Search

Irgarol 1051 is an herbicide extensively utilized in antifouling paint due to its ability to inhibit photosynthesis. Irgarol and its photodegradation products are highly persistent in waters and sediments, although they are present in low concentrations. However, our understanding of the harmful effects of Irgarol on non-target organisms remains limited. In this study, we assessed the effects of acute (24 h) and chronic (14 days across three generations) exposure to different concentrations (including the 1/10 NOEC, NOEC, and 1/10 LC50 calculated from the 24-h acute toxicity test) of Irgarol using the water flea Moina macrocopa. Acute exposure to 1/10 LC50 significantly decreased survival, feeding rate, thoracic limb activity, heart rate, and acetylcholinesterase activity. Elevated levels of intracellular reactive oxygen species and malondialdehyde, along with a significant increase in catalase and superoxide dismutase activity, suggested the induction of oxidative stress in response to 1/10 LC50. An initial boost in glutathione level and the enzymatic activities of glutathione peroxidase and glutathione reductase, followed by a plunge, implies some compromise in the antioxidant defense system. Upon chronic exposure to the NOEC value, both generations F1 and F2 displayed a significant decrease in survival rate, body length, number of neonates per brood, and delayed sexual maturation, suggesting maternal transfer of potential damage through generations. Taken together, Irgarol induced acute toxicity through physiological and cholinergic damage, accompanied by the induction of oxidative stress, in the water flea. Even its sub-lethal concentrations can induce detrimental effects across generations when consistently exposed. [Display omitted] • Water flea, non-target animals can be exposed to Irgarol during life cycle across generation. • Chronic exposure to sub-lethal concentrations of Irgarol altered physiological and biochemical parameters. • Significant growth retardation observed at the third generation upon NOEC values of Irgarol. • Sub-lethal concentrations of Irgarol inhibited reproduction. [ABSTRACT FROM AUTHOR]

The present study aims to compare the toxicity effect of Copper and Irgarol 1051 as antifouling agents on metabolites products in marine algae Dunaliella salina. Different concentrations of Cu (5, 15 & 25 mg/l) and Irgarol 1051 (0.012, 0.025 & 0.050 μg/l) were laboratories prepared and their impacts on growth, protein, and carbohydrates in Dunaliella salina were tested. Selections of these concentrations were initiated based on the response of the studied alga which had slightly or marked effects on its growth, and also to avoid the non-effective and directly lethal concentrations on the experimented alga. The obtained results showed stimulation in the growth of algae under the effect of the lowest concentration of the two tested antifoulings, however, there was a suppression of algal growth by increasing the concentration of the two antifoulings but with different degrees. There was a clear inhibition of protein and carbohydrate production by increasing the concentration of the two tested antifoulings. Also, Irgarol 1051 showed a toxic effect higher than Copper, which is one of the essential micronutrients in the marine ecosystem. [ABSTRACT FROM AUTHOR]

Highlights • Changes in growth, photosynthetic activity, and metabolomic profiles induced by artificially stresses were evaluated in eelgrass. • Decreased levels of sugar and increased levels of amino acids in a herbicide-exposed and insufficient light groups are distinctive. • Autophagy is possibly involved in changes in the metabolomic profiles. Abstract This study aimed to elucidate the biological responses of eelgrass (Zostera marina) to artificially induced stresses such as herbicide (Irgarol 1051, Irg) exposure, insufficient light, and high water temperature (27 ± 1.0 °C) by evaluating growth inhibition, photosynthetic activity, and metabolomic profiles. After 14 days, all treatments inhibited growth, but photosynthetic activity was only reduced in the Irg-exposed group. In the Irg-exposed and insufficient light groups, the metabolomic profiles were characterized by decreased levels of sugar (sucrose) and increased levels of amino acids such as glutamine, glycine, and leucine. Biochemical and ultrastructural analyses revealed that the loss of sugar-derived metabolic energy was compensated for by energy generated during autophagic protein degradation. Furthermore, the level of myo-inositol, which has various biological roles and participates in several cellular processes such as cell wall synthesis, stress response, and mineral nutrient storage, was markedly increased in the Irg-exposed and insufficient light groups. A combination of metabolomic analysis with other analyses such as measurement of photosynthetic activity might further elucidate the response of eelgrass to ambient stresses in the natural environment. [ABSTRACT FROM AUTHOR]

An interferometric nanobiosensor for the specific and label-free detection of the pollutant Irgarol 1051 directly in seawater has been settled. Due to the low molecular weight of Irgarol pollutant and its expected low concentration in seawater, the sensor is based on a competitive inhibition immunoassay. Parameters as surface biofunctionalization, concentration of the selective antibody and regeneration conditions have been carefully evaluated. The optimized immunosensor shows a limit of detection of only 3 ng/L, well below the 16 ng/L set by the EU as the maximum allowable concentration in seawater. It can properly operate during 30 assay-regeneration cycles using the same sensor biosurface and with a time-to-result of only 20 min for each cycle. Moreover, the interferometric nanosensor is able to directly detect low concentrations of Irgarol 1051 in seawater without requiring sample pre-treatments and without showing any background signal due to sea matrix effect. [ABSTRACT FROM AUTHOR]

Since the ban of tri-butyl tin, other various alternative antifouling agents have been used. In this study, the contamination levels from these antifouling agents were examined in the main harbors in Korea. The sampled harbors were classified into four types and the levels of contamination from the antifouling agents were analyzed. The highest degree of contamination was found in the big harbors, followed by the fishing harbors, harbors near agricultural areas, and military and coast guard harbors. In addition, an increase in the number of ships that entered the ports significantly influenced the contamination by the antifouling agents. Correlation analysis was conducted to characterize the alternative antifouling agents. The results revealed strong correlations between the dichlofluanid and chlorothalonil, and between the chlorothalonil and TCMTB, because unlike Irgarol 1051 and SEA-NINE 211, which are used only as antifouling agents, chlorothalonil, dichlofluanid, and TCMTB are also used in agriculture. [ABSTRACT FROM AUTHOR]

Ship groundings and ice-breakers can cause pollution of the polar environment with antifouling biocides such as diuron and Irgarol 1051. The present study used pulse amplitude modulated fluorometry to compare single and joint toxicities of diuron and Irgarol 1051 on two freshwater taxa of microalgae ( Chlorella and Chlamydomonas ) originating from Arctic and temperate regions. 30 min acute toxicity tests using chlorophyll a (Chl a ) fluorescence revealed that Arctic strains of microalgae were more sensitive to herbicides than their temperate counterparts. Diuron and Irgarol 1051 had equal toxicities in the Arctic species, while Irgarol 1051 was more toxic (EC 50 = 5.55–14.70 μg L −1 ) than diuron (EC 50 = 12.90–>40 μg L −1 ) in the temperate species. Toxicity assessment of various mixtures of diuron and Irgarol 1051 revealed antagonistic, additive, and synergistic effects. Our data suggest that herbicides can adversely affect photosynthesis in Arctic microalgae at relatively low levels, and their impact can increase under complex mixture conditions. [ABSTRACT FROM AUTHOR]

In the present work, microfunnel-supported liquid-phase microextraction method (MF-LPME) based on applying low density organic solvent was developed for the determination of antifoulings (Irgarol 1051, diuron and 3,4-dichloroaniline) from seawater samples. In this method, home-designed MF device was used for facile loading and retrieving of organic solvent during the extraction procedure. The extraction was carried out with introduction of 400µL of toluene via syringe into the MF device placed on the surface of sample solution (300mL) containing analytes. After the extraction, extractant layer was narrowed into the capillary part of MF by pushing the device inside the sample and withdrawn by using a syringe to evaporate by nitrogen purging. The residual redissolved into 50µL methanol, diluted to 100µL with deionized water and injected into the high performance liquid chromatography with UV detection (HPLC-UV). Several factors influencing the extraction such as the type and volume of extraction solvent, sample pH, extraction time and ionic strength were investigated and optimized. Under the optimized conditions, the limits of detection in seawater were 1.4, 4.8 and 1.0ngL-1 for 3,4-dichloroaniline (DCA), diuron and Irgarol 1051, respectively. Enrichment factors were obtained 333, 150 and 373 for DCA, diuron and Irgarol 1051, respectively. The precision of the technique was evaluated in terms of repeatability which was less than 12.0% (n=5). The applicability of the proposed method was evaluated by the extraction and determination of antifoulings from seawater samples collected from harbors of Bushehr located in northern Persian Gulf coast. [ABSTRACT FROM AUTHOR]

Accumulation of Ot alternative antifoulants in sediment is the focus of this research. Much research had been done on surface sediment, but in this report, the accumulation in the sediment core was studied. The Ot alternative antifoulants, Diuron, Sea-Nine211, and Irgarol 1051, and the latter's degradation product, M1, were investigated in five samples from the northern part of Hiroshima Bay. Ot compounds (tributyltin (TBT) and triphenyltin (TPT)) were also investigated for comparison. In addition, metal (Pb, Cu, Zn, Fe and Mn) levels and chronology were measured to better understand what happens after accumulation on the sea floor. It was discovered that Ot alternative antifoulant accumulation characteristics in sediment were like Ot compounds, with the concentration in the sediment core being much higher than surface sediment. The concentration in sediment seems to have been affected by the regulation of Ot compounds in 1990, due to the concentration of Ot alternative antifoulants and Ot compounds at the survey point in front of the dock, showing an increase from almost the same layer after the regulation. [ABSTRACT FROM AUTHOR]

Highlights: [•] HepG2 cell were exposed to 0.04–40mg/L Irgarol 1051. [•] Positive staining by Annexin V and caspase-3 activity enhancement were recorded. [•] Induction of caspase-9 indicated the apoptosis through the mitochondrial pathway. [•] Mitochondrial dysfunction and oxidative stresses may be the cause for apoptosis. [Copyright &y& Elsevier]

Abstract: Cyanobacteria are prokaryotic algae found in oceans and freshwaters worldwide. These organisms are important primary producers in aquatic ecosystems because they can provide essential food for grazers and herbivores. In this study, the physiological and biochemical responses of the freshwater cyanobacterium Synechococcus sp. PCC7942 to two organic booster biocides Irgarol 1051 and diuron were compared and evaluated using 96h growth tests in a batch-culture system. The 96h median effective concentrations (EC50) were 0.019 and 0.097μmolL−1 for Irgarol 1051 and diuron, respectively, which indicate that Irgarol 1051 is about 5 times more toxic than diuron to cyanobacteria. Moreover, remarkable physiological and biochemical responses occurred in the Irgarol 1051 and diuron treatments. Irgarol 1051 and diuron stimulated cyanobacterial growth, increased the soluble protein content, and enhanced the catalase (CAT) activity at low concentrations, but inhibited them at high concentrations. However, the malondialdehyde (MDA) and polysaccharide content of the cyanobacteria were only significantly affected by Irgarol 1051. These observations suggest that Irgarol 1051 and diuron are toxic to Synechococcus sp. PCC7942, and their use should be restricted in maritime industries. [Copyright &y& Elsevier]

Abstract: After the widespread ban of TBT, due to its severe impact on coastal biocoenoses, mainly related to its immunosuppressive effects on both invertebrates and vertebrates, alternative biocides such as Cu(I) salts and the triazine Irgarol 1051, the latter previously used in agriculture as a herbicide, have been massively introduced in combined formulations for antifouling paints against a wide spectrum of fouling organisms. Using short-term (60min) haemocyte cultures of the colonial ascidian Botryllus schlosseri exposed to various sublethal concentrations of copper(I) chloride (LC50 =281μM, i.e., 17.8mgCuL−1) and Irgarol 1051 (LC50 >500μM, i.e., >127mgL−1), we evaluated their immunotoxic effects through a series of cytochemical assays previously used for organotin compounds. Both compounds can induce dose-dependent immunosuppression, acting on different cellular targets and altering many activities of immunocytes but, unlike TBT, did not have significant effects on cell morphology. Generally, Cu(I) appeared to be more toxic than Irgarol 1051: it significantly (p <0.05) inhibited yeast phagocytosis at 0.1μM (∼10μgL−1), and affected calcium homeostasis and mitochondrial cytochrome-c oxidase activity at 0.01μM (∼1μgL−1). Both substances were able to change membrane permeability, induce apoptosis from concentrations of 0.1μM (∼10μgL−1) and 200μM (∼50mgL−1) for Cu(I) and Irgarol 1051, respectively, and alter the activity of hydrolases. Both Cu(I) and Irgarol 1051 inhibited the activity of phenoloxidase, but did not show any interactive effect when co-present in the exposure medium, suggesting different mechanisms of action. [Copyright &y& Elsevier]

A solid phase extraction (SPE) technique for seawater samples coupled to quantification using liquid chromatography tandem-mass spectrometry (LC-MS/MS) is described to quantify relevant antifouling booster biocides of ecotoxicological concern (Diuron, TCMTB, Irgarol 1051 and Dichlofluanid). The optimised methodology provides a sensitive, easy to use and efficient analytical procedure with detection limits in the range of between 0.1 and 0.2 ng L−1 and appropriate reproducibility (with analytical standard deviations of less than 10%). Spiked recoveries for all compounds exceeded 72%. The method was tested through a thorough monitoring regime of commercial port and marinas on the island of Gran Canaria (off the north-west coast of Africa) over a period of several months in 2008. Results provide the first data for antifouling booster biocides in the Canary Islands. Concentrations of Diuron and Irgarol 1051 in samples ranged between 2 and 195 ng L−1 and 2 and 146 ng L−1, respectively. TCMTB and Dichlofluanid were not detected. [ABSTRACT FROM AUTHOR]

n analytical procedure was developed to allow for the study of the levels of concentration of biocides in the various different ports on the island of Gran Canaria, The Canary Islands. The analytes studied were extracted from water samples using solid-phase extraction and then determined by high-performance liquid chromatography using a diode array detector. The relative standard deviations of the developed procedure were under 12%. Recoveries over 85% and limits of detection between 0.007 and 0.4 μg/L were obtained for all the analytes. The method was applied to the analysis of sea water samples from the ports and marinas on the island of Gran Canaria. [ABSTRACT FROM AUTHOR]

Abstract: Diverse new antifouling agents are being used as replacements for the organotin compounds that are currently being banned. A comprehensive study on Korea''s major seaports was conducted between 2006 and 2009 to assess the concentrations of butyltin compounds and new antifouling agents (chlorothalonil, dichlofluanid, Irgarol 1051). The constituents of the pollution due to antifouling agents in major seaports on the Korean peninsula are shifting from butyltin compounds to new antifouling agents. Also, the distribution of traditional butyltin compounds has centered on the east and west coasts, and the new antifouling agents have polluted the south and east coasts. With the results of this study, our lab was able to identify key locations within Korea where focused pollution control of antifouling agents is necessary. [Copyright &y& Elsevier]

Abstract: A new sample treatment method for the determination of four common booster biocides (Diuron, TCMTB, Irgarol 1051 and Dichlofluanid) in harbour sediment samples has been developed that uses liquid chromatography–tandem mass spectrometry (LC–MS/MS) after microwave-assisted extraction, followed by clean-up and a solid phase extraction preconcentration step (MAE–SPE). The effects of different variables on MAE–SPE were studied. The recoveries obtained were greater than 75%, and the relative standard deviation was less than 7%. The detection limits ranged between 0.1 and 0.3ngg−1. The developed methodology was successfully applied to the evaluation of the presence of booster biocides in sediment samples from different harbours and marinas of Gran Canaria Island (Canary Islands, Spain). [ABSTRACT FROM AUTHOR]

Abstract: In the present study we tested the hypothesis that environmental concentrations of the antifouling agent Irgarol 1051, as measured in coastal Western European waters, affect marine phytoplankton performance. The impact of Irgarol was investigated in the phytoplankton species Thalassiosira weissflogii, Emiliania huxleyi, Tetraselmis sp. and Fibrocapsa japonica. EC50 concentrations for growth, effective quantum yield of PSII and viability were calculated from dose response relationships established during 72 h exposures to six Irgarol concentrations. Furthermore, the biological recuperation from a temporary exposure to a high Irgarol concentration (39.47 nM l−1) was monitored. Growth rates and effective quantum yield were strongly affected by Irgarol, however viability loss was never observed. EC50 values differed five fold between species and ranged from 0.43 to 2.38 nM for effective quantum yield and from 0.46 to 2.44 nM for growth rate. For all species, complete biological recuperation was shown within 3–4 days after the Irgarol treatment, both for effective quantum yield and growth rate. All calculated EC50 values and EC20 values fall within the Irgarol concentration range measured in Western European coastal waters. We therefore conclude that present day Irgarol 1051 levels may affect the in situ performance of marine phytoplankton in this area. [Copyright &y& Elsevier]

The toxicity and persistence of antifouling booster biocides are of major concern. This study reports the occurrence of Irgarol 1051 and its degradation product M1, in coastal waters of Southern England, during 2004–2005. The highest concentrations of Irgarol 1051 were 89 ng/L in water and 45 ng/g dry weight in sediments, with an overall mean (n =108) of 13 ng/L and 16 ng/g in water and sediments, respectively. As the degradation product of Irgarol 1051, M1 was less widespread, with the highest concentration of 30 ng/L in water and 14 ng/g in sediments, with an overall mean (n =108) of 5 ng/L and 4 ng/g in water and sediments, respectively. Overall, the concentration of Irgarol 1051 and M1 decreased significantly during the sampling period and in comparison to earlier studies during 2000 to early 2004, indicating that control measures by restricting the use of Irgarol 1051 are effective in reducing its concentrations in coastal waters. The distribution of Irgarol 1051 between sediments and water was significantly related to sediment organic carbon content. In addition, significantly higher concentrations of Irgarol 1051 were detected in paint particles than in sediment. The rate of release of Irgarol 1051 from paint residues is very slow, with a half life of approximately 1 y. Two important findings are emerging, first the importance of organic rich sediments and paint residues as major sites of storage for Irgarol 1051, and secondly Irgarol 1051 may be classified as a persistent organic pollutant due to its long half life. [Copyright &y& Elsevier]

Abstract: To investigate the deteriorating health of coral reefs in Okinawa, Japan, natural sediment samples were analyzed for diuron, Irgarol 1051, chlorpyrifos, and bisphenol A (BPA) which are hazardous to corals. Samples were analyzed by solid-phase extraction (SPE) followed by high-performance liquid chromatography with tandem mass spectrometry (LC–MS–MS). Although diuron and chlorpyrifos usage is only well recorded for farms and not for cities, these chemicals were detected in both rural and urban areas. Additionally, diuron concentration in urban areas was in some cases higher than in rural areas, which might be caused by greater consumption of these chemicals in home gardens in city areas. Irgarol 1051 was detected in downstream river areas, which are situated far from the source sites such as pier or fishery harbor (0.6–3.2km). This result suggested that Irgarol 1051 could be transported from the river mouths to the sampling sites during flood tides. High BPA concentrations were associated with urban areas (<1.2–22.0μgkg−1), while low concentrations were associated with rural areas (nd–6.8μgkg−1). The river sediments under study are delivered to coral reefs in large quantity through runoff caused by typhoons and other heavy rains. The highly hazardous chemicals are carried into coral reefs on these sediments. Therefore, these hazardous chemical substances may already be influencing the coral reefs. [Copyright &y& Elsevier]

Abstract: Single and joint effects of two antifouling booster biocides, irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and diuron (1-(3,4 dichlorophenyl)-3,3 dimethyl urea), their metabolites, M1 (2-methylthio-4-tert-butylamino-s-triazine), DCPMU (1-(3,4-dichlorophenyl)-3 methyl urea), DCPU (1-(3,4 dichlorophenyl urea) and DCA (3,4-dichloroaniline), respectively, as well as copper were examined. Two phytoplanktonic microorganisms, the green alga Dunaliella tertiolecta and the diatom Navicula forcipata were exposed to various concentrations of the aforementioned compounds both alone and in binary mixtures during a period of 96h. Estimation of EC50 values was performed by daily cell number counting of the tested microorganisms. The toxicity of the six compounds and the metal, applied singly, was found to be, in decreasing order, irgarol 1051>diuron>M1>DCPMU>DCA>Cu>DCPU and irgarol 1051>diuron>M1>DCA for the green alga and the diatom, respectively. Diatoms were found to be more sensitive in the presence of all the tested compounds, except diuron. Co-existence of irgarol 1051 and M1 revealed additive effects on both microorganisms. Same results were observed owing to the joint action of copper with either irgarol 1051 or M1 for almost all the examined mixtures. Combined effects of diuron with its metabolites DCPMU and DCA resulted in synergism in almost all cases, for both species of phytoplankton. On the contrary, antagonistic effects were observed owing to the joint action of copper with either diuron or one of its metabolites. [Copyright &y& Elsevier]

The effect of resuspending sediment contaminated with Irgarol 1051 based antifouling paint particles on the green macroalga Ulva intestinalis was examined. U. intestinalis was also exposed to sediment spiked with Irgarol 1051. The macroalga were exposed over 21 days to the resuspension of sediments containing 61.2mgkg−1 of antifouling paint particles containing Irgarol 1051 that provided aqueous Irgarol 1051 concentrations of approximately 0.3μgl−1, Irgarol 1051 and appropriate controls. The growth response was compared with that for ‘clean’ sediment. Resuspension of sediment was associated with reduced growth when compared to seawater alone. Resuspension of sediment spiked with Irgarol 1051 was associated with a greater reduction in growth, with growth being significantly reduced when sediment containing antifouling paint particles was resuspended. The data suggest that the prolonged disturbance of sediments containing antifouling paint particles in marinas represents a potential and as yet unquantified hazard to photosynthetic organisms. [Copyright &y& Elsevier]

Abstract: Two major antifouling biocides used worldwide, Irgarol 1051 and diuron, and their degradation products in Shoreham Harbour and Brighton Marina, UK were studied during 2003–2004. The highest concentrations of Irgarol 1051 were 136 and 102 ng L−1 in water and 40 and 49 ng g−1 dry weight in sediments for Shoreham Harbour and Brighton Marina, respectively. As the degradation product of Irgarol 1051, M1 was also widespread, with the highest concentration of 59 ng L−1 in water and 23 ng g−1 in sediments in Shoreham Harbour, and 37 ng L−1 in water and 5.6 ng g−1 in sediments in Brighton Marina. The target compounds showed enhanced concentrations during the boating season (May–July), when boats were being re-painted (January–February), and where the density of pleasure crafts was high. Overall, the concentration of Irgarol 1051 decreased significantly from late 2000 to early 2004, indicating the effectiveness of controlling its concentrations in the marine environment following restricted use. Diuron was only detected in 14% of water samples, and mostly absent from sediment samples. [Copyright &y& Elsevier]

Abstract: A method for the trace analysis of antifouling agent Irgarol 1051 and its decyclopropylated degradation product in seawater was developed by using reversed-phase LC–MS with quadrupole time-of-flight mass spectrometry detection. Atrazine-d5 was used as the internal standard for the LC–MS determination. Irgarol 1051 and the major degradation product were detected at trace levels in seawater samples collected from several marinas in Hong Kong. The water samples were pre-concentrated by solid-phase extraction with a polystyrene-divinylbenzene cartridge. Quadrupole time-of-flight tandem mass spectrometry in positive ion electrospray ionization was used for the identification and quantitation. The recoveries of Irgarol 1051 and degradation product were >85%. Method detection limits were 0.2ngl−1 and 0.8ngl−1 for the antifouling agent and the decyclopropylated degradation product, respectively. [Copyright &y& Elsevier]

Abstract: Antifouling paints are used to reduce the attachment of living organisms to the submerged surfaces of ships, boats and aquatic structures, usually by the release of a biocide. Two ‘booster’ biocides in common use are the triazine herbicide Irgarol 1051 (N-2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), and diuron (1-(3,4-dichlorophenyl)-3,3-dimethylurea), which are designed to inhibit algal photosynthesis. Previous research has been directed at the effects of these compounds in marine and estuarine environments. In 2001 we sampled the main rivers and shallow freshwater lakes (Broads) of East Anglia UK for Irgarol 1051, its metabolite GS26575 (2-methylamino-4-tert-butylamino-6-amino-s-triazine) and diuron in order to establish the baseline environmental concentrations of these compounds in freshwater systems of eastern UK and to investigate their possible effects on aquatic plants. Irgarol 1051, GS26575 and diuron were found in water samples collected from 21 locations. The highest concentrations were found in the Norfolk and Suffolk Broads in May. The rivers Great Ouse, Wissey, Bure and Yare also contained all three compounds, as did the Great Ouse Cut-off Channel. The toxicity of these biocides to three macrophyte species (Apium nodiflorum, Chara vulgaris, and Myriophyllum spicatum) was investigated. Deleterious effects on relative growth rate, the maximum quantum efficiency (Fv/Fm) of photosystem II and, for Apium, root mass production were found. C. vulgaris was generally most sensitive; growth, especially of roots, was strongly affected in A. nodiflorum; growth rate of M. spicatum was sensitive to diuron. No observed effect concentrations (NOEC) were interpolated using standard toxicological analysis. These were compared with measured environmental concentrations (MEC) to determine the ranges of risk quotients (MEC/NOEC). Both Irgarol 1051 and diuron represented significant risks to A. nodiflorum and C. vulgaris in this area. [Copyright &y& Elsevier]

Abstract: A programme of research was initiated to provide information on the efficacy of the antifouling agents Irgarol 1051™ and Sea-Nine 211™ to zygotes of the fucoid alga Fucus serratus Linnaeus. The development of methodologies that incorporated the use of image capture and analysis, which minimised the problems of subjectivity and bias that can be typical, are also described. The generation of macro-instructions allowed rapid generation and interpretation of accurate quantitative data. Emphasis was placed on the use of methodologies that did not rely on the subjective determination of spore germination. Consequently, affects due to the biocides were determined that, otherwise, would not have been realised through normal analytical routines. Zygotes were exposed, in static non-renewal systems, for 3 days, to a range of concentrations of biocide dissolved in seawater. Data for seven zygote parameters were recorded daily and values of percentage germination were calculated. From these data, NOEC values of 8 μg l−1 were calculated for both Sea-Nine 211 and Irgarol 1051. An EC50 of 19.4 μg l−1 was also determined for Sea-Nine 211. It is, therefore, suggested that F. serratus zygote germination and early development is unaffected by published environmental concentrations of these biocides. Additionally, it has been demonstrated that the image capture and analysis methodologies developed provide an invaluable tool for use in future bioassays. [Copyright &y& Elsevier]

Abstract: A method for the simultaneous determination of two antifouling booster biocides, diuron (1-(3,4 dichlorophenyl) 3,3 dimethyl urea) and irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), and their metabolites, DCPMU (1-(3,4 dichlorophenyl)-3 methyl urea), DCPU (1-(3,4 dichlorophenyl) urea), DCA (3,4 dichloroaniline) and M1 (2-methylthio-4-tert-butylamino-s-triazine) in seawater by high performance liquid chromatography–diode array detector (HPLC–DAD) was developed. The optimization of the extraction procedure included the type of sorbent and the type of the organic solvent for the elution. Optimization of the liquid chromatography (LC) separation was also performed and the robustness of the developed separation was tested, in respect to the effect of three factors (column temperature, flow rate and initial strength of acetonitrile) on the retention times, peak resolution and peak area of the six compounds. The optimized procedure included off-line extraction of these compounds from seawater samples using C18 solid phase extraction (SPE) cartridges. The inter-day precision of the developed procedure was less than 14% (as R.S.D.s) for all the tested compounds. Satisfactory recoveries (higher than 82%) were obtained for all substances, except for DCA, for which low recovery was obtained (30.5%). The limits of detection (LODs) of the substances varied between 0.005 (DCPMU) and 0.026 (M1) μgL-1. [Copyright &y& Elsevier]

A polyclonal antiserum to Irgarol 1051 was developed in sheep and used to construct an enzyme immunoassay method for the measurement of the antifouling compound in river and seawater samples. The antiserum was generated by a hapten derivative, 2-(tert-butylamino)-4-(cyclopropylamino)-6-(thiopropionic acid)-1,3,5-triazine, coupled to a mixture of keyhole limpet hemocyanin and bovine serum albumin, and the competitive enzyme immunoassay was constructed using a plate-coating antigen made of a heterologous new hapten derivative, 2-(tert-butylamino)-4-(cyclopropylamino)-6-(phenoxybenzoic acid)-1,3,5-triazine, linked to gelatine. The assay showed a sensitivity of about 5 ng L-1 in river and seawater matrices with reasonable specificity with respect to commonly used triazines such as atrazine (3%), simazine (>0.1%) and desethylatrazine (>0.01%). However, high cross-reactivity levels were found with ametryn (56%) and prometryn (60%). Tests on the effects of organic solvents on assay performance indicated a high tolerance to methanol but much less so to acetonitrile. The assay was found to be highly reproducible and robust owing to the stability of the sheep antibody and the highly optimised competitive assay reagents which included the use of the new triazine-O-phenoxybenzoic acid derivative. [ABSTRACT FROM AUTHOR]

A microwave-assisted extraction (MAE) method for the determination of Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and its main degradation product M1 (2-methylthio-4-tert-butylamino-s-triazine) in marine sediments by gas chromatography–mass spectrometry (GC–MS) was developed. The key parameters of MAE procedure, including the amount of the sediment, the volume of the extraction solvent, the duration and the temperature of the extraction procedure were optimized. The extraction procedure was followed by solid-phase extraction (SPE) on reverse phase C18 cartridges. The isolation of the target compounds from the matrix was found to be efficient when 3g of marine sediment were extracted with 30ml of water for 10min at 115°C. Final determination was accomplished by GC–MS. Quantification was performed with matrix-matched calibration using atrazine-d5 as internal standard. Mean recoveries higher than 85.4% were obtained for both compounds at three fortification levels with relative standard deviations (R.S.D.) ≤ 14%. The limits of detection (LOD) of the developed method were 0.9 and 1.7ngg-1 dry weight for M1 and Irgarol 1051, respectively. [Copyright &y& Elsevier]

The objective of this study was to determine the ecological risk of the antifoulant Irgarol 1051 and its major metabolite (GS26575) in United States surface waters by using a probabilistic approach. Distributions of environmental exposure data were compared with the distribution of species response data from laboratory studies to quantify the likelihood and significance of ecological risk. Water monitoring data from both the Chesapeake Bay (2001) and southeast Florida (1999-2001) were used to characterize exposure. Toxicity testing has demonstrated that plants are much more sensitive to Irgarol and G526575 than animals; therefore, the conservative effects benchmark used to characterize risk was the plant 10th centile for both Irgarol (251 ng/L) and G526575 (12,500 ng/L). Ecological risk from Irgarol exposure in Chesapeake Bay marinas, a river, and a mainstem area was generally low with the possible exception of the Port Annapolis marina in Annapolis, Maryland. This enclosed marina has a high density of boats, a low flushing rate, and has historically been reported as a "worst case scenario" for other antifoulants such as tributyltin. Ecological risk from G526575 exposure at Chesapeake Bay sites was judged to be very low as all environmental concentrations were an order of magnitude below the effects threshold for plants. Ecological risk from Irgarol exposure in southeast Florida surface waters was found to be low at various marina, port, river, bay/embayment, channel, and ocean areas. Even the highest Irgarol concentration reported in southeast Florida waters (182 ng/L) was less than the conservative Irgarol effects benchmark of 251 ng/L (plant 10th centile). Ecological risk from G526575 exposure in southeast Florida waters was also very low. The objective of this study was to determine the ecological risk of the antifoulant Irgarol 1051 and its major metabolite (GS26575) in United States surface waters by using a probabilistic approach. Distributions of environmental exposure data were compared with the distribution of species response data from laboratory studies to quantify the likelihood and significance of ecological risk. Water monitoring data from both the Chesapeake Bay (2001) and southeast Florida (1999-2001) were used to characterize exposure. Toxicity testing has demonstrated that plants are much more sensitive to Irgarol and G526575 than animals; therefore, the conservative effects benchmark used to characterize risk was the plant 10th centile for both Irgarol (251 ng/L) and G526575 (12,500 ng/L). Ecological risk from Irgarol exposure in Chesapeake Bay marinas, a river, and a mainstem area was generally low with the possible exception of the Port Annapolis marina in Annapolis, Maryland. This enclosed marina has a high density of boats, a low flushing rate, and has historically been re- ported as a "worst case scenario" for other antifoulants such as tributyltin. Ecological risk from G526575 exposure at Chesapeake Bay sites was judged to be very low as all environmental concentrations were an order of magnitude below the effects threshold for plants. Ecological risk from Irgarol exposure in southeast Florida surface waters was found to be low at various marina, port, river, bay/embayment, channel, and ocean areas. Even the highest Irgarol concentration reported in southeast Florida waters (182 ng/L) was less than the conservative Irgarol effects benchmark of 251 ng/L (plant 10th centile). Ecological risk from G526575 exposure in southeast Florida waters was also very low. [ABSTRACT FROM AUTHOR]

Tides and freshwater inflow which influence water movement in estuarine areas govern the exposure-regime of pollutants. In this experiment, we examined the in situ impact of double pulses of copper and the herbicide Irgarol 1051 on the photosynthesis of the seagrass, Zostera capricorni. Despite a 4-day recovery period between the two 10 h pulses of toxicant, the effective quantum yield of photosystem II (ΔF/Fm′) and total chlorophyll concentrations indicated that multiple-pulses had a greater impact than a single pulse. During the first exposure period, samples exposed to Irgarol 1051 had ΔF/Fm′ values as low as zero while controls remained around 0.6 relative units. After the second exposure period, treated samples recovered to only 0.4 relative units. Samples exposed to copper had ΔF/Fm′ values around 0.3 relative units during the first exposure period and while these samples recovered before the second dose, they remained below 0.2 relative units after the second exposure period.Alternate samples were also exposed to one toxicant, allowed to recover and then exposed to the other toxicant. ΔF/Fm′ values indicated that copper exposure followed by Irgarol 1051 exposure was more toxic than Irgarol 1051 exposure followed by copper exposure. [Copyright &y& Elsevier]

Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), a derivative of s-triazine herbicide, is an antifouling compound used as an alternative to organotins. The compound is highly persistent and is known to be biodegraded only by the white rot fungus, Phanerochaete chrysosporium. We used partially purified manganese peroxidase (MnP) prepared from P. chrysosporium to evaluate its capacity to degrade Irgarol 1051. MnP degraded Irgarol 1051 to two major products, one identified as M1 (identical to GS26575, 2-methylthio-4-tert-butylamino-6-amino-s-triazine) and the other not identified but with same mass spectrum as M1 and a different ultraviolet spectrum. This report clearly demonstrates that this ligninolytic enzyme is involved in the degradation of Irgarol 1051. [Copyright &y& Elsevier]

In 1989, the EU restricted the use of tributyl-tin (TBT) and the International Maritime Organisation (IMO) decided for a world-wide ban on TBT in 2003. As a replacement for TBT, new antifouling agents are entering the market. Environmental risk limits (ERLs) are derived for substances that are used as TBT-substitutes, i.e. the compounds Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB. ERLs represent the potential risk of the substances to the ecosystem and are derived using data on (eco)toxicology and environmental chemistry. Only toxicity studies with endpoints related to population dynamics are taken into account.For Irgarol 1051 especially plants appear to be sensitive; the mode of action is inhibition of photosynthetic electron transport. Despite the higher sensitivity of the plants, the calculated ERL for water based on plants only is higher than the ERL based on all data due to the lower variability in the plant only dataset. Because there is a mechanistic basis to state that plants are the most sensitive species, we propose to base the ERL for water on the plants only dataset. As dichlofluanid is highly unstable in the water phase, it is recommended to base the ERL on the metabolites formed and not on the parent compound.No toxicity data of the studied compounds for organisms living in sediments were found, the ERLs for sediment are derived with help of the equilibrium partitioning method. For dichlofluanid and chlorothalonil the ERL for soil is directly based on terrestrial data, for Irgarol 1051 and ziram the ERL for soil is derived using equilibrium partitioning.Except for Irgarol 1051, no information was encountered in the open literature on the environmental occurrence in The Netherlands of the chemicals studied. The measured concentrations for Irgarol 1051 are close to the derived ERL. For this compound it is concluded that the species composition and thereby ecosystem functioning cannot be considered as protected. [Copyright &y& Elsevier]

A method for the simultaneous determination of two antifouling booster biocides, diuron [1-(3,4-dichlorophenyl)-3,3-dimethylurea] and irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and their degradation products, DCPMU [1-(3,4-dichlorophenyl)-3-methylurea], DCPU [1-(3,4-dichlorophenyl) urea], DCA [3,4-dichloroaniline] and M1 (2-methylthio-4-tert-butylamino-s-triazine), in marine sediments by high performance liquid chromatography–diode array detection (HPLC–DAD) was developed. The extraction of these compounds from sediment was achieved by means of methanolic ultrasonic extraction. The optimization of the extraction procedure included the variation of the volume of the extraction solvent, the amount of the extracted sediment, the duration and the temperature of sonication. C18 solid phase extraction (SPE) cartridges were used for the cleaning of the extracts. The relative standard deviations (R.S.Ds) of the developed procedure was <10% for all the tested compounds, except for DCA, where R.S.Ds up to 15% were obtained. Satisfactory recoveries were obtained (higher than 80% for all substances), except for DCA, which gave a recovery in the range of 35–50%. The limits of detection (LODs) of the substances varied between 1.7 (DCPU) and 4.0 (DCPMU) ng g−1 of dry sediment. [Copyright &y& Elsevier]

We used photosynthetic activity (measured as chlorophyll a fluorescence) and photosynthetic pigment concentrations to assess the effect of pulsed exposure to catastrophic levels of the herbicides Atrazine, Diuron and Irgarol 1051 on the seagrass Zostera capricorni Aschers. in laboratory and field experiments. Custom-made in situ chambers were developed so seagrasses could be dosed within the meadow. Zostera capricorni was exposed to 10 and 100 μg l−1 herbicide solutions for 10 h. During this time and for the subsequent 4-day recovery period, chlorophyll a fluorescence parameters (maximum quantum yield: Fv/Fm and effective quantum yield: ΔF/Fm′) were measured. Laboratory samples exposed to these herbicides were severely impacted during the exposure period and most treatments did not recover fully. ΔF/Fm′ was a more sensitive indicator of herbicide impact than Fv/Fm. In situ samples were also severely impacted by Irgarol and Diuron exposure whereas samples recovered completely after exposure to Atrazine at the same concentrations as the laboratory experiments. Total chlorophyll concentrations showed only limited impact in both laboratory and field situations. This study suggests that laboratory experiments may overestimate the on-going impact of herbicides on seagrass. [Copyright &y& Elsevier]

This paper describes a database containing mass spectra from gas chromatography–mass spectrometry (GC–MS) measurements as a tool for easy screening for multiple compounds. In this way additional compounds can be reported from the same run together with routine pesticide monitoring with little effort. The relevant analytical data from the GC–MS measurements are transferred automatically to a database. Search algorithms in the database, containing the US EPA and Dutch NEN GC–MS identification criteria as standard settings, are used to identify compounds in the data. Screening of samples analysed in our laboratory show the ubiquitous presence of—up until now in monitoring largely overlooked—compounds in surface waters in The Netherlands. Most frequently found compounds include TAED (complexing agent), 2-methyl quinoline (industrial solvent), atrazin and desethylatrazin (pesticide and degradation product), caffeine (human consumption), surfinol-104 (anti foaming agent), HHCB (Galaxolide) and AHTN (Tonalide; fragrances). The database can also be used to quickly search a large number of datafiles for rare contaminants. This way, some interesting compounds such as pentoxifilin (a pharmaceutical) and Irgarol 1051 (an antifouling compound) were found. [Copyright &y& Elsevier]

A sensitive LC–electrospray MS–MS method using off-line solid-phase extraction for the determination of diuron and Irgarol 1051 has been developed, enabling determination of both compounds at sub-ppt levels. Diuron and Irgarol 1051 are used as alternatives for tributyltin in antifouling paints that prevent growth on boats, and an increase in their application is anticipated because of the upcoming ban on tributyltin in 2003. In 2000, a survey was carried out to assess contamination with diuron and Irgarol 1051 of a number of Dutch marinas and coastal waters. Depending on the time of year, both compounds were encountered at levels higher than the maximum permissible concentrations of 430 and 24 ng/l for diuron and Irgarol 1051, respectively. Outside marinas at reference locations, concentrations were much lower, depending on the geographical situation and the nature of the water exchange with the environment related to tidal cycles. A seasonal influence was observed with highest levels in summer, corresponding to the yachting season for both compounds. For diuron, use in agriculture could have contributed to the high concentration encountered in surface waters. [Copyright &y& Elsevier]

A simple and rapid extraction method based on headspace solid phase microextraction (HS-SPME) has been developed for the analysis of two antifouling agents, currently licensed for use in marine antifouling paints. Irgarol 1051 and Sea Nine 211 were extracted from aqueous solutions using polydimethylsiloxane–divinylbenzene (PDMS–DVB) 65 μm fiber and analyzed by gas chromatography (GC) with flame thermionic, electron capture and mass spectrometric detection. The extraction time, addition of Na2SO4 and the influence of organic matter, such as humic acid on extraction efficiency were examined in order to achieve a sensitive method. The optimized procedure was applied to spiked natural waters, such as sea water, river water and lake water in a concentration range of 0.5–50 μg l−1 in order to obtain the analytical characteristics. The linear calibration curve obtained (R2>0.990) for both analytes indicate that the presence of interfering compounds had no significant effect due to the high affinity of both analytes to the PDMS–DVB 65 μm fiber coating. Recoveries were in relatively high levels over >82% in all types of natural waters. The limits of detection (LODs) ranged from 0.002 to 0.030 μg l−1, depending on the detector and the compound investigated, with relative standard deviations in the range of 3–12% at all concentration levels tested. Finally, the proposed method was applied in real water samples from different marinas of Epirus region (NW Greece) in order to investigate its performance in precise and routine environmental analysis. [Copyright &y& Elsevier]

Organic booster biocides were recently introduced as alternatives to organotin compounds in antifouling products, after restrictions imposed on the use of tributyltin in 1987. In this study, the concentrations of three biocides commonly used as antifoulants, Irgarol 1051 (2-methylthio-4-tertiary-butylamino-6-cyclopropylamino-s-triazine), dichlofluanid (N-dichlorofluoromethylthio-N′,N′-dimethyl-N-phenyl sulphamide) and chlorothalonil (2,4,5,6-tetrachloro isophthalonitrile) were determined in sediments from ports and marinas of Greece. Piraeus (Central port, Mikrolimano and Pasalimani marinas), Thessaloniki (Central port and marina), Patras (Central port and marina), Elefsina, Igoumenitsa, Aktio and Chalkida marinas were chosen as representative study sites for comparison with previous monitoring surveys of biocides in coastal sediments from other European countries.Samples were collected at the end of one boating season (October 1999), as well before and during the 2000 boating season. All the compounds monitored were detected at most of sites and seasonal dependence of biocide concentrations were found, with maxima during the period June–September, while the winter period (December–February) lower values were encountered. The concentrations levels ranged from 3 to 690 ng/g dw (dry weight). Highest levels of the biocides were found in marinas (690, 195 and 165 ng/g dw, for Irgarol, dichlofluanid and chlorothalonil respectively) while in ports lower concentrations were observed. Antifouling paints are implicated as the likely sources of biocides since agricultural applications possibly contributed for chlorothalonil and dichlofluanid inputs in a few sampling sites. [Copyright &y& Elsevier]

This study considered the inputs of antifouling paint booster biocides into the aquatic environment directly from painted hulls and high pressure hosing operations, the occurrence of booster biocides in marinas, harbours and docks, and the influence of degradation and water–sediment partition on their environmental fate. Irgarol 1051, the Irgarol 1051 degradation product GS26575, diuron, and the diuron degradation products 1-(3-chlorophenyl)-3,1-dimethylurea (CPDU), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and 1-(3,4-dichlorophenyl)urea (DCPU) were all detected at measurable concentrations in surface waters. Irgarol 1051, GS26575 and diuron were also detected in bottom sediments. A preliminary study of biocide input during both normal use and foreshore hull hosing showed that hosing may be a significant point source input and also be a cause for future concern since much of this input is in the form of paint particles. Field based measurements and laboratory experiments showed that Irgarol 1051 and diuron persist in the water column, due to a low affinity to partition onto sedimentary material and high resistance to degradation. Other biocides such as chlorothalonil, dichlofluanid, and Sea-Nine 211 were all found to be rapidly removed from the water column and be less persistent. [Copyright &y& Elsevier]

The photochemical degradation of irgarol 1051 has been studied in different natural waters (sea, river, lake) as well as in distilled water under natural and simulated solar irradiation. The effect of dissolved organic matter (DOM) such as humic and fulvic substances on the photodegradation rate was also studied under simulated sunlight. The addition of DOM in distilled water was shown to greatly increase the rate of degradation, however, a decrease was observed in natural waters. The photodegradation proceeds via pseudo-first-order reaction in all cases with half-lives ranged from 2 to 1432 h. In natural and humic water irgarol 1051 photodegradation gave rise to the dealkylated derivative demonstrating that the transformation of irgarol 1051 depend on the constitution of the irradiated media and especially from DOM concentration and type. The byproducts identified by GC–MS techniques were: 2-methylsulfonyl-4-terbutylamino-6-cyclopropylamino-s-triazine, 2-hydroxy-4-terbutylamino-6-cyclopropylamino-s-triazine, 2-methylthio-4-terbutylamino-6-ethylamino-s-triazine, 2-methylsulfonyl-4-terbutylamino-6-amino-s-triazine and diaminohydroxy-s-triazine. [Copyright &y& Elsevier]

The partitioning behaviour of the organic biocides, Irgarol 1051 and diuron and two inorganic biocides (copper and zinc) was investigated using six sediments of differing physico-chemical properties collected from unimpacted sites along the south coast of England. The kinetics of sorption and equilibrium partitioning between the sediments and seawater were investigated over a period of 20 days. Resulting organic carbon/water partition coefficients (log Koc) were related to suspended sediment concentration and ranged from 2.28 to 5.20 for diuron; and from 2.41 to 4.89 for Irgarol 1051. Sediment/water partition coefficients (log Kp) for copper and zinc varied from 2.46 to 5.08 l/kg and from 2.49 to 4.97 l/kg, respectively. Kinetic data indicated that there were significant interactions between the dissolved and particulate phases at the start of the experiments, just after mixing. This is thought to be a result of redistribution of organic carbon between the two phases. [Copyright &y& Elsevier]