Distribution and bioaccumulation of organochlorine pesticides (OCPs) in food web of Nansi Lake,China

The concentration of 12 organochlorine pesticides (OCPs) were measured in water, sediment, aquatic plant, and animal (shrimp and fish) of Nansi Lake by gas chromatography equipped with an electron capture detector. The total OCPs concentrations were 65.31–100.31 ng L^?1 in water, 2.9–6.91 ng g^?1 dry weight (dw) in sediments, 1.29–6.42 ng g^?1 dw in aquatic plants and 7.57–17.22 ng g^?1 dw in animals. The OCPs composition profiles showed that heptachlor compounds was also the predominant OCPs contaminants in addition to hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in Nansi Lake. According to the source of HCHs and DDTs in sediment samples, there was no new input and the HCHs pollution mainly came from the use of Lindane in Nansi Lake. Bioaccumulation of OCPs in aquatic biota indicated that DDTs and heptachlor compounds had a strong accumulation, followed by HCHs and drins. The accumulation abilities of fish for OCPs were higher than those of plants and shrimps. The OCPs biota-sediment accumulation factor values of Channa argus was the highest in fish samples, followed by Carassius auratus, and Cyprinus caspio. Risk assessment of sediment showed that heptachlor epoxide had a higher occurrence possibility of adverse ecological effects to benthic species. Based on the calculation of acceptable daily intake and hazard ratio, HCHs in fish and shrimps from Nansi Lake had a lifetime cancer risk of greater than one per million. The risk assessment of water, sediment, and fish indicated the water environment of Nansi Lake is at a safe level at present.     

Occurrence,sources, and ecological risks of PBDEs,PCBs, OCPs,and PAHs in surface sediments of the Yangtze River Delta city cluster,China

Polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in 25 surface sediments in three cities (Nantong, Wuxi, and Suzhou) in the Yangtze River Delta, eastern China were measured. The mean concentrations were 378, 45.8, 1.98, 4,002 ng/g for PBDEs, OCPs, PCBs, and PAHs, respectively. Their levels in the sediments in the three cities were generally consistent with the city industrialization. PBDEs and OCPs were markedly dominated by deca-BDE (>90 %) and DDTs (>70 %). A principle component analysis of the analytes identified three major factors suggesting different sources of the contaminants in the sediments. PBDEs and the organic carbon in the sediments have common sources from industrial activities; whereas OCPs and PCBs, correlated with the second factor, were mainly from historical sources. The third factor with loadings of PAHs is indicative of various combustion sources. Ecological risk assessment indicated that the potential highest risk is from DDTs, for which 22 sites exceed the effects range low (ERL) values and three sites exceed the effects range median (ERM) value.     

Screening for Stockholm Convention persistent organic pollutants in the Bosna River (Bosnia and Herzogovina)

The Stockholm Convention, which aspires to manage persistent organic pollutants (POPs) at the international level, was recently ratified in Bosnia and Herzegovina (BiH). Despite this fact, there is in general a paucity of data regarding the levels of POPs in the environment in BiH. In the present study, screening for POPs was conducted in one of the country’s major rivers, the Bosna. A two-pronged approach was applied using passive samplers to detect the freely dissolved and bioavailable concentrations in the water phase and sediment analysis to provide an integrated measure of historical contamination. At several places along the river, the concentrations of polycyclic aromatic hydrocarbons (PAH) were high and exhibited potential for both chronic and acute effects to biota. River water also showed elevated concentrations of PAH, up to 480 ng L^?1 near the city of Doboj, and diagnostic ratios suggested combustion sources for the contamination present in both types of sample. The levels of the other contaminants measured—polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers—were generally low in the water phase. However, PCBs and some OCPs were present in river sediments at levels which breach the international criteria and thus suggest potential for ecological damage. Additionally, the levels of heptachlor breached these criteria in many of the sites investigated. This study presents the first screening data for some of these Stockholm Convention relevant compounds in BiH and reveals both low concentrations of some chemical groups, but significant point sources and historic contamination for others.     

Distribution and sources of polycyclic aromatic hydrocarbons in the surface water of Taizi River, Northeast of China

Spatial and seasonal distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs), identified as priority pollutants by the US Environmental Protection Agency, were investigated in the surface water of the Taizi River in Liaoning Province, northeast of China. Samples were collected from the mainstream, and tributaries of the Taizi River in dry, wet, and normal seasons. Five important industrial point sources were also monitored. The total PAH concentrations ranged from 454.5 to 1,379.7 ng l^?1 in the dry season, 1,801.6 to 5,868.9 ng l^?1 in the wet season, and 367.0 to 5,794.5 ng l^?1 in the normal season. The total PAH concentrations were significantly increased in the order of wet season > normal season > dry season. The profile of PAHs in the surface water samples was dominated by low molecular weight PAHs particularly with two- and three-ring components in the three seasons, suggesting that the PAHs were from a relatively recent local source. Source identification inferred that the PAHs in the surface water of the Taizi River came from both petrogenic inputs and pyrogenic sources.     

Polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Bizerte Lagoon,Tunisia: levels,sources, and toxicological significance

To assess the status of polycyclic aromatic hydrocarbon (PAH) contamination in sediments from the Bizerte Lagoon (northern Tunisia), 18 surface sediment samples were collected in March 2011 and analyzed for 14 US Environmental Protection Agency priority PAHs by high-performance liquid chromatography. The total concentrations of the 14 PAHs (ΣPAHs) ranged from 16.9 to 394.1 ng g^?1 dry weight (dw) with a mean concentration of 85.5 ng g^?1 dw. Compared with other lagoons, coasts, and bays in the world, the concentrations of PAHs in surface sediments of the Bizerte Lagoon are low to moderate. The PAHs’ composition pattern was dominated by the presence of four-ring PAHs (45.8 %) followed by five-ring (26.8 %) and three-ring PAHs (12.7 %). The PAH source analysis suggested that the main origin of PAHs in the sediments of the lagoon was mainly from pyrolytic sources. According to the numerical effect-based sediment quality guidelines of the USA, the levels of PAHs in the Bizerte Lagoon should not exert adverse biological effects. The total benzo[a]pyrene toxicity equivalent values calculated for the samples varied from 3.1 to 53.7 ng g^?1 dw with an average of 10.6 ng g^?1 dw.     

Spatial distribution and seasonal variation of polycyclic aromatic hydrocarbons (PAHs) contaminations in surface water from the Hun River, Northeast China

The objectives of this study were to investigate the levels, dispersion patterns, seasonal variation, and sources of 16 priority polycyclic aromatic hydrocarbons (16 EPA-PAHs) in the Hun River of Liaoning Province, China. Samples of surface water were collected from upstream to downstream locations, and also from the main tributaries of the Hun River in dry period, flood period, and level period, respectively. After appropriate preparation, all samples were analyzed for 16 EPA-PAHs. Total PAHs concentrations varied from 124.55 to 439.27 ng l^?1 in surface water in dry period, 1,615.75 to 5,270.04 ng l^?1 in flood period, and 2,247.42 to 7,767.9 ng l^?1 in level period. The 16 EPA-PAHs concentrations were significantly increased in the order of level period > flood period > dry period. The composition pattern of PAHs in surface water was dominated by low molecular weight PAHs, in particular two- to three-ring PAHs. In addition, two-ring PAH accounted for 39.33 to 88.27 % of the total PAHs in level period. Low molecular weight PAHs predomination together with higher levels of PAHs in flood and level period suggested a relatively recent local source of PAHs. Special PAHs ratios such as phenanthrene/anthracene and fluoranthene/pyrene indicated that under dry weather season conditions, the PAHs found in surface water were primarily from petrogenic source, while under wet weather season conditions they were from mixed source of both petrogenic inputs and combustion sources. The comparison of PAHs contamination among different types of areas in China suggested that atmospheric depositions might be the most important approaches of PAHs into water system. Although the Hun River exists low PAHs ecological risk now, potential toxic effects will be existed in the future especially in flood and level period.     

Polycyclic aromatic hydrocarbons in water, sediment and soil of the Songhua River Basin, China

The Songhua River is the third largest river in China and the primary source of drinking and irrigation water for northeastern China. The distribution of 16 priority polycyclic aromatic hydrocarbons (PAHs) in water [dissolved water (DW) and suspended particulate matter (SPM)], sediment, and soil in the river basin was investigated, and the associated risk of cancer from these PAHs was also assessed. The total concentration of PAHs ranged from 13.9 to 161 ng L^?1 in DW, 9.21 to 83.1 ng L^?1 in SPM, 20.5 to 632 ng g^?1 dw (dry weight) in sediment, and from 30.1 to 870 ng g^?1 dw in soil. The compositional pattern of PAHs indicated that three-ring PAHs were predominant in DW and SPM samples, while four-ring PAHs dominated in sediment and soil samples. The spatial distribution of PAHs revealed some site-specific sources along the river, with principal component analysis indicating that these were from pyrogenic sources (such as coal and biomass combustion, and vehicle emissions) and coke oven emission distinguished as the main source of PAHs in the Songhua River Basin. Based on the ingestion of PAH-contaminated drinking water from the Songhua River, cancer risk was quantitatively estimated by combining the Incremental Lifetime Cancer Risk assessment model and BaP-equivalent concentration for five age groups of people (adults, teenagers, children, toddlers, and infants). Overall, the results suggest that the estimated integrated lifetime cancer risk for all groups was in acceptable levels. This study is the first attempt to provide information on the cancer risk of PAHs in drinking water from the Songhua River.     

A complex investigation of the extent of pollution in sediments of the Sava River: part 2: persistent organic pollutants

Sediment pollution of the biggest Danube tributary, the Sava River, was investigated within the sixth framework European Union project “Sava River Basin: Sustainable Use, Management and Protection of Resources” (SARIB). The extent of pollution was estimated by determining the amount of inorganic and persistent organic pollutants in sediment samples at 20 selected sampling sites along the Sava River. For the purpose of clarity, the findings are presented and published separately (part I: selected elements and part II: persistent organic pollutants). This study presents an investigation into the presence of organic pollutants in the Sava River sediment. According to the Water Framework Directive, the following persistent organic pollutants were investigated: polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), selected chlorinated pesticides and organotin compounds. The results reveal that PAHs were present in moderate concentrations (sum of 16 PAHs: up to 4,000 ng g^???1) and their concentrations increased downstream. Concen trations of PCB were low (sum of seven indicator PCBs: below 4 ng g^???1) and among the pesticides analyzed only p,p-dichlorodiphenyltrichloroethane was found in moderate concentrations at two sampling sites in Croatia (up to 3 ng g^???1) and hexachlorobenzene was found in a high concentration in the city of Belgrade (91 ng g^???1), although the use of these persistent pesticides has been banned for decades. Repeated sampling at the same location revealed point pollution near Belgrade. Among the organic pollutants surveyed, organotin compounds were not detected. Overall results reveal the presence of persistent organic pollutants in 20 of the Sava River sediments tested that is, in general, comparable or lower than the levels in the Danube River and other moderately polluted European rivers.     

Organochlorine pesticides in the surface water and sediments from the Peacock River Drainage Basin in Xinjiang, China: a study of an arid zone in Central Asia

Fourteen surface water and nine surface sediment samples were collected from the Peacock River and analyzed for organochlorine pesticides (OCPs) by gas chromatograph?Celectron capture detector (GC-ECD). All the analyzed organochlorine pesticides, except o,p ^??-DDT, were detected in sediments from the Peacock River; but in the water samples, only ??-HCH, HCB, p,p ^??-DDD, and p,p ^??-DDT were detected at some sites. The ranges for total OCPs in the water and sediments were from N.D. to 195 ng l^???1 and from 1.36 to 24.60 ng g^???1, respectively. The only existing HCH isomer in the water, ??-HCH, suggested that the contamination by HCHs could be attributed to erosion of the weathered agricultural soils containing HCHs compounds. Composition analyses showed that no technical HCH, technical DDT, technical chlordanes, endosulfans, and HCB had been recently used in this region. However, there was new input of ??-HCH (lindane) into the Peacock River. The most probable source was water flowing from Bosten Lake and/or agricultural tailing water that was returned directly into the Peacock River. DDT compounds in the sediments may be derived mainly from DDT-treated aged and weathered agricultural soils, the degradation condition was aerobic and the main product was DDE. HCB in the sediment might be due to the input from Bosten Lake and the lake may act as an atmospheric deposition zone. There was no significant correlation between the concentrations of OCPs (including ??HCH, ??DDT, chlordanes, endosulfans, HCB and total OCPs) and the content of fine particles (<63 ??m). The concentrations of OCPs were affected by salinity.     

Sources and distribution of polycyclic aromatic hydrocarbons in street dust from the Chang-Zhu-Tan Region, Hunan, China

Street dusts collected from 20 locations in the Chang-Zhu-Tan (Changsha, Zhuzhou, and Xiangtan) region, Hunan, China, in May to July 2006, were investigated for sources of polycylic aromatic hydrocarbons (PAHs). The individual PAH concentrations were in the range of 10–4316 ng g^?1, and ∑PAHs₁₆ levels were in the range of 3,515–24,488 ng g^?1, with a mean of 8,760 ng g^?1. The high-molecular-weight PAHs (four to six rings), ranging from 47.51 to 82.11 %, with a mean of 74.79 %, were the dominant PAH compounds in almost all of the dusts. The isomer ratios suggested a rather uniform mixture of coal combustion and petroleum PAH sources. Factor analysis and multiple linear regression analysis indicate that the main sources of the 16 PAHs were coal combustion/vehicle exhaust, coking/petroleum, and plant combustion, with contribution rates of 50.9, 35.01, and 14.08, respectively. The spatial distributions of PAH concentrations were significantly related to the distribution of industries, traffic circulation, and farmland in this region.     

Polycyclic aromatic hydrocarbon levels in European catfish from the upper Po River basin

Polycyclic aromatic hydrocarbons (PAHs) are a major concern in environmental studies as many of them have been labeled as probable carcinogens by the International Agency for Research on Cancer (IARC 1983). Due to their lipophilic properties and resistance to degradation, PAHs can accumulate in organic tissue. As a consequence, alarming concentrations of these compounds have been found in many aquatic species. The European catfish (Silurus glanis) is a top food chain predator that is considered to be a reliable bio-indicator of environmental pollution. From 2009 to 2011, 54 specimens of S. glanis were captured from four different sites covering the area of the Po River basin (Northern Italy). Fish muscles were analyzed in the laboratory to determine the levels of nine PAHs, namely naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, pyrene, benz[a]anthracene, chrysene, and benz[a]pyrene (BaP), which were detected by high-performance liquid chromatography (HPLC). The total average concentration of PAHs was 26.90?±?49.50 ng g^?1 (min 0.60, max 275.75 ng g^?1). Analysis showed that 9.20 % of the fish muscles exceeded the maximum levels of 2 ng g^?1 set for BaP by European regulations (Commission Regulation (EC), 2006). Values measured for benz[a]pyrene ranged from 0.05 to 8.20 ng g^?1 (mean 1.07?±?1.58 ng g^?1). Chrysene and benz[a]anthracene, both considered potential human carcinogens (PAH2), were found at levels of 4.40 and 0.05 ng g^?1 (mean values), respectively. The highest mean concentration was recorded for anthracene (12.92 ng g^?1), which has been recently included in the list of substances of very high concern (SVHC) as reported by the European Chemicals Agency (ECHA 1–9, 2009).     

Organochlorine pesticide contamination in marine organisms of Yantai coast,northern Yellow Sea of China

To evaluate the contamination of organochlorine pesticides (OCPs) in marine organisms and their potential health risk on consumers in the northern Yellow Sea of China, mollusks, wild shrimps, and crabs were collected from the Yantai coast, and the OCP contents in the samples were analyzed and compared. The results indicate that all the samples have been contaminated by OCPs, and OCP concentrations varied in individual species and in sampling sites. Among the studied OCPs, ∑HCH and ∑DDT concentrations ranged from 0.91 to 13.92 ng g^?1 and from 10.16 to 411.19 ng g^?1, respectively. Meretrix was highly enriched with HCHs, while the highest DDT concentration was found in Crassostrea. For the OCP isomers, β-HCH was the predominant isomer of HCHs, and p,p′-DDE concentration was much higher than other isomers of DDTs. The concentrations of other OCPs (HCB, t-CHL, endrin, and mirex) were relatively low. For the shrimp and crab samples, Alpheus distinguendus samples accumulated a higher level of HCHs but lower DDTs than Oratosquilla aratoria and Carcinoplax vestitus in all sampling areas. HCHs in the samples of contrast area were not significantly lower than that of the sewage outfall area and port area, whereas DDTs in the samples of contrast area were relatively lower than that of the other two areas. Generally, all the OCP contents in the samples are in the range of the edible hygienic criteria except the total concentration of DDTs in Crassostrea.     

Occurrence and distribution of organochlorine pesticides (DDT and HCH) in sediments from the middle and lower reaches of the Yellow River, China

Sediments used in this study were selected from 23 stations in the middle and lower reaches of the Yellow River and its tributaries in November 2005. The levels and distribution patterns of selected organochlorine pesticides (OCPs = p,p ^′-DDT, o,p ^′-DDT, p,p ^′-DDE, p,p ^′-DDD, α-, β-, γ-, and δ-HCH) in samples were investigated by analysis of gas chromatography coupled with micro-electronic capture detector. Concentration of OCPs in the sediments from the Yellow River ranged from 0.05 to 5.03 ng g^???1 (mean, 1.02 ng g^???1) for ∑DDT, 0.09–12.89 ng g^???1 (mean, 1.08 ng g^???1) for ∑HCH. The concentration distribution of ∑DDT and ∑HCH varied significantly with different sampling station, indicating their different contamination sources. Composition analyses demonstrated that residues of DDTs in sediments came from the previous inputs of organochlorine pesticides, while β-HCH and γ-HCH significantly dominated in the sediments for HCHs.     

Identification of sources of elevated concentrations of polycyclic aromatic hydrocarbons in an industrial area in Tianjin, China

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector in 105 topsoil samples from an industrial area around Bohai Bay, Tianjin in the North of China. Results demonstrated that concentrations of PAHs in 104 soil samples from this area ranged from 68.7 to 5,590 ng g^???1 dry weight with a mean of ∑16PAHs 814 ± 813 ng g^???1, which suggests that there exists mid to high levels of PAH contamination. The concentration of ∑16PAHs in one soil sample from Tianjin Port was exceptionally high (48,700 ng g^???1). Ninety-three of the 105 soil samples were considered to be contaminated with PAHs (>200 ng g^???1), and 25 were heavily polluted (>1,000 ng g^???1). The sites with high PAHs concentration are mainly distributed around chemical industry parks and near highways. Two low molecular weight PAHs, naphthalene and phenanthrene, were the dominant components in the soil samples, which accounted for 22.1% and 10.7% of the ∑16PAHs concentration, respectively. According to the observed molecular indices, house heating in winter, straw stalk combustion in open areas after harvest, and petroleum input were common sources of PAHs in this area, while factory discharge and vehicle exhaust were the major sources around chemical industrial parks and near highways. Biological processes were probably another main source of low molecular weight PAHs.     

The levels and composition of persistent organic pollutants in alluvial agriculture soils affected by flooding

The concentrations and composition of persistent organic pollutants (POPs) were determined in alluvial soils subjected to heavy flooding in a rural region of Poland. Soil samples (n?=?30) were collected from the upper soil layer from a 70-km² area. Chemical determinations included basic physicochemical properties and the contents of polychlorinated biphenyls (PCBs), hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polycyclic aromatic hydrocarbons (PAHs, 16 compounds). The median concentrations of Σ7PCB (PCB28?+?PCB52?+?PCB101?+?PCB118?+?PCB138?+?PCB153?+?PCB180), Σ3HCH (α-HCH?+?β-HCH?+?γ-HCH) and Σ3pp′(DDT?+?DDE?+?DDD) were 1.60?±?1.03, 0.22?±?0.13 and 25.18?±?82.70 μg kg^?1, respectively. The median concentrations of the most abundant PAHs, phenanthrene, fluoranthene, pyrene, benzo[b]fluoranthene and benzo[a]pyrene were 50?±?37, 38?±?27, 29?±?30, 45?±?36 and 24?±?22 μg kg^?1, respectively. Compared with elsewhere in the world, the overall level of contamination with POPs was low and similar to the levels in agricultural soils from neighbouring countries, except for benzo[a]pyrene and DDT. There was no evidence that flooding affected the levels of POPs in the studied soils. The patterns observed for PAHs and PCBs indicate that atmospheric deposition is the most important long-term source of these contaminants. DDTs were the dominant organochlorine pesticides (up to 99 %), and the contribution of the parent pp′ isomer was up to 50 % of the ΣDDT, which indicates the advantage of aged contamination. A high pp′DDE/pp′DDD ratio suggests the prevalence of aerobic transformations of parent DDT. Dominance of the γ isomer in the HCHs implies historical use of lindane in the area. The effect of soil properties on the POP concentrations was rather weak, although statistically significant links with the content of the <0.02-mm fraction, C_total or N_total were observed for some individual compounds in the PCB group.     

Retrospective monitoring of persistent organic pollutants,including PCBs,PBDEs, and polycyclic musks in blue mussels (Mytilus edulis) and sediments from New Bedford Harbor,Massachusetts, USA: 1991–2005

Blue mussels (Mytilus edulis) and sediments collected from 1991 to 2005 from New Bedford Harbor (NBH), MA, were analyzed for two polycyclic musks (HHCB or Galaxolide® and AHTN or Tonalide®), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs). HHCB and AHTN were found in mussel tissues at mean concentrations of 836 and 376 ng/g lipid weight (lw), respectively, which were two- to seven-fold higher than those found at a reference site. Mean concentrations of HHCB and AHTN in NBH sediments were 12 and 6.3 ng/g dry weight (dw), respectively. Four- and five-ringed PAHs, such as phenanthrene, anthracene, fluoranthene, and pyrene, collectively accounted for 61 % of the ∑PAHs concentrations in mussels from NBH. Mean ΣPCB concentrations in mussels from upper and lower NBH were 942 and 182 μg/g lw, respectively, and were dominated by tetra- and penta-chlorobiphenyl congeners, collectively accounting for 61 % of the ΣPCB concentrations. The mean concentration of ∑PBDEs in mussels from NBH was 277 ng/g lw, and no significant difference existed in the concentrations between upper and lower NBH. DDTs were the major OCP found in mussels, found at a mean concentration of 778 ng/g lw. The concentrations of HHCB, AHTN, ΣPBDEs, ΣPAHs, and DDTs in mussels decreased significantly (r ²?≥?0.56, p?≤?0.052) from 1991 to 2005. The concentrations of PCBs and chlordanes did not exhibit a decreasing trend in mussel tissues (r ²?<?0.50; p?>?0.076) from 1991 to 2005. Based on the temporal trends in the concentrations of HHCB, AHTN, ∑PAHs, and ∑PBDEs found in mussels from NBH, it was estimated that between 5.5 and 12 years were required for the concentrations of these compounds to decrease by half (i.e., environmental halving time) of the levels found in 1991.     

Assessing organic contaminant fluxes from contaminated sediments following dam removal in an urbanized river

In this study, methods and approaches were developed and tested to assess changes in contaminant fluxes resulting from dam removal in a riverine system. Sediment traps and passive samplers were deployed to measure particulate and dissolved polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the water column prior to and following removal of a small, low-head dam in the Pawtuxet River, an urbanized river located in Cranston, RI, USA. During the study, concentrations of particulate and dissolved PAHs ranged from 21.5 to 103 μg/g and from 68 to 164 ng/L, respectively. Overall, temporal trends of PAHs showed no increases in either dissolved or particulate phases following removal of the dam. Dissolved concentrations of PCBs were very low, remaining below 1.72 ng/L at all sites. Particulate PCB concentrations across sites and time showed slightly greater variability, ranging from 80 to 469 ng/g, but with no indication that dam removal influenced any increases. Particulate PAHs and PCBs were sampled continuously at the site located below the dam and did not show sustained increases in concentration resulting from dam removal. The employment of passive sampling technology and sediment traps was highly effective in monitoring the concentrations and flux of contaminants moving through the river system. Variations in river flow had no effect on the concentration of contaminants in the dissolved or particulate phases, but did influence the flux rate of contaminants exiting the river. Overall, dam removal did not cause measurable sediment disturbance or increase the concentration or fluxes of dissolved or particulate PAHs and PCBs. This is due in large part to low volumes of impounded sediment residing above the dam and highly armored sediments in the river channel, which limited erosion. Results from this study will be used to improve methods and approaches that assess the short- and long-term impacts ecological restoration activities such as dam removal have on the release and transport of sediment-bound contaminants.     

Integration of multi-disciplinary geospatial data for delineating agroecosystem uniform management zones

The aim of this study was the development of analytical methods for the simultaneous determination of 25 selected pharmaceuticals, metabolites, and pesticides, belonging to the various chemical classes, in river sediments and their corresponding surface and ground water with the purpose of monitoring the contamination levels. The methods were based on the solid-phase extraction as the sample preparation method for water samples, and the ultrasonic solvent extraction for the sediment samples, followed by the liquid chromatography–tandem mass spectrometry. High recoveries were achieved for extraction from both water and sediment samples for the majority of analytes. Low limits of detection were achieved for all investigated compounds in the water sample (1–5 ng L^?1) as well as in the sediment (1–3 ng g^?1). Applicability of the developed methods was demonstrated by determination of pharmaceutical and pesticide residues in 30 surface water, 44 groundwater, and 5 sediment samples from the Danube River Basin in Serbia. Sixty percent of target compounds were detected in environmental samples. The most frequently detected analytes in river sediments were the pesticides dimethoate and atrazine, while carbamazepine and metamizole metabolites 4-AAA and 4-FAA were the most frequently found in water samples.     

Determination of organochlorine pesticide concentrations in flathead mullet (Mugil cephalus) caught from the western Black Sea coast of Turkey

The objective of this study was to determine the levels of 14 organochlorine pesticides (OCPs) in flathead mullet (Mugil cephalus) caught from the western Black Sea coast of Turkey. The fish samples were caught from five different locations of the western Black Sea coast of Turkey in August 2009. Organochlorine pesticides were extracted from the liver tissues, and then the levels of OCPs were measured using gas chromatography with an electron capture detector. Organochlorine pesticides were detected in all locations. The levels of total OCPs in fish samples ranged between 0.224 and 1.103 μg g^?1 dry weight in the western Black Sea coast of Turkey. DDT, beta-HCH, and endosulfan I were the dominant OCPs in the fish samples. The levels of DDT in fish samples ranged between 0.081 and 0.186 μg g^?1 dry weight. The levels of total HCH in fish samples ranged between 0.007 and 0.376 μg g^?1 dry weight in the western Black Sea coast of Turkey. Although the usage of OCPs was banned in Turkey, the results of this study clearly indicated the presence of OCPs in the western Black Sea coast of Turkey and exposure of living organisms to these chemicals.     

Distributions, sources, and ecological risks of DDT-related contaminants in water, suspended particulate matter, and sediments from Haihe Plain, Northern China

The residual levels of dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDXs, including p,p′-DDT, DDD, and DDE) in water, suspended particulate matter (SPM), and sediments from major rivers, lakes, and reservoirs in Haihe Plain were measured with a gas chromatograph equipped with a ⁶³Ni microelectron capture detector. In the fall of 2004, the contents of the total DDXs in the water and SPM were 0.29?±?0.69 ng L^?1 and 423.13?±?577.85 ng g^?1 dry wt., respectively. In the spring of 2005, the total DDXs were 0.36?±?0.91 ng L^?1 for water and 35.93?±?62.65 ng g^?1 dry wt. for SPM. The average concentration of DDXs for sediments was 7.10?±?7.57 ng g^?1 dry wt. during the two seasons. The Eastern-Hebei-Province Coastland River System was the most polluted, which was mainly attributable to the extensive use of DDT pesticide and dicofol in that system. Recent DDT inputs still occur in some regions, as indicated by DDT/(DDD + DDE) > 1 at 29–36 % of the sites for water and 55–61 % of the sites for SPM. The potential ecological risks of DDT in the water were assessed using a species sensitivity distribution model. Only shrimp and crabs were found to have potentially affected fraction values of 1.63?×?10^?3 to 2.27?×?10^?4, with probabilities beyond the hazardous concentration for 5 % of species (HC5) values of 1.90–2.56 %, suggesting only slight risks. DDXs in the sediments of some sites were also of potential risk to benthic organism based on consensus-based sediment quality guidelines.