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We analyzed the fate of organotins in seawater and sediments from Tokyo Bay, Japan, by gas chromatography/inductively coupled plasma mass spectrometry. We also measured the toxicity of methylated butyltins by in vitro bioassays, the retinoid X receptor (RXR) activation method, and the marine luminescent bacterium Vibrio fischeri. Concentrations of tributyltin (TBT) and tributylmonomethyltin (TBMMT) in seawater were 0.0636 to 0.419 and 0.0050 to 0.108 ng Sn/L and in sediment were 7.51 to 17.8 and 3.67 to 6.87 ng Sn/wet weight g, respectively. Methylated butyltins did not activate RXR and were not toxic to bacteria. Tributylmonomethyltin in seawater would elute from sediment since TBMMT-to-TBT ratios showed a positive correlation (r² = 0.858) between sediment and deep seawater. Both methylation and debutylation of TBT seem to be major routes of decomposition of TBT in sediment. Methylation of TBT would not only cause subsequent volatilization but also decrease the toxicity of TBT species in the marine environment. [ABSTRACT FROM AUTHOR]

Organotins are widespread in the world's oceans and have a detrimental effect on organisms. However, there is little information on their distribution in the Southern hemisphere. We analyzed organotins in seawater from the Southern Ocean and Suruga Bay, Japan, using gas chromatography/inductively coupled plasma mass spectrometry. Organotins were compared in two contrasting environments—one in shallow, temperate coastal waters (Suruga Bay) and the other in cold, deep waters of the far Southern Ocean. Twelve kinds of organotins were detected from Suruga Bay, with tributyltin (0.184-13.6 ng Sn/L) and total organotins (0.801-19.7 ng Sn/L). In contrast, three kinds of organotins were detected in the Southern Ocean, with total organotins (from not detected to 0.266 ng Sn/L). The ratios of degraded products of tributyltin and triphenyltin from the Southern Ocean were higher than those in Suruga Bay, suggesting that fresh input of organotins into the Southern Ocean is relatively low. The presence of butyltins in Antarctic sediments and biota has been demonstrated previously; however, the present study is the first to describe trace levels of organotins in the Southern Ocean approximately 1,000 km from Antarctica. [ABSTRACT FROM AUTHOR]

Abstract: The daily dietary intake of inorganic arsenic (InAs) and some of organic arsenic (OrAs) species of Japanese subjects were estimated by determining the concentrations of As species in two different sets of total diet sample: duplicated diet samples collected from 25 subjects in Japan and a certified reference material with total diet matrix (NIES CRM No. 27 Typical Japanese Diet, TJD). The concentration of InAs and OrAs in diet samples were determined by LC-ICP-MS using a photo-oxidation and hydride generation system. The median intake of InAs for the 25 subjects was 3.8μgday−1 (2.0–57μgday−1) and intake of 27μgday−1 was estimated from TJD. The median intake of MMA, DMA and TMAsO were <0.18, 1.1 and <0.053μgday−1 for the 25 subjects and that of MMA, DMA, AB and TMAsO was estimated to be 3.9, 11, 140 and 5.9μgday−1, respectively, based on TJD analysis. On the basis of InAs intakes estimated and the oral slope factor of the US EPA and Health Canada, excess cancer risk was estimated to exceed acceptable level. Cancer risk posed by the dietary InAs of the general Japanese may not be negligible. [Copyright &y& Elsevier]

Abstract: The association between oxidative stress and exposure to environmental chemicals was assessed in a group of Japanese preschool children. The concentrations of 8-hydroxy-2′-deoxyguanosine (8-OHdG), 1-hydroxypyrene (1-OHP), inorganic arsenic (iAs) and monomethylarsonic acid (MMA), and cotinine in spot urine samples, collected from 134 children (3–6yrs) from a kindergarten in Kanagawa, Japan, were measured as biomarkers of oxidative stress or exposure to environmental chemicals. For 76 subjects of the 134, intakes of anti-oxidant nutrients (vitamins A, C, and E, manganese, copper, zinc and selenium (Se)) were estimated from a food consumption survey carried out 2–4weeks after urine sampling and by urine analysis (Se). The median (min–max) creatinine-corrected concentrations of urinary biomarkers were 4.45 (1.98–12.3), 0.127 (0.04–2.41), 4.78 (1.18–12.7), and 0.62 (<0.6–19.0)μg/g cre for 8-OHdG, 1-OHP, iAs+MMA, and cotinine, respectively. Multiple regression analysis was carried out using 8-OHdG concentration as a dependent variable and urinary biomarkers of exposure and Se intake, intakes of vitamins and biological attributes of the subjects as independent variables. To explain 8-OHdG concentrations, intake of vitamin A and age were significant variables with negative coefficients, while 1-OHP concentration had a positive coefficient. These results indicated that oxidative stress of children is affected by chemical exposure at environmental levels, by nutrient intake and by physiological factors in a complex manner. On the other hand, unstable statistical results due to sub-grouping of subject, based on the availability of food consumption data, were found: the present results should further be validated by future studies with suitable research design. [Copyright &y& Elsevier]

The concentrations of arsenic (As) species in 19 food composites prepared from 159 food items purchased in Shizuoka city, Japan, were determined (1) to estimate total daily intake of inorganic As (InAs) and some organic As species and (2) to determine food contributing to total daily InAs intake. As analysis included extraction of As species with a synthetic gastric juice (0.07 mol/L HCl + 0.01 % pepsin) from food composite and high-performance liquid chromatography-high efficiency photo-oxidation-hydride generation-inductively coupled plasma mass spectrometry. InAs was detected in 9 of 19 food composites at a concentration of 0.423-450 ng As/g fresh-weight. Daily intake of InAs from cereals was greatest (13 μg/person/day) followed by algae (5.7 μg/person/day), and the intake from the two categories constituted 90 % of the total daily InAs intake of adults (21 μg/person/day on a bioaccessible-fraction basis and 24 μg/person/day on a content basis). Analysis of individual food items showed that rice and hijiki contributed virtually 100 % of InAs from cereals and algae, respectively. The present survey indicated that InAs from rice and hijiki consumption contributed to total daily InAs intake and consequently to significant cancer risk of the general Japanese population. Daily intake of some organic forms of As and their contributing food categories was also estimated.

Uwakai of Japan is famous for pearl and yellowtail fish culture. Recently, pearl culture farming in that region has suffered from a low production of pearls. An illegal use of organotin antifouling paints on fishing nets was reported. In the line of pollution studies, thus, the present investigation was carried out to examine the contamination status and fate of organotin compounds. Totally, 23 water, 10 sediment and 8 pearl oyster tissue samples were analyzed for tributyltin (TBT), triphenyltin (TPT), and their breakdown products (di- and mono compounds) by gas chromatography combined with inductively coupled plasma mass spectrometry (GC/ICP-MS). The results show that the TBT concentrations in water, sediment and biota were in the range from 0.11 to 10.6 ng Sn l(-1), 0.35 to 2500 ng Sn g(-1), and 50.4 to 181 ng Sn g(-1), respectively. The values for sediment and biota are expressed on the dry-weight basis. Triphenyltin in water, sediment and biota were in the range from 0.009 to 0.108 ng l(-1), non-detect to 12.7 ng g(-1), and non-detect to 6.83 ng g(-1), respectively. Although the TBT concentration in seawater is below the tentative assessment level of 10 ng l(-1) set by the Japanese Environment Agency in 1992, it may cause endocrine disruption/other effects in aquatic organisms. Octyltin compounds (mono-, di- and trioctyltin) were also quantified in seawater and sediment. The detection of dibutyldimethyltin (DBDMT) and tributylmonomethyltin (TBMMT) in sediment (methylated butyltins comprised 2.8-31% of total butyltins), and TBMMT in seawater suggested that biomethylation of anthropogenic tributyltins is a significant transformation pathway in the coastal environment.