A retrospective mortality study of workers exposed to arsenic in a gold mine and refinery in France

A historical mortality study of a cohort of employees of a gold mining and refining company was carried out in Salsigne, France. A major goal of the study was to investigate the relationship between lung cancer mortality and exposure to arsenic, radon, silica, and other contaminants of the working environment. A twofold excess of lung cancer was found both among miners and smelters, mainly concentrated among workers who had experienced exposure to past levels of arsenic, radon, and silica. The consistency of the results in the mine and the refinery are suggestive of a carcinogenic risk from both soluble and insoluble arsenic, although the potential role of other factors cannot be dismissed. © 1994 Wiley-Liss, Inc.     

Residential radon and lung cancer characteristics in never smokers

Abstract

Purpose: The aim of this study is to assess if there is a relationship between residential radon and lung cancer histological types and patients’ age at diagnosis.

Materials and methods: We conducted a multicenter hospital-based case-control study with eight participating hospitals. We included 216 never-smoking cases with primary lung cancer and 329 never-smoking controls. Controls were frequency matched with cases on age and sex distribution. Of them, 198 cases (91.7%) and 275 controls (83.5%) had residential radon measurements.

Results: Lung cancer risk reached statistical significance only for adenocarcinoma (Odds ratio [OR] 2.19; 95% Confidence interval [CI] 1.44–3.33), for other histologies the results were marginally significant. Residential radon level was higher for patients diagnosed before 50 and 60 years old than for older lung cancer cases.

Conclusions: Residential radon in never smokers seems to be a risk factor for all lung cancer histologies. Individuals diagnosed at a younger age have a higher residential radon concentration, suggesting an accumulative effect on lung cancer appearance.     

Performance comparison of electronic radon monitors

The electronic radon monitors are noted for their convenience and acceptable accuracy. Even so, it is necessary to reassure their data quality regularly. We utilized a performance comparison system for this purpose. The instruments in our laboratories (Alphaguard, RAD7, RTM-2100 and Safety Siren) were tested via the comparison experiments. We conclude that by utilizing this system with the concept of calibration factor, it can be helpful to decide whether to send the monitors back to the original manufacturers for adjustment.     

青海省环境中氡及其子体浓度所致居民内照射剂量

本文对青藏高嫌北部的青海省室内外氡-222及其子体进行了测量。采用闪烁法测氡浓度, 托马斯三段法测氡子体α潜能浓度。测量了162个居室和161个室外的氡及其子体浓度。全省室内外氡的平均浓度分别为：20.94Bq·m^-3和8.01mq·m^-3。     

河南省环境氡水平及所致公众剂量

用闪烁室法测量了河南省室内外空气中氡浓度。结果表明, 室内外环境氡浓度量对数正态分布, 95%的居室氡浓度小于55Bq·m^-3。全省室内外平均氡浓度分别为21.5Bq·m^-3和16.4Bq·m^-3。若室内外平衡因子F分别米取0.5和0.6, 则氡子体所致公众年有效剂量为0.97mSv, 年集体有效剂量约为7× 10⁴man·sv。     

固体径迹图像分析法测量环境空气中氡浓度的研究

作者利用计算机图像识别技术，建立了测量环境空气中氧浓度测定的固体径迹图像分析方法，并在营房、坑道的氡水平调查中得到了应用．该方法与国家二级计量站标准氡室的比对结果为１０６．８±３．４Ｂｑ·ｍ￣（－３），和后期告知的标准氧暴露量１１５．６±４．３Ｂｑ·ｍ￣（－３），相对误差约为７．６％。测量速度较显微镜目测法有很大的提高，适合环境空气中氡浓度的测定和大规模氡水平调查。     

基于局部Radon变换和卡尔曼滤波的超声图像肌束方向自动跟踪方法

超声成像是一种无创、实时和便捷的成像方法,已被广泛用于人体肌肉运动分析。临床上目前主要采用手工处理的方法来提取超声图像中的形态结构, 不仅依赖于操作者的主观经验,且耗时严重、重复性低。提出一种自动计算与跟踪超声图像序列中肌束方向的新方法,利用基于约束互信息的自由变换算法自动提取感兴趣区域,然后基于局部Radon变换对超声图像进行投影,并利用相邻帧间肌束的连贯性,采用卡尔曼滤波的图像处理方法。对6名试验对象进行步行实验,共采集小腿内侧腓肠肌的动态超声影像1 080帧,并用所提出的方法计算肌束方向。实验结果表明,所提出的自动检测方法有较好的鲁棒性。与人工检测结果相比,两者的平均相关系数为0.92±0.02,平均误差为0.30°±0.62°。该方法可以一定程度地替代人工测量,在处理大量超声数据时具有较大的优势。     

空气中天然放射性气溶胶的测量及其所致呼吸器官受照剂量的估算

本实验以相对半定量的全小肠嗜银染色计数嗜银细胞的方法对⁶⁰Coγ线不同剂量及不同时间全身一次性照射后小鼠全小肠嗜银细胞的变化进行了观察,发现1～7Gy照射后72小时,嗜银细胞数量随着照射剂量的增加逐渐增多,7Gy达峰值,8 Gy后则随剂量的增加呈指数减少,至160Gy仅为对照的11%.变化最显著的区域在10～30Gy.照射后不同时间的变化结果表明,8.10Gy照后1天嗜银细胞减少60%,2天开始回升,4～7天出现超常,2周时恢复正常.15、20Gy照后1夭减少显著,2天略见回升,8～5天又复减少.30Gy照后嗜银细胞呈进行性减少直至动物死亡.这一实验结果提示小肠嗜银细胞与电离辐射的量效关系有独特的规律性变化.     

未结合氡子体份额的研究

表征未结合氡子体性质的主要参数是扩散系数,作者使用扩散管在常温常压下,测量得出该系数为0.059cm^-·s^-1。未结合氡子体份额的大小与空气中的气溶胶微粒浓度有关,我们的测量说明了这一点,工作区平均f_a=0.07,无人作业区f_a=0.11。使用Raabe的计算模型得出了不同微粒浓度下的来结合氡子体份额f_p。ICRP应用f_p=0.05计算剂量,导出的空气限制浓度,只有当微粒浓度大于10⁵cm^-3时,限制值才是安全的。当微粒浓度在10⁴cm^-3时,就不一定安全了。近来一些调查资料发现,单位暴露量产生的肺癌发病率比早年的要高,可能是现代矿井通风比早年的要好,微粒浓度降低,f^p值增大之故。日前使用通风降氡、过滤清除氡子的防护措施,需从微粒浓度和f^p值的测定上做进一步研究。     

湖北地区室内外空气中氡及氡衰变子体浓度的调查

用抓样调查法,在全省83个调查点,随机测定了380间房屋内的²²²Rn和1920间房屋内的²²²Rn子体潜能浓度。结果表明,它们的浓度频率分布近似对数正态分布；全省室内²²²Rn的几何均值为17.5Bq·m^-3222Rn子体潜能为2.1mWL; 90%以上被调查房间内的平衡等效²²²Rn浓度在16Bq·m^-3以下,超过46Bq·m^-3以上的房间只占1%,约半数房闻内的浓度在7.4mt·mq^-3以下。此外还测定了部分房屋内、外的。加的²²⁰Rn子俸潜能浓度。全省成人居民受室内、外²²²Rn和²²⁰Rn子体照射的人均年有效剂量当量为0.82mSv,集体年有效剂量当量约为4×10⁴人·Sv.