室内氡及氡子体的卫生学调查及致癌效应研究

天然放射性元素-铀、镭广泛地存在于自然界的土壤和岩石中,由于镭的衰变所形成的放射性气体(Ｒｎ—222)通过岩石裂缝、土壤间隙不断向空气中释放,成为人类本底辐射的重要来源。根据ＵＮＳＣＥＡＲ1993年报告书[1],人均年有效剂量当量为24ｍＳｖ,其中氡和氡子体的辐射造成的剂量贡献为12ｍＳｖ,占一半。从剂量学的观点来考虑,氡的短寿命子体是造成人体内照射剂量的最主要部分。已知氡有27种同位素,其中于人群健康密切相关的是222Ｒｎ,它是238Ｕ蜕变链的组成元素。218ＰＯ、214Ｐｂ、214Ｂｉ、214Ｐｏ是在蜕变过程中产生的4个短寿命的氡子体。…     

Plasma chloroform concentrations in swimmers using indoor swimming pools

This study evaluated swimmers and visitors who were exposed to chloroform (CHCl3) at three indoor swimming pools in Modena, Italy. Chloroform was measured in plasma samples of 127 subjects present at the pools and in 40 nonexposed subjects. The analyses were performed by head-space gas chromatography. Chloroform was present in all samples collected from the 127 subjects who attended the pools (median = 7.5 nmol/l; range = 0.8-25.1 nmol/l). Agonistic swimmers who trained for competitions showed a significantly higher mean value of plasma CHCl3 than nonagonistic swimmers and visitors. Plasma CHCl3 levels were significantly correlated with (a) CHCl3 concentrations in water and in environmental air, (b) the number of swimmers in the pools, and (c) the time spent swimming. Covariance analysis showed that plasma CHCl3 levels also depended on the intensity of the sport activity (total explained variance = 67.4%).     

Determinants of chlorination by-products in indoor swimming pools

Water and air quality of fifteen swimming pools using chlorine disinfection was measured during eight sampling campaigns in Rennes, France. Concentrations of trihalomethanes (THMs) and trichloramine (NCl₃) in air as well as concentrations of parameters, including total organic carbon (TOC), chlorine (free, combined and total), pH, Kjeldhal nitrogen (KN), chloride ions and THMs in water and air temperature, were measured. Water and air samples were collected during 3 h in the morning and afternoon, during high and low attendance days, in summer and winter. Data analysis was perfomed by multivariate ordinary least square (OLS) and quantile (QR) regressions, from both data quality and other parameters such as the ratio between the number of visitors and the volume of water available V/W, the proportion of air re-circulated and the number of swimmers during sampling. The geometric means (GM ± 95% CIs) of the sum of THMs (TTHM) and NCl₃ in air were 74.9 ± 6.7 μg/m³ and 190 ± 10 μg/m³, respectively. As expected, concentrations of TTHM in air were correlated to concentrations of TTHM in water. Concentrations of TTHM and NCl₃ in air measured in winter were significantly higher than in summer, depicting that low air exchange rate in winter lead to accumulation of pollutants. NCl₃ (especially at higher quantiles) and TTHM concentrations in air were associated to the number of swimmers. NCl₃ was also linked to air temperature and pH. Moreover TTHM and NCl₃ in air seemed to be affected by additional determinants including the volume of hall and the ratio V/W. In a process of reducing exposure, the OLS regression provides useful information on key parameters influencing concentrations of THMs and NCl₃ in indoor swimming pools. In addition, QR allows identifying factors associated to elevated levels of contamination.     

Determinants of chlorination by-products in indoor swimming pools

Water and air quality of fifteen swimming pools using chlorine disinfection was measured during eight sampling campaigns in Rennes, France. Concentrations of trihalomethanes (THMs) and trichloramine (NCl₃) in air as well as concentrations of parameters, including total organic carbon (TOC), chlorine (free, combined and total), pH, Kjeldhal nitrogen (KN), chloride ions and THMs in water and air temperature, were measured. Water and air samples were collected during 3 h in the morning and afternoon, during high and low attendance days, in summer and winter. Data analysis was perfomed by multivariate ordinary least square (OLS) and quantile (QR) regressions, from both data quality and other parameters such as the ratio between the number of visitors and the volume of water available V/W, the proportion of air re-circulated and the number of swimmers during sampling. The geometric means (GM ± 95% CIs) of the sum of THMs (TTHM) and NCl₃ in air were 74.9 ± 6.7 μg/m³ and 190 ± 10 μg/m³, respectively. As expected, concentrations of TTHM in air were correlated to concentrations of TTHM in water. Concentrations of TTHM and NCl₃ in air measured in winter were significantly higher than in summer, depicting that low air exchange rate in winter lead to accumulation of pollutants. NCl₃ (especially at higher quantiles) and TTHM concentrations in air were associated to the number of swimmers. NCl₃ was also linked to air temperature and pH. Moreover TTHM and NCl₃ in air seemed to be affected by additional determinants including the volume of hall and the ratio V/W. In a process of reducing exposure, the OLS regression provides useful information on key parameters influencing concentrations of THMs and NCl₃ in indoor swimming pools. In addition, QR allows identifying factors associated to elevated levels of contamination.     

Distribution and determinants of trihalomethane concentrations in indoor swimming pools

Objectives: For many decades chlorination has been used as a major disinfectant process for public drinking and swimming pool water in many countries. However, there has been rising concern over the possible link between disinfectant byproducts (DBPs) and adverse reproductive outcomes. The purpose of this study was to estimate the concentrations of trihalomethanes (THMs) in some indoor swimming pools in London and their variation within and between pools and any correlation with other factors.

Methods: Water samples were collected from eight different indoor swimming pools in London. A total of 44 pool samples were collected and analysed for total organic content (TOC) and THMs. Water and air temperature were measured along with the pH during the collection of pool samples. The level of turbulence and the number of people in the pool at the time were also assessed.

Results: The geometric mean concentration for all swimming pools of TOC was 5.8 mg/l, of total THMs (TTHMs) 132.4 µg/l, and for chloroform 113.3 µg/l. There was a clear positive linear correlation between the number of people in the swimming pool and concentrations of TTHMs and chloroform (r=0.7, p<0.01), and a good correlation between concentrations of TOC and TTHMs (r=0.5, p<0.05) and water temperature and concentrations of TTHMs (r=0.5, p<0.01). There was a larger variation in THMs within pools than between pools.

Conclusion: Relatively high concentrations of THMs were found in London's indoor swimming pools. The levels correlated with the number of people in the pool, water temperature, and TOC. The variation in concentrations of THMs was greater within pools than between pools.

     

Exposure to chloramines in the atmosphere of indoor swimming pools

Specific sampling and analytical methods were developed to assess the concentration of chloramines in the atmosphere of indoor swimming pools because swimming instructors had complained of irritation (mainly eye and lung). The sampling method is based upon the reduction of chloramines to chlorides which are then analysed by ion chromatography. The chloramine concentration in the atmosphere of 13 swimming pools (including five recreational centres and one reeducation centre) was measured, showing that the concentrations were higher in the recreational centres. The influence of slides, bubbling baths, waves and other activities were demonstrated. A correlation was made between the level of pollutants and the complaints registered, leading to the proposal of a ‘comfort’ limit value.     

南宁市游泳池水质卫生状况分析

摘要:目的　了解南宁市2011-2013年游泳池水质卫生状况,为制定卫生监测策略提供依据。方法　按《公共场所卫生标准检验方法》（GB/T18204-2000）对游泳池865份水样进行检测,按GB9667-1996《游泳场所卫生标准》进行评价分析。结果　游泳池水质总体合格率为75.49%,2011-2013年合格率分别为71.47%、80.53%、75.56%,差异有统计学意义（χ2＝6.51,P＜0.05）;各水质检测项目中,尿素合格率最低,其次为游离性余氯,分别为91.21%和93.18%;专营、酒店、学校和小区4种类型游泳池,合格率分别为72.02%、72.94%、83.84%、74.27%,差异有统计学意义（χ2＝9.977,P＜0.05）。结论　南宁市游泳池水质卫生状况不容乐观,应进一步加强卫生监管,提高游泳池水质,保障游泳者身体健康。