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1.
In Asembagus (East Java, Indonesia) irrigation water is contaminated with effluent from the hyperacid Ijen Crater Lake resulting in a low pH and high levels of various elements. As a first step towards a risk assessment, locally produced food items (rice, maize, cassava leaf, cassava root, peanuts) were collected and concentrations of As, B, Ca, Cd, Co, Cu, Fe, Mg, Mn, Mo, Ni, Pb, V, Zn were compared to samples from a reference area and with literature values. Further, concentrations in rice were compared to total soil concentrations in paddy fields. Compared to the reference area, food items produced in the contaminated area had increased levels of Cd, Co, Ni and Mn in particular, while levels of Mo were lower. In contrast, total soil concentrations of Cd and Mn in particular have decreased whereas especially Mo was increased. In combination with the observed soil acidification, it is likely that the bioavailable concentration of most elements in the contaminated soil is higher (except for Mo) due to an increased weathering rate and/or input via the contaminated irrigation water. In terms of human health, concentrations in foods were generally within normal literature values. However, it was observed that essential elements (in particular Fe) known for their inhibitory effects on e.g. Cd and Mn toxicity did not accumulate in crops whereas Cd and Mn did.  相似文献   

2.
To determine the role of echinoderms as bioindicators of seawater pollution we collected sea‐water and urchin samples from two sites in N. Peloponnesus, Greece. One site was in Patraicos gulf (Patras) and was influenced by point source pollution (urban sewage outfalls) while the second was in Korinthiacos gulf (Akoli) with no evident habitat pollution.

Three heavy metals (copper, nickel and zinc) have been measured in the gonads of two edible species of echinoderms, Arbacia lixula and Paracentrotus lividus.

Statistical treatment of the results showed statistically significant differences in bioaccu‐mulation related to the dry‐weight of gonads, to species, to sex of echinoderms, to season of sampling and to sampling station.

The concentrations of zinc were higher than those of Ni and Cu at in both sampling sites.

Microbiological analysis showed that contamination of the urchins was correlated to that of the surrounding seawater.

Finally both sampling sites seems to be influenced, directly or indirectly, by heavy metal and bacterial habitat pollution.  相似文献   

3.
随着城市点源污染控制不断完善,城市面源污染已成为危害中国城市水体的重要污染源.由城市土地利用变化引起的地表径流污染是导致湖泊水质恶化和富营养化的主要因素,加强面源污染的源-汇效应研究是控制、管理流域污染的重要途径之一.研究选取中国最大的城市湖泊武汉市东湖为研究对象,运用遥感和GIS技术,进行流域划分和地类解译,建立土地利用基础数据库,后对水质统计数据进行定量化处理,通过建立了地类——湖泊水质关系模型,科学地分析了用地与水质的关系,并对城市湖泊水质的季节动态、影响因素进行了初步探索.研究结果表明土地利用和气候变化对流域内湖泊水质的影响显著.其中,农田和建设用地是城市湖泊面源污染的主要来源,绿地和坑塘水面能够有效的截流、吸收污染物,起到保护湖泊水质的作用;受降水、温度等气候因子的影响,湖泊水质状态呈现季节性波动.研究选取东湖为研究对象,研究面源污染的源-汇效应,具有代表性,对于更好保护城市湖泊,合理利用湖泊资源提供了理论依据.  相似文献   

4.
本文以桑树和家蚕为试验生物,采用静态模拟熏气和自然污染调查相结合的方法,对大气苯酚污染蚕桑引起家蚕生长发育障碍进行了观察、分析,认为大气苯酚以间歇性较高浓度侵入蚕室时,会直接致蚕中毒;大气中苯酚以持续较低浓度作用时桑叶内会累积苯酚,间接对象蚕有毒害。家蚕受害后,轻则表现力食欲不振,群体发育不齐,体色灰暗、体重减轻、主要经济性状下降,重则死亡。,F_(0.01)=2.80说明因熏气处理次数引起盛食蚕体重变化的差异极显著,也即较高浓度的苯酚气会直接危害家蚕生长、发育。综上所述,在有关工厂附近大气内苯酚浓度虽然不是很高,也没有被正式列入监测范围,因此也没有监测指标。但此浓度下桑叶内会累积苯酚,家蚕食叶则会间接遭受其危害;如急性排放的苯酚气侵入蚕室,则会对家蚕直接致害,造成经济性状下降,甚至死亡。苯酚是有机毒物,食品上禁用早有规定,如何防止大气苯酚在生态系统中积累、迁移,保障陆地生物包括人类免受其毒害,是值得引起重视的环境问题。  相似文献   

5.
The study of gold sites in the Migori Gold Belt, Kenya, revealed that the concentrations of heavy metals, mainly Hg, Pb and As are above acceptable levels. Tailings at the panning sites recorded values of 6.5–510 mg kg–1 Pb, 0.06–76.0 mg kg–1 As and 0.46–1920 mg kg–1 Hg. Stream sediments had values of 3.0–11075 mg kg–1 Pb, 0.014–1.87 mg kg–1 As and 0.28–348 mg kg–1 Hg. The highest metal contamination was recorded in sediments from the Macalder stream (11075 mg kg–1 Pb), Nairobi mine tailings (76.0 mg kg–1 As) and Mickey tailings (1920 mg kg–1 Hg). Mercury has a long residence time in the environment and this makes its emissions from artisan mining a threat to health. Inhaling large amounts of siliceous dust, careless handling of mercury during gold panning and Au/Hg amalgam processing, existence of water logged pits and trenches; and large number of miners sharing poor quality air in the mines are the major causes of health hazards among miners. The amount of mercury used by miners for gold amalgamation during peak mining periods varies from 150 to 200 kg per month. Out of this, about 40% are lost during panning and 60% lost during heating Au/Hg amalgam. The use of pressure burners to weaken the reef is a deadly mining procedure as hot particles of Pb, As and other sulphide minerals burn the body. Burns become septic. This, apparently, leads to death within 2–3 years. On-site training of miners on safe mining practices met with enthusiasm and acceptance. The use of dust masks, air filters and heavy chemical gloves during mining and mineral processing were readily accepted. Miners were thus advised to purchase such protective gear, and to continue using them for the sake of their health. The miners' workshop, which was held at the end of the project is likely to bear fruit. The Migori District Commissioner and other Government officials, including medical officers attended this workshop. As a result of this, the Government is seriously considering setting up a clinic at Masara, which is one of the mining centres in the district. This would improve the health of the mining community.  相似文献   

6.
苏南太湖地区农田水中COD的调查研究   总被引:1,自引:0,他引:1  
本文在苏南太湖地区5个县7个试验田,对农业非点源有机物污染进行封闭集水区农田径流研究。结果表明:输入农田的污染量以污染比负荷量2年平均值表示,水田为-24.45~10.95kg/ha·a,旱地为-11.70~1.65kg/ha·a,说明农田排水中有机物质对水系水质污染很小。  相似文献   

7.
太湖零点行动前后水质状况对比分析   总被引:6,自引:0,他引:6  
根据 1 998年 1 1月和 1 999年 1 0月的监测数据 ,对零点行动前后太湖各监测点位的水质状况及DO、CODMn、TP、TN、Chla等主要指标的空间分布进行了对比 ,发现污染状况并未得到明显改善 ,除了人为因素外 ,非点源污染的贡献和底泥营养物质的释放是影响水质改善的 2个重要因素  相似文献   

8.
Two parallel sediment cores collected from tidal flat located in the Shuangtaizi River estuary were analyzed for heavy metal concentrations and chemical speciations. Based on the 137Cs activity profile, mean sedimentation rate at the sampling site during the past 50 years was estimated to be 1.3 cm·a-1. Correlation analyses show that almost all the metals are associated with each other, suggesting that these metals might be derived from same sources and/or affected by same geochemical processes. Influence of total organic carbon (TOC) content on the concentrations of Cr, Ni, Cu and Cd is evident. Silt and clay contents, instead of sand content, play an important role in the distribution of these metals. The dominant binding phases for most of the metals (except for Cd) are the residual. The relative decrease of the residual fraction of Cd and Pb in the upper 66 cm of the core is striking. The distribution of chemical fraction confirms that the residual fractions of these metals have a natural origin, while only the non-residual fractions of Cd and Pb increased upward the core due to pollution in the past five decades. Pollution assessment on these heavy metals based on Index of Geoaccumulation (Igeo) also demonstrates that most of the metals are unpolluted. The weak pollution as observed in the sediments is perhaps related to a local plant, the Suaeda heteroptera Kitag, which may have played a significant role in the biodegradation of these metals and the metal distribution in the estuary.  相似文献   

9.
对鄱阳湖南矶山湿地、吴城自然保护区、白沙洲国家湿地公园及鄱阳湖龙口等典型湿地进行沉水植物群落的调查与采样,并测定各样点水样及底泥重金属含量,采用地累积指数法和潜在生态危害指数法对底泥重金属污染进行评价,采用Shannon-Wiener多样性指数和Pielou均匀度指数等方法对研究区沉水植物群落结构进行评价,对水体、底泥重金属含量与沉水植物的生物量、物种多样性等进行Pearson相关性分析,评价鄱阳湖湿地水土环境重金属污染现状,探讨水体与底泥重金属Cu、Pb、Cd等污染物对其水体沉水植物群落的影响。结果表明:各采样点水体与底泥中Cu、Pb、Cd等3种重金属元素中含量最高的为Pb;各样点水体(除白沙洲水体ρ(Pb)外)ρ(Cu)、ρ(Pb)和ρ(Cd)等均未超出地表水环境质量Ⅲ类标准限值,水体重金属含量最高的区域为鄱阳湖东部的白沙洲(ρ(Cu)为50.826μg·L-1,ρ(Pb)为68.660μg·L-1,ρ(Cd)为0.337μg·L-1),最低的区域为鄱阳湖西南部的南矶山湿地(ρ(Cu)为4.316μg·L-1,ρ(Pb)为7.301μg·L-1,ρ(Cd)为0.167μg·L-1)。两种重金属污染评价方法的结果均表明,受纳乐安河下游来水的龙口区域为底泥重金属污染最严重区域;但两种评价方法的结果存在一定差异,地累积指数法评价龙口区域的结果为偏中度或轻度污染,潜在生态危害指数法的评价结果为轻度污染。研究区野外调查中共发现11种沉水植物,隶属7科9属,其中南矶山湿地的沉水植物物种多样性较丰富,但其物种分布的均匀度较低,水体与底泥重金属含量与其水体中沉水植物的生物量或物种多样性间无显著相关性。  相似文献   

10.
根据数理统计的原理,将环境质量标准,平均值,标准偏差以及样本容量综合进行考虑,提出了污染分界线的计算公式,并以表格形式给出了不同显著性水平下,不同的相对标准偏差和样本容量所对应的污染分界线,对污染分界线与样本容量及相对标准的偏差的关系进行了讨论,指出提高监测精度和适当增加监测数据个数,可以使污染分界线接近评价标准。  相似文献   

11.
为检验二元联合作用藻红外测试方法的可行性,用Cu~(2+)、Fe3+、Mn~(2+)、Al3+、Cr3+、Hg~(2+)、Cd~(2+)、Pb~(2+)、Zn~(2+)进行了二元联合作用测试实验。结果显示:联合药液的参照浓度与单药液的参照浓度比为0.5:0.25的有15组二元组合,为2.0:1.0的有10组二元组合,为1.0:0.5的有11组二元组合;在9种重金属的36组二元联合作用测试结果中出现拮抗作用、相加作用、协同作用,表明联合作用类型表现出多样性;14组拮抗作用中单组的再现性为50%~100%、多组的再现性的出现率为93%、单组的重现性为67%~100%、多组的重现性的出现率为100%,21组相加作用中单组的再现性为50%~100%、多组的再现性的出现率为86%、单组的重现性为67%~100%、多组的重现性的出现率为100%,1组协同作用重现性67%;36组联合作用测试结果的再现性为50%~100%、再现性的出现率为86%,重现性为67%~100%、重现性的出现率为100%。上述分析可知,9种重金属的36种二元联合作用测试结果具有较好的多样性、再现性、重现性,表明测试条件、藻温测试方法、三指标评价法能够保证藻响应温差和藻响应药品评价结果的质量,参照浓度分析方法、联合作用评价方法能够控制联合作用分析结果的质量;藻响应的有毒有害物都存在敏感浓度,用参照浓度分析方法可分析出藻响应有毒有害物的参照浓度。因此,藻红外测试技术可以用于测试重金属、农药、有机药品、抗生素等的二元联合作用。  相似文献   

12.
The US Environmental Protection Agency's Office of Research and Development has initiated the Environmental Monitoring and Assessment Program (EMAP) to monitor status and trends in the condition of the nation's near coastal waters, forests, wetlands, agro-ecosystems, surface waters, deserts and rangelands. the programme is also intended to evaluate the effectiveness of Agency policies at protecting ecological resources occurring in these systems. Monitoring data collected for all ecosystems will be integrated for regional and national status and trends assessments. the near coastal component of EMAP consists of estuaries, coastal waters, and the Great Lakes. Near coastal ecosystems have been regionalized and classified, and an integrated sampling strategy has been developed. EPA and NOAA have agreed to coordinate and, to the extent possible, integrate the near coastal component of EMAP with the NOAA National Status and Trends Program. A demonstration project was conducted in estuaries of the mid-Atlantic region (Chesapeake Bay to Cape Cod) in the summer of 1990. in 1991, monitoring continued in mid-Atlantic estuaries and was initiated in estuaries of a portion of the Gulf of Mexico. Preliminary results indicate: there are no insurmountable logistical problems with sampling on a regional scale; several of the selected indicators are practical and sensitive on the regional scale; and an efficient effort in future years will provide valuable information on condition of estuarine resources at regional scales.  相似文献   

13.
The US Environmental Protection Agency's Office of Research and Development has initiated the Environmental Monitoring and Assessment Program (EMAP) to monitor status and trends in the condition of the nation's near coastal waters, forests, wetlands, agro-ecosystems, surface waters, deserts and rangelands. the programme is also intended to evaluate the effectiveness of Agency policies at protecting ecological resources occurring in these systems. Monitoring data collected for all ecosystems will be integrated for regional and national status and trends assessments. the near coastal component of EMAP consists of estuaries, coastal waters, and the Great Lakes. Near coastal ecosystems have been regionalized and classified, and an integrated sampling strategy has been developed. EPA and NOAA have agreed to coordinate and, to the extent possible, integrate the near coastal component of EMAP with the NOAA National Status and Trends Program. A demonstration project was conducted in estuaries of the mid-Atlantic region (Chesapeake Bay to Cape Cod) in the summer of 1990. in 1991, monitoring continued in mid-Atlantic estuaries and was initiated in estuaries of a portion of the Gulf of Mexico. Preliminary results indicate: there are no insurmountable logistical problems with sampling on a regional scale; several of the selected indicators are practical and sensitive on the regional scale; and an efficient effort in future years will provide valuable information on condition of estuarine resources at regional scales.  相似文献   

14.
Concentrations of nine heavy metals (Cr, Cd, Pb, Ni, Cu, Zn, Mn, As, and Fe) in the muscles of four fish species (O. niloticus, C. gariepinus, P. latipinna, and A. d. dispar) collected from the Riyadh River were detected using atomic absorption spectrophotometry in two different seasons in 2012. The concentrations of the studied heavy metals except Cd, Pb, Ni, and Cu in Aphanius d. dispar and Poecilia latipinna were found to be below the safe limits suggested by various authorities. This study also showed that Zn was predominant, while Cr was least accumulated metal in the studied fish muscles. Data demonstrated that there was a significant variation in the heavy-metal concentrations in different fish species in the Riyadh River. Significant positive correlations between heavy-metal concentrations in fish muscles were also found both in pre- and post-monsoon seasons. Metal pollution index was calculated to distinguish polluted from unpolluted ecosystems based upon current knowledge of metal bioavailability, bioconcentration, and bioaccumulation patterns. From the human health point of view, this study showed that there was a possible health risk to consumers due to the intake of Aphanius d. dispar and Poecilia latipinna under the current consumption rate in the country.  相似文献   

15.
A quantitative assessment of drifting net plankton crossing a reef-flat biotope was obtained on a Caribbean coral reef. The spatial distribution and abundance of plankton were sampled to provide estimates of the removal of this potential food resource by suspension-feeding populations. Sampling was largely confined to the reef flat and adjacent waters of Laurel Cay, a flourishing coral reef present on the insular shelf off southwestern Puerto Rico. A prior study provides information on the meteorological and hydrographic characteristics of this area. Evidence for plankton accrual was found in the quantitative depletion of qualitatively similar populations sampled downstream of densely populated reef communities. Numerically, the diatom crop was reduced by 91% and zooplankton by 60% in water streaming off the reef. Significant diel and seasonal variations in plankton abundance were obcerved, as well as notable differences in volume flow, the latter closely related to the local wind regime. A time course of net plankton accrual was calculated, taking into account these various factors. During the summer season (July–August), when zooplankton was relatively abundant and water movement over the reef vigorous, the total gain from plankton reached 0.25 gC/m2/day; 75% of this occurred during a 4 h period at sunrise and sunset. Plankton retained on the reef flat in January of February and in September was around 0.1 g C/m2/day. Zooplankton biomass contributed the greatest share, exceeding that of diatoms by a factor of 10 during the day and 42 in the early evening. A mean annual accrual of 0.18 g C/m2/day is equivalent to 4 to 13% of net community metabolism.  相似文献   

16.
The objective of this investigation was to examine the heavy metal status of the lower basin of Kainji dam (used for hydroelectricity generation), which includes Lakes Kainji/Jebba, Nigeria, and the potential for human exposure to heavy metals from eating fish caught in the lakes. Water, sediments and fish were sampled from the lakes and evaluated for As, Cu, Co, Cr, Fe, Hg, Mn, Ni, Pb, Sb, Ti, V and Zn using the EDXRF technique. Fe and Mn were found to be present at high mean concentrations in the water (13 and 9 μg L-1), sediment (7092 and 376 μg g-1) and fish (11.4 and 4.6 μg g-1) samples. Sb (3.2 μg L-1), Ti (4.1 μg L-1), Cr (2.2 μg L-1), Co (1.2 μg L-1), Cu (1.3 μg L-1) and Pb (1.2 μg L-1) in the water samples and Sb (29 μg g-1), Ti (27 μg g-1), V (27 μg g-1), Cr (27 μg g-1), Co (40 μg g-1), Ni (33 μg g-1), Cu (25 μg g-1), Zn (59 μg g-1) and Pb (19 μg g-1) in the sediment samples were found to be of medium mean concentrations. The other metals were present at trace levels (<1 μg), including As and Hg in the fish and sediment samples. There was an appreciable increase in␣metal concentrations in going from the water to the sediment samples. The probable source of the pollutants is anthropogenic, arising from agricultural activities, corrosion/abrasion of the ferrous steel material and additives in the lubricants and insulation used for auxiliary services on the turbine floor of the dam constructed on the lakes. However, natural geological sourcing from the underlying lake rock cannot be totally ignored, particularly the high levels of Fe and Mn in the sediment samples. The potential risk for human exposure to these metals emanates from the fish caught in the lakes and subsequently consumed, as there are already significant levels of these metals in the two fish species analysed, Tilapia (Oreochromis niloticus) and Chrysicthys (Chrysicthys auratus).  相似文献   

17.
18.
讨论了洞庭湖演变对湖区农业生态环境的影响,认为湖体演变带来了诸如湖泊效应降低、洪涝灾害频繁、土壤潜育化严重、血吸虫病流行以及水产资源破坏等一系列生态环境问题,并提出了保护和改善湖区农业生态环境的对策与措施。  相似文献   

19.
农业磷素流失途径及控制方法研究进展   总被引:9,自引:0,他引:9  
王道涵  梁成华 《生态环境》2002,11(2):183-188
综合评述了农业磷素面源污染产生的原因及其控制方法方面的国内外研究进展。在控制磷污染源方面要注意磷肥用量和磷肥有效性的提高,减少磷素在土壤中的积累;在控制磷素流失方面要针对磷素地表和土体内迁移流失采取有效措施,减少磷素对地表水和地下水污染。磷素污染的治理关键是切断磷源和流失途径的联系,根据磷污染源的等级划分因地制宜地采取治理措施;要将磷和氮综合治理,制定适合我国国情的BMP管理模式。  相似文献   

20.
非点源污染对人类健康影响的研究进展   总被引:1,自引:0,他引:1  
职锦  郭太龙  廖义善  卓慕宁 《生态环境》2010,26(6):1459-1464
社会经济的发展,在使社会得以进步、物质得以丰富的同时,也产生了一系列的工业点源、农业或城市非点源的污染问题,而这些污染对人类健康造成了极大的威胁。尽管非点源污染与人类健康息息相关,但在大多数情况下,人们只考虑污染对环境质量本身的影响,而由非点源污染直接或间接影响到人类健康的问题却没有得到足够的重视。文章综述了目前国内外对非点源污染直接和间接影响人类健康的研究进展,提出了控制非点源污染及减缓它对人类健康影响的对策。。  相似文献   

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