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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 Pacific oyster (Crassostrea gigas) is an important species in oyster farming worldwide, including in Japan. Hiroshima Bay is one of the most important oyster farming areas in Japan. We investigated the occurrence of antifouling biocides used worldwide including diuron, Irgarol 1051 (Irgarol), and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), which have been detected at sub-ppb levels in seawater in Japan, and estimated their no observed effect concentrations (NOECs). In recent years, the spat settlement of Pacific oysters has become poor, which presents a challenge for oyster aquaculture in Hiroshima Bay; hence, we conducted embryotoxicity and larva settlement tests using Pacific oysters. Compared to diuron and Irgarol, DCOIT exhibited a higher toxicity toward oyster embryos, and the minimum 24-h NOEC toxicity value for the oyster embryos was <3 ng/L. The highest concentrations of diuron, Irgarol, and DCOIT in the environmental seawater in the Seto Inland Sea were 27.6, 3.2, and 24 ng/L, respectively. Considering the NOECs, the environmental concentrations of these biocides suggest that the ecological risks posed by diuron and Irgarol are low, whereas those posed by DCOIT are high. However, the rate of detection of DCOIT was low because it degraded rapidly in the seawater before treatment for chemical analysis, except in the case of the treatment on the research vessel. [ABSTRACT FROM AUTHOR]

Irgarol 1051 and diuron are photosystem II inhibitors in agricultural activities and antifouling paints in the shipping sector. This study focused on three major ports (western, southern, and eastern) surrounding Peninsular Malaysia to construct the distribution of both biocides on the basis of the seasonal and geographical changes. Surface seawater samples were collected from November 2011 to April 2012 and pretreated using the solid-phase extraction technique followed by quantification with GC-MS and LC-MS-MS for Irgarol 1051 and diuron, respectively. Generally, the distribution of Irgarol 1051 was lowest during November 2011 and highest during April 2012, and similar patterns were observed at all ports, whereas the distribution of diuron was rather vague. The increasing pattern of Irgarol 1051 from time to time is probably related to its accumulation in the seawater as a result of its half-life and consistent utilization. On the basis of the discriminant analysis, the temporal distribution of Irgarol 1051 varied at Klang North Port, Klang South Port, and Pasir Gudang Port, whereas diuron was temporally varied only at Kemaman Port. Furthermore, Irgarol 1051 was spatially varied during November 2011, whereas diuron did not show any significant changes throughout all sampling periods. Ecological risk assessment exhibited a high risk for diuron and Irgarol 1051, but Irgarol 1051 should be of greater concern because of its higher risk compared to that of diuron. Thus, it is recommended that the current Malaysian guidelines and regulations of biocide application should be reevaluated and improved to protect the ecosystem, as well as to prevent ecological risks to the aquatic environment. [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]

To elucidate the effects of the herbicide Irgarol 1051 on the gene expression of heat shock protein 90 ( HSP90 ) in hard corals, we isolated a full-length cDNA encoding HSP90 from Acropora tenuis , which has a deduced open reading frame of 732-amino acid residues with a predicted molecular mass of 84.5 kDa. The amino acid sequence of A. tenuis HSP90 showed a high degree of similarity with the hermatypic-coral HSP90 families. After a 7-d exposure to 1 or 10 μg/L of Irgarol, the body colours of corals in the 10 μg/L treatment group were significantly whiter (bleached), whereas no such effects were observed in the corals in the 1 μg/L treatment group. However, the expression level of coral HSP90 was significantly downregulated after exposure to both 1 and 10 μg/L Irgarol. These results suggest that A. tenuis HSP90 may be a useful molecular biomarker to predict bleaching caused by herbicides. [ABSTRACT FROM AUTHOR]

We examined the effect of two herbicides (Irgarol 1051 and Diuron) on symbiotic dinoflagellates in the hard coral Acropora digitifera using delayed fluorescence (DF), specifically assessing changes in molecular membrane transport, i.e. inflow and outflow rates, and the binding of the herbicides to target proteins in photosystem II. The DF approach is rapid ( e.g. measurement time, 60 s) and non-invasive, and can provide data on the extent of a photosynthetic system and the activity of its electron carriers. The DF of A. digitifera is inhibited 2 h after exposure to 1 μg/L of either Irgarol or Diuron. Analysis of DF inhibition over time by a compartment model suggests that Irgarol exposure results in a relatively higher inflow rate and lower outflow rate than does Diuron exposure. This suggests that Irgarol exposure more strongly inhibits photosynthesis and that the coral symbiotic dinoflagellates recover less from inhibition. [ABSTRACT FROM AUTHOR]

Colour change in Acropora tenuis , a representative species of Indo-Pacific hard coral, in response to low concentrations of Irgarol 1051 was examined in the laboratory. Branches of A. tenuis were exposed to 0, 1, and 10 μg Irgarol 1051/L for 14 days, and photographed daily using digital camera. These Irgarol 1051 concentrations were similar to those recorded at a number of sea ports. Red, green and blue (RGB) coral colour values were quantified from the photographs, with black represented by R = G = B = 0 and white as R = G = B = 255. Exposure to Irgarol 1051 caused RGB values to increase, moving towards the ‘white’ end of the spectrum as Irgarol 1051 concentration increased. These results suggest that the ambient levels of Irgarol 1051 recorded from port environments could be implicated in coral bleaching, if concentrations over nearby reef ecosystems are similar. [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 study, antifouling paint booster biocides, Irgarol 1051 and diuron were measured in ports and marinas of Bushehr, Iran. Results showed that in seawater samples taken from ports and marinas, Irgarol was found at the range of less than LOD to 63.4 ng L − 1 and diuron was found to be at the range of less than LOD to 29.1 ng L − 1 (in Jalali marina). 3,4-dichloroaniline (3,4-DCA), as a degradation product of diuron, was also analyzed and its maximum concentration was 390 ng L − 1 . Results for analysis of Irgarol 1051 in sediments showed a maximum concentration of 35.4 ng g − 1 dry weight in Bandargah marina. A comparison between the results of this study and those of other published works showed that Irgarol and diuron pollutions in ports and marinas of Bushehr located in the Persian Gulf were less than the average of reports from other parts of the world. [ABSTRACT FROM AUTHOR]

The biocide Irgarol 1051 has been reported to have negative effects on a large number of living components including non-target organisms, but information on its impact on the marine meiofauna and benthic prokaryotes is completely lacking. Here, we report the results of long-term experimental studies in which we determined the effects of increasing Irgarol concentrations (from 11.5 to 315 ng g sediment dry weight) on meiofauna and benthic prokaryotes. We found that this biocide had a significant impact on meiofauna abundance, even at the lowest concentrations, causing a drastic decline in the abundance of nematodes (the dominant meiofaunal taxon) and an increase of the relative importance of oligochaetes. Even if no direct effects of Irgarol were found on prokaryotic abundance and biomass, the molecular fingerprinting analyses (automated ribosomal intergenic spacer analysis) showed that the prokaryotic diversity was significantly altered by the biocide. The results of the present study indicate that Irgarol 1051 in marine sediments has a significant impact on the smallest eukaryotic and microbial components also at very low concentrations (ca 12 ng g). [ABSTRACT FROM AUTHOR]

The occurrence and distribution of tributyltin (TBT) and alternative biocides were investigated in sediment from semi-enclosed bays, fishing ports, and large commercial harbors in Korea. Extremely high concentration of TBT (55,264 ng Sn/g) was detected near a large shipyard, even after a total ban on its use in Korea. Diuron was the biocide with the highest detection frequency and concentration levels, followed by Irgarol 1051. Sea-Nine 211 was detected at 3 of 32 stations surveyed. Dichlofluanid, zinc and copper pyrithiones levels were below the detection limits at all the stations surveyed. The relatively high levels of Diuron (9–62.3 ng/g) and Irgarol 1051 (1.5–11.5 ng/g) were detected in harbor and shipyard areas. Diuron and Irgarol 1051 levels including TBT in sediments from hot spots in Korea exceeded global sediment quality guidelines. [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: [•] TBT levels still exceed water quality criteria 6 years after a total ban on TBT use. [•] Diuron and Irgarol 1051 were the common alternative biocides identified in the samples. [•] Diuron levels recorded greatly exceeded water quality criteria. [•] Irgarol 1051 levels were marginally lower than the relevant water quality criteria. [Copyright &y& Elsevier]

Highlights: [•] Effects of irgarol on settlement and growth of Ulva lactuca zoospores. [•] Settlement and growth of zoospores was not inhibited, even at high concentrations. [•] Irgarol causes greening and possibly and increased attachment. [•] Irgarol constitutes a selection pressure in the marine environment. [Copyright &y& Elsevier]

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]

Diuron and Irgarol 1051 are widely used antifouling booster herbicides to control the growth of redundant algae on submerged structures. They pose serious threats to the marine ecosystem especially on the non-target algal species which is of serious environmental concern. In the present study, the acute (1 h) individual and joint toxicities of the foresaid herbicides were assessed in the economically important cyanobacterium Arthrospira maxima, using robotic chlorophyll a (Chl a) fluorescence imaging method. When tested individually, Diuron was found to be more toxic to photosynthesis than Irgarol 1051, with median effective concentration (EC) values of 4.96-9.51 μg L and 7.15-14.80 μg L, respectively. The most sensitive endpoint was the effective quantum yield (Y (II)) of photosystem II (PSII) for Diuron and the relative maximum electron transport rate (rETR) for Irgarol 1051. Mixture toxicity of Diuron and Irgarol 1051 was evaluated based on a factorial design with two factors at two levels, considering Y (II) as the sensitive biomarker. There were additive effects when low concentration of Irgarol 1051 (6.5 μg L) was mixed with high and low concentrations of Diuron (5 μg L and 2.5 μg L, respectively), with ratio of inhibition (RI) being 1.07±0.17 and 0.92±0.13, respectively. In contrast, high concentration of Irgarol 1051 (13 μg L) resulted in antagonistic effects when added to low and high concentrations of Diuron, showing RI values of 0.89±0.03 and 0.81±0.06, respectively. The observations presented here indicate the need of consideration of interactive mode of action in evaluating herbicide toxicities in natural waters. [ABSTRACT FROM AUTHOR]

Abstract: Irgarol 1051 is a common antifouling biocide and is highly toxic to non-target plant species at low ng/L concentrations. We measured up to 254ng/L Irgarol in water and up to 9ng/g dry weight Irgarol in sediments from Southern California recreational marinas. Irgarol’s metabolite, M1, concentrations were up to 62ng/L in water and 5ng/g dry weight in sediments. Another antifouling biocide, diuron, reached up to 68ng/L in water and 4ng/g dry weight in sediments. The maximum Irgarol concentrations in water were greater than the Irgarol concentration recommended as the plant toxicity benchmark (136ng/L), suggesting that Irgarol concentrations may be high enough to cause changes in phytoplankton communities in the sampled marinas. Irgarol concentrations measured in sediments were greater than calculated Environmental Risk Limits (ERLs) for Irgarol in sediments (1.4ng/g). Antifouling pesticide accumulation in sediments may present a potential undetermined risk for benthic organisms. [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]

Booster biocides are organic compounds that are added to antifouling copper-based paints to improve their efficacy. Due to their widespread use, they are common pollutants of marine ecosystems. Some of these compounds show acute and chronic toxic effects in non-targeted organisms at concentrations as low as ng L. The determination of these compounds is therefore important, and for some, which are prioritized in the EU water framework directive, a necessity. Because of their low concentrations and the matrix effect, these contaminants often require a suitable sample preparation step (extraction/pre-concentration) prior to chromatographic determination. The aim of the present article is to review extraction and chromatographic methodologies related to the determination of common booster biocides in marine samples published in the scientific literature. These methodologies include liquid-liquid extraction (LLE), solid phase extraction (SPE), solid phase microextraction (SPME), single drop microextraction (SDME), Soxhlet extraction, microwave-assisted extraction (MAE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) as extraction methods, and both gas and liquid chromatography as determination techniques. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

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: The presence of booster biocides in the aquatic environment has been associated with a risk to non-target species due to their proven toxicity. The aim of the present study was to determine the spatial and temporal distribution of common booster biocides in different harbours of the island of Gran Canaria (Spain) and evaluate, by means of a probabilistic risk assessment (PRA), the ecological risk posed by these compounds. With these objectives, a monitoring campaign was conducted between January 2008 and May 2009, collecting a total of 182 seawater samples. Four common booster biocides (TCMTB, diuron, Irgarol 1051 and dichlofluanid) were monitored. Diuron levels ranged between 2.3 and 203ng/L and Irgarol 1051 between 2.4 and 146.5ng/L. The ecological risk associated with these levels was always low, however, with probabilities of exceeding the 10th percentile of autotroph toxicity below 3.5%. [Copyright &y& Elsevier]

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]

fter prohibition of use of organic tin compounds, new antifouling agents have been used as substitute paints. In 2009, this lab re-conducted the same research from 2006 that focused on concentrations of chlorothalonil, dichlofluanid, and Irgarol in the major bays of Korea, in order to assess changes in concentrations. Among the new antifouling agents detected in 2006, chlorothalonil, dichlofluanid, and Irgarol 1051 were detected up to 4.19, 61.69, and 23.80 ng/L, respectively. However, in 2009, up to 67.96, 74.79, and 67.64 ng/L were detected. Compared to 2006, there were apparent increases in the concentration of all three compounds in all areas where the research was conducted. These results indicate the need for further research regarding the hazards of these compounds. [ABSTRACT FROM AUTHOR]

In this work the risk posed to seawater organisms, predators and humans is assessed, as a consequence of exposure to 12 organic micro-pollutants, namely metronidazole, trimethoprim, erythromycin, simazine, flumequine, carbaryl, atrazine, diuron, terbutryn, irgarol, diphenyl sulphone (DPS) and 2-thiocyanomethylthiobenzothiazole (TCMTB). The risk assessment study is based on a 1-year monitoring study at a Spanish marine fish farm, involving passive sampling techniques. The results showed that the risk threshold for irgarol concerning seawater organisms is exceeded. On the other hand, the risk to predators and especially humans through consumption of fish is very low, due to the low bioconcentration potential of the substances assessed. [Copyright &y& Elsevier]

Risks posed by antifouling agents (irgarol 1051, diuron and dichlofluanid) to the aquatic environment of the Gulf of Napoli have been estimated. Seawater samples were collected monthly in selected harbours and marinas of this area during the boating season (March to November 2005) and off-season (January 2006). Concentration levels have been measured, and the resulting data used to perform a probabilistic ecological risk assessment independently on each biocide. Diuron exhibited higher concentration levels than irgarol 1051 in all the investigated locations: Dissolved concentrations of diuron ranged from <1 to 1,380 ng l−1, whereas dissolved concentrations of irgarol 1051 ranged from <0.2 to 173 ng l−1. Contamination appears to be largely dependent on the type and configuration of sampling sites and on the residence time and the density of boats. High levels of booster biocides were associated with marinas housing several recreational water craft and/or fishing boats, whilst commercial ports usually exhibited low concentrations. A seasonal influence was observed, with peak and lowest values found in early summer months and during winter, respectively. The comparison of the respective toxicity benchmarks, expressed as 10th percentiles, suggests that plant species are more sensitive to irgarol 1051 (297 ng l−1) than diuron (4,846 ng l−1). Based on these conservative effect thresholds for plants, ecological risk from the single investigated biocides can be judged to be low in the study area. [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]

Due to deleterious effects on non-target organisms, the use of organotin compounds on boat hulls of small vessels (<25m) has been widely prohibited. The International Maritime Organisation (IMO) resolved that the complete prohibition on organotin compounds acting as biocides in antifouling systems should commence in 2008. As a result of restrictions on the use of organotin based paints, other antifouling formulations containing organic biocides have been utilised. This survey was conducted to assess the contamination of replacement biocides in the marine environment following the ban of TBT-based paints. Surface sediments samples were collected in the major ports and marinas along the France Mediterranean coastline (Cote d’Azur) and analysed for organotin compounds, Irgarol 1051, Sea-nine 211TM, Chlorothalonil, Dichlofluanid and Folpet. Every port and marina exhibited high levels of organotin compounds, with concentrations in sediments ranging from 37ng Sn g−1dry wt in Menton Garavan to over 4000ng Sn g−1dry wt close to the ship chandler within the port of Villefranche-sur-Mer. TBT degradation indexes suggested that fresh inputs are still made. Among the other antifoulants monitored, only Irgarol 1051 exhibited measurable concentrations in almost every port, with concentrations ranging from 40ng g−1dry wt (Cannes) to almost 700ng g−1dry wt (Villefranche-sur-Mer, ship chandler). [Copyright &y& Elsevier]

The effect of Irgarol 1051 on the biofilm-forming diatom, Amphora coffeaformis, and on natural biofilm (NBF) was assessed. A reduction in the number of A. coffeaformis cells within a biofilm was observed after treatment with Irgarol 1051, confirming its role as an inhibitor of photosynthetic activity. The impact of this compound on the development of nauplii of Balanus amphitrite was evaluated through its impact on Chaetoceros calcitrans, which was provided as food for the larvae. A reduction in the number of cells of C. calcitrans was observed when treated with Irgarol 1051. When larvae of B. amphitrite were reared using C. calcitrans in the presence of Irgarol 1051, their mortality increased with an increase in the concentration of Irgarol 1051 (13% at 1 µg l-1 to 40% at 1000 µg l-1) compared with the control (6%). Nauplii reared in the presence of Irgarol 1051 developed more slowly (6-7 days) compared with control larvae (4-5 days). Cyprid bioassay results indicated an increase in percentage metamorphosis (76%) when NBFs were treated with the highest concentration of Irgarol 1051, compared with untreated biofilm (28%). The enhanced rate of metamorphosis appeared to be related to an increase in bacterial numbers in the biofilm, which may have been due to lysis of diatoms caused by Irgarol 1051. A. coffeaformis biofilms grown in the presence of antibiotics showed a significant reduction in cell numbers, which on further treatment with Irgarol 1051 showed an increase in cell numbers. Thus, it can be hypothesised that A. coffeaformis cells that were subjected to stress twice may have expressed resistant genes. Furthermore, if plasmids are present in the biofilms, they may enhance transfer to the surviving cells making them more resistant to hostile conditions. [ABSTRACT FROM AUTHOR]

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]