Arsenic In Marine Organisms Research Articles

Toxic Effects of Arsenic on Four Freshwater Aquatic Species and Its Transformation Metabolism in Crucian Carp (Carassius auratus).

Inorganic arsenic is a well-known carcinogen that is much more toxic than its organic counterpart. While much is known about the accumulation and transformation of arsenic in marine organisms, little is known regarding these processes in freshwater aquatic species. In this study, the acute toxicity and toxicological effects of inorganic arsenic on four freshwater organisms (Cyprinus carpio, Misgurnus anguillicaudatus, Pseudorasbora parva, Eriocheir sinensis) commonly found in rice-fish farming systems were investigated. The organisms exhibited different levels of sensitivity to inorganic arsenic, with crustaceans being more sensitive than fish. Fish were found to be more tolerant to As(V) than As(III). The study also investigated the accumulation, transformation, and release of inorganic arsenic in crucian carp, an omnivorous species with high environmental tolerance. The fish accumulated As(III) rapidly in various tissues, and were able to transport it to other tissues through gills, intestines, and skin. The accumulated As(III) was converted into less toxic forms, such as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), via methylation. The fish also converted As(III) into arsenate (AsV) via enzymatic and oxidative reactions. After the transferal to clean water, the forms of arsenic in the various tissues decreased rapidly, but the rates of excretion of the four forms of arsenic were not the same among the different tissues. Our results suggest that crucian carp can reduce the environmental toxicity of As(III) at certain concentrations by transforming it into less toxic forms within their bodies.

Recent developments in speciation and determination of arsenic in marine organisms using different analytical techniques. A review.

Marine organisms play a vital role as the main providers of essential and functional food. Yet they also constitute the primary pathway through which humans are exposed to total arsenic (As) in their diets. Since it is well known that the toxicity of this metalloid ultimately depends on its chemical forms, speciation in As is an important issue. Most relevant articles about arsenic speciation have been investigated. This extended not only from general knowledge about As but also the toxicity and health related issues resulting from exposure to these As species from the food ecosystem. There can be enormous side effects originating from exposure to As species that must be measured quantitatively. Therefore, various convenient approaches have been developed to identify different species of As in marine samples. Different extraction strategies have been utilized based on the As species of interest including water, methanol and mixtures of both, and many other extraction agents have been explained in this article. Furthermore, details of hyphenated techniques which are available for detecting these As species have been documented, especially the most versatile and applied technique including inductively coupled plasma mass spectrometry.

Arsenolipids in marine oils and fats: A review of occurrence, chemistry and future research needs

Numerous studies have focused on arsenic in marine organisms, and relatively high natural levels of the element have been reported in marine samples. Despite their seemingly consistent presence in marine oils and fats, there is currently only limited knowledge available on arsenic compounds that exhibit lipid soluble characteristics, the arsenolipids, in contrast to the water-soluble arsenic species. The development of analytical techniques has, however, renewed the interest in these arsenic species and significant novel findings have been published in the last couple of years. The aim of this review is to present current knowledge on the occurrence and chemistry of arsenolipids in marine oils, and to identify future research needs. The occurrence of arsenolipids and their relevance in marine organisms will be discussed, in addition to their relevance for consumers and industry, with respect to feed and food safety and legislative issues. Analytical techniques, including techniques in the early work on arsenolipids in addition to methods employed today, and relevant sample preparation will be discussed.

Total arsenic in marine organisms from Cienfuegos bay (Cuba)

Levels of total arsenic were determined in muscle tissues of species of fish, crustaceans and molluscs from Cienfuegos Bay, Cuba. The arsenic content in the samples was determined using an energy dispersive X-ray fluorescence (EDXRF) method. The highest concentrations of total arsenic were found in crustaceans and average values for fish, molluscs and crustaceans were 10.2, 22 and 26.5μgg−1drywt, respectively.

Characterization of arsenic content in marine organisms from temperate, tropical, and polar environments

Arsenic is a widely distributed element which occurs in several chemical forms in the marine environment. Inorganic arsenic mediates the most toxic effects and predominates in sea water and sediments, while organisms generally accumulate non-toxic organic forms to concentrations probably reflecting species-specific characteristics in arsenic metabolism. This work represents an additional contribution to our knowledge on natural levels and chemical speciation of arsenic in marine organisms; basal concentrations were characterized in several species (bivalves, crustaceans, and fishes) from different environments (polar, temperate, and tropical latitudes), and results revealed an elevated variability with values ranging from less than 5 to about 200 μg g−1. No significant effects were observed as a function of the geographical area, with the only exception of crustaceans always showing more elevated arsenic concentrations in Mediterranean species (about 45–110 μg g−1) compared with tropical species (lower than 30 μg g−1). Chemical speciation of arsenic was investigated in representative species from the three studied taxa; the predominance of organic forms confirmed the general tendency of marine organisms to bioaccumulate non-toxic arsenic compounds, probably resulting from a detoxification pathway.

Risk assessment of trace elements in the stomach contents of Indo-Pacific Humpback Dolphins and Finless Porpoises in Hong Kong waters

The potential health risks due to inorganic substances, mainly metals, was evaluated for the two resident marine mammals in Hong Kong, the Indo-Pacific Humpback Dolphin ( Sousa chinensis) and the Finless Porpoise ( Neophocaena phocaenoides). The stomachs from the carcasses of twelve stranded dolphins and fifteen stranded porpoises were collected and the contents examined. Concentrations of thirteen trace elements (Ag, As, Cd, Co, Cr, Cs, Cu, Hg, Mn, Ni, Se, V and Zn) were determined by inductively coupled plasma mass spectrometer (ICP-MS). An assessment of risks of adverse effects was undertaken using two toxicity guideline values, namely the Reference Dose (RfD), commonly used in human health risk assessment, and the Toxicity Reference Value (TRV), based on terrestrial mammal data. The levels of trace metals in stomach contents of dolphins and porpoises were found to be similar. Risk quotients (RQ) calculated for the trace elements showed that risks to the dolphins and porpoises were generally low and within safe limits using the values based on the TRV, which are less conservative than those based on the RfD values. Using the RfD-based values the risks associated with arsenic, cadmium, chromium, copper, nickel and mercury were comparatively higher. The highest RQ was associated with arsenic, however, most of the arsenic in marine organisms should be in the non-toxic organic form, and thus the calculated risk is likely to be overestimated.

Decomposition of organoarsenic compounds for total arsenic determination in marine organisms by the hydride generation technique

The conditions necessary for the complete decomposition of six organic arsenic compounds, namely methylarsonic acid (MMAA), dimethylarsinic acid (DMAA), trimethylarsine oxide, tetramethylarsonium iodide, arsenocholine bromide (AsC) and arsenobetaine (AB), were investigated. The degree of decomposition of the arsenic compounds was monitored using a hydride generation (HYD) technique, because the response from this system depends strongly on the chemical species of arsenic, with inorganic arsenic (the expected product from these decomposition experiments) giving a much more intense HYD signal than the organic arsenic compounds. The arsenic compounds were decomposed by heating them with three types of acid mixture, namely HNO3HClO4, HNO3HClO4HF, or HNO3HClO4H2SO4. Both MMAA and DMAA were decomposed completely using any of the mixed acids at a decomposition temperature of 200 °C or higher. The HNO3HClO4H2SO4 mixture was the most effective for decomposing AsC and AB, which are the most difficult compounds among all types of organic arsenic compound to decompose and render inorganic. The complete decomposition of AB was only achieved, however, when the temperature was 320 °C or higher, and the sample was evaporated to dryness. When the residue from this treatment was examined by high-performance liquid chromatography combined with inductively coupled plasma atomic emission spectrometry, all of the arsenic was found to be present as arsenic(V). The optimized conditions (HNO3HClO4H2SO4 at 320 °C) for decomposing AB were then used to determine the total amount of arsenic in marine organisms known to contain AB. Copyright © 2005 John Wiley & Sons, Ltd.

A preliminary risk assessment of trace elements accumulated in fish to the Indo-Pacific Humpback dolphin ( Sousa chinensis) in the Northwestern waters of Hong Kong

In order to assess the potential risks associated with consumption of contaminated prey items to the Indo-Pacific Humpback dolphin ( Sousa chinensis), fish species ( Collichthys lucida, Pseudosciaena crocea, Johnius sp., Thryssa sp., Mugil sp. and Trichiurus sp.) representing the main food items of the dolphin were collected from the Northwestern waters of Hong Kong, including the Sha Chau and Lung Kwu Chau Marine Park, which form the main habitat of the dolphin in Hong Kong. Within these waters, there are several potential sources of pollution including significant inputs from the Pearl River catchment, several major sewage outfalls and a series of mud pits that receive contaminated dredged sediments. Concentrations of thirteen trace elements (Ag, As, Cd, Co, Cr, Cs, Cu, Hg, Mn, Ni, Se, V, and Zn) in the fish tissue were analyzed by inductively coupled plasma mass spectrometer (ICP-MS). An assessment of the risks of adverse effects on the dolphin due to consumption of tainted fish was undertaken using two toxic reference benchmarks, namely the reference dose (RfD) and toxicity reference value (TRV). The risk quotient (RQ) calculated for each element showed that the risks from consumption of fish were generally low and within safe limits. The risks associated with arsenic, cadmium and mercury were, however, elevated. The highest calculated RQ was associated with total arsenic; however, the majority of arsenic in marine organisms tends to be in the non-toxic organic form, and the actual risk to the dolphin due to this metalloid is likely to be lower.

Synthesis, NMR spectra and chromatographic properties of five trimethylarsonioribosides

AbstractFive trimethylarsonioribosides were prepared from naturally occurring and synthetic dimethylarsinylribosides (arsenosugars) by reducing them with 2,3‐dimercaptopropanol and quaternizing the resultant arsine with methyl iodide. The trimethylarsonioribosides prepared in this manner were the four novel compounds methyl 5‐deoxy‐5‐trimethylarsonio‐β‐D‐riboside (as the iodide), (2′R)‐2′, 3′‐dihydroxypropyl 5‐deoxy‐5‐trimethylarsonio‐β‐D‐riboside (as the formate), 3′‐[(2″, 3″ ‐dihydroxypropyl)hydroxyphosphinyloxy] ‐ 2′ ‐hydroxypropyl 5‐deoxy‐5‐trimethylarsonio‐β‐D‐riboside and 3‐(5′‐deoxy‐5′‐trimethylarsonio‐β‐D‐ribosyloxy)‐(2S)‐2‐hydro xypropanesulfonate, and the known (2′S)‐2′‐hydroxy‐3′‐(sulfooxy)propyl 5‐deoxy‐5‐trimethylarsonio‐β‐D‐riboside. They were synthesized to serve as standards for chromatographic analyses of arsenic compounds in marine samples and for investigations into the biotransformation of arsenic in marine organisms. NMR spectral and chromatographic data for the five trimethylarsonioribosides are presented and compared with those of their dimethylarsinyl analogues.

Organometallics in the nearshore marine environment of Australia

AbstractThis review draws together published information on the occurrence and biogeochemical cycling of selenium, arsenic and tin in the nearshore marine environment of Australia. The selenium content of marine organisms is well documented but little information is available on the selenium content of waters and sediments. The speciation of selenium in organisms, water and sediments is unknown although it appears that selenium is associated with proteins. The occurrence and speciation of arsenic in marine organisms has been extensively studied, with arsonobetaine being isolated as the probable end‐product of arsenic metabolism in marine food chains. However, organisms can produce other organoarsenic compounds, e.g. trimethylarsine oxide, which may be metabolized to toxic end‐products. Little is known about the occurrence and speciation of arsenic in waters and sediments. Arsenic(V) is dominant in oxygenated waters, with appreciable quantities of arsenic(III) in some deoxygenated waters.There are few data for tin in water, sediments or organisms and no data on naturally occurring tin species. Tributyltin has been measured in water, sediment and organisms from areas affected by boating activity.

Distribution of inorganic arsenic and methylated arsenic in marine organisms

AbstractInorganic arsenic and methylated arsenic compounds in 60 specimens of marine organisms were investigated by hydride generation derivatization and cold‐trap gas chromatography–mass spectrometry (GC MS). Chloroform–methanol extracts from seaweeds, shellfish, fish, crustaceans and other marine organisms were separated into water‐soluble and lipid‐soluble fractions. The arsenic compounds in each fraction were identified and analysed as arsine, methylarsine, dimethylarsine and trimethylarsine.Trimethylarsenic compounds were distributed mainly in the water‐soluble fraction of muscle of carnivorous gastropods, crustaceans and fish. The amounts of dimethylated arsenic compounds were found to be larger than that of trimethylated arsenic in the lipid‐soluble fraction of fish viscera. Dimethylated arsenic compounds were distributed in the water‐soluble fraction of Phaeophyceae.

Metabolic pathways involving arsenic in marine organisms: A unifying hypothesis

Arsenic is potentially a highly toxic element in marine ecosystems, and in inorganic form represents a threat to consumers of marine products, including man. Chemical forms of arsenic in marine biota are diverse, however, and are usually of uncertain toxicological significance. The element has been reported in association with lipids, as arsenobetaine and as arseno-sugars. These data are critically reviewed, and a novel hypothesis is presented to account for the chemical forms of arsenic reported to date. The hypothesis relies upon the replacement of nitrogen by arsenic in substrates involved in phospholipid synthesis. This would give rise to a large number of arsenic-containing intermediates, which would be either water-soluble or lipid-soluble. The derivation of the arseno-sugars found recently in brown kelp and giant clams is explained as an incidental side-product of the phospholipid biosynthesis in algae. These various arsenic-containing compounds are all thought to be catabolised (in some cases by several organisms in sequence) as they pass through the food web, yielding arsenobetaine as a stable end-product.

Arsenic in marine organisms

A review of the nature and accumulation of arsenic in marine organisms is presented. A study of the literature has revealed a lack of information about the mechanisms of uptake, molecular transformations, and biochemical associations of arsenic within organisms, and it remains unclear whether a few forms of arsenic are ubiquitous. The arsenic forms present in marine sediments and their role in the biogeochemical cycling of arsenic are also largely unknown.

Inorganic arsenic in marine organisms

Inorganic arsenic in marine organisms

Selective determination of inorganic arsenic(III), (V) and organic arsenic in marine organisms.

Selective determination of inorganic arsenic (III), (V) and organic arsenic by the solvent extraction method was done with 20 species of marine organisms, including fish, ascidian, holo-thurian, sea urchin, crustacean, shellfish, cephalopod, polychaete, and seweed. In all species, inorganic arsenic, which is more highly toxic than organic arsenic, comprised only a small part (0-7%) of the total arsenic; the one exception was in a seaweed Hizikia fusiforme, in which inorganic arsenic accounted for 60% of the total arsenic. Furthermore, when arsenic in water-soluble and fat-soluble fractions was determined, the ratio of water-soluble arsenic reached 58-97% of the total arsenic. Especially in the cephalopod (3 species) and fish (6 species), more than 84% of the total arsenic was found in the water-soluble fraction. These results strongly suggested that most arsenicals in marine organisms are present in water-soluble organic forms.

Digestion method of marine organisms for determination of total arsenic by atomic absorption spectrometry.

A wet digestion method adding nickel ion for the determination of total arsenic in marine organisms was evaluated from the characteristics of arsenic in graphite furnace atomic absorption spectrometry. The necessity of an addition of nickel ion in a wet digestion process could not be confirmed in any case examined. The concentrations of arsenic in marine organisms determined by graphite furnace and arsine generation atomic absorption spectrometry after digested with nitric acid, perchloric acid and sulfuric acid were in good agreement with each other. The accuracy of each method was studied by analyzing NBS SRM 1566 oyster tissue.

Study on wet digestion method for determination of total arsenic in marine organisms by continuous flow arsine generation and atomic absorption spectrometry using some model compounds.

A wet digestion method to determine total arsenic in marine organisms by continuous flow arsine generation and atomic absorption spectrometry was studied using some model compounds. Conditions for the generation of arsine were also studied for inorganic arsenite and arsenate, methylarsonic acid, dimethylarsinic acid, and phenylarsonic acid. The methylated arsenic species, phenylarsonic acid and arsenobetaine were completely decomposed to inorganic arsenate by the wet oxidation with nitric acid-perchloric acid-sulfuric acid system; an addition of nickel ion in the digestion process was not needed. Perchloric acid was essential to the complete decomposition of arsenobetaine when digestion was carried out on a hot plate.

Trace metals of toxicological significance to man in Hong Kong seafood

Samples of marine organisms derived either by direct capture methods in local waters, or by purchase from retail markets in Hong Kong, Kowloon and the New Territories, were analysed for between six and nine trace elements during 1976 and 1978. The results indicated significantly elevated concentrations of arsenic and cadmium in many samples. Whilst arsenic in marine organisms is not considered to be a toxicological threat to man, as the majority of this element is present in seafood in an organic form readily excreted by man, cadmium may be of significance as a human health hazard. The other metals studied were either only weakly elevated in certain classes of organism (lead) or only rarely attained levels which are considered a threat to human health (chromium, mercury). Antimony, copper, tin and zinc were also not present in high enough concentrations to cause detrimental health effects in the population of Hong Kong. Further monitoring of selected elements in seafood is considered necessary, both to delineate any temporal change in trace metal levels in locally available organisms and to ensure that concentrations of cadmium do not increase further.

Fractionation of arsenous, arsenic, methanearsonate and dimethylarsinic acid by using strong-acid cation-exchange resin

Behavior of arsenous, arsenic, disodium methanearsonate (DSMA) and dimethylarsinic acid (DMAA) with a strong-acid cation-exchange resin was investigated. Dowex 50W×8 {(50100) mesh, hydrogen from} was used. A mixed solution, modified to pH 2, of these arsenicals was applied to the top of a short column (1.5cm×12cm) connected to a long column (1.9cm×118cm) and then eluted at a flow rate of (911)cm3cm-2h-1. The effluent was monitored for arsenic by using atomic absorption spectrophotometer equipped with graphite furnace atomizer. Arsenic, arsenous and DSMA were separately eluted with water in this order from the long column. DMAA held strongly on the short column was eluted with aqueous ammonia after the connection of the two columns was cut. Almost 100% of these arsenicals was recovered in the effluents. From an aqueous extract from a brown seaweed, Hizikia fusiforme, 4 arsenic peaks corresponding to the reference arsenic, arsenous, DSMA and DMAA were obtained by the method. This method is effectively applicable for studying chemical forms and metabolic fate of arsenic in marine organisms.

Separation and analysis of organic-bound and inorganic arsenic in marine organisms.

AbstractA method for the separation of stable arseno‐organic compounds from inorganic arsenic and the subsequent determination of both forms of arsenic is described. The separation is based on volatilisation of inorganic arsenic as arsenic trichloride by addition of hydrochloric acid to 6.6 N and subsequent removal by distillation at 100 °C. Remaining arsenic is bound in arseno‐organic compounds that are stable under these conditions.Total arsenic in the samples analysed is reduced by 0.5 to 3 parts/million by this treatment. Determination of arsenic was performed by neutron activation and X‐ray fluorescence.