山美水库流域表层沉积物中DDTs农药的残留特征及风险评估

利用GC-ECD检测了山美水库流域表层沉积物中DDTs农药含量,分析了其残留与组成特征及生态风险.结果表明,表层沉积物中DDTs平均含量为4.07 ng/g,其含量范围为0.96～8.20 ng/g;DDTs含量大小顺序为桃溪与湖洋溪汇流(8.20 ng/g)>湖洋溪(4.67 ng/g)>桃溪(4.59 ng/g)>山美水库(1.96 ng/g).表层沉积物中新的DDTs输入量比较少;沉积物中DDTs主要来自于早期残留或是施用农药长期风化后的土壤;大多数采样点DDTs发生好氧生物降解,降解产物以DDE为主.对照Ingersoll风险评估标准,表层沉积物中DDTs农药残留具有较高的生态风险.     

南昌市周边农田土壤中多环芳烃的污染特征及来源分析

采集南昌市周边三个县的18个农田表层土壤样品,采用液固萃取-层析净化-高效液相色谱分析技术,研究了土壤中16种优控多环芳烃类物质的含量和组分特征,运用主成分因子荷载方法分析了其污染来源,并初步评价了其风险水平。结果表明,该区域内农田土壤33.3%轻度污染,最高污染样点PAHs含量为422.8ng/g,最低污染样点PAHs含量为75.2ng/g,平均含量为197.9ng/g,且远离城市的农田土壤残留水平明显低于靠近城市的农田土壤;PAHs的组分特征为以毒性水平较低的低环化合物为主;其污染来源主要是煤、天然气和汽油燃烧组成的混合源。     

南四湖表层沉积物中多氯联苯的空间分布特征

采用气相色谱-电子俘获检测(GC-ECD)方法对从南四湖湖区采集表层沉积物中的12种多氯联苯(PCBs)同系物进行了分析测定。PCBs的含量范围为7.84~42.8ng/g,主要以低氯代物为主。湖内各监测点位的PCBs浓度要高于入湖河口各监测点位;湖内各监测点位中,上级湖各点位的浓度要高于下级湖的点位。污染物来源分析表明,PCBs主要来自造纸漂白过程和焚烧炉排放。与类似水体相比,南四湖表层沉积物中PCBs含量属中低含量水平。整体而言,南四湖表层沉积物中PCBs的含量属于低生态风险水平。     

长江口-杭州湾海洋生物中双酚A和三氯生的浓度分布特征

双酚A(BPA)和三氯生(TCS)是两种受广泛关注的典型环境内分泌干扰物,而长江口-杭州湾是我国最主要的海产品生产海域之一,因此,长江口-杭州湾海洋生物中BPA和TCS的污染特征应引起重视。检测了长江口-杭州湾26种海洋生物体(17种鱼类、6种软体动物、3种甲壳类)肌肉组织中BPA和TCS的浓度分布特征,结果显示:所有海洋生物样品中都可检出BPA,其浓度为0.14~18 ng/g(平均5.2 ng/g);73%的海洋生物样品中含有TCS,其浓度为P<0.01);鱼类、软体动物、甲壳类中BPA和TCS的平均浓度分别为5.8、5.2、2.3 ng/g和12、15、28 ng/g;据估算,浙江普通居民通过食用海洋生物对BPA和TCS的每日摄入量均值分别为5.6 ng/kg和15 ng/kg。     

对卧龙自然保护区作为清洁背景地区研究POPs迁移规律的合理性分析

以卧龙自然保护区土壤中POPs的含量为研究对象,利用MS-MS方法测定POPs在该地区土壤中的含量,其中PCBs含量范围为0.046~1.14ng/g,DDT含量范围为0.42~8.88ng/g,HCH含量范围为0~56.61ng/g,HCB含量范围为7.77~28.41ng/g,并与它们在世界其他地区的含量进行比较,论证了其作为清洁对照区研究POPs迁移规律的合理性。     

南四湖上级湖表层沉积物中多环芳烃的含量及分布特征

对南四湖上级湖表层沉积物中的15种美国环保暑(US EPA)优控多环芳烃(PAHB)进行了定量分析.测定结果表明,沉积物中15种PAHs总合量范围为163.0～2983.8ng/g dry wt..相关分析表明,南四湖上级湖表层沉积物中PAHs浓度的空间分布受入湖河流影响较大,与入湖河流两岸的工农业布局和城市分布存在一定的相关性;南四湖上级湖表层沉积物中的多环芳烃主要来源于煤炭、木材及石油的不完全燃烧;目前南四湖上级湖表层沉积物样品中的PAHs含量处于低风险水平,尚未对生物造成显著的负面影响.     

中国表层水体沉积物中多环芳烃源解析及评价

采用索氏提取气相色谱-质谱法测定中国6个重点水体表层沉积物中16种多环芳烃的含量。各化合物含量范围分别为长江6.20~163 ng/g、淮河7.90~249 ng/g、海河12.1~401 ng/g、松花江5.75~152 ng/g、太湖29.1~2 810 ng/g和滇池19.1~795ng/g；16种多环芳烃的总量分别为：长江1 147 ng/g、淮河1 723 ng/g、海河2 595 ng/g、松花江793 ng/g、太湖12472 ng/g、滇池3 714 ng/g，属中等污染水平。利用特征分子比值法分析结果表明6条水体表层沉积物中PAHs均可能以燃料（包括柴油、汽油、煤、木材）燃烧以及焦化污染为主。淮河和滇池还可能存在轻微石油泄漏污染。利用沉积物质量基准法（SQGs）和沉积物质量标准法分别对6条水体表层沉积物中多环芳烃的风险评估表明严重的多环芳烃生态风险在这些水体表层沉积物中不存在，但长江、淮河、松花江、海河均可能存在一定的潜在风险，负面生物毒性效应会偶尔发生，风险主要来源于荧蒽和菲。太湖和滇池水体中存在的潜在多环芳烃风险种类较多，风险主要来源于菲、荧蒽、芘、苯并（a）蒽、苊和蒽，对水生生物毒性效应较高，有必要进行更深入细致的调查研究高风险区域底栖生物的受损状况、污染来源和途径，以制定合理的污染控制对策。     

污灌农田土壤镉污染状况及分布特征研究

对沈阳郊区某河沿岸部分乡镇的污灌农田土壤中重金属全镉含量进行了分析,评价了土壤镉污染状况,并探讨了该河沿岸土壤中镉的沿程分布特征、横向分布特征和垂向分布特征.结果表明,农田土壤重金属镉含量范围为0.15～8.23mg/kg,均值为1.75mg/kg.用土壤环境质量标准二级标准值对土壤中的全镉含量进行评价,平均镉污染指数为5.95,为重度污染;用土壤背景值标准评价,平均镉污染指数为5.95,超过当地背景值水平8.39倍,污灌已造成该地区重金属镉污染,且污染程度十分严重.该河渠从上游到下游,沿岸土壤镉含量呈降低趋势;横向分布上,距离该河渠越远,镉含量有逐渐减少的趋势;垂向分布上,表层土壤镉含量最高.     

江苏省茶园和农田土壤中拟除虫菊酯类农药残留与污染特征分析

于2018年4—6月采集了江苏省10个市的茶园和农田表层土壤样品,采用气相色谱-三重四级杆质谱仪分析样品中12种拟除虫菊酯类农药的质量比和组成。结果表明,江苏省茶园和农田土壤中广泛检出拟除虫菊酯类农药,总量分别为27.1~50.7,56.9~97.0 ng/g。研究区域的拟除虫菊酯类农药含量存在差异,但组成相近,均是高效氯氟氰菊酯和联苯菊酯的比例较高。与国内其他地区土壤相比,江苏省茶园和农田土壤中拟除虫菊酯含量处于中等水平。     

贵州农作物土壤中OCPs残留现状与差异性分析

通过在贵州主要农作物种植区域采集5 cm、10 cm、15 cm深度的土壤样品,检测其中22种OCPs的残留量。结果表明：在所有水稻土壤样品中除了环氧七氯-A、反式九氯和狄氏剂未检出外,其余19种OCPs均有不同程度检出;OCPs在上述3种深度土壤中总残留量分别为0.526 ng/g、0.497 ng/g、1.605 ng/g。DDTs在3种深度水稻土壤中的总残留量(0.359 ng/g)低于HCHs总残留量(1.135 ng/g)。水稻土壤中γ-HCH、δ-HCH残留量显著高于玉米土壤。水稻土壤中HCHs和硫丹残留主要源自历史上工业制剂的使用,DDTs在水稻土壤中的降解方式主要为厌氧。农作物种植区域土壤中OCPs残留量均符合国家农用地土壤污染风险管控标准。     

河流沉积物中有机污染物的分析研究进展

总结了近年来河流沉积物中有机污染物的研究进展 ,集中评述了国内有关沉积物中多环芳烃、有机氯农药和多氯联苯的分析研究现状 ,包括样品采集、样品前处理和样品分析 ,并对今后河流、湖泊及水库沉积物中污染物的分析工作作了展望     

Trends in Nitrogen Transport in Swedish Rivers

Concern about nitrogen loads in marine environments has drawn attention to the existence and possible causes of long-term trends in nitrogen transport in rivers. The present study was based on data from the Swedish environmental monitoring programme for surface water quality; the continuity of these data is internationally unique. A recently developed semiparametric method was employed to study the development of relationships between runoff and river transport of nitrogen since 1971; the observed relationships were then used to produce time series of flow-normalised transports for 66 sites in 39 river basins. Subsequent statistical analyses of flow-normalised data revealed only few significant downward trends (p 0.05) during the time period 1971–1994, and the most pronounced of these downward trends were caused by reduced point emissions of nitrogen. The number of significant upward trends was substantially larger (15 for total-N and 18 for NO₃-N). Closer examination of obtained results revealed the following: (i) the most pronounced upward trends were present downstream of lakes, and (ii) observed increases in nitrogen transport coincided in time and space with reduced point emissions of phosphorus or organic matter. This indicated that changes in the retention of nitrogen in lakes were responsible for the upward nitrogen trends. The hypothesis that nitrogen saturation of forest soils has caused a general increase in the riverine export of nitrogen from forested catchments in Sweden was not confirmed. Neither did the results indicate that improved agricultural practices have reduced the export of nitrogen from agricultural catchments.     

Fluoride in groundwater in selected villages in Eritrea (North East Africa)

A study was undertaken to estimate fluoride content in thegroundwater in certain parts of rural Eritrea, North-East Africa,along the River Anseba. Standard procedure was adopted for fluoride detection. Results indicate elevated concentration offluoride in groundwater. The highest concentration was found tobe 3.73 mg L^-1, well above the safety level for consumption.Geological basis for the high concentration of high fluoride hasbeen established; it is presumed to be the pegmatite intrusion hosted by a granitic batholith. Extensive dental fluorosis has been observed in the population exposed to drinking water of highfluoride content.     

HPLC法测定饲料中维生素A、维生素D 3 和维生素E

建立了以w(C2H5OH)=95 %乙醇直接提取,高效液相色谱仪在波长280 nm和254 nm处连续测定饲料中维生素A、维生素D3和维生素E的方法.色谱柱为大连依利特Hypersil ODS C18(25 cm×4.6 mm×5 μm),流动相为甲醇-水,流速为1.2 mL/min.维生素A、维生素D3、维生素E的质量浓度分别在1.0 mg/L～20.0 mg/L、0.5 mg/L～15.0 mg/L 、2.5 mg/L～50.0 mg/L范围内与峰面积呈良好的线性关系,检测限分别为0.3×10-6 μg、0.04×10-6 μg、5.0×10-6 μg,相对标准偏差分别为1.6 %、2.7 %、2.4 %,平均回收率分别为99 %、102 %、98 %.     

丽水市空气中Pb污染调查

为调查丽水市空气中Pb污染现状，在机动车相对集中的市区布设5个测点，测点高度1．2m；监测周期为1a，每星期采样1d或2d，每天采集1个样，每次采样6h；监测项目为TSP、Pb；评价标准采用GB3095—1996《环境空气质量标准》。结果表明，丽水市各测点空气中Pb最大的季均值、年均值均未超标；常规测点和交通路口测点之间TSP、Pb质量浓度值均存在显著的差异性。     

Organochlorines and Mercury in Waterfowl Harvested in Canada

Samples of breast muscle from 32 species of waterfowl collected from 123 sites across Canada were analyzed for chlorobenzenes (CBz), chlordane-related compounds (CHL), hexachlorocyclohexanes (HCH), DDT, mirex, dieldrin, PCBs and mercury. ΣDDT, ΣCBz and ΣPCB were the compounds most frequently found above trace levels. ΣHCH and ΣMirex were detected the least often. Mercury was detected in all of the mergansers, over 50% of dabbling, bay and sea ducks, and in less than 2% of the geese analysed. The highest levels of contaminants were generally found in birds feeding at higher trophic levels such as sea ducks and mergansers. With the exception of a few samples of mergansers and long-tailed ducks from eastern Canada, which contained ΣPCB concentrations of 1.0–2.4 mg kg⁻¹, ΣPCB levels were less than 1 mg kg⁻¹ wet weight. Only one merganser from eastern Canada had a ΣDDT concentration (2.6 mg kg⁻¹ ww) which was greater than 1 mg kg⁻¹ ww. The highest ΣCHL (0.10 mg kg⁻¹ ww) was also found in mergansers from eastern Canada. Levels of total mercury in breast muscle were either low (< 1 mg kg⁻¹ ww) or below detection limits with the exception of a few samples of mergansers from eastern Canada which contained mercury concentrations of 1.0–1.5 mg kg⁻¹ ww. Health Canada determined that the organochlorine and mercury levels found in samples of breast muscle of ducks and geese analysed in this study did not pose a health hazard to human consumers and therefore these waterfowl were safe to eat.     

兰州市冬季和春季PM2.5金属元素浓度水平与分布

为了解兰州市大气PM2.5中金属元素的污染水平和分布,于2013年冬季和春季在兰州市区4个在线监测点进行PM2.5样品采集,利用ICP-MS分析金属元素浓度。结果表明,Pb、B元素含量高于200 ng/m3,V、Fe元素含量在100~200 ng/m3,其余元素含量低于100 ng/m3,其中Pb含量最高,平均含量达到373.8 ng/m3.各监测点元素含量在冬季和春季各有不同,整体上是冬季高于春季。金属元素在兰州市区的空间分布与兰州市工业排放和气象因素有关,工业排放为主导因素。     

中国1998年度环境质量状况

对我国１９９８年度的环境空气质量，酸雨，主要流域水质，近岸域海水水质，地下水水位与水质，城市声环境、射环境质量，典型区域生态环境的状况进行了综述了与分析，指出了我国的环境污染问题主要是城市空气污染，地面水体污染和城市噪声污染。     

Characteristic Air Temperature Distributions Observed in Summer and Winter in Urban Area in Japan

The air temperature distributions in August (summer) and December (winter) were measured in an approximately 15 × 15-km urban area in Hyogo Prefecture, Japan, in order to study the spatial distribution of the air temperature and to propose effective measures against the heat island phenomenon. The air temperature was measured mainly by using thermometer shelters installed in an elementary school and a junior high school. The characteristic air temperature distribution depended on the season. The air temperature was higher inland than in the coastal region in August but was higher in the coastal region in December. The air temperature index indicated that the area where higher air temperatures would most likely appear was 5 to 10 km inland from the coast in August and around the coast in December. The seasonal air temperature distribution was presumably due to the strength of solar radiation and anthropogenic exhaust heat.     

天津市空气颗粒物中酞酸酯的分布特征

采用气相色谱-质谱仪(GC-MS)对天津市空气颗粒物中15种酞酸酯(PAEs)夏季和冬季的浓度进行了分析测定,研究了酞酸酯污染水平的季节变化,不同季节酞酸酯的功能区差异,15种酞酸酯在颗粒物中的分布特征,以及DBP和DEHP在夏冬两季中的污染特点,分析了产生上述结果的原因,基本说明了天津市空气颗粒物中酞酸酯的污染状况和特点。