水中砷、汞的双道原子荧光测定法

目的 探讨水中砷、汞的双道原子荧光测定法。方法 酸性条件下，砷、汞能同时与新生态氢气生成氢化物，采用氢化物原子荧光光度法进行测定，砷、汞灯电流均为80mA，砷的主一辅电流之比为50：30，采用1％硼氢化钾的0．2％氢氧化钠溶液作为还原剂。结果 砷在0-10μg／L内线性良好，r=0．9999，相对标准偏差为2．0％-5．3％，回收率为84％-113％。汞在0-5μg/L内线性良好，r=0．9993，相对标准偏差为1．9％-5．7％，回收率为84％-107％。结论 该方法灵敏度高，操作简便快捷，结果准确可靠，可同时测定水中砷和汞。     

武汉市桶装饮用水生产企业洁净灌装间的净化效果

目的了解武汉市桶装饮用水生产企业灌装间空气洁净装置的净化效果。方法于2002年按照GB50073—2001《洁净厂房设计规范》、GB／T16294—1996（（医药工业洁净室（区）悬浮粒子的测试方法》、GB／T16249一1996（医药工业洁净室（区）沉降菌的测试方法》，对32家桶装水生产企业的灌装车间空气洁净度进行检测，依据GB17324—1998（瓶装饮用纯净水卫生标准》、GB8537—1995（（饮用天然矿泉水卫生标准》、CJ94-1999（饮用净水水质标准》进行检测。结果32家企业灌装间尘埃数的合格率为78．1％，细菌总数合格率为81．3％。按洁净度分级结果显示，符合10000级标准的灌装车间为25户，占78．1％；符合1000级的有8户，占25％；而生产线局部符合100级的有2户，占6.3％。灌装间温度、照度、噪声的合格率均为84．4％；风速的合格率最高，为87．5％；相对湿度合格率为46．9％；室内外压差合格率为34．4％，实施卫生规范化管理后，桶装饮用水的微生物指标合格率从2001年的61．1％上升为2002年的84．1％。结论桶装饮用水灌装问采用洁净装置可以提高桶装饮用水的微生物学的卫生质量。     

Examining the effects of lipopolysaccharide and cholecystokinin on water ingestion: comparing intake and palatability

Lipopolysaccharide (LPS) and cholecystokinin (CCK) have been shown to have anorectic properties in a variety of species. The present study examined the effects of LPS and CCK, both alone and in combination, on two different aspects of water ingestion, water intake and palatability. On test days, animals were first injected intraperitoneally (i.p.) with either LPS (200 microg/kg) or NaCl vehicle, and 2 h later received a second injection of either CCK (8 microg/kg) or NaCl vehicle. In Experiment 1, water intake was monitored for 1 h on 3 separate test days 72 h apart; while in Experiment 2, water palatability was assessed using the taste reactivity test (TRT), on two separate test days 72 h apart. Both LPS and CCK significantly (p<0.05) reduced water intake, with the effects of combined LPS with CCK being more pronounced than either agent injected alone. Rats developed a rapid tolerance to the effects of LPS on water intake on subsequent exposures to LPS. Results from the TRT indicated that LPS enhanced water palatability (p<0.05), as evidenced by a high level of ingestive responding, whereas CCK produced a pattern of responding indicative of satiety. LPS plus CCK reduced ingestive responding on the first test day, but these responses were significantly increased on the second test day (p<0.05). These results demonstrate that although LPS reduces water intake, it enhances water palatability. The results further underscore the necessity for examining palatability changes in addition to intake measures when studying the regulation of feeding and drinking.     

Directed sampling for electrolyte analysis and water content of micro-punch samples shows large differences between normal and ischemic rat brain cortex

Changes in sodium, potassium, and water content in brain tissue are important in the progression of pathology that follows ischemic stroke. Determining these parameters regionally in rodent models of experimental ischemia has been limited because typical tissue weights of more than 35 mg are too large. Identifying ischemic tissue to direct tissue sampling towards ischemic cortex is also represents a difficult generally unresolved area. We suggest that larger differences between normal and ischemic cortex of sodium, potassium, and water content than previously observed can be obtained from directed sampling of 2-mg brain tissue in a model of focal cerebral ischemia. In five rats, the middle cerebral artery and both common carotid arteries were occluded for 4.9+/-0.13 h (mean+/-SEM). Punch-sampling of 1-mm diameter tissue cores for water content (H(2)O%) by the wet-dry method, and [Na(+)] and [K(+)] by flame photometry, was guided by the observation of a subtle change in the surface reflectivity of ischemic cortex of quickly dried, 20-microm frozen brain sections, that was confirmed by MAP2 immunohistochemistry. The ratio of the lesion areas as determined by the reflective change and MAP2 immunoreactivity was 0.96+/-0.03 (n=5). In ischemic cortex H(2)O% was 79.9%+/-0.8%, [Na(+)] was 550+/-25 mEq/kg dry-weight, and [K(+)] 94.2+/-19.2 mEq/kg dry-weight (n=5), all significantly different from the values in border zone cortex, and in cortex contralateral to ischemic cortex and border zone (for all samples n=60, mean wet weight 2.037+/-0.046 mg). Differences between ischemic and normal cortex were 5.4+/-1.1%, 317+/-21 mEq/kg dry-weight, -304+/-27 mEq/kg dry-weight (n=5) for H(2)O%, [Na(+)], and [K(+)]. These differences between ischemic and normal cortex are 1.4-2.5, 1-3.11, and 1.4-3.5 times greater, respectively, than previous results obtained using samples weighing 35 mg or more. These results extend the association of sodium and potassium with ischemic brain edema in the rodent model, and show that these classical measurements can keep pace with the regionality of histochemical and morphological methods.     

水处理各环节对血液透析用水质量的影响分析

目的 研究水处理各环节对血液透析用水质量的影响。方法 2003年对湖南地区99家透析中心水处理方式、各部件更换消毒情况以及反渗水生物学及理化特征进行卫生学调查和测定。结果 前处理填料及反渗膜更换时间、消毒间隔时间以及反渗水输送模式对反渗水生物学特性及理化特性均有影响。结论 定期做好水处理消毒及填料更换以及采用闭路循环输送反渗水是保证透析用水水质合格的关键所在。     

南水北调后微山湖区环境改变对姜片虫病流行影响的研究

目的研究南水北调后微山湖生态环境改变对姜片虫病流行的影响.方法调查湖区微山县的自然环境、水面积变化并对动植物感染姜片虫情况进行流行病学调查,调查居民的卫生状况,应用改良加藤(Kato-kata)厚涂片法粪检易感人群.结果南水北调后湖区水面积扩大,污染得到治理,有利于中间宿主水生动植物繁殖和扩散.本次调查水生动植物及猪体未查到姜片虫幼虫和成虫.居民的姜片虫病防治知识贫乏,人群姜片虫感染率为0.06%.结论微山湖区生态环境的改变,居民不良卫生习惯,可能导致姜片虫病流行和扩散,但是通过姜片虫病防治知识的广泛宣传和教育,制定相应的防治对策,可防止姜片虫病在湖区流行.     

2003年四川省饮用水及集中式供水抽检结果分析

为了解我省饮用水健康相关产品、集中式供水卫生许可批件的持证情况和卫生质量状况 ,2 0 0 3年 5～ 9月 ,我省组织开展了卫生监督抽检工作。结果表明 :家用水处理器持证率 2 5 %;集团用水处理器持证率4 2 .86 %;管材持证率 96 .3 6 %;水处理剂持证率 84 %和集中式供水单位持证率 1 0 0 %;水处理剂合格率 1 0 0 %;二次供水合格率 96 %;市政集中式供水出厂水合格率 1 0 0 %;末梢水合格率 98.77%;自建集中式供水出厂水合格率 4 5 %;末梢水合格率 4 6 .4 3 %。     

饮水与上消化道癌症的关系

目的 探讨不同饮水类型与上消化道癌症(肝癌、胃癌、食管癌)发病危险度的关系。方法 在江苏省泰兴市进行以人群为基础的病例．对照研究，包括肝癌、胃癌、食管癌病例各204、206、218例，对照415例。Logistic回归计算OR值及95％可信区间。结果 所有饮水类型中，浅井水和河水所占比例最高，平均饮用年限最长。饮河水史与胃癌、食管癌上升的危险度有关，而饮浅井水显示与胃癌下降的危险度有关，均呈明显剂量一效应关系；将只有自来水饮用史而无河水饮用史的人群作为参照组进行比较，河水饮用在3种癌症中呈现不同程度的剂量效应关系；当饮用年限大于37年时，肝癌、胃癌、食管癌调整的危险度分别上升到3.37(95％可信区间：1．36～8．39)，5.41(95％可信区间：2．24～13．11)，5．93(95％可信区间：2.35～14．93)。此外，肝癌危险度随个体饮生水频率的增高而上升，剂量-效应关系显著，经常饮用肝癌危险度上升到3.4。结论 河水暴露可能与当地胃癌、食管癌的高发有关，饮生水可能增高个体患肝癌的危险度，自来水则对3种癌症均有一定程度的保护作用。     

河源市高氟区改水降氟效果调查分析

目的 :通过对河源市各高氟区饮用水、灌溉水、土壤、稻谷氟含量的测定及 8～ 15岁儿童氟斑牙患病率的调查 ,评价改水降氟效果 ,为加快改水降氟步伐提供科学依据。方法 :水氟含量测定采用氟离子选择电极法进行检测 ,土壤氟测定用水浸 -电极法 ,稻谷氟测定用酸浸 -电极法 ;儿童氟斑牙诊断采用三型九度法。结果 :河源市高氟区经改水降氟后 ,水氟含量为 (0 .12± 0 .0 38～ 1.99± 3.97) mg/ L,较改水前有明显下降 ;但灌溉水、土壤及稻谷中氟含量均有部分超标 ,超标倍数范围分别为 0 .0 3～ 9.19、2 .5 8～ 12 .2 8、2 .79～ 8.72 ,超标率分别为 5 0 %、6 0 %、70 % ;通过 t检验或秩和检验 ,灌溉水与稻谷、土壤与稻谷中的氟含量比较均有显著性差异 (P<0 .0 5 )。改水后 ,紫金、龙川、和平及东源 4县 8～ 15岁儿童氟斑牙患病率均下降 ,分别由改水前的 79.6 %、86 .1%、96 .7%、80 .8%下降到 37.6 %、5 6 .0 %、71.0 %、6 4 .2 % ,但源城区则没有变化 ,改水前后均高达 10 0 %。结论 :河源市各高氟区改水降氟有明显效果 ,但改水工作各地不平衡 ,改水年份差别较大 ,仍有部分镇、村饮水氟含量较高 ,氟斑牙患病率高居不下。     

电导滴定法测定水中溶解氧的研究

〔目的〕建立一种测定水中溶解氧的新方法。〔方法〕用盐酸标准溶液滴定金属铊与水中溶解氧反应的产物 ,以电导法指示滴定终点。〔结果〕相对标准偏差为 0 .3 8% -0 .97% ,相对误差为 -1.96% -1.85 %。〔结论〕本法准确度好 ,快捷灵敏 ,抗干扰能力强 ,是一种测定水中溶解氧的简便可靠的方法。