 referents frequency-matched for age. The tests measured general cognitive function, motor and psychomotor function, attention, memory, and learning. The groups were similar in educational level, age, and verbal comprehension. The mean exposure time to mercury vapor in the index group was 7.9 (range 1.1-36.2) years with an annual mean urinary mercury concentration of 539 (range 41-2921) nmol/(l x year). The mean time since the cessation of exposure was 12.7 (range 1.0-35.0) years. RESULTS: Performance on the grooved pegboard (dominant hand 75.8 versus 70.9 seconds, P<0.05; nondominant hand 82.2 versus 76.3 seconds, P=0.02) and the Benton visual retention test (mean number of correct reproductions 6.9 versus 7.5, P<0.05) was poorer among the formerly exposed workers when compared with the referents. In addition the subjects who had experienced the highest intensity of exposure [cumulative urinary mercury index > or =550 nmol/(l x year)] had a poorer performance on the trailmaking test, part A and B, on the digit symbol test, and on the word pairs test (retention errors). CONCLUSIONS: The presented results suggest a slight persistent effect of mercury vapor exposure on the central nervous system, mainly involving motor functions and attention, but also possibly related to the visual system. Previous exposure does not seem to have affected the workers' general intellectual level or their ability to reason logically.     

医务人员血源性病原体职业暴露调查

目的了解医务人员发生血源性病原体职业暴露的特点和危险因素,探讨防治对策。方法采用回顾性调查方法,运用《医务人员血源性职业暴露登记表》对某院2013年1月1日—2015年12月31日发生的血源性病原体职业暴露事件进行调查分析。结果共发生血液/体液职业暴露246例。职业暴露人群以在职护士为主(95例,占38.62%);职业暴露发生地点主要为病房(148例,60.16%);职业暴露方式以锐器伤为主(219例,占89.02%);医务人员发生职业暴露时的操作环节主要为手术意外(69例,占28.05%);暴露源主要为乙型肝炎病毒(HBV),共123例(占50.00%);暴露医务人员经局部处理和预防用药后,无1例发生感染。结论医疗机构应加强医务人员血源性病原体职业暴露相关培训,提高防护意识,规范操作行为,改善工作环境,最大限度地减少职业暴露的发生。     

Occupational physical activity and mortality among Danish workers

Purpose  

The relationship between occupational physical activity (OPA) and mortality has mainly been studied among males and shows conflicting results. This study examines this relationship in a cohort of both male and female workers.     

Medical effects and risks of exposure to ionising radiation

Effects and risk from exposure to ionising radiation depend upon the absorbed dose, dose rate, quality of radiation, specifics of the tissue irradiated and other factors such as the age of the individual. Effects may be apparent almost immediately or may take decades to be manifest. Cancer is the most important stochastic effect at absorbed doses of less than 1 Gy. The risk of cancer induction varies widely across different tissues; however, the risk of fatal radiation-induced cancer for a general population following chronic exposure is about 5% Sv(-1). Quantification of cancer risk at doses of less than 0.1 Gy remains problematic. Hereditary risks from irradiation that might result in effects to offspring of humans appear to be much lower and any such potential risks can only be estimated from animal models. At high doses (over 1 Gy) cell killing and modification causes deterministic effects such as skin burns, and bone marrow depression, in which case immunosuppression becomes a critical issue. Acute whole body penetrating gamma irradiation at doses in excess of 2 Gy results in varying degrees of acute radiation sickness and doses over 10 Gy are usually lethal as a result of combined organ injury.     

Occupational exposure to Aspergillus and aflatoxins among food-grain workers in India

Background:

Aflatoxins are a metabolite of Aspergillus molds and are widespread in the natural environment. Workers who handle food grains are at increased risk of exposure to aflatoxins and subsequently certain respiratory conditions. In India, more than half of the employed population is engaged in some type of agricultural work, yet little known about the respiratory problems as a result of exposure to aflatoxins among workers who handle food grains in India.

Objectives:

The aim of this study was to determine the risk of occupational exposure to aflatoxins in food-grain workers compared to workers who are not occupationally exposed to food grains.

Methods:

Bronchoalveolar lavage (BAL) and serum samples from 46 food-grain workers and 44 non-food-grain workers were analyzed for the presence of aflatoxins. Microscopy and culture of BAL samples were performed to detect Aspergillus species.

Results:

Aflatoxins were detected in 32.6% of the food-grain workers and 9.1% of non food grain workers (P<0.01). A significant difference was also found in BAL culture for Aspergillus (P<0.01) between the two groups. About 47.8% of the food-grain workers and 11.4% of non-food-grain workers had chronic respiratory symptoms.

Conclusion:

Occupational exposure to aflatoxins in food-grain workers was found to be associated with the increased presence of respiratory symptoms.     

Occupational pesticide exposure and semen quality among Chinese workers

This study investigated the association between occupational pesticide exposure and semen quality among Chinese workers. Male workers, 32 who were exposed to organophosphate pesticides and 43 who were not exposed were recruited from two nearby factories and interviewed. Following a work shift, semen and urine samples were collected for pesticide metabolite analysis. Semen samples were analyzed for sperm concentration, percentage of motility, and percentage of normal structure. Within the exposed group, the mean end-of-shift urinary p-nitrophenol levels were 0.22 and 0.15 mg/L for the high- and low-exposure subgroups, respectively. Linear regression analysis of individual semen parameters revealed a significant reduction of sperm concentration (35.9 x 10(6) vs 62.8 x 10(6), p < 0.01) and percentage of motility (47% vs 57%, p = 0.03) but not percentage of sperm with normal structure (57% vs 61%, p = 0.13). Multivariate modeling showed a significant overall shift in the mean semen parameter. Occupational exposure to ethylparathion and methamidophos seems to have a moderately adverse effect on semen quality.     

Leukemia among nuclear workers with protracted exposure to low-dose ionizing radiation.

We conducted an analysis of leukemia mortality and protracted exposure to low-dose ionizing radiation. We used data from seven published epidemiologic studies of nuclear workers that reported individual monitoring information for radiation exposure. We found 83 leukemia deaths among white males from a combined total of more than 1.4 million person-years. We calculated an overall relative risk for leukemia of 1.5, after adjustment for age and calendar time, for workers with cumulative occupational doses of 10 mSv (1 rem) or greater, compared with those with cumulative doses of less than 10 mSv. An adjusted relative risk of 1.8 was observed when individuals with 10-50 mSv (1-5 rem) were compared with those who had cumulative occupational doses of less than 10 mSv. The adjusted relative risk for those with doses greater than 50 mSv relative to those with doses less than 10 mSv was 1.2, although the data were especially sparse in this dose range. These combined data indicate a small elevated risk of leukemia for doses of ionizing radiation under 50 mSv.     

Occupational exposure and 12-year spirometric changes among Paris area workers.

A follow-up study over 12 years was conducted among 556 men aged 30 to 54 in 1960 and working at that time in factories around Paris (France). Various occupational exposures were recorded at the time of the 1960 survey after a technical study of each workplace. The annual rate of decline of FEV1 during 12 years was estimated for each subject from the measurements in 1960 and 1972. This rate (the FEV1 slope) was related independently of FEV1 level (which reflects the loss since the beginning of adult life) and of smoking habits to occupational exposure to dust, gases, and heat. FEV1 slope was significantly related to inhalation of mineral dust (even in the absence of silica) as well as to grain dust, and the slope was steeper with increased intensity of exposure to dust. Analysis of job changes showed that among heavily exposed subjects, those who changed jobs had a less steep slope than those who did not. Our results support the hypothesis of a causal role of exposure to dust in the development of chronic airflow obstruction and of a benefit when exposure to dust ceases. Exposure to dust, gas, and heat usually occurred together so data on gas and heat were analysed after taking account of exposure to dust. The influence of heat on FEV1 decline showed a clear trend. Results suggest that exposure to gases associated with exposure to dust or heat or both had a deleterious effect. After adjusting for age, smoking, and FEV1 level (ASLA) the following average slopes were obtained: 44 ml/a (for exposure to none or to only a slight amount of dust, or to gases alone), 51 ml/a (heat), 53 ml/a (noticeable dust), 55 ml/a (noticeable dust and heat), 60 ml/a (noticeable dust, heat, and high concentration of gases). Independently of the occupational exposures, ASLA FEV1 slopes among manual workers were related to skill, being 44 ml/a for skilled and 51 ml/a for unskilled men. Independently of social class and occupational exposures recorded, there were differences in FEV1 slopes by factory, suggesting that one should not rely on using one factory as the control of studies of occupational exposure to another.     

Occupational sunlight exposure in relation to suicide among electric utility workers

BACKGROUND: Occupational sunlight exposure was examined in relation to death from suicide in a United States cohort of 138,905 male electric utility workers. METHODS: Case-control sampling included 536 deaths from suicide and 5,348 eligible controls randomly selected from the cohort. Exposure was classified based on work history linked to indices of cumulative sunlight exposure. RESULTS: Mortality from suicide was not associated with estimates of recent and career occupational sunlight exposure, with adjusted odds ratios around unity. Occupational sunlight exposure was positively associated with nonviolent suicides, but no dose-response gradient was observed and risk estimates were notably imprecise. CONCLUSIONS: These data provide evidence against an association between occupational sunlight exposure and mortality from suicide.     

杭州市场罐头类食品的双酚A污染调查及其膳食风险评估

人类通过多种途径暴露于双酚A（BPA）,膳食暴露是普通人群暴露途径之一。人群膳食暴露量评估资料表明,BPA的膳食暴露量远低于美国推荐的可耐受每日摄入量（50 μg/kg·bw/d）。BPA进入人体后表现为弱的雌激素作用,干扰人体内分泌系统,对人体健康风险表现在影响女性激素水平、胎儿的生长发育和男性生殖系统功能,与儿童肥胖、复发性流产、多囊卵巢综合征、2型糖尿病相关。研究表明,人群暴露于BPA呈现出多途径、低剂量、长期暴露的特点,该特点的暴露会对人体健康有一定影响。     

中国医务人员职业暴露与防护工作的调查分析

目的了解医务人员职业暴露与防护工作现状,为制定职业暴露防护措施提供依据。方法采用分层抽样方法于2016年4月6日—5月6日向全国13个省份158所不同级别医院发放调查问卷进行调查,分别调查各所医院开展职业暴露监测首年、2010年及2015年的职业暴露与防护管理及监测情况。结果81.65%（129/158）的医院医务人员职业暴露管理工作由医院感染管理部门负责;98.73%（156/158）的医院制定了相关规章制度;77.22%（122/158）的医院存在医务人员职业暴露漏报现象。共发生职业暴露事件11 116例,调查首年发生1 542例,2010年发生2 474例,2015年发生7 100例。锐器伤在各类职业暴露类型中占96.76%;职业暴露人员职业分布中,护理人员占53.90%;职业暴露人员科室来源主要为普通病房、手术室、重症监护病房等;引起医务人员职业暴露器具主要为注射器、头皮钢针、手术缝针等;静脉注射、针头丢入利器盒、手术缝针等是引起医务人员职业暴露的高危操作;在职业暴露源阳性分布中,以乙型肝炎病毒（HBV）为主,占58.69%。结论我国医务人员面临职业暴露的风险大,危害重,形势严峻,应通过政府立法、推广应用安全器具、规范医务人员操作行为、正确使用个人防护用品、强化医务人员教育与培训、建立健全职业暴露报告、评估和随访机制等措施,以切实减少职业暴露的发生。