海河干流、大沽排污河沉积物中有机氯农药的残留状况

调查了海河干流和大沽排污河沉积物中持久性有机氯杀虫剂(OCPs)的残留状况.在所选取的16个断面沉积物样品中均有大量HCHs、DDTs检出,表明海河和大沽排污河的DDT和HCH污染相当严重.海河沉积物中HCHs和DDTs总质量浓度分别为3.30～75.96、1.57～221.57 ng/g.大沽排污河沉积物中HCHs和DDTs的残留量分别为2.30～124.61、11.28～237.30ng/g.与国内外部分河流表层沉积物中HCHs、DDTs的含量相比,海河和大沽排污河沉积物中有机氯农药含量较高.最后根据两条河流沉积物中的OCPs的残留量,分析了其可能的污染源.     

渤海湾潮间带表层和柱状沉积物中有机氯农药的沉积记录

测定了渤海湾潮间带表层和柱状沉积物样品中有机氯农药(OCPs)浓度,探讨了OCPs的垂直分布特征,结合柱状沉积物测年结果,研究了该区域OCPs的污染历史。结果表明,潮间带表层沉积物样品中OCPs为78.51～172.10 ng/g(以干质量计,下同),平均值为112.92 ng/g;六六六(HCHs)、滴滴涕(DDTs)、七氯的检出率和残留量均较高,其中HCHs为8.08～56.33 ng/g,平均值为26.35 ng/g;DDTs为5.18～45.02 ng/g,平均值为28.25 ng/g;七氯为10.15～77.16 ng/g,平均值为48.33 ng/g。该区域20世纪50年代开始使用OCPs,70年代达到最高峰。成分分析的结果表明,可能存在着DDTs类物质的输入。     

河蚬对太湖梅梁湾沉积物中HCHs和DDTs的生物富集

以采自清洁水体的河蚬(Corbicula fluminea)为实验生物,利用生物富集实验测试了河蚬对太湖梅梁湾水源地沉积物中HCHs和DDTs的生物富集.研究结果表明,将河蚬暴露于有机氯农药污染程度相似的太湖梅梁湾沉积物中(HCHs和DDTs浓度分别为1.5-1.8.S/S(以干重计)和1.1-1.7 as/g(以干重计))后,随着暴露时间的延长(24～168h),河蚬对有机氯农药的富集量随着暴露时间逐渐增加.试验结束时各样点中河蚬对HCHs和DDTs的富集量分别为(9.4±2.2)ng/g(以干重计)、(20.7±7.6)ng/g(以干重计).实验水体沉积物中HCHs和DDTs的生物沉积物富集因子(BSAF)分别为1.5±0.1和4.4±0.7.生物-沉积物富集因子(BSAF)与有机物的辛醇-水比值(Kow)存在显著正相关.     

(汍)汊湖水体和表层沉积物中有机氯农药分布特征

用GC/ECD内标法定量测定了(汍)汉湖水体和表层沉积物中的有机氯农药(OCPs).(汍)汊湖水样和表层沉积物中20种OCPs均有检出.表层沉积物上层中(0～2 cm)的OCPs明显高于下层(2～10 cm),这是(汍)汉湖具有稳定的水动力条件所致.氯丹在表层沉积物中浓度最高,与该化合物在环境中的强稳定性以及在该地区的大量使用有关.表层沉积物样品DCHsO2上层OCPs中o,p'-DDT主要成分,表明近期可能有新的DDTs,特别是含大量o,p'-DDT的三氯杀螨醇的使用.DDD/DDE则显示表层沉积物上层DDTs的降解主要处在厌氧条件下,而下层处在好氧条件下.     

绿狐尾藻人工湿地底泥中磷形态分布特征研究

构建处理不同负荷养殖废水的绿狐尾藻人工湿地,采集湿地表层(0~5cm)、中层(5~10cm)和底层(10~20cm)底泥样品,测定TP及有机磷含量,并用五步化学分级提取法将无机磷逐级提取为水溶性磷、铝结合态磷(Al-P)、铁结合态磷(Fe-P)、闭蓄态磷(O-P)和钙结合态磷(Ca-P),对比了各形态无机磷水平和垂直分布差异。结果表明,绿狐尾藻人工湿地表层底泥TP质量浓度在167~965mg/kg,其中有机磷占TP的66.0%(质量分数,下同)~79.2%。各形态无机磷的含量排序为:O-PFe-PCa-PAl-P可溶性磷。不同形态无机磷随着底泥深度的增加变化不同,总体来看,从表层到中层,Al-P、Fe-P和Ca-P含量呈现降低趋势,中层到底层无明显变化规律;低负荷湿地中,O-P含量随深度增加逐渐降低,而在中、高负荷湿地中O-P含量随深度增加逐渐增加。相关分析结果显示,Al-P、Fe-P、O-P含量与底泥pH和溶解性有机碳(DOC)呈显著或极显著正相关,说明磷在底泥中的行为易受底泥pH和DOC影响。     

活性炭固定沉积物中HCHs和DDTs的研究

在对沉积物的修复技术中,原位覆盖技术能够降低污染物向水体的释放,降低污染物对底栖生物和水生生物的生物可利用性,以及能够减少污染物向下游的迁移.在本研究中,将活性炭添加到受HCHs、DDTs污染的沉积物中,考察了活性炭剂量、粒径以及活性炭与沉积物接触的方式对HCHs、DDTs水相平衡浓度的影响,及对半渗透膜(SPMD)吸...     

产芝水库底泥和其间隙水中氮、磷分布特征

在现场调查和样品采集的基础上,对产芝水库主要采样点底泥及其间隙水中TN、NH+-N、NO3--N和TP浓度进行了测定,并对底泥TN,TP和其间隙水中TN、总溶解性磷(TDP)浓度进行了相关性分析.研究结果表明,产芝水库底泥含水率和有机质含量在表层均较高;而底泥中氮、磷浓度自深度为10 cm处向表层多表现出增加的趋势,间...     

冀中典型农业区农作物中有机氯农药的生物富集特征与健康风险评价

分析了冀中典型农业区土壤-农作物体系中有机氯农药(OCPs)残留与生物富集特征,探讨了该地区所产农作物的可食部分对人体健康产生的潜在风险。结果表明:11种OCPs以滴滴涕(DDTs)和六六六(HCHs)为主要残留物。土壤中DDTs和HCHs残留量总计达36.52~73.45ng/g,在各自的异构体中p,p’-DDT和γ-HCH所占比例最高,表明OCPs污染主要为近期输入所致。玉米和小麦各器官中,OCPs均在籽粒中最高,分别残留20.66~33.33、19.14~34.57ng/g。小麦和玉米对HCHs的富集能力均强于DDTs。研究显示,该地区玉米与小麦籽粒中OCPs含量虽未超过《农产品安全质量无公害蔬菜安全要求》(GB 18406.1—2001)和《食品安全国家标准食品中农药最大残留限量》(GB 2763—2012),但OCPs致癌总风险相对较高,玉米和小麦中均超过了1×10-6,小麦中OCPs的非致癌总风险和致癌总风险均大于玉米,因此该地区应该优先关注OCPs对小麦所造成的粮食安全问题。     

罗时江河口湿地沉积物磷的空间分布及污染风险评价

以云南洱海罗时江入湖河口湿地为典型对象,利用柱状底泥分层采样器采集罗时江河口湿地沉积物样品,0~10 cm为表层,10~30 cm为中层,30~60 cm为底层,分析了3层沉积物的总磷含量。研究结果表明,(1)从水平方向看,罗时江河口湿地各层(表层、中层、底层)沉积物总磷分布均呈现出沿2条主水道(水道Ⅰ和水道Ⅱ)向岸边递减,并在入水口处出现峰值的规律;垂直方向上看,总磷含量随着沉积深度增加而减少,表层富集明显。表层、中层和底层沉积物总磷平均含量分别为1.09、1.03和0.99 g/kg。(2)运用单因子污染指数评价法对沉积物总磷进行了评价,3层沉积物总磷总体属于中度污染,局部出现重度污染。各层污染程度从大到小依次为表层(1.81)中层(1.72)底层(1.65),重度污染主要集中在水道Ⅰ上。     

重庆典型岩溶区地下河表层沉积物OCPs初步研究

利用GC-ECD对重庆典型岩溶区地下河表层沉积物中19种有机氯农药进行分析,结果表明,研究区总有机氯农药浓度为4.73～286.03 ng/g,DDTs浓度为0.35～181.78 ng/g,HCHs浓度为nd～23.53 ng/g。与国内外其他河流表层沉积物有机氯农药相比为高,说明重庆典型岩溶区地下河已处于较高污染状态。统计DDE/DDD发现,除姜家溶洞外,其他取样点DDE/DDD均大于1,表明研究区DDT降解主要在好氧环境中进行。除靛水地下河,其他取样点表层沉积物(DDD+DDE)/DDT均大于0.5,表明这些地区近年来没有新的DDT类农药输入。     

Distribution characteristics of organochlorine pesticides in surface and vertical sediments from the Zha Long Wetland, China

Introduction

The Zha Long Wetland, the first water bird conservation area in China, lies on the northern bank of the Song Nen Plain with an area of 2,100 km². In many areas of the Zha Long Wetland, water pollution has led to a decrease in the wetland??s ecological function, vegetation degradation, a decrease in the number of bird species, and the depletion of fish resources.

Materials and methods

The sediments used in this study were collected from the surface sediment of seven sites and from different depths in three types of marshes in the Zha Long Wetland in northeast China in late October 2006. The levels and distribution patterns of 17 organochlorine pesticides (OCPs; ??-HCH, ??-HCH, ??-HCH, ??-HCH, p,p??-DDE, p,p??-DDD, p,p??-DDT, endosulfan I, endosulfan II, endosulfan sulfate, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, endrin aldehyde, and methoxychlor) in surface sediments as well as hexachlorocyclohexane (HCH) and 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) in vertical sediments were investigated.

Results and discussion

The concentrations of HCHs, DDTs, endosulfans, heptachlors, aldrin, and methoxychlor in surface sediments ranged from 10.44 to 41.97 ng/g, nd (undetectable levels) to 211.88 ng/g, nd to 69.89 ng/g, nd to 28.10 ng/g, 9.81 to 623.83 ng/g, and from nd to 3.99 ng/g, respectively. The highest levels of OCPs were detected in Tangtugangzi at a total concentration of 727.72 ng/g, where the dominant compound was endrin at a concentration of 483.04 ng/g. In the vertical sediments, the HCHs and DDTs were in the ranges of nd?C136.00 and nd?C214.06 ng/g, respectively.

Conclusions

Different distributions of HCHs, DDTs, and other OCPs indicated that they originated from different contamination sources. Composition analyses in surface sediments indicated recent OCP usage or discharge at some sample sites in the Zha Long Wetland.     

Distribution of organochlorine pesticides in sediments from Kyeonggi Bay and nearby areas, Korea

The residues of oragnochlorine pesticides (OCPs) in 62 sediments from Kyeonggi Bay and nearby areas in the west coast of Korea were determined. The concentrations of chlordanes (CHLs) and DDTs showed a distinctive gradient of contamination between inner and outer sites of Incheon North Harbor (INH), whereas hexachlorocyclohexanes (HCHs) were uniformly distributed at most sites studied. The distribution of CHLs and DDTs was strongly correlated with total organic carbon contents in sediments while HCH residue levels were independent. Relationship between contaminant's concentration and environmental factors was analyzed by principal component analysis. Distribution patterns of T-CHLs, T-DDTs, and TOC were similar while those of T-HCHs, mud content, and grain size were similar. The notable contamination by CHLs and DDTs was found in INH where these levels were one or two orders of magnitude higher than other sites. The dominant OCPs in sediments were beta-HCH among HCH compounds, trans-chlordane among CHL compounds, and p,p'-DDD among DDT compounds. The higher concentrations and compositional pattern of OCPs in INH sediments indicate that INH is in the vicinity of the source.     

Pine needle and semi-permeable membrane device derived organochlorine compounds (OCPs) concentrations in air in Mersin Province to Taurus,Turkey

Abstract

Organochlorine pesticides (OCPs) were analyzed in three different ages (half-, 1.5-, 2.5-year-old) for needles and semi permeable membrane devices (SPMDs) at three deployment periods from sea level to 1881 meter above sea level. Individual HCHs concentrations ranged between 1.4 and 129?pg/g fw depending on the age and sampling season while 2.5-year-old needles showed higher HCHs levels compared to half and 1.5- year-old. Correlation between elevation and HCH concentration in SPMDs was found but not in needle samples. Concentrations of HCHs in SPMDs indicated clearly cold condensation effect on accumulation in winter period and increased with altitude. Concentrations of DDTs in half and 1.5-year-old needles were lower than 2.5-year-old needles. The highest total concentration of DDTs was detected in 1-year-period SPMD. Higher concentrations were found in 2.5-year-old needles for other OCPs. Seasonal and altitude-dependent changes were not observed for other OCPs in SMPDs. Total accumulation of OCPs in SPMDs were found higher than in needles. On the contrary, an increased accumulation rate was observed for HCHs in SPMD. In general, Total concentrations of DDTs and HCHs were similar to total of other OCPs in all altitudes when dominating endosulfan wasnot taken into account in the computation of total concentration of other OCPs.     

Concentration and fate of persistent organochlorine pesticides in estuarine sediments using headspace solid-phase microextraction

The concentration and fate of persistent organochlorine pesticides (OCPs) in estuarine surface sediments in Erh-jen and Lan-yang rivers, Taiwan were investigated using headspace solid-phase microextraction (HSSPME) method to evaluate the possible pollution potential and guideline for OCP concentrations in Taiwan. The HSSPME method exhibits a good analytical performance with low detection limits for OCP determination in sediment. In addition, results obtained using the developed HSSPME method were in good agreement with those obtained using Soxhlet extraction in a certified sample. The developed analytical method was further applied to the determination of concentrations of OCP residues in surface sediments from the estuaries of the selected rivers in Taiwan. A total of 20 surface sediments from each river was collected from 10 sampling stations. The total OCP concentrations in sediments from Erh-jen River ranged from 0.17 to 5.04 ng/g-dw with the mean values of 0.25–1.24 ng/g-dw for HCHs, 0.10–0.89 ng/g-dw for cyclodienes and 0.16–0.64 ng/g-dw for DDTs. The concentrations of OCPs in sediments from Lan-yang River were in the range 0.37–0.9 ng/g-dw with an average of lower than 0.5 ng/g-dw. HCHs and DDTs were abundant in the estuarine sediments from the selected rivers. Results obtained in this study show that the origin of OCPs in the surface sediments from Erh-jen River is a combination of erosion of the weathered soils and long-range atmospheric transport, while the OCP concentrations found in Lan-yang River could be regarded as the background levels of OCPs in Taiwan.     

HCHs and DDTs in salt marsh plants (Scirpus) from the Yangtze estuary and nearby coastal areas, China

HCHs and DDTs in salt marsh plants taken from intertidal flats in the Yangtze estuary and coastal area in April and July 2002 were determined by GC-ECD. A significant seasonal effect was observed for HCHs and DDTs in sources and concentration levels in different sample types including above-ground tissues and roots as well as the whole plants and rhizospheric sediments. The results indicated that the concentration of t-HCH was higher in the above-ground tissues than in their roots in April; however, the partitioning of DDTs between contaminated sediments and the roots showed the higher concentrations of t-DDT in their roots. HCHs and DDTs concentration levels were higher in above-ground tissues than in roots in July. BCFs of HCHs and DDTs exhibited lower values with higher levels of contaminants in sediments, and higher values with lower levels in sediments.     

Contamination of organochlorine pesticides in water and sediments from a waterbird-inhabited lake,East Central China

Seventeen organochlorine pesticides (OCPs) were investigated in the water and sediments from a waterbird-inhabited lake (Yangchaihu Lake) to evaluate their current pollution levels and potential risks. The concentrations of total OCPs in water and sediments were 10.12–59.75 ng/l and 4.25–27.35 ng/g dry weight, respectively. Hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were the most abundant OCPs, while HCB and cyclodiene pesticides were detected with low levels. Levels of ∑OCPs (sum of 17 OCPs) at sites highly influenced by waterbirds were significantly higher than the sites with no significant waterbird populations (one-way ANOVA, P?相似文献   

Distribution and ecological risk assessment of organochlorine pesticides in surface sediments from the East Lake,China

Organochlorine pesticides (OCPs) are ubiquitous pollutants, and their presence in urban lakes is a concern for human and ecological health. Surface sediments in the East Lake, China, were collected in winter 2012 and summer 2013 to investigate concentrations, distribution patterns, possible sources, and potential ecological risks of OCPs in this area. The total concentrations of 14 OCPs ranged from 6.3 to 400 ng g^?1 dry weight (dw) with an average concentration of 79 ng g^?1 dw. The mean values of hexachlorocyclohexanes (HCHs) (α-, β-, γ-, and δ-HCH) and dichlorodiphenyltrichloroethanes (DDTs) (p,p’-DDE, p,p’-DDD, and p,p’-DDT) were 36 and 7.6 ng g^?1 dw, accounting for 45 and 10 % of the total OCPs, respectively. The concentrations of OCPs in sediment samples collected in winter were significantly higher than those in summer, especially the HCHs, of which in winter were two times greater than summer. Composition analyses indicated that DDTs and endosulfan were mainly from historical contribution. Historical use of technical HCH and new input of lindane were probably the source of HCHs in the East Lake. Most sampling sites of HCHs and DDTs were found to have the potential ecological risk based on levels specified in the sediment quality standards.     

Spatial distribution of organochlorine pesticides (OCPs) and effect of soil characters: A case study of a pesticide producing factory

The distribution and concentration of some organochlorine pesticides (OCPs) in the soil around a pesticide factory in Zibo, China, were examined, including dichlorodiphenyltrichloroethane (DDT) and its metabolites, isomers of hexachlorocyclohexane (HCH) and endosulfan (ENDO). The results showed that the OCPs concentrations were extraordinary high in this region. The concentrations of DDTs, HCHs, and ENDO were measured in the range of 0.775–226.711, 0.248–42.838, and 0.081–1.644 mg kg^?1, respectively. DDT and its isomers were identified to be the dominate contaminants in most of the sampling sites. In the vertical direction, the distribution pattern of the total OCPs was in order of DDTs, HCHs, and ENDO in the 0–20 cm, but in 20–40 and 40–60 cm the trends were unobvious. Although no recent input occurred in most areas, the residues of OCPs remained in deep soil due to their persistence. Unlike ENDO, DDTs and HCHs appeared to have the similar property in terms of not only the migration pattern in soil, but also the relationship to the same dominant impact factor (i.e. organic matter). DDTs and HCHs were affected positively by the organic matter, whereas ENDO was affected negatively. Due to the interrelationship among various impact factors, the spatial distribution of pesticides in the soil was considered to be a combined result.     

National survey of the levels of persistent organochlorine pesticides in the breast milk of mothers in China

The occurrence of persistent organochlorine pesticides (OCPs) in breast milk samples collected from mothers from twelve provinces in mainland China was investigated. Dichlorodiphenyltrichloroethanes (DDTs) were the most prevalent agent, followed by HCHs and HCB, whereas levels of chlordane compounds, drins and mirex were lower. The relatively lower DDE/DDT ratio in the Fujian rural area suggested more recent exposure to DDT than in other areas. The mean level of DDTs in breast milk from the southern China was higher than those from northern China (p < 0.05). A positive correlation was observed between concentration of DDTs in human milk and consumption of animal-origin food, suggesting that this parameter could play an important part in influencing OCPs burdens in lactating women. The mean estimated daily intakes of different OCPs for breastfed infants were lower than the tolerable daily intake.