A new cytotoxic polychlorinated sulfolipid from contaminated Adriatic mussels

A detailed analysis of toxic shellfish collected in the Adriatic sea in October 2000 allowed us to isolate a new cytotoxic chlorosulfolipid (3). Its gross structure has been elucidated through an extensive NMR analysis including various 2D techniques; the relative stereochemistry has been solved by applying the Murata's method. Compound 3 showed to posses cytotoxic activity against WEHI 164 and J774 cells. The presence of chlorosulfolipids in toxic mussels from the northern Adriatic sea has not to be considered incidental as we have been detecting these cytotoxic compounds since 1998. Their simultaneous and constant presence together with typical marine biotoxins represents a further risk both to consumers' health and aquacultures economic proceeds.     

The toxicity of alkyllead compounds to Scrobicularia plana (Da Costa)

Conventional (whole animal) toxicity tests were made with Scrobicularia plana (Da Costa), an infaunal estuarine bivalve, and compared with the responses recorded from siphonal preparations. Exposure of Scrobicularia to low concentrations of triethyllead chloride and trimethyllead chloride, for 35 and 60 days respectively, produced typical response curves. However, mortality had not become asymptotic with time at lower concentrations, suggesting further mortality with increased exposure time. An approximate incipient lethal concentration was predicted. A siphonal preparation technique with isolated and in-situ inhalent siphons of Scrobicularia was used to estimate the lowest effect concentrations of alkyllead compounds. Response to alkyllead was indicated by contraction of the siphon, recorded via an isotonic transducer. Trialkyllead compounds were more toxic than the respective dialkylleads and inorganic lead. Toxicity of trialklleads and inorganic lead. Toxicity of trialkylleads increased with alkyl chain length. Pure tetraethyllead did not cause any siphonal contraction even when applied directly to the preparation. It was concluded that tetraethyllead has a low toxicity or is non-toxic in pure form.     

The analyses of alkyllead compounds in fish and environmental samples in Ontario,Canada (1981–1987)

Analyses of fish and other environmental samples (clams, macrophytes, sediments and waters) from areas upstream and downstream from two alkyllead manufactures beside the St Lawrence and St Clair Rivers, Ontario, show a clear indication of elevated alkyllead levels in samples near the industries. Most species of fish contained alkyllead compounds with tetraethyllead and triethyllead as the predominant forms. Most fish from the contaminated areas contained 50–75% of total lead as alkylleads. Carp, yellow perch and white sucker were generally the most contaminated species while pike, alewife and rock bass were the least contaminated. Average alkyllead levels varied from year to year but declined steadily after 1981. For example, the geometric mean of alkyllead compounds in carp from the St Lawrence River decreased from 4207 μg kg^?1 in 1981 to 2000 μg kg^?1 in 1982 and to 49 μg kg^?1 in 1987, reflecting the reduction of alkylleads in the effluents and the closure of one of the manufactures in 1985. Alkyllead levels were consistently lower in muscle and carcass samples in comparison with whole fish containing fatty intestines. However, muscle levels were generally equal to carcass levels. The concentrations of alkyllead compounds were generally low in clams, macrophytes, sediments and waters except from the immediate vicinity of the manufactures' final effluent discharges.     

The determination of tetra-alkyllead and ionic alkyllead compounds in seafood

Extraction methodologies were developed for tetra-alkyllead and ionic alkyllead compounds in seafood. Tetra-alkylleads were extracted with n-hexane after the samples had been enzymatically hydrolyzed. The ionic alkylleads were complexed with diphenylthiocarbazone (dithizone) at pH 8 and 9 from enzymatically hydrolyzed samples to optimize recovery. The dithizone extracts were butylated prior to analysis by gas chromatography–atomic absorption spectrometry (GC AA). Instrumental detection limits ranged between 1.6 and 2.3 pg lead. Application to a limited number of seafood samples indicated the possible presence of trace amounts (ca 1 ng g^?1) of trimethyllead in some samples. No other alkylleads were detected.     

Determination of tributyltin oxide in coastal marine sediments and mussels by electrothermal atomic absorption spectrometry

We have devised a new method for bis(tributyltin)oxide (TBTO) determination in marine sediments and mussels. This technique involves an n-hexane/methylene chloride mixture extraction and extract purification with a sodium hydroxide wash in order to eliminate interfering compounds. TBTO is then extracted again by nitric acid and converted into an inorganic tin species; the analysis has been effected using Zeeman graphite furnace-atomic absorption spectrophotometry. The method detection limit for the matrices examined is 0.004 μg TBTO g^?1 (wet weight) and is sufficient for the analysis in real samples. The percentage recovery of TBTO from sediments and mussels samples is higher than 85% and 95% respectively. This method has been applied to TBTO level determination in sediments and mussels (Mytilus galloprovincialis) sampled in the harbour area in Taranto, where mussel culture activities are much developed; the TBTO levels obtained in sediments and mussels were in the range 15-47 ng g^?1 (wet weight) and 11-30 ng g^?1 (wet weight) respectively. Such values are comparable with those found in other harbour areas in the Mediterranean Sea.     

Environmental sources and sinks of alkyllead compounds

Evidence is presented in favour of a natural environmental alkylation process as a source of atmospheric vapour-phase alkyllead. Several species of marine flora have been cultured under laboratory conditions with added doses of inorganic lead, and production of alkyllead, predominantly trimethyllead (Me₃Pb⁺), has been measured. Atmospheric concentrations and ratios of alkyl and inorganic lead at urban, rural and remote sites suggest that differential decay and deposition processes for different species, together with an environmental alkylation source, may explain enhanced ratios of total alkyllead/total lead in maritime air masses.     

Bioaccumulation of organic micropollutants from sediments and suspended particulates by aquatic animals

Summary Non-polar organic micropollutants, such as polycyclic aromatic hydrocarbons, polychlorinated biphenyls and some pesticides, which are adsorbed to sediments have a low bioavailability to freshwater and marine animals. Bioaccumulation factors from sediments (concentration in animal/concentration in sediment) of the organic pollutants investigated range from less than 0.1 to about 20, several orders of magnitude lower than bioaccumulation factors from the water for the same compounds. Bioavailability of sediment-adsorbed organic micropollutants is directly related to the solubility of the compound and sediment grain size, and inversely related to sediment organic carbon concentration and animal size. Organic micropollutants adsorbed to sediments are only slightly bioavailable, but sediments in contaminated areas often contain high concentrations of adsorbed pollutants; therefore they represent an important source of contamination of freshwater and marine animals.

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Bioakkumulation organischer Mikro-Verunreinigungen in Seetieren aus Sedimenten und suspendierten Teilchen

Zusammenfassung Nicht-polare organische Verunreinigungen, wie polycyclische aromatische Kohlenwasserstoffe, polychlorierte Biphenyle und einige Pesticide, die an Sedimente adsorbiert sind, besitzen eine niedrige Bioverfügbarkeit für Süßwasser- und Seetiere. Die Bioakkumulationsfaktoren aus den Sedimenten (Konzentration im Tier/Konzentration im Sediment) reichen für die untersuchten Verunreinigungen von weniger als 0,1 bis etwa 20, d.h. mehrere Größenordnungen kleiner als die entsprechenden Faktoren aus Wasser. Die Bioverfügbarkeit der an Sediment adsorbierten Verunreinigungen steht im direkten Verhältnis zu der Löslichkeit der Betreffenden Verbindung und der Korngröße des Sediments, und ist umgekehrt proportional zu der Konzentration an organischem Kohlenstoff im Sediment und der Größe des Tieres. Die an Sediment adsorbierten Verunreinigungen sind nur gering bioverfügbar, die Sedimente in kontaminierten Gebieten enthalten aber oft hohe Konzentrationen an Verunreinigungen. Daher stellen die Sedimente eine bedeutende Verunreinigungsquelle für Süßwasser- und Meerestiere dar.

     

The effects of organolead compounds on a freshwater and a marine alga

There are conflicting reports concerning the toxicity of tetraalkyllead (TAL) compounds to algae. A number of groups have found the TAL's to be comparable in toxicity with the trialkyllead compounds (R₃Pb⁺), whereas in a recent report it is suggested that the TAL's themselves are completely non-toxic and any apparent toxicity is due to R₃Pb⁺ breakdown products. With the object of identifying the toxic agent, the effect of Et₄Pb (TEL) on two algal species was re-examined. Analyses were carried out during the course of the incubations to establish the nature and concentrations of organoleads present in both media and algae, and hence evaluate their relative contributions to total toxicity. Algae were also cultured in the presence of Me₄Pb (TML), Me₃PbCl, Et₃PbCl, Bu₃PbCl and Et₂PbCl₂ to assess relationships between alkyl chain length and degree of substitution around the lead on algal activity. Additions of selenide and sulphide were made to the Et₃Pb⁺ and Et₂Pb²⁺ systems to see if these environmentally abundant species reduced or enhanced organolead toxicity. Problems were encountered in the analysis of the heterogeneous TEL containing media. Regardless of the analytical problems, the results confirm the previous findings that TAL's are non-toxic to algae and it is the R₃Pb⁺ breakdown products which are responsible for the apparent toxicity of the TAL's. The trialkylleads were the most toxic of the several alkyllead species studied, and within the trialkyl series toxicity increased with alkyl chain length. Neither selenide or sulphide had any significant ameliorative effect on alkyllead toxicity. It was found that the ionic organoleads were complexed on the TAL's and this complexing led to a number of unexpected results.     

Speciation of alkyllead compounds by GC-AAS: A state of affairs

A synopsis of the organolead studies performed at our University is given. The different environmental applications such as air, wet atmospheric deposition and dust are summarized and the analytical characteristics of the extraction/derivatization/gas chromatography—atomic absorption spectrometry methodology for the species specific determination of ionic alkyllead species are described.     

The biotransformation of monomethylarsonate and dimethylarsinate into arsenobetaine in seawater and mussels

Water-soluble ³H-labeled arsenic compounds were phenol-extracted from mussels (Mytilus edulis) and seawater after exposure to [³H]monomethylarsonate (MMAA) and [³H]dimethylarsinate (DMAA). Varying amounts of [³H] arsenobetaine were found in mussels and seawater, depending upon the experimental conditions. The results indicate that arsenobetaine is principally biosynthesized by microscopic organisms in the seawater and that it is bioaccumulated by mussels. Total arsenic concentrations in mussel flesh, byssal threads and shells were also determined, showing concentration increases in all three compartments.     

Speciation of waste water sediments

A sequential extraction procedure for waste water sediments was elaborated based on CO₂ and water extractants using supercritical fluid extraction instrumentation. The procedure gives information on water-soluble, carbonate-bound and mobile organic-bound trace metal fractions. The chemical interpretation of this procedure is comparable with the BCR recommended three-stage sequential extraction. The validation of the proposed procedure requires more detailed investigations.     

Metals in water and surface sediments from Henan reaches of the Yellow River,China

The concentrations of Cd,Cr,Cu,Ni,Pb and Zn were determined in the water and surface sediments from the Henan reaches of the Yellow River.Twenty-three sampling sites along the Yellow River and its tributaries were selected.Generally,metal concentrations were found to decrease in sequences of Zn>Cu>Pb>Cr>Ni>Cd in water and Zn>Cr>Pb>Ni>Cu>Cd in sediments.High levels of metal concentration were determined at a few stations of the river and its tributaries,such as Yiluo River,Si River and Qin River.The pollutio...     

Analysis and environmental levels of endocrine-disrupting compounds in freshwater sediments

An overview of analytical methods for target endocrine-disrupting compounds (EDCs) in freshwater sediments is presented. Among the EDCs we have selected five groups of compounds that are of priority within European Union and USA research activities: alkylphenols, polychlorinated compounds (dioxins, furans and biphenyls), polybrominated diphenyl ethers, phthalates and steroid sex hormones. Various aspects of current analytical methodology, such as sample preparation, extraction, purification and final determination, are discussed. Levels found in freshwater sediment are reviewed.     

Bioaccumulation of arsenic by freshwater algae (Nostoc sp.) and the application to the removal of inorganic arsenic from an aqueous phase

An arsenic-resistant blue-green alga, Nostoc sp., was screened from an arsenic-polluted environment. The effects of the culture conditions on the growth and the arsenic bioaccumulation were investigated. In five culture media tested, Microcystis aeruginosa medium was found to be optimum for the growth. The effects of the concentration of five nutrients (P, Co, Fe, Mo and N) in the MA medium on arsenic bioaccumulation by the Nostoc sp. were also investigated. From the experimental results, the authors proposed a new culture medium which was designed for effective arsenic bioaccumulation by the Nostoc sp. The new medium was named the Modified MA medium (abbreviated as MMA). Removal of arsenic from an aqueous phase by means of arsenic bioaccumulation by the Nostoc sp. was investigated. When arsenic-polluted water was enriched with the nutrients of MMA, the arsenic level was found to be effectively lowered by the Nostoc sp. to 0.05 ppm.     

Simplified procedures for the analysis of polycyclic aromatic hydrocarbons in water, sediments and mussels

We describe in this paper simple and robust analytical protocols to determine the 16 polycyclic aromatic hydrocarbons (PAHs) of the US Environmental Protection Agency priority list in water, sediment and mussels. For water samples, eight different solid-phase extraction (SPE) sorbents have been compared and among them, C18 provided highest recoveries and limits of detection of 0.3-15 ng/L. For lyophilized sediments, Soxhlet and ultrasonic extraction were compared, and the last one permitted to recover all analytes with highest repetitivity and was validated by analysing a certified reference material. Finally, the analysis of mussels was undertaken using Soxhlet, ultrasonic and pressurized liquid extraction (PLE) and the performance of several clean-up steps are compared. Whereas for the former two, incomplete recovery or losses of some analytes were evidenced, PLE permitted a more efficient extraction and although alkaline digestion was necessary to remove coextracted compounds, the method gave acceptable recoveries and limits of detection of 0.5-7.7 microg/kg dry mass, as for sediments. In all cases, analysis was performed by gas chromatography coupled to mass spectrometry and internal standard quantification was performed using five deuterated PAHs. Each method performance is discussed for the three matrices analysed and the paper reports advantages and disadvantages of each for their routine application in monitoring programs.     

Geochemical fractions and modeling adsorption of heavy metals into contaminated river sediments in Japan and Thailand determined by sequential leaching technique using ICP-MS

In order to provide information on the chemical processes in sediment fractions and their adsorption models, we investigated the contaminated sediments of the Sumida River in Tokyo, Japan and the Chao Phraya River in Bangkok, Thailand. Samples were leached through a sequential leaching technique to perform metal concentration analysis for the sediment fraction assessment and then samples were tested for the model adsorption of the highest level of sediments contaminated by heavy metals using the isotherm Langmuir and Freundlich equations. Metal (Pb, Cd, Zn, As, Cu, Ca, Fe, and Mn) concentration in the leached solutions was analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The pattern of geochemical fractions in both sediment samples showed the maxima leached levels of Cd (38.6 %), Ca (55.2%), and Mn (41.3%) in the soluble fraction; Pb (52.1%), and Zn (56.7%) in the reducible fraction; Cu (61.2%) in the oxidizable fraction; and As (47.1%) and Fe (55.9%) in the residual fraction. The total level fractions of Pb (62.6 ppm), Zn (240 ppm), As (27.2 ppm), Fe (16,636 ppm) and Mn (419 ppm) in the Chao Phraya River sediments were higher compared to those in the Sumida River, indicating the high anthropogenic effect in Bangkok. In the most contaminated sediments, the higher adsorption capacity of heavy metal concentrations was contributed by SiO_2, CaCO_3, and Al₂O₃ determined by the X-ray diffraction and organic contents. The model of adsorption of Cd fitted to the linear form of Langmuir’s equation with the correlation coefficients (r² = 0.94), b (0.467) and k (7137), whereas Pb, Cu, Cr, and Zn conformed to the model of the Freundlich equation.     

Removal of fluoride from fluoride contaminated industrial waste water by electrolysis

Wastewater containing fluoride are generally treated with lime or calcium salt supplemented with aluminium salts. Wastewater generated from different industries does not always behave in the same way due to the presence of interfering contaminants. A number of techniques have been developed and studied for the removal of excessive fluoride. Most of these are based on use of aluminium salt. In alum coagulation the sorption properties of product of hydrolysis of aluminium salts and capacity of fluoride for complex formation plays a very important role. These hydrolysis products of aluminium can be produced by passing direct current through aluminium electrode. The text presented in the paper deals with the various aspect of removal of fluoride by electrolysis using aluminium electrode from fluoride chemical based industrial wastewater.     

Behaviour of several solid adsorbents for sampling tetraalkyllead compounds in air

The behaviour of various solid adsorbents for collecting tetraalkyllead compounds has been studied. A synthetic atmosphere containing a known concentration of tetraethyllead was produced and the tetraethyllead compound was trapped in a glass tube containing the solid adsorbent. The trapped compound was extracted with hexane in an ultrasonic bath, and the resulting solution was analysed by GC-MS. Porapak and Tenax, with retention efficiencies of 92 and 96%, respectively, were shown to be the more efficient at trapping this alkyllead compound than Chromosorb, active charcoal, Amberlites and polyurethane foam. The behaviour of both Porapak and Tenax for trapping other tetraalkyllead compounds in the presence of gasoline vapour was also studied.     

Occurrence of butyltin compounds in marine sediments and bivalves from three harbour areas (Saigon,Da Nang and Hai Phong) in Vietnam

A survey of organotin compounds comprising tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediment and clam (Meretrix meretrix) was undertaken in Vietnam in 2003. Samples were collected from dry docks and cargo harbours in Ho Chi Minh (south), Da Nang (centre) and Hai Phong (north) cities. Measurable amounts of TBT, DBT and MBT were found in all samples. The total concentration of the butyltin compounds (ΣBTs) in sediment from shipyards and vessel repair yards (Nam Trieu, Song Cam, Lach Tray and Ba Son) were always higher than those measured in cargo ports (Hai Phong, Da Nang, and Sai Gon). The highest ΣBTs concentration (as tin: 122 ng g^?1 dry wt) was found in the sediment from Song Cam station, where seven shipyards are located. The lowest concentrations of ΣBTs occurred in sediments from the Da Nang and Hai Phong cargo ports (as tin: 21–22 ng g^?1 dry wt). This implies that the major source of BTs in the marine environment in Vietnam is from the shipbuilding activities. The ratio of TBT to Σ(MBT + DBT) in sediment was 0.67 ± 0.03 for all the sampling sites, indicating the recent use of TBT in Vietnam. For the clam (M. meretrix), the concentration of ΣBTs (as tin) varied in the range 11.2–60.1 ng g^?1 wet wt. There was a good correlation (R² = 0.85) between total organic matter‐normalized ΣBTs in sediment and hexane‐extractable organic matter‐normalized ΣBTs in clam soft tissue. The mean biota–sediment accumulation factors (organic carbon/lipid) for MBT, DBT and TBT in clam's soft tissue were found to be 1.83 ± 0.66, 1.44 ± 0.23 and 1.16 ± 0.47 respectively, indicating that sediment‐bound BTs might be an important source of contamination for the clam. Copyright © 2005 John Wiley & Sons, Ltd.     

Determination of organotin compounds in marine sediments using graphite furnace atomic absorption spectrometry

Organotin compounds, especially tributyltin, began to cause concern 10 years ago due to a high toxicity towards marine organisms. Several methods of analysing organotin compounds in various matrices have already been developed to determine organotin species simultaneously, but these are quite expensive as special equipment and specialized staff are needed. A simple screening method, which determines the organic tin compounds in the sediment, has therefore been developed and validated. The method can easily be implemented in laboratories accustomed to tracelement analyses; the sediment is extracted by a two-phase extraction and the organic extract is analysed using graphite furnace atomic absorption spectrometry (GF AA.) The screening method has been validated using high-pressure liquid chromatography-inductively coupled plasma mass spectrometry (HPLC–ICP MS).