Butyltins in muscle and liver of fish collected from certain Asian and Oceanian countries

Concentrations of butyltin residues were determined in muscle tissue of fish collected from local markets and sea food shops in India, Bangladesh, Thailand, Indonesia, Vietnam, Taiwan, Australia, Papua New Guinea and the Solomon Islands. Contamination levels were determined in the Asia-Pacific region and human exposure was estimated. Similarly, corresponding liver samples of fish muscle collected in Australia, Papua New Guinea and the Solomon Islands were analyzed to obtain information on partitioning of butyltin compounds between muscle and liver tissues. Butyltin compounds were detected in most of the samples which suggested widespread contamination in Asia and Oceania. The concentrations of butyltin compounds were, on average, an order of magnitude higher in liver than in muscle. Residue concentration of Sigmabutyltin in liver was found to be correlated significantly (p < 0.02) with those in muscle. Intensive ship-scrapping activities, sewage disposal and antifouling paints are considered the major sources of butyltins in this region. Increased proportions of MBT over DBT and TBT in samples from most locations indicated degradation of TBT to MBT in fish tissues during storage at 4 degrees C in the dark over 1-2 years. The possibility that fish have been subject to increased exposure to MBT and that TBT degrades to MBT quite rapidly in tropical environments are also considered. Butyltin concentrations in fish from Asia and Oceania were lower than those reported for Japan, Canada and the USA. Although the number of samples analyzed from each country was small, it is tentatively suggested that intake of butyltins by humans via consumption of fish in these countries was < 25% of the tolerable daily intake of 250 ng kg bw(-1) day(-1). To our knowledge, this is the first study reporting on butyltin pollution in developing Asian countries.     

Individual PCBs as predictors for concentrations of non and mono-ortho PCBs in human milk

32 Dutch human milk samples were analyzed for PCBs with either HRGC-ECD or HRGC-LRMS in the NCI mode. Samples were collected from three different locations in The Netherlands: Amsterdam, Rotterdam and Groningen. Quantitatively, no differences could be observed between the three localities, while in addition the congener specific pattern showed a striking similarity for all individual samples. Only principal component analysis revealed slight individual differences. Based on similarities in the PCB profiles, linear relationships were calculated between 2,3′4,4′,5-PnCB (#118) or 2,2′4,4′5,5′HxCB (#153) and the most relevantnon andmonoortho PCBs exhibiting dioxinlike activity. These PCBs included 2,3,3′,4,4′-PnCB (#105), 3,3′,4,4′5-PnCB (#126) 2,3,3′,4,4′,5-HxCB (#156), 2,3,3′,4,4′,5′-HxCB (#157), 2,3′,4,4′,5,5′-HxCB (#167) and 3,3′,4,4′,5′5-HxCB (#169). Good linear relationships were observed between individual PCBs. Based on the results of this study, PCB #118 can be used to predict concentrations of the PCBs #105 and #126. PCB #153 can be used as a predictor for the PCBs #156, #157, #167 and #169, but also for the total toxic equivalencies (TEQs) ofnon andmonoortho PCBs present in human milk. This method using certain PCBs as predictors for other toxicological relevant congeners, can be useful and cost effective, e.g. for epidemiological studies. However, before applied a number of conditions should be met. These are:

1. A stable composition of the PCB matrix should be established.
2. A possible time dependent change in composition of the matrix should first be excluded when used over different time periods.

     

Wastes of multilayer containers as substrate in composting processes

An evaluation of the influence and degradation of ground multilayer containers, such as Tetra Brik Aseptic (TBA), in the composting process of municipal solid wastes (MSW) is presented. Two composting piles were formed by mixing, in different proportions, an organic fraction of MSW and TBA material ground as flakes or stripes. Piles were periodically aerated by mechanical mixing. Evolution of the composting was followed by frequent measurements of suitable parameters such as temperature, moisture, ashes, total organic carbon (TOC), nitrogen, C/N ratio, pH, conductivity, nutrients, and heavy metals. As expected, aluminum and polyethylene films from TBA were not degraded during the processes, but the cardboard fraction of TBA showed a partial decomposition that was more intense in the material ground as flakes. After two months of curing, the composts were refined and analyzed to determine their nutrient and heavy-metals contents. Despite their poor aesthetic properties, mainly resulting from the presence of little pieces of plastic and aluminum films, the composts contained the required amounts of nutrients; furthermore, their heavy-metals content was below the limits proposed by some official European organizations.     

Estimations of real-world N2O emissions from road vehicles by means of measurements in a traffic tunnel

Ambient air measurements of N2O, NOx, CO, and HC based on grab sampling were conducted in a major traffic tunnel in Sweden, that carries up to 4,000 vehicles per hour, in order to estimate real-world emissions of N2O for road traffic. Two different methods--relative and mass balance-were used to calculate a N2O emission factor for the mixed vehicle fleet, which gave an average emission factor, at average speeds of 30-70 km/h, of approximately 25 mg N2O/ km, with a range of 7-56 mg/km.     

Validation of estuarine gammarid collectives (Amphipoda: Crustacea) as biomonitors for cadmium in semi-controlled toxicokinetic flow-through experiments

Concentrations of chemicals in organisms are regarded as being indicators of the bioavailable fraction of those substances in the environment. Three gammarid collectives (assemblages) from the Weser-estuary (NW Germany), showing different species compositions, were used as experimental units to evaluate their suitability as biomonitors. Uptake and clearance of cadmium was investigated in semi-controlled dynamic flow-through tests. Kinetic data obtained from two compartment models confirmed a net accumulation strategy of gammarids for Cd and resulted in similar bioconcentration factors (BCFs) within the same experimental treatments. Deviations in bioconcentration factors between two treatments (BCFs: 377-542 vs 947-1190, based on dry wt) obtained under similar exposures (17 +/- 2 and 23 +/- 2 microg Cd litre(-1)) could not be assigned to significant fluctuations of both Cd levels and particulate matter in the flow-through systems. The biological half-life of Cd in gammarids was 6 to 12 days. It is concluded that gammarid collectives of different species composition may be used as experimental units in biomonitoring studies. This conclusion was confirmed by homogeneous Cd concentrations in field samples of gammarids from the Weser-estuary (0.34 +/- 0.03 mg kg(-1) dry wt., mean +/- 95% confidence intervals, N = 58).     

Physiological ecology of a mussel with methanotrophic endosymbionts at three hydrocarbon seep sites in the Gulf of Mexico

In situ growth rates were determined, using two, 1-yr mark/recapture experiments, conducted between September 1991 and July 1993, for an undescribed mytilid, Seep Mytilid Ia, at three hydrocarbon seep sites in the Gulf of Mexico. The sites are located at depths of 540 to 730m, approximately 27°45N; 91°30W, and are separated by distances of 6 to 18 miles. These seep mytilids harbor methanotrophic endosymbionts and use methane as both a carbon and energy source. The mussel habitats were chemically characterized by analysis of water samples taken from precisely located microenvironments over, among and below the mussels, using small-volume, interstitial water samplers and the Johnson Sea Link submersible. Substantial differences were found in habital conditions, growth rates, and population structure for the mussels at the three sites examined. The growth rate of these seep mytilids reflects the methane concentration in their immediate habitat. Mussels at sites with abundant methane had growth rates that were comparable to shallow water mytilids at similar temperatures (5 to 8°C) with increases in shell length up to 17 mm yr^–1 documented for smaller mussels (<40 mm shell length). In conjunction with measurements of growth rates, three condition indices (glycogen content, tissue water content, and the ratio of ash-free dry weight to shell volume) were used to determine the relationship between the condition of the mussels, their growth rates, and their habitat chemistry. The three condition indices were correlated with growth rate and were often significantly different between mussels in different samples.     

Acute and chronic toxicity of tributyltin (TBT) to pediveliger larvae of the bivalve Scrobicularia plana

A static renewal test was run for 30 d to assess the effects of the antifoulant tributyltin (TBT, nominal concentrations of 50, 125, 250 and 500 ng Sn l^-1) on the survival and growth of 240 m-long pediveliger larvae of the bivalve Scrobicularia plana (da Costa) settling in fine sand. Exposure to nominal TBT levels of 125 ng Sn l^-1 (actual range of 37 to 102 ng Sn l^-1, as analysed) resulted in substantial mortalities and negligible shell growth of individuals. More importantly, larval shell growth at the lowest concentration tested (i.e. nominal 50 ng Sn l^-1 or 14 to 32 ng Sn l^-1, as analysed) was significantly reduced (by a factor of 4) and grossly abnormal. In contrast, some control postlarvae had begun developing siphons as they attained a length of 600 to 700 m by the end of this test, thereby completing metamorphosis and becoming juveniles. The results are discussed in relation to the widespread disappearance of S. plana in North Atlantic European estuaries during the 1980s and the concurrent TBT pollution in their waters. It is inferred that TBT is likely to have contributed to the reported demise of clam populations by preventing the successful and timely progress of their pediveliger larvae.     

Ruminant uptake of nickel and other elements from industrial air pollution in the Norwegian-Russian border area

Concentrations of the elements aluminium, arsenic, cadmium, chromium, cobalt, copper, lead, mercury, nickel, selenium and zinc in liver, and of nickel in kidneys, were studied in reindeer, moose and sheep from South Varanger in eastern Finnmark and comparable districts in western Finnmark, Norway. The study included samples from 31 reindeer, 10 moose and 10 sheep from Jarfjord (South Varanger); 31 reindeer, 27 moose and 15 sheep from Pasvik (South Varanger); and 40 reindeer, 16 moose and 15 sheep from western Finnmark. Levels of arsenic, copper, nickel and selenium were much higher in reindeer from one or both areas in South Varanger than in reindeer from western Finnmark. Levels of chromium, cobalt and zinc were also significantly higher in South Varanger reindeer than in reindeer from the reference area. Within South Varanger the highest levels of these elements were invariably found in the Jarfjord area. For the other elements studied hepatic levels in South Varanger were similar to or lower than in western Finnmark. Also in moose, higher levels of nickel and of selenium (Jarfjord only) were found in the South Varanger samples than in samples from western Finnmark. In sheep, on the other hand, levels in South Varanger samples were similar to levels in western Finnmark for all the elements studied. Comparing the results with reports on pollution of air and vegetation, it was concluded that for all the elements showing higher levels in reindeer and moose from South Varanger compared to the reference areas, the effect most probably was a result of atmospheric transport of industrial pollution from the nearby Russian towns Nikel and Zapoljarnij. The geographical and interspecies differences within the South Varanger samples support this conclusion.