[银行建筑物中氡水平的评估：对意大利一家大型银行集团的调查结果]

Urso Patrizia, Ronchin M, Lietti Barbara, Izzo A, Colloca G, Russignaga D, Carrer P

Dipartimento di Medicina del Lavoro, Ospedale L. Sacco, Università degli Studi di Milano.

Med Lav. 2008 May-Jun;99(3):216-33.

UNLABELLED

Radon, the second cause of lung cancer after smoking, is a natural, radioactive gas, which originates from the soil and pollutes indoor air, especially in closed or underground spaces. Italian legislation recommends an action level of 500 Bq/m3 per year for occupational exposure in underground premises.

OBJECTIVES

Since banks usually use various underground premises (archives, safe-deposit room), a study was made of the radon levels on such premises with the aim of identifying useful monitoring strategies.

METHODS

134 branches of a major Italian banking group were examined using 1817 nuclear track dosimeters at ground level and underground level premises. The branches were located in 7 Italian regions in the north (Piedmont, Lombardy, Veneto), centre (Lazio) and south (Campania, Apulia, Sicily). Information on measurement points was recorded in a technical sheet and statistical analysis was carried out.

RESULTS

Annual underground measurements gave an average concentration of 157 Bq/m3, with 5.1% for 400 < C < 500 Bq/m3 and 2.9%for C > 500 Bq/m3. Seasonal variability was reflected in a significant decrease in concentrations between winter and spring (delta(mean)% = -47.3%) and good stability between autumn and winter (delta(mean)% = 3%); moreover quarterly concentrations account for 85% of the variability of the corresponding annual level. A multiple linear regression model (R2 = 0.33) indicated geographic location as the principal factor in radon accumulation, followed by underground level, humidity, use, lack of windows, heating and natural ventilation, and direct contact of at least one wall with ground rock; whereas the safe-deposit room structure seems to protect from radon accumulation. Moreover, the ground level measurement results were significantly associated with the corresponding underground average concentrations (p < 0.001).

CONCLUSIONS

The results could be a useful tool in planning a monitoring strategy for assessment of bank worker exposure, especially for banking groups with a large number of branches.

未标注

氡是仅次于吸烟的肺癌第二大病因，是一种天然放射性气体，源自土壤，污染室内空气，尤其是在封闭或地下空间。意大利立法建议地下场所职业暴露的行动水平为每年500贝克勒尔/立方米。

目的

由于银行通常使用各种地下场所（档案室、保险箱存放室），因此对这些场所的氡水平进行了研究，以确定有用的监测策略。

方法

使用1817个核径迹剂量计，对意大利一家大型银行集团的134个分支机构的地面和地下场所进行了检测。这些分支机构位于意大利北部的7个地区（皮埃蒙特、伦巴第、威尼托）、中部（拉齐奥）和南部（坎帕尼亚、阿普利亚、西西里）。测量点信息记录在技术表格中并进行了统计分析。

结果

地下年度测量的平均浓度为157贝克勒尔/立方米，其中400＜C＜500贝克勒尔/立方米的占5.1%，C＞500贝克勒尔/立方米的占2.9%。季节变化表现为冬季到春季浓度显著下降（平均变化百分比= -47.3%），秋季到冬季稳定性良好（平均变化百分比= 3%）；此外，季度浓度占相应年度水平变化的85%。多元线性回归模型（R2 = 0.33）表明地理位置是氡积累的主要因素，其次是地下楼层、湿度、用途、无窗户、供暖和自然通风，以及至少一面墙与地面岩石直接接触；而保险箱存放室结构似乎可防止氡积累。此外，地面测量结果与相应的地下平均浓度显著相关（p＜0.001）。