硒弹对工业氟污染区山羊有关血清酶及免疫机能的影响

为了探讨硒弹对山羊工业氟中毒的预防效果,把160只6—10月龄的本地山羊,分成一个对照组和三个补硒组,在氟重污染牧场上放牧18个月.同时,对一些血清酶及免疫功能进行了测定.补硒组与对照组相比,GSH-px及T-淋巴细胞转化率升高,而NAP.ALP、骨源性ALP、GOT降低.最后讨论了硒预防山羊氟中毒的机理及硒弹的应用前景.     

自然富硒土中Se对不同水稻籽粒吸收Cd的影响

通过水稻盆栽试验,在高低两种自然富硒土壤上种植3种水稻。结果发现,水稻籽粒Se含量与土壤中Se含量呈正相关,而土壤硒含量过高会降低水稻籽粒的产量。在添加Cd下,高富硒土种植的博优998、秋优998、金稻优998等水稻籽粒Cd含量比低富硒土分别降低了26.99%、10.28%、13.48%,说明土壤中适量的Se对水稻籽粒吸收Cd有拮抗作用。另外,秋优998富集Se、Cd的能力最强,生物产量最低,金稻优998达到富硒效果,而富集Cd的能力最弱,且生物产量较高,在筛选品种时,应优选金稻优998。     

原子荧光光度法测定海水中硒的不确定度评定研究

通过实例对原子荧光法测定海水中硒的不确定度进行评定。根据(JJF 1059-1999)《测量不确定度评定与表示》中对测量和评定不确定度的要求评估了不确定度。测量不确定度的产生包括标准溶液的逐级稀释、工作曲线的非线性和原子荧光光度计的测量性能及取样体积。结果表明取样体积是导致该方法不确定度产生的主要影响因素,在测定时应加强这方面的控制,从而提高测量结果的准确性。当海水中硒的含量为1.99μg/L时,硒含量的扩展不确定度为0.40μg/L,置信水平为95%。     

沈阳和大连市居民血硒水平的评价

采用新极谱法测定了沈阳和大连市健康居民的全血样品的含量。沈阳和大连市分别为296例和300例,全血硒含量分别为153.8±48.5μg/L和146.5±51.0μg/L。沈阳市男性159例,女性137例,全血硒含量分别为157.3±49.6μg/L和149.3±46.6μg/L。大连市男性159例,女性141例,全血硒含量分别为148.1±50.2μg/L和144.7±51.9μg/L。沈阳和大连市居民血硒水平处于营养状态,均比9年前血硒水平显著提高(p<0.001)。     

大气对人体硒、碘、氟的直接影响研究

对一个磷肥厂周围12个村庄的人发、粮食和饮水硒、碘、氟进行了测定,利用改进的模糊数学中的群体识别法对以上数据进行分析,所得结果表明,受污染较重的几个村庄人体硒、碘、氟含量确实受到来自磷肥厂的大气高浓度硒、碘、氟的直接影响.     

海水中Se的分析方法

对国内外学者近些年来有关海水中Ｓｅ的测定方法（包括吕保存、富集分离方法及测定方法）作了较为系统的综述。对几种海水中痕量Ｓｅ测定的常用方法（原子吸收法、原子荧光法、阴极溶出伏安法等）作了重点的介绍，并对各种测定的发展历史，优劣进行了评价。     

Role of interaction between selenium and organic matters on causes of Kaschin-Beck disease

Influences of organic matters of soil and water on speciation and biological utilization of selenium are discussed. Humic acid is found to be the main pool of selenium in soil and affects the bio-availability of the element in soil-plant system. Fulvic acid from drinking water inhibits the absorption of selenium taken from diet. The relationship between high content of organic matters of water and selenium deficiency on the causes of KBD could be reflected in the limited synthesis of glutathione peroxidase, which is generally stimulated by fulvic acid from drinking water.     

Sources and Concentrations of Mercury and Selenium In Compartments within the Las Vegas Wash During A Period of Rapid Change

The Las VegasWash, which drains the Las Vegas valley watershed and provides the second largest inflow to Lake Mead, is being dramatically altered with erosion control structures and wetland restoration efforts. The impact of these changes on the cycling and distribution of Hg and Se is of particular interest because of their tendency to bioaccumulate and because of a lack of information on these contaminants in the Wash. In this study, we determined concentrations of Hg and Se in surface water (monthly), groundwater (once) and sediments (quarterly) from strategic locations within and along theWash during 2002 and 2003. The data was used to characterize Se sources and loading into theWash. Samples containing resurfacing groundwater and urban runoff (LW10.75 and Duck Creek) had significantly higher yearly means (13.7 ± 4.4 and 23.8 ± 4.1μg/L, respectively) compared with mainstream samples containing primarily treated wastewater (2.8 ± 0.8μg/L). Investigation of Se in tributaries, street runoff and rain suggest that the source of the elevated Se is likely groundwater seeps located within a relatively narrow geographic band on the southeast side of the valley. Se content of sediments was similar, except for LW10.75 which was rich in organic matter. Hg concentrations in the water and sediments were low, averaging 4±5 ng/L and 34±20 ng/g, dw, respectively. Overall, this study suggests that water quality remains relatively stable despite changes in theWash and managers of developing wetlands should not use tributary water as source water.     

Microtrace Metalloids Speciation in Lakes Water Samples (Poland)

This paper presents the results of the determination of arsenic, antimony and selenium concentrations of inorganic speciation in surface water samples from Gniezno city (western Poland) and its neighborhood. The concentration of elements were up to 1.85 ng/ml for arsenic, 1.61 ng/ml for antimony and 0.45 ng/ml for selenium (detection limits: 0.04 ng/ml for As and Sb and 0.03 ng/ml for Se). A variety of concentrations for the determined elements has been obtained in waters from Gniezno city’s neighborhood and in water from down-town reservoirs which are under strong anthropogenic pressure.     

Metals in feathers of sooty tern, white tern, gray-backed tern, and brown noddy from islands in the North Pacific

Levels of heavy metals are usuallyhigher in adult than young birds because they eatlarger, more contaminated prey, or because they havehad longer to accumulate metals in their tissues.Further, levels of contaminants are usually less inbirds nesting on remote, offshore islands than inbirds breeding closer to mainland areas that areurbanized and industrialized. We examined the featherlevels of arsenic, cadmium, chromium, lead, manganese,mercury, and selenium in adult sooty terns (Sterna fuscata), gray-backed terns (Sterna lunata), and brown noddy (Anous stolidus, and adult and young white terns (Gygis alba, fromMidway Atoll, and in adult and young sooty terns andadult brown noddy from Manana Island, Hawaii (chicksof other terns were not available). We tested andrejected the null hypotheses that metal levels are notsignificantly different among species, ages, andlocations. Despite their small size, adult white ternshad the highest levels of lead, arsenic and tin. Brownnoddies had the highest levels of cadmium, chromium,manganese, and selenium. Sooty and white terns had thehighest levels of mercury. Sooty tern adults hadsignificantly higher levels of cadmium, mercury, andselenium than young, while young had significantlyhigher levels of arsenic and manganese. White ternadults had significantly higher levels of selenium andtin than young, while young had higher levels ofcadmium and mercury than adults. Except for mercury,there were significant inter-location differenceswithin species in all heavy metals. Contrary toexpectation, where the differences were great, metalsgenerally were higher in the feathers of terns andnoddies from Midway than from Manana.