Occurence of pesticides in fish tissues,water and soil sediment from Manzala Lake and River Nile

Pesticides constitute the major source of potential environmental hazard to man and animal as they are present and concentrated in the food chain. This study was conducted on 136 samples of water, sediment and fish for detection and determination of pesticide residues in this ecosystem. Highly significant differences were found in levels of lindan, heptachlor, endrin, dieldrin, P,P′-DDE and propoxur in River Nile water when compared with that of Manzala Lake. Levels of lindan, endrin, malathion and diazinon were significantly higher in soil sediment of Manzala Lake, while the levels of heptachlor, aldrine, P,P′-DDE, DDT, parathion, propoxur and zectran were significantly higher in soil sediment of River Nile. Boury fish of Manzala Lake contained higher levels of heptachlor, aldrin, P,P′-DDE and malathion, while boury fish of River Nile contained a higher level of zectran only. This survey, thus indicated that Manzala Lake and even the River Nile which was used as control are heavily contaminated with chlorinated hydrocarbons (lindan, heptachlor, aldrin, endrin, dieldrin, P,P′-DDE and DDT), organic phosphorus compounds (malathion, dimethoat, diazinon and parathion) and carbamate pesticides (propoxur and zectran).     

PAHs in dated sediments of Ashtabula River, Ohio, USA

Polycyclic aromatic hydrocarbons (PAHs) in dated sediments from Ashtabula River, Ohio, were determined, and a chemical mass balance (CMB) model was used to apportion sources. Three cores (AR-1,AR-2,AR-3) were dated by correlating uranium-supported 210Pb peaks with 1964, 1972, 1977, and 1979 maxima in the discharge record for Ashtabula River. These cores had sedimentation rates between 7.1 and 4.4 cm/year, while a fourth (AR-4) exhibited a much higher rate of 27.8 +/- 18 cm/year. The highest PAH concentration was 11,500 ng/g found in layer 6 of AR-1 (1986), and the lowest was 621 ng/g found in layer 8 of AR-2 (1982). The source contributions to the total PAH concentrations estimated by the CMB model are 0.1-2.2%, 16.8-22.8%, and 78.1-83.8% for wood burning (WB), coke oven (CO), and highway dust (HWY), respectively. Petroleum generated PAHs have maximal contribution during 1977-79, and wood burning PAHs show minimal emissions during 1975-77 in accordance with U.S. consumption records and other studies. Among six PAH markers, only phenanthrene may be subjected to aerobic biodegradation or photolysis with an apparent half-life of 0.005-0.025 year. No anaerobic degradation was observed based on the CMB model. The model works well for the nonmarker compounds, fluoranthene, and benzo[b]fluoranthene/benzo[k]fluoranthene.     

Concentration-dependent mobility, retardation, and speciation of iodine in surface sediment from the Savannah River Site

Iodine occurs in multiple oxidation states in aquatic systems in the form of organic and inorganic species. This feature leads to complex biogeochemical cycling of stable iodine and its long-lived isotope, (129)I. In this study, we investigated the sorption, transport, and interconversion of iodine species by comparing their mobility in groundwaters at ambient concentrations of iodine species (10(-8) to 10(-7) M) to those at artificially elevated concentrations (78.7 μM), which often are used in laboratory analyses. Results demonstrate that the mobility of iodine species greatly depends on, in addition to the type of species, the iodine concentration used, presumably limited by the number of surface organic carbon binding sites to form covalent bonds. At ambient concentrations, iodide and iodate were significantly retarded (K(d) values as high as 49 mL g(-1)), whereas at concentrations of 78.7 μM, iodide traveled along with the water without retardation. Appreciable amounts of iodide during transport were retained in soils due to iodination of organic carbon, specifically retained by aromatic carbon. At high input concentration of iodate (78.7 μM), iodate was found to be reduced to iodide and subsequently followed the transport behavior of iodide. These experiments underscore the importance of studying iodine geochemistry at ambient concentrations and demonstrate the dynamic nature of their speciation during transport conditions.     

Effect of UV irradiation on organic matter extracted from treated Ohio River water studied through the use of electrospray mass spectrometry

Ohio River water was treated by settling, sand filtration, and granular activated carbon filtration. It was then irradiated by low-pressure (monochromatic) and medium-pressure (polychromatic) UV lamps to investigate the effects of UV irradiation on the extracted organic matter (EOM). When the EOM, collected by solid phase extraction cartridges, was analyzed by conventional UV spectroscopy and size exclusion chromatography (SEC), no significant changes in the EOM were revealed for various UV doses. Positive and negative electrospray ionization mass spectrometry (ESI-MS) of the EOM produced mass spectra that vary significantly with UV dose. The UV dosage conditions also appear to affect the reactivity of the EOM to subsequent chlorination. The magnitude of the spectral changes is generally greater for medium-pressure lamps than for low pressure and increases with UV exposure. Based on the observed MS peaks, the changes may be due to the presence of lignin, resulting perhaps from photooxidation and/or photo rearrangement of macromolecules in the sample. When chlorination is used for secondary disinfection, these results suggest that it may be important to consider the effects of UV irradiation on the organic matter in the water before applying UV disinfection technology to a particular source water.     

Polychlorinated biphenyl release from resuspended Hudson River sediment

Three shear turbulence resuspension mesocosms (STORM tanks) were used to examine the release of polychlorinated biphenyls (PCBs) from resuspended Hudson River sediment. Twenty-two percent of the resuspended PCBs desorbed after 2 h, and 35% +/- 8% of PCBs were in the dissolved phase after apparent steady state was reached in 2 days. After the first resuspension event, the solids were allowed to settle and the quiescent time was varied to determine whether the labile pool of PCBs is recharged during sediment consolidation. The steady-state log Koc values for the third subsequent resuspension were higher than for the first event due to lower dissolved PCB concentrations; the particulate PCB concentrations were constant between events. With 1 day of consolidation between resuspension events, the dissolved concentration of all congeners decreased an average of 8% +/- 5% between subsequent resuspension events. With 4 days between events, only the dissolved pentachlorinated PCBs decreased significantly (p = 0.002), suggesting that the easily desorbable PCBs recharge when there is sufficient time between resuspension events.     

Persistence of pesticides in water,sediment and fish from fish farms in Kolleru Lake,India

Kolleru Lake is a freshwater lake in south‐eastern India with a high potential for aquaculture. It is located between 61°32′ and 61°47′N latitude and 81°15′ and 81°27′E longitude. Various chemicals such as pesticides are used to control diseases and ectoparasites in intensive aquaculture farms in India. The main aim of this paper was to determine selected pesticides in water, sediment and fish from 12 fish farms located in Kolleru Lake in order to assess the quality of fish for human consumption and to improve the further risk assessment and management of such chemicals in aquaculture and also to evaluate the impact of aquaculture chemicals on the Kolleru Lake environment. The chemicals used in intensive aquaculture farms were documented. Water, sediment and fish samples were collected from the fish farms during the production period and analysed for the pesticides α‐BHC, γ‐BHC, malathion, chloropyrifos, isodrin, endosulfan, dieldrin and p,p′‐DDT using gas chromatography. © 2002 Society of Chemical Industry     

Time trends of polybrominated diphenyl ethers in sediment cores from the Pearl River Estuary, South China

The present study provides information on the time trend of PBDEs in three sediment cores from the Pearl River Estuary (PRE), South China, using 210Pb dating technique. The sigmaPBDEs (except for BDE 209) concentrations in all sediment cores increased gradually from the bottom (mid-1970s) to the middle layer (later 1980s and early 1990s) followed by different temporal trends in different locations to the surface sediments, reflecting the variations in the consumption of commercial penta-BDEs mixture in different regions of the Pearl River Delta. The BDE 209 concentrations remained constant until 1990 and thereafter increased exponentially to the present, with doubling times of 2.6 +/- 0.5-6.4 +/- 1.6 years, suggesting the increasing market demands for deca-BDE mixture after 1990 in China. The inventories of sigmaPBDEs and BDE 209 in sediments of the PRE were 56.0 and 368.2 ng cm(-2), respectively, and the total burden of PBDEs in the PRE were estimated at 8.6 metric tons. The current sigmaPBDEs and BDE 209 fluxes to the PRE were 2.1 and 29.7 ng cm(-2) yr(-1), respectively. The concurrent increase of BDE 209 fluxes and the annual gross industrial output values of electronics manufacturing revealed that the rapid growth of electronics manufacturing in this region since the early 1990s was responsible for the sharp rise of BDE 209 fluxes in the past decade. The PBDE congener compositions of the cores indicated the various input pathways for PBDEs transport to different locations of the estuary.     

Abundances, depositional fluxes, and homologue patterns of polychlorinated biphenyls in dated sediment cores from the Pearl River Delta, China

Despite the recent efforts to investigate the distribution and fate of persistent organic pollutants in the tropical and subtropical regions of Asia, very little was known about the temporal change of polychlorinated biphenyls (PCBs) in the environmental ecosystem of China. In this study, three dated sediment cores collected from the Pearl River Delta of southern China were analyzed for a large suite of PCB congeners, from which the temporal profiles of PCB abundances, fluxes, and homologue patterns were constructed. The sedimentary inventories of total PCBs at the sampling sites ranged from 480 to 1310 ng/cm2, at the low end of the worldwide figures. Although production and use of PCBs have been banned or highly restricted in China since the early 1980s, the fluxes of total PCBs continued to increase in the Pearl River Delta sediments. There was a concurrent increase of PCB fluxes and gross domestic product per capita in the region from 1980 to 1997, and a decline of agricultural land use was evident at the same time. Apparently, large-scale land transform since the early 1980s as well as emissions from the PCB-containing electrical equipments were responsible for the sharp rise of PCB fluxes in the recent sediments. The difference in the PCB homologue patterns from 1940 to the mid-1970s was probably indicative of the different timelines of PCB usage in Macao/Hong Kong and mainland China and the differenttypes of technical PCBs commercially used. PCBs were detectable in sediments deposited well before the time frame when production of PCBs began (before 1930) and were relatively enriched in the less chlorinated homologue groups (3Cl and 4Cl PCBs), suggesting the downward mobility of lightly chlorinated PCB congeners in the sediment column.     

Occurrence and bioavailability of polybrominated diphenyl ethers and hexabromocyclododecane in sediment and fish from the Cinca River, a tributary of the Ebro River (Spain)

Fish and sediments from four places along the Spanish River Cinca were analyzed for polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). The samples were collected up- and downstream from Monzón, a heavily industrialized town draining to the river. PBDEs and HBCD were found in sediments at levels ranging from 2 to 42 ng/g dry weight and from not detected (nd) to 514 ng/g dry weight, respectively. Twenty-three fish samples (Barbus graellsi) collected at the same places were also analyzed, showing levels from nd to 446 ng/g wet weight for PBDEs and from nd to 1172 ng/g wet weight for HBCD. The lowest values for both sediment and fish samples were found upstream of the industry. Of 40 congeners (from mono- to deca-BDEs) included in the analytical work, 8 PBDE congeners were detected in river sediments, whereas 17 different PBDEs were found in fish samples. Large fish-to-sediment ratios for these brominated compounds indicate that they are highly bioavailable, with the exception of deca-BDE which was only detected in sediment samples. Concentrations of PBDEs and HBCD were slightly higher in muscle tissues than in liver samples obtained from the same specimen of fish. Moreover, PBDE and HBCD concentrations are correlated with fish length indicating the bioaccumulation of these contaminants.     

PCB loading from sediment in the Hudson River: congener signature analysis of pathways

The upper Hudson River (NY) was subjected to massive PCB contamination over a period of three decades. A large inventory of PCBs remains in contaminated sediments of the river, most notably in the Thompson Island Pool. During the summer, flow crossing the Thompson Island Pool exhibits a large and consistent PCB load gain. This load gain is not associated with scouring flows and is not accompanied by an increase in suspended solids. A variety of hypotheses have been proposed to explain this load gain, including flux of contaminated porewater and dissolution of unverified reservoirs of pure PCBs. A wealth of congener-specific PCB data is available for the site throughout the 1990s. Interpretation of the Thompson Island Pool load gain is facilitated by examination of the PCB congener signature of the gain and comparison to the signature of potential sources. This examination suggests that neither the flux of porewater nor the dissolution of unaltered Aroclors are the predominant source of the load gain. Instead, the congener signature is consistent with a mixed source consisting of porewater flux and non-scour flux of contaminated sediments. The non-scour sediment flux, which reaches a maximum in the beginning of the summer growing season, is likely driven by a variety of biological and anthropogenic processes, including bioturbation by benthic organisms, bioturbation by demersal fish, scour by propwash, mechanical scour by boats and floating debris in nearshore areas, and uprooting of macrophytes.     

Perfluorinated compounds in house dust from Ohio and North Carolina, USA

The perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), have come under increasing scrutiny due to their persistence, global distribution, and toxicity. Given that their human exposure routes remain poorly characterized, the potential role of house dust needs to be more completely evaluated. In this study, new methods for the analysis of 10 PFAAs and three fluorinated telomer alcohols (FTOHs) were developed for dust samples collected from homes (n = 102) and day care centers (n = 10) in Ohio and North Carolina in 2000-2001. FTOHs were measured by GC/ MS and PFAAs were analyzed by LC-MS/MS. PFOS and PFOA were the most prominent compounds detected, occurring in over 95% of the samples at median concentrations of 201 and 142 ng/g of dust, respectively. Maximal concentrations of PFOS were 12 100 ng/g (95th percentile, 2240 ng/g), PFOA 1960 ng/g (95th percentile, 1200 ng/g), and perfluorohexanesulfonate (PFHS) 35 700 ng/g (95th percentile, 2300 ng/g). The 8:2 FTOH, which is volatile and can degrade to PFOA, had a maximum concentration of 1660 ng/g dust (95th percentile, 669 ng/g). These results indicate that perfluorinated compounds are present in house dust at levels that may represent an important pathway for human exposure.     

Dynamic model for the accumulation of cadmium and zinc from water and sediment by the aquatic oligochaete, Tubifex tubifex

In aquatic environments, organisms are exposed to and accumulate metals via waterborne and dietary routes including ingested sediment. A key element in understanding metal uptake and accumulation is information concerning the relative importance of the routes of uptake and the kinetics of the processes. In this work the bioaccumulation of the essential element zinc and the nonessential element cadmium were studied from the aqueous and sediment phase, in the cosmopolitan oligochaete Tubifex tubifex, using the radiotracers 109Cd and 65Zn. A compartmental kinetic model was constructed and parametrized by fitting the model to metal body concentrations. Using the pharmacokinetic modeling approach and taking into account the distribution of the metal between water and sediment, the different routes were quantitatively separated. Under the experimental conditions, the sediment phase accounted for 9.8% of the cadmium and 52% of the zinc uptake. These values are based on the uptake of the radiotracers spiked sediments and therefore likely represent maximal values since it was shown that under the specific conditions this was the most mobile metal fraction. This difference was largely explained by the large difference in assimilation efficiency between cadmium and zinc. Simulations of different conditions showed that both dissolved and sediment-associated metal can be important sources of metal exposure for the worms and that the relative importance strongly depends on the metal and exposure conditions including the lability of the metals in the sediment phase.     

Methylantimony and -arsenic species in sediment pore water tested with the sediment or fauna incubation experiment

In this study, the speciation of arsenic (As) and antimony (Sb) across a water-sediment interface and the formation of mono-, di-, and trimethylated species overtime in a microfiltered pore water solution were examined. We used an experimental technique, known as the sediment or fauna incubation experiment (SOFIE), which enables the determination of chemical speciation across redox zones in undisturbed systems. Five different incubation experiments were run: Over a 76 day incubation period, pore water was sampled and speciated 5 times. These experiments revealed the complete methylated species pattern for arsenic and antimony in the microfiltered sediment pore water. This constitutes the first report of methylated As and Sb species in a true pore water solution of sediments. Predominant organic species were dimethylantimony (DMSb up to 2.7 microg/L) and dimethylarsenic (DMAs up to 4.3 microg/L) followed by monomethylated species (MMAs and MMSb). These data (i) indicate that methylation significantly influences the translocation of As and Sb in sediments, (ii) demonstrate good agreement between the occurrence of methylantimony and the occurrence of methylarsenic in the pore water, (iii) reveal that As transformation in sediments is faster than Sb transformation but is more susceptible to disturbances from acidification, and (iv) regarding the translocation of these elements and antimony in particular, methylation is clearly a relevant, and perhaps as yet underestimated, factor.     

Alkylphenol and bisphenol A levels in rubber products

Levels of p-t-butylphenol (PTBP), p-t-octylphenol (PTOP), p-nonylphenol (NP) and bisphenol A (BPA) in rubber products in food-contact use, infant-related use and other uses are reported. Of 60 rubber products tested, PTOP was found in three in a concentration range of 2.2-37 μg g^-1, and NP in 15 in a concentration range of 2.6-513 μg g^-1. PTBP and BPA were not found in any sample. PTOP and NP were not detected in any infant-related sample, regardless of the material type. In contrast, among the samples with food contact and with other uses, the percentages containing PTOP or NP were 33 and 43%, respectively. A migration test was performed on eight samples containing NP and used in food-contact environments. The migration level of NP from spatulas to n-heptane was 0.83-1.52 μg ml^-1. The average migration rates to water, 20% ethanol and n-heptane were 0.03, 0.7 and 6.6%, respectively.     

Beryllium-7 as a tracer of short-term sediment deposition and resuspension in the Fox River, Wisconsin

Short-term (approximately monthly) sediment deposition and resuspension rates of surficial bed sediments in two PCB-laden impoundments on the Fox River, WI, were determined in the summer and fall of 1998 using 7Be, a naturally occurring radioisotope produced in the atmosphere. Decay-corrected activities and inventories of 7Be were measured in bed sediment and in suspended particles. Beryllium-7 activities generally decreased with depth in the top 5-10 cm of sediments and ranged from undetectable to approximately 0.9 pCi cm(-3). Inventories of 7Be, calculated from the sum of activities from all depths, ranged from 0.87 to 3.74 pCi cm(-2), and the values covaried between sites likely reflecting a common atmospheric input signal. Activities of 7Be did not correlate directly with rainfall. Partitioning the 7Be flux into "new" and "residual" components indicated that net deposition was occurring most of the time during the summer. Net erosion, however, was observed at the upstream site from the final collection in the fall. This erosion event was estimated to have removed 0.10 g (cm of sediment)(-2), corresponding to approximately 0.5 cm of sediment depth, and approximately 6-10 kg of polychlorinated biphenyls (PCBs) over the whole deposit. Short-term accumulation rates were up to approximately 130 times higher than the long-term rates calculated from 137Cs profiles, suggesting an extremely dynamic sediment transport environment, even within an impounded river system.     

Bioaccumulation and metabolism of polybrominated diphenyl ethers in carp (Cyprinus carpio) in a water/sediment microcosm: important role of particulate matter exposure

Microcosms were built up to simulate a pond system with polybrominated diphenyl ether (PBDE) contaminated sediment and bioorganisms. The microcosms were divided into groups A and B. In group A, both benthic invertebrates (tubificid worms) and carp (Cyprinu carpio) were added, while in group B, only fish were added. After exposure for 20 d, the fish were sampled (exposure I). A net was fixed in the microcosms, and new fish were added (exposure II). These fish were prohibited from contacting the sediment by the net, and the accumulation and depuration of PBDEs in the fish were investigated. Among 11 monitored PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, BDE-206, BDE-207, BDE-208, and BDE-209), only 5 congeners (BDE-28, BDE-47, BDE-100, BDE-153, and BDE-154) were detected in the carp fillets and liver. BDE-99 and BDE-183 were not detected in the fish because of the efficient metabolic debromination in carp tissues. The uptake of PBDEs in exposure I was significantly higher/faster than that in exposure II, since the fish in exposure I had an opportunity to take in more of the highly contaminated particles. The uptake kinetics (k(s)) and elimination (k(e)) rate coefficients showed a general trend of decreasing with increasing log K(ow). No significant difference was observed in uptake/depuration kinetics between groups A and B, indicating that the tubificids' reworking does not affect the bioaccumulation of sediment-associated PBDEs in fish significantly. All the PBDE congeners, including nona- and deca-BDEs, were bioaccumulated in the tubificid worms. The PBDE concentrations in the worms were significantly higher than those in the fish, and the congener profile of the sevem major congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) was distinctly different from that of fish tissues. The biota-sediment accumulation factors in the worms ranged from 0.01 to 5.89 and declined with increasing bromination and log K(ow.).     

草鱼鱼鳞多糖的提取分离与初步鉴定

鱼鳞具有抗癌、抗衰老、降低血清总胆固醇和甘油三酸酯等功能,为研究草鱼鱼鳞及其多糖的基本组成结构和生物活性,以及充分利用草鱼鱼鳞。本文主要通过木瓜蛋白酶和碱性蛋白酶复合酶解提取草鱼鱼鳞多糖。提取的多糖再经三氯乙酸除蛋白、乙醇沉淀、DEAE-Sephasoe fast flow离子交换柱层析和Sepharose 6 fast flow凝胶柱层析分离纯化,并进行初步鉴定。柱层析首次从草鱼鱼鳞中分离得到3种多糖。各多糖组分经化学鉴别、紫外、红外光谱和元素分析表明,草鱼鱼鳞含有壳聚糖和4硫酸化硫酸软骨素,以及另外一种新型糖胺聚糖,其结构有待进一步鉴定。      

奶瓶中双酚A、烷基酚及烷基酚聚氧乙烯醚残留量的高效液相色谱-荧光测定法

建立了奶瓶中双酚A、烷基酚及烷基酚聚氧乙烯醚残留量的高效液相色谱-荧光测定方法.样品用二氯甲烷-甲醇提取后,采用高效液相色谱分离,荧光检测器检测.BPA、OP、NP、OPEO在0.05～1.0 μg/mL,NPEO在0.2～1.0 μg/mL范围呈线性.对奶瓶样品作添加回收试验,各种成分的平均回收率在81.1%～100.3%之间,相对标准偏差在2.7%～5.5%之间.方法检出限:BPA为1 mg/kg;OP、NP、OPEO为2 mg/kg ;NPEO为5 mg/kg.结果表明,该法简便、灵敏、精确度高,适用于奶瓶中双酚A、烷基酚及烷基酚聚氧乙烯醚的残留分析.