Levels of PBDEs, PCDDs, PCDFs, and coplanar PCBs in edible fish from California coastal waters

The levels of polychlorinated dibenzo-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), coplanar polychlorinated biphenyls (coPCBs), and polybrominated diphenyl ethers (PBDEs) were measured in fish collected from San Francisco Bay in 2000 and from the California coast in 2001. The samples were composites of only the edible portions of the fish (skin on, skin off, or whole body minus head and guts) of comparable size and from distinct geographical areas. Sixty-five composite samples were analyzed for PCDD/PCDF/coPCBs, and 43 composite samples were analyzed for PBDEs. For all fish of all species from all sampling areas, the mean concentration of the sum of BDEs 47, 99, 100, 153, and 154 was 302 ng/g lipid weight, with BDE 47>100>99 approximately 154>153. For all fish of all species from all sampling areas, the mean PCDD/PCDF International Toxic Equivalent (I-TEQ) was 33.1 pg/g lipid. For the three coPCBs (77, 126, 169), the mean I-TEQ for all fish of all species from all sampling areas was 109 pg/g lipid. The highest concentrations of both PCDD/PCDF/coPCBs and PBDEs were found in the highly populated areas of San Francisco Bay, the Los Angeles area, and San Diego Bay.     

Distribution of organochlorine pesticides, polychlorinated biphenyls and alpha-HCH enantiomers in pork tissues

The distribution of HCH isomers, DDT analogues and selected PCB congeners in pork organs collected from the same individuals raised in Romanian farms was investigated. Organochlorine pesticides (HCHs and DDTs) were the principal contaminants in all samples, while PCB concentrations were low, in accordance with previously reported concentrations from Romanian animal farms. The most part of the pollutant load in the body is retained in the adipose tissue, with HCHs ranging between 16 and 27.7 ng/g lipid and with higher concentrations of DDTs ranging between 65.9 and 334.5 ng/g lipid. The highest PCB levels (up to 32 ng/g lipid) were measured in lung and liver. The lipid-normalized concentrations in the brain were lower than in all other tissues due to the presence of the blood-brain barrier or due to a lower proportion of the neutral lipids such as triglycerides. The highest concentrations of DDTs were measured in muscle and fat, with p,p'-DDE being the principal contributor and with a variable contribution of p,p'-DDD and p,p'-DDT. In liver, p,p'-DDD has a higher contribution to the sum DDTs, while in all analyzed livers, the concentration of p,p'-DDT was very low. beta-HCH was the most persistent HCH isomer in all tissues, accounting for 40-97% of sum HCHs. For all animals, the highest concentrations of beta-HCH and HCHs were found in liver, while the lowest HCH concentrations were measured in brain and spinal marrow. Additionally, the distribution of alpha-HCH enantiomers in the tissues was discussed. In all samples (except 2 brain samples), (+) alpha-HCH was depleted and (-) alpha-HCH was enantioenriched. Enantiomeric ratios in brain were the highest measured values between all organs. For all studied animals, ERs increased in the order fat < muscle < liver < brain.     

Effects of pH on the mortality and accumulation of copper in tissues of Oreochromis niloticus

In the present study, effect of pH on the mortality and accumulation of copper in various tissue and organs of Oreochromis niloticus were tested at varying concentrations of copper in the medium and over different periods of time. Experimental animals were exposed to pH 5.5, 7.8 and 9.5 and 0.1, 0.5, 1.0 and 5.0 ppm copper over periods of 7, 15 and 30 days in liver, gills and muscle were determined using atomic absorption spectrophotometric techniques. The rate of mortality at 1.0 and 5.0 ppm Cu was 100% after 7 days of exposure at pH 5.5 while at 5.0 ppm Cu was 66% after 30 days of exposure at pH 7.8. No mortality was observed in any of the copper concentrations tested at pH 9.5. In all pH levels, tissue accumulation of copper increased with increasing concentrations of copper in the medium at a given exposure period. In all pH values tested, highest levels of copper were found in the liver of O. niloticus, followed by the gills and muscle tissues. Accumulation of copper in all tissues were higher at pH 5.5 compared with the other pH values in all the conditions tested.     

Distribution pattern of ambient cadmium in wetland ponds distributed along an industrial complex

Water and sediment samples collected from 18 wetland ponds within and outside industrial areas were examined for cadmium concentration and water quality parameters during the period of January to July 1996. The Cd contents in gill, liver, mantle and shell of freshwater mussel (Lamellidens marginalis) as well as leaves and roots of water hyacinth Eichhornia those occurred in these ponds were also estimated. Cd concentration ranged from 0.006 to 0.7025 mg/l in water and from 7 to 77 microg/gdw in sediments of all the ponds investigated. The amount of Cd occurring in water and sediment was much higher in concentrations in the ponds located in Captain Bheri and Mudiali farm close to industrial areas, compared to remaining ponds located outside the industrial belt. Lamellidens marginalis procured from Mudiali and Captain Bheri ponds showed regardless of size, tissue and season of collection significantly higher Cd concentration than did those from other ponds. Likewise, tissue Cd in Eichhornia collected from Mudiali pond was as high as 125-152 microg/gdw in root and 21-63 microg/gdw in leaves compared to 40-108 microg/gdw in root and 9-43 microg/gdw in leaves in the remaining ponds. Seasonal variability of Cd was clear-cut; the concentration was relatively higher in water and sediment in all ponds during summer than during monsoon season or winter. Size-wise, smaller groups showed the highest concentrations of Cd in all tissues of Lamellidens compared with medium and large size groups. Concentration factor for all tissues of Lamellidens regardless of size and season, was inversely proportional with the ambient Cd concentrations. Concentration factor estimated for all tissues in all ponds and all seasons was in the order: liver>gill>shell>mantle. As all ponds located outside the industrial belt showed Cd concentrations ranging from 0.006 to 0.049 mg/l, it is suggested that these wetlands do not pose serious risk to the environment.     

High NOx levels and lack of ozone in downtown Caracas

An evaluation of the NO, NO₂ and O₃ concentrations in downtown Caracas atmosphere at two different heights (1.5 and 56 m ) during the dry and wet season was performed.The qualitative variation of NO and NO₂ concentrations throughout the day was the same for all conditions. The profiles are explained considering the automobile emissions and the fates by photochemical reactions and dispersion. The daily mean averages for NO_x exceed all available air quality standards, making the downtown Caracas air polluted with these compounds at harmful levels.The O₃ concentrations are lower than the natural background levels practically all day long for all conditions. This lack of O₃ is explained mainly by the very high continuous NO emissions occuring in Caracas. NO reacts very fast with O₃ consuming all the O₃ produced by photochemical reactions. Possible health implications of the low O₃ levels are pointed out.     

潮汐对江水致突变性的影响

对某潮汐河流从下游至上游共设A、B、C、D、E五个采样点,用Ames试验、双微核试验及单细胞凝胶电泳试验(彗星试验)检测涨潮和落潮时江水中有机污染物的致突变性.结果表明,Ames试验各采样点样品都有致突变性,且从上游至下游逐渐增强;对TA98加S9致突变性增加;双微核试验、彗星试验检测出染色体及DNA损伤剂,并以A点作用最强.涨潮时各点致突变强度较落潮时强.     

Transport and degradation of pesticides in a biopurification system under variable flux Part II: A macrocosm study

Transport of bentazone, isoproturon, linuron, metamitron and metalaxyl were studied under three different flows in macrocosms. The aim was to verify the observations from Part I of the accompanying paper, with an increase in column volume and decrease in chemical and hydraulic load. Very limited breakthrough occurred in the macrocosms for all pesticides, except bentazone, at all flows.From batch degradation experiments, it was observed that the lag time of metamitron and linuron decreased drastically in time for all flows, indicating a growth in the pesticide degrading population. This in contrast to isoproturon and metalaxyl, where an increase in lag time could be observed in time for all flows. From the batch degradation experiments, it could be concluded that the influence of flow on the lag time was minimal and that the inoculation of the pesticide-primed soil had a little surplus value on degradation.     

COD对强化生物除磷系统的影响及OUR的变化规律

以实际生活污水为研究对象,在SBR系统中采用厌氧/好氧运行方式,考察强化生物除磷(EBPR)系统中好氧阶段COD浓度对聚磷菌除磷性能的影响以及不同好氧阶段COD浓度下的OUR变化规律.实验分4个阶段进行,分别为不投加外碳源、厌氧结束时投加不同体积的乙酸钠作为外碳源,使COD分别提高50、100和300mg/L.4种工况...     

The abundances of rarer trace elements in paddy (rice) soils of Sri Lanka

Concentrations of Ti, Ga, As, Sc, Zr, Sn, Hf, Th, U and Y have been determined for 70 paddy soils from 14 villages, selected throughout Sri Lanka by means of ICP-MS. The mean elemental contents of all paddy soil samples were 6120 Ti, 14.1 Ga, 0.84 As, 7.26 Sc, 129 Zr, 2.27 Sn, 3.64 Hf, 12.71 Th, 1.53 U, and 13.35 Y (all data in microg/g). Paddy soils were classified into groups based on morphology and climate. Higher contents of Th and U were found in the wet zone lowland soils whereas the higher Ti contents were observed in dry zone soils. Arsenic, Zr and Hf contents were comparatively similar in all regions. Factor analysis was used to identify the relationships between the contents of elements.     

The presence of bacterial virus in groundwater and treated drinking water

Ten raw urban well water samples and twelve water samples collected from distribution lines after the well waters were treated were examined for bacteriological and coliphage/bacteriophage populations. The raw well waters were found to contain <1/100 ml total coliforms and fecal streptococci, but they all contained varying concentrations of coliphage and bacteriophage. The treated waters were all found to have <1 total coliforms and fecal streptococci per 100 ml with the exception of one treated water sample from Community C. However, even though the treated water samples contained free and total chlorine levels varying from 0.05 to 1.5 ppm, they were all found to contain usually greater amounts of coliphage and bacteriophage than the raw well waters.     

An evaluation of the heat of formation of chlorinated dioxins and its application to isomer abundance predictions

Heats of formation for dibenzo-p-dioxin and all chlorinated dioxins are derived and combined with standard entropies and heat capacities to obtain a computational database for prediction for these compounds. Databases based on a published preditive method for dioxins, and on general group additivity data have also been constructed. The predicted relative abundances of the isomers for all degrees of chlorination from the three databases are compared. The abundances of the tetra- to heptachlorodioxin isomers are compared with those predicted by Unsworth using MOPAC, and with experimentally determined concentrations from combustion systems.     

Development,validation of QuEChERS-based method for simultaneous determination of multiclass pesticide residue in milk,and evaluation of the matrix effect

Extraction and quantification of pesticide residue from the milk matrix at or below the established maximum residue limit (MRL) is a challenging task for both analytical chemists and the regulatory institutions to take corrective actions for the human health and safety. The main aim of the study is to develop a simple rapid and less expensive QuEChERS extraction and cleanup method for simultaneous analysis of 41 multiclass pesticide residue in milk by gas chromatography-electron capture detector (GC-ECD), followed by confirmation of the residues with gas chromatography-mass spectrometer (GC-MS). Effect of sorbent type, temperature, spiking concentration, matrix effect (ME), measurement uncertainty (MU), inter- and intra-assay repeatability, reproducibility of recovery, and trueness of the results were investigated to validate the effectiveness of the method. Limit of determination (LOD) and limit of quantitation (LOQ) for all the analytes ranged within 0.001–0.02 and 0.002–0.05 µg mL^?1, respectively. The % recovery of all the pesticides ranged between 91.38 and 117.56% with relative standard deviation (RSD) below 2.79%. The MU for all the analytes was ≤29% of respective LOQs, and except for few pesticides, the ME was largely negative. The method fulfilled all the SANTE guidelines and thus can be extended for routine analysis of multiclass pesticide residue in milk.     

A screening level examination of the potential risks of acetone in aquatic and terrestrial environments using multi-media modeling

Approximately half of the approximately 40 million tonnes per annum (t/a) of acetone released worldwide arises via natural processes. The remaining releases of acetone are the focus of this assessment and arise either as a photo-degradation by-product of other organic compounds (approximately 20 million t/a) or by entering the environment from manufacturing and end uses (59,000 t/a). Multi-media modeling was used to estimate regional concentrations of acetone in air, water, soil and sediment that may occur based on these anthropogenic releases to the environment. US toxics release inventory data were used to calculate local surface water concentrations. The distributions of all regional and local concentrations in all media were below applicable predicted no effect concentrations (PNECs). Calculated regional and local concentrations of acetone, originating from all anthropogenic sources, appear unlikely to cause adverse risks to the environment.     

Effect of farmyard manure application on boron adsorption-desorption characteristics of some soils

Boron (B) availability to crop plants depends on soil properties as well as management practices like liming, fertilization and use of organic manures. To assess the effect of farmyard manure (FYM) application on availability of added B, adsorption-desorption of B was investigated in five different soils receiving varying doses of FYM (0, 5 and 10 g FYM kg(-1) soil). Two surfaces Freundlich model was found best to account for B adsorption-desorption data of all soils. Application of FYM increased B adsorption capacities pertaining to low (K1) and high (K2) concentration ranges in all soils, except Soil C (Alfisol) having a pH of 9.8, in which the higher rate of FYM decreased the value of K2. Application of FYM did not change B desorption capacities of soils corresponding to low B concentration range (K(1)(1)) significantly, however, it increased B desorption capacity pertaining to high B concentration (K(1)(2)) in all soils, except Soils C (Alfisol) and E (Entisol) having pH of 9.8 and 5.1, respectively. Application of FYM increased the desorption slope factor applicable to low concentration range (1/n(1)(1)) in Soil A (Inceptisol), but decreased it in Soil E (Entisol). The 1/n(1)(2) (desorption slope factor applicable to high concentration range) decreased with FYM application in all soils except Soil E (Entisol), where it was increased. Boron desorption index (slope(ads)/slope(des)) decreased with FYM application in low B concentration range, but increased in high concentration range for all soils except soil E (Entisol, pH 5.1), in which a reverse trend was observed. Application of FYM increased the retention of added B in soils and may help reducing the leaching losses.     

Healthcare facility effluents as point sources of select pharmaceuticals to municipal wastewater

Effluents from four healthcare facilities were characterized for the concentration of 16 common active pharmaceutical ingredients. The sampled facilities included a hospital, nursing care, assisted living, and independent living facility located within a single municipal wastewater system in Texas. Eleven of the 16 monitored pharmaceuticals were detected in at least 1 healthcare facility effluent and 2 measured antibiotics (sulfamethoxazole and trimethoprim) were detected in all 4 facility effluents. Active pharmaceutical ingredient concentrations ranged from non-detectable levels for several corticosteroids in all facility effluents to 180 microg/L sulfamethoxazole in the nursing care wastewater effluent. The mass of active pharmaceutical ingredients discharged to the municipality's wastewater conveyance system was determined by combining individual facility concentration data and daily wastewater flow. The estimated daily mass loading of all 16 pharmaceuticals ranged from 0.16 g/day to 23 g/day in the assisted living facility and nursing wastewater effluents, respectively. The combined active pharmaceutical ingredient mass loading for all four facilities was 42.6 g/day. These findings provide source characterization data for 16 common pharmaceuticals in healthcare facility wastewater and provide a basis for risk assessment of pharmaceuticals present in healthcare facility wastewaters.     

Residue levels of chlorinated hydrocarbon compounds in water and sediment samples from Nile branches in the Delta, Egypt.

Water and sediment samples were collected from eight different locations along the River Nile and its branches. Residues of hexachlorocyclohexane (HCH's), hexachlorobenzene (HCB), DDT's, cyclodienes and polychlorinated biphenyls (PCB's) were analyzed by GLC. Data on Grand Total (GT) concentration values pointed out that Rosetta Branch was more polluted with all components than Demietta Branch. Kafr El-Ziate was the most polluted location showing 1355.8 ng/L for water and 7396.9 ng/g for sediments, while Delta Barrage was the least polluted site. The concentrations of gamma-HCH were higher than the other isomers (alpha- and beta-HCH) in all studied sites. The results showed that HCB was the smallest pollutant at all locations on comparison with other chlorinated hydrocarbons. El-Mansoura, Rosetta and Kafr El-Ziate sites contained the highest concentrations of DDT's in both water and sediment samples. P,P'-DDE was dominate in all locations of water samples, but P,P'-DDT was in sediment samples. Also, the results showed the prominent presence of cyclodienes when compared with the other OC's compounds in sediment samples, especially Aldrin. Kafr El-Ziate was the most polluted location by PCB's, particularly the Ar1242. However, there were increasing levels of chlorinated hydrocarbons in the sediment samples parallel to percentage extractable organic matter (% EOM). Sediment/water ratios were calculated for all locations.     

利用气相色谱法测定剩余污泥厌氧消化产生的混合VFA

厌氧消化是剩余污泥处理的重要方法,消化过程中会产生大量的挥发性脂肪酸(VFA)。讨论了气相色谱在恒温条件下对剩余污泥厌氧消化过程中产生乙酸、丙酸、异丁酸、正丁酸、异戊酸、正戊酸测定的可行性。结果表明:各种酸出峰时间间隔清晰,易于识别;从数据平行测试的变异系数看,异戊酸的变异系数最大,也仅为3.23%,表明测试方法具有良好的可重复性;回收率实验表明,剩余污泥消化液中各种VFA组分的回收率在96%～105%之间,符合文献规定的测试要求。     

Distribution and sources of polycyclic aromatic hydrocarbons in the middle and lower reaches of the Yellow River, China

In this study, concentrations, distribution between different phases, transition along the Middle and Lower reaches of the Yellow River and possible sources of PAHs were assessed. Results demonstrated that the relative proportions of 15 PAHs in all stations of the main River were similar, with concentrations of benzo[a]pyrene all above drinking water standards in most of the stations sampled. PAHs concentrations in tributaries were higher than those in the corresponding sites in the main River. PAHs concentrations of suspended particles were mainly correlated with contents of total organic carbon. However, PAHs concentrations in sediments were mainly correlated to the volume of particles with size smaller than 0.01 mm. The distribution of PAHs in all media sampled indicated that sediments could act as a sink/source for PAHs in different sections and source analysis revealed that PAHs mainly originated from coal burning, although in some tributaries PAH inputs could come from combustion of petroleum.     

Effect of dissolved humic matters on the leachability of PCDD/F from fly ash--laboratory experiment using Aldrich humic acid

The effect of dissolved humic matters (DHM) on the leachability of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in fly ash was studied theoretically and in laboratorial condition to verify the previous results for pilot and field experiment of incineration residues landfill. In theoretical review, it was shown that DHM could influence the actual solubility and leachability of PCDD/F. The higher concentration of DHM showed the higher leachability of PCDD/F. In the leaching test, three different DHM concentrations and pHs of solutions were adopted to fly ash samples imaging the various characteristics of municipal solid waste leachate. It was proved experimentally that the leachability of PCDD/F increased with increasing DHM concentration in all pH conditions. The highest leachability was shown at the highest pH. Isomer distribution patterns of PCDD/F in all leachates were similar in all pH conditions. It backed up the distribution theory of PCDD/F between DHM and water.     

Oxidative degradation of p-toluenesulfonic acid using hydrogen peroxide

The oxidative degradation of p-toluenesulfonic acid using thermally activated hydrogen peroxide was investigated. The concentrations of all aromatic and aliphatic intermediates were determined by means of HPLC. From the identification of all intermediates, a detailed reaction mechanism for the oxidative degradation of p-toluenesulfonic acid is proposed. Experiments show that the oxidation with hydrogen peroxide is an effective process for the destruction of organic pollutants. Only substoichiometric amounts of hydrogen peroxide are required to convert this refractory model compound to easily biodegradable substances.