巢湖悬浮物中有机氯农药的分布、来源与风险

利用GC-MS测定了2010年5月至2011年4月巢湖4个采样点悬浮物中有机氯农药(OCPs)含量,分析了悬浮物中OCPs残留水平的时空变化及其组成特征,探讨了悬浮物中主要OCPs的可能来源与生态风险.结果表明:(1)巢湖悬浮物中共检出17种OCPs,分别为六六六类(HCHs)农药的4种异构体(α-、β-、γ-、δ-HCH)、滴滴涕类(DDTs)农药的两种母体(o,p'-、p,p'-DDT)和3种代谢产物(o,p'-、p,p'-DDE,p,p'-DDD)、六氯苯、七氯、艾氏剂、异艾氏剂、氯丹的两种异构体(α-、γ-chlordane)、硫丹-I和灭蚁灵.(2)巢湖悬浮物中∑OCPs含量为172.7±434.9 ng/g,其中∑HCHs含量为15.1±10.3 ng/g,∑DDTs含量为138.8±407.3 ng/g;DDTs在夏季污染水平达到最高;空间上,污染程度为:东部湖区西部湖区中部湖区.(3)DDTs在总OCPs中占有绝对优势,DDTs比例夏季最高而秋季最低;HCHs仅在秋季为主要污染物.(4)HCHs主要来源于近期林丹的非法使用;而DDT主要来源于工业DDT的使用,在春季可能存在DDT的非法使用;悬浮物中DDT的降解环境主要为有氧环境.(5)巢湖悬浮物中p,p'-DDT和o,p'-DDT会对水生生物产生潜在的不利影响.     

太湖表层沉积物中有机氯农药残留及遗传毒性初步研究

采用GC-ECD对太湖表层沉积物中的有机氯农药含量进行了定性定量分析.太湖20个采样点均有不同程度的有机氯农药检出,16种有机氯农药总量为4.22-460.99ng/g(dw),北部湖区、潮心区以及沿岸区等均有高值点出现,与沉积物有机质含量、氮磷营养盐含量分布并不一致.检出率最高的有机氯农药组分为DDTs、HCHs.DDTs含量检出顺序为P,P'-DDT>P,P'-DDD>P,P'-DDE,说明环境中可能仍然具有DDT箱入特征;HCHs中?HCH,?HCH检出相当,怃-HCH检出较高,主要为早期残留.结合鼠伤寒沙门氏菌/哺乳动物微粒体酶系(Ames)试验研究太湖典型溯区表层沉积物中有机污染物的遗传毒性,初步确定可能的生态风险因子.     

北京官厅水库-永定河水系水体中持久性有机氯农药污染

报道了官厅水库-永定河水系中持久性有机氯农药的污染水平,研究发现在水体中存在六六六(HCHs), 滴滴涕(DDTs), 七氯等在内的有机氯污染物,在所有13个采样点的水样中,18种有机氯农药的浓度为4.2-96.9 ng/L,其中六六六、滴滴涕的含量分别为0.09-53.5ng/L和nd-46.8 ng/L.对污染来源进行分析,发现除了主要是源于历史上农田中有机氯农药的残留外,近期可能有新的农药污染源进入水环境,如林丹和三氯杀螨醇的使用可能造成了新的有机氯农药污染.和国内主要河流相比,官厅水库-永定河水系中有机氯农药的污染属轻度污染.     

鄱阳湖周溪湾沉积物中有机氯农药和多环芳烃的垂直分布特征

通过分析鄱阳湖周溪湾柱状沉积物中有机氯农药(OCPs)和多环芳烃(PAHs)的垂直分布特征,初步探讨该区OCPs和PAHs的污染历史.结果表明,周溪湾柱状样中OCPs总含量范围在40.4~174.1 ng/g(dw)之间,六六六(HCHs)是其主要影响的化合物(16.5~153.6 ng/g(dw)),其次为氯丹类(Chlordanes)和滴滴涕类(DDTs),含量分别为3.4~44.0和1.0~33.4 ng/g(dw).垂直分布特征显示:沉积相上OCPs的残留量比实际使用情况向后推迟10~20年,1950s 1990s OCPs曾被大量使用,到2000年左右在沉积物残留上达到顶峰,随后残留量逐渐降低;而近20年来,该区已经鲜有新的HCHs、Chlordanes以及DDTs输入.PAHs总含量范围为41.3~384 ng/g(dw),芘和菲的含量最高,分别为17.1~67.1和2.68~139 ng/g(dw).垂直分布特征显示,1972年以前,PAHs总含量变幅不大,然而近10年来PAHs的排放量急剧上升.此外,自20世纪末开始,周溪湾区域PAHs的主要来源由以前的煤燃烧释放转化为交通污染排放,并伴随有石油泄漏情况.     

千岛湖表层沉积物中有机氯农药的残留特征及生态风险评价

对千岛湖表层沉积物中21种有机氯农药(OCPs)的残留现状进行调查,明确HCHs与DDTs的组成特征及源解析,并评估其生态风险.结果表明,千岛湖表层沉积物中共检出12种OCPs,各采样点位OCPs总量的浓度范围在0.43~12.70 ng/g之间,平均值为5.28±4.84 ng/g,处于低残留水平,其中DDTs是主要的残留物,街口、大坝前点位样品出现OCPs高残留.工业DDTs的历史使用是千岛湖表层沉积物DDTs残留的主要来源,仅街口点位样品存在林丹的污染并有新的DDTs输入,应引起重视.利用沉积物质量基准法、沉积物质量标准法分别对千岛湖表层沉积物中OCPs的生态风险进行评价,结果表明部分点位样品中OCPs的残留现状对该区生物可能存在生态风险.     

巢湖表层水体中DDTs农药的残留特征、来源解析与风险评价

2009年8月采集了巢湖河流及湖泊表层水体共15个样点,利用固相萃取-气相色谱-电子捕获检测器(SPE-GC-ECD)方法测定滴滴涕类(DDTs)农药的含量,分析了其残留特征、来源及风险.结果表明:1)巢湖丰水期DDTs含量范围为1.52-21.79ng/L,平均含量为9.98±4.73ng/L.2)DDT残留主要来自...     

白洋淀表层沉积物中有机氯农药和全多氯联苯的分布特征及风险评估

为了解白洋淀表层沉积物中有机氯农药(OCPs)和多氯联苯(PCBs)的污染情况,采用改进的GC-μECD方法对白洋淀11处沉积物进行了20种OCPs和全部209种PCB单体的定量检测和分析.结果显示:白洋淀11个沉积物样品共检出10种OCPs和24种PCBs,∑OCPs和∑PCBs的含量范围分别为1.22～52.45 ng/g(DW)和nd～37.61 ng/g,在国内处于中等水平; OCPs组成中以HCHs和Dieldrin(狄氏剂)为主,分别占到∑OCPs的39.9%和31.5%,其中7个采样点的HCHs以林丹输入为主,4个采样点以工业六六六污染为主.DDTs检出率较低,来源主要为历史残留;检出的PCB单体以低氯联苯为主,其中一氯、二氯和三氯联苯占∑PCBs的64.73%;采用沉积物质量标准法进行生态风险评估,结果表明白洋淀地区沉积物中p,p'-DDD和∑PCBs生态风险较低,Dieldrin生态风险尚需关注,γ-HCH生态风险较高,不容忽视.     

Occurrence of organochlorine pollutants in the eggs and dropping-amended soil of Antarctic large animals and its ecological significance

Persistent organochlorine pollutants (POPs) are analyzed for the dropping-amended soils from the habitats of Antarctic seabirds and seals in Fildes Peninsula and Ardley Island. The concentration ranges are 0.21 to 3.85 ng/g for polychlorinated biphenyls (ΣPCBs),0.09 to 2.01 ng/g for organochlorine pesticides (ΣDDT),and 0.06 to 0.76 ng/g for hexachlorocyclohexanes (HCHs). Among these,hepata-chlorobiphenyls,hexachlorobiphenyls,p,p′-DDE and α-HCH compounds are dominant. The concentra-tion ranges of ΣPCB,DDT and HCH in the eggs of skuas were 91.9―515.5 ng/g,56.6―304.4 ng/g and 0.5―2.0 ng/g respectively; those in the eggs of penguins were 0.4―0.9 ng/g,2.4―10.3 ng/g and 0.1― 0.4 ng/g; and those in the eggs of giant petrel were 38.1―81.7 ng/g,12.7―53.7 ng/g and 0.5―1.5 ng/g respectively. The dominant POP compounds in the eggs are PCB180,PCB153,p,p′-DDE and hexa-chlorobenzene (HCB). The present study shows that the concentration of POPs in the sea-bird-inhabited-dropping-amended soil varies with the extent of predation and nest occupancy of dif-ferent seabird populations. Statistical analysis on the POP concentrations from the different seabird eggs implies that the difference in the bio-concentration levels of the birds depends on the bio-habits of the species,such as the range of activity,distance of immigration,feeding pattern,and nest occupation. Among these,the most important factor is the location of the seabirds in the food chain and their feeding pattern. This shows that POPs accumulated in the seabirds resulted from the bio-concentration through the food chain. In addtion,210Pb dating for the dropping-amended soils (AD1-a and AD2) was performed,which provided the POP accumulation rate and the historic record for the soil profile. It indicates that POP will continuously affect the Antarctic ecosystem for a long time.     

广东新丰江水库表层水体CO2分压及其影响因素

于2012年7月和2013年1月定点采集新丰江水库表层水样,测定水样的理化及生物学参数,计算水体中二氧化碳分压(p(CO_2))大小并分析其时空变化,探讨新丰江水库p(CO_2)的影响因素及其CO_2源/汇机制.结果表明:丰水期p(CO_2)变化范围为16~3545μatm,均值为999μatm,从水库上游到坝前p(CO_2)逐渐升高;枯水期p(CO_2)变化范围为399~1355μatm,均值为756μatm,从水库上游到坝前p(CO_2)呈下降趋势.丰水期p(CO_2)受温度影响较小,与营养盐(NO-3、DSi)浓度呈正相关,与叶绿素a(Chl.a)、溶解有机碳(DOC)浓度呈负相关,与溶解无机碳(DIC)浓度没有明显相关性;枯水期p(CO_2)受温度影响也较小,受碳酸盐体系的影响,与NO-3、DSi、Chl.a、DIC浓度呈正相关,与DOC浓度没有明显相关性.新丰江水库相对于大气来说是一个通量值偏低的CO_2源.     

新丰江库区二维P波速度结构——英德—河源—陆河深地震测深剖面探测结果

以新丰江水库为中心完成了一条深地震宽角反射/折射剖面.采用动力学射线追踪方法获得了沿剖面的壳幔二维速度结构图像.结果表明:在新丰江水库东南的大坝峡谷区至河源一带,上地壳基底界面至C1界面(上地壳上部的底面)之间速度结构存在较明显的纵横向非均匀性,速度以高、低速相间分布为特征.结合近期新丰江库区地方震精确定位结果分析发现...     

Spatial and vertical distribution of organochlorine pesticides in sediments from Daya Bay, South China

The spatial and vertical distribution of organochlorine pesticides (OCPs) has been investigated in Daya Bay, China. The concentration of total OCPs in surface sediment range from 16.66 to 44.04ng/g dry weight with a mean concentration of 26.60ng/g. DDTs and HCHs were the predominant species. The ratios of (DDD+DDE)/DDT reflected a cocktail input pattern of fresh and weathered DDTs. The predominant alpha-HCH and the alpha/beta-HCH ratios indicated that the technical HCH contamination was mainly due to historical usage, although there was fresh input of lindane. The variation profiles of concentrations showed that OCPs were extensively applied between the late 1950s and early 1980s in China. A recent increasing trend in concentrations of DDTs and HCHs was found in both cores. The increasing ratios of (DDE+DDD)/DDT with corresponding decreases of DDE/DDT ratio implied that most of the DDTs deposited after their production ban were more likely "weathered" DDTs derived from soil residues.     

Persistent organochlorine residues in sediments from the Black Sea

The extent of contamination of the Black Sea by selected organochlorine compounds has been assessed through the analysis of surficial sediments taken from throughout the region. Concentrations of HCHs at sites influenced by the Danube delta are among the highest recorded on a global basis (up to 40 ng g(-1) dry wt). The ratio between the alpha- and gamma-isomers was relatively low indicating contamination through the use of lindane. Concentrations of DDTs (0.06-72 ng g(-1) dry wt) and PCBs (0.06-72 ng g(-1) dry wt) were not especially high in comparison to levels reported from throughout the world. The DDE/DDT ratio was, however, low indicating fresh inputs and hence current usage of DDT within the Black Sea region.     

Distribution of persistent organic pollutants in bivalves from the northeast coast of China

To assess the levels of organochlorine compounds (OCs) in the Chinese coastal environment, monitoring study using bivalves was conducted in 2005. A total of 21 bivalve samples covering the northeastern coast of China were collected and analyzed. Organochlorine compounds were widely distributed in the Chinese coastal environment, with dichlorodiphenyltrichloroethane (DDT) contamination being particularly prevalent. The overall concentrations of PCBs, DDTs, HCHs, chlordane compounds (CHLs), dieldrin, and endosulfans in bivalves were in the ranges of 3.27-25.4, 54.8-2680, 1.42-25.5, n.d. (not detected)-2.28, n.d.-4.02, and n.d.-9.55 ng g(-1) on a dry weight basis, respectively. The concentrations of DDT and HCH compounds are relatively higher than those from the coastal areas of other Asian countries. DDT metabolites were predominant, suggesting that the degradation of DDT is in progress in the Chinese coastal environment. Still, however, DDTs of high concentration exceeding 1000 ng g(-1) were observed at 19% of the stations surveyed. Among HCH compounds, beta-HCH, which is an isomer with strong persistency, was observed predominantly. Compositions of DDT and HCH compounds imply that fresh input of the two compounds into the Chinese coasts is possibly low.     

Time Trend of BHCs and DDTs in a Sedimentary Core in Macao Estuary, Southern China

BHCs and DDTs in a ²¹⁰Pb dated sedimentary core in Macao estuary were analysed with supercritical CO₂ extraction and GC-ECD. The concentrations of BHCs in the core sediment dated from 1962 ranged from trace level (相似文献   

Organochlorine pesticides in sediments of Laizhou Bay and its adjacent rivers, North China

Organochlorine pesticides (HCHs, DDTs and HCB) have been investigated in sediments of Laizhou Bay and its adjacent rivers. The average concentrations of HCHs, DDTs and HCBs are 0.09 ng/g dw, 0.59 and 0.05 for marine sediments and 0.55, 8.6 and 1.1 for riverine sediments, respectively. Laizhou Bay is less contaminated by HCHs and DDTs in comparison with other coastal regions around the world, including the other two biggest bays in Bohai Sea. Fresh input of lindane and dicofol-type DDT were found in several riverine sites. Relatively strong TOC-dependence of HCB distribution in the entire studied area suggested no point source existed and/or water-sediment equilibrium achieved. No significant difference of α/γ-HCH ratios have been observed between marine and riverine sediments. However, o,p′-DDT/p,p′-DDT ratios varied largely between the two regions.     

Organochlorine pesticides and PCB residues in sediments of Alexandria Harbour,Egypt

Persistent organochlorine compound concentrations were determined for 23 surface sediment samples collected from Alexandria Harbor, Egypt. Total PCB concentrations ranged from 0.9 to 1210 ng/g with four to seven Cl-substituted biphenyls being the most prevalent PCBs congeners. Different PCB congener distribution patterns were observed, probably reflecting different inputs and attenuation at various locations. Total DDT concentrations varied from <0.25 ng/g to 885 ng/g. The ratios of DDTs (2,4^′- and 4,4^′-DDT)/total DDTs (DDTs plus metabolites) in sediment samples from certain sites were 0.86 or higher, indicating little attenuation or recent input of DDT. Total chlordane (the sum of heptachlor and its epoxide, oxy-, γ- and -chlordane and cis+trans-nonachlor) ranged from <0.25 to 44 ng/g with the highest concentration found in the Arsenal Basin. The geographic distributions of PCBs, total DDTs and total chlordane were similar. Chlorinated benzenes (CBs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin, endrin, chloropyrifos, endosulfan, mirex and pentachloroanisole were below detection limits or detected at low concentrations in most of the samples. Sites that were contaminated with high concentrations of organochlorine compounds were associated with dense population and low energy environment. The contamination levels of PCBs, total DDTs and total chlordane were in high range compared to other locations worldwide.     

Distribution and sources of organochlorine pesticides in sediments of the coastal East China Sea

Forty-two surface sediment samples collected from the southern coastal East China Sea (ECS) were analyzed for organochlorine pesticides (OCPs). The results showed high concentrations of DDTs and parent DDT fractions in the nearshore area, suggesting that there is still a fresh input of these species from non-point sources, probably due to the recent usage of relevant products. However, for HCHs, the high concentrations with elevated β-HCH fraction were focused at the local major river estuaries, indicating that soils-released HCH input was mainly from the major river runoffs. The distribution and composition of OCPs in the coastal ECS could be more prominently controlled by the direct regional inputs rather than the general natural sorption process on particulate organic carbon. DDTs and chlordane are more important for their potential ecotoxicological risk on neighboring benthic community in the nearshore region and the local major river estuaries.     

Distribution of persistent organic pollutants in bivalves from the northeast coast of China

To assess the levels of organochlorine compounds (OCs) in the Chinese coastal environment, monitoring study using bivalves was conducted in 2005. A total of 21 bivalve samples covering the northeastern coast of China were collected and analyzed. Organochlorine compounds were widely distributed in the Chinese coastal environment, with dichlorodiphenyltrichloroethane (DDT) contamination being particularly prevalent. The overall concentrations of PCBs, DDTs, HCHs, chlordane compounds (CHLs), dieldrin, and endosulfans in bivalves were in the ranges of 3.27–25.4, 54.8–2680, 1.42–25.5, n.d. (not detected)–2.28, n.d.–4.02, and n.d.–9.55 ng g⁻¹ on a dry weight basis, respectively. The concentrations of DDT and HCH compounds are relatively higher than those from the coastal areas of other Asian countries. DDT metabolites were predominant, suggesting that the degradation of DDT is in progress in the Chinese coastal environment. Still, however, DDTs of high concentration exceeding 1000 ng g⁻¹ were observed at 19% of the stations surveyed. Among HCH compounds, β-HCH, which is an isomer with strong persistency, was observed predominantly. Compositions of DDT and HCH compounds imply that fresh input of the two compounds into the Chinese coasts is possibly low.     

Organochlorine contamination (PCBs, DDTs, HCB, HCHs) in sediments from Cienfuegos bay, Cuba

The spatial distribution of various organochlorinated compounds, e.g. PCBs, DDTs, HCB and HCHs, were investigated in sediments from Cienfuegos bay, Cuba. Their concentrations appeared to be relatively low by global standards and only sediments receiving the impact from the residual waters of the city and thermoelectrical power approached the sediment quality guidelines for PCBs and DDTs. Relatively higher ΣDDT concentrations and high DDT/DDE + DDD ratios in two sites near the outfalls of the city indicated a current DDT usage, probably linked to public health emergencies. These results contribute to the sparse regional database for organochlorinated compounds in the Caribbean marine environment.