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Assessment of adsorption behavior of dibutyltin (DBT) to clay-rich sediments in comparison to the highly toxic tributyltin (TBT).

The sorption behavior of dibutyltin (DBT) to four types of natural clay-rich sediments as a function of pH and salinity was studied. The strongest affinity of DBT was found to the montmorillonite-rich sediment, which is characterized by the highest specific surface area and cation exchange capacity of the four used sediments. Kd values range between 12 and 40 (l/kg) on simulated marine conditions (pH 8, salinity 32%). A maximum of DBT adsorption was found at a salinity of 0% and pH 6. Desorption occurred over the entire studied pH range (4-8) when contaminated sediments interact with butyltin-free water. The maximum of desorption coincided with the minimum of adsorption, and vice versa. The results of DBT adsorption are compared with tributyltin (TBT), and the mechanism of the adsorption process is discussed.

Adsorption↗

Legionella pneumophila in cooling water systems. Report of a survey of cooling towers in London and a pilot trial of selected biocides.

Fourteen recirculating cooling water systems were surveyed during the summer, 1981, to see what factors might influence the prevalence of Legionella pneumophila. The effect on the organism of three anti-microbials was studied, each in two systems, by intermittent treatment at two week intervals. L. pneumophila was isolated from six of the 14 cooling systems at the beginning of the trial but by the end was present in ten. An association was found between the presence of the organism and the concentration of dissolved solids, and chlorides and the pH. There also appeared to be associations with exclusion of light and higher water temperatures. Repeated tests on eight untreated systems showed that two were consistently infected, three became and remained infected, one was infected on a single occasion and two were never infected with L. pneumophila. Treatment of a contaminated system, either with a 10 p.p.m mixture of a quaternary ammonium compound and tributyltinoxide or slow release chlorine briquettes (maximum recorded free chlorine level 1.2 p.p.m.), did not eliminated legionellae. Treatment of two infected towers with a chlorinated phenol (100 p.p.m.) eliminated legionellae for at least three days, but after 14 days the organism was again found.

Air Conditioning↗

Species-specific isotope dilution analysis and isotope pattern deconvolution for butyltin compounds metabolism investigations.

A methodology for the study of the absorption and metabolism of butyltin compounds in laboratory animals using isotopically enriched species was developed. The method is based on the oral administration of 119Sn-labeled monobutyltin (MBT), 118Sn-labeled dibutyltin (DBT), and 117Sn-labeled tributyltin (TBT) to the animals and the measurement of both the concentration and isotopic composition of these compounds in the different tissues by GC-ICPMS. The degradation of butyltin compounds during their metabolism was computed using least-squares isotope pattern deconvolution, and their concentration was measured by reverse isotope dilution analysis using natural-abundance MBT, DBT, and TBT standards. Male Wistar rats were used as models to evaluate the proposed methodology. Preliminary toxicological results obtained with one rat indicate that TBT is highly absorbed (64.4%), and it is found in all organs with relatively high levels in stomach and intestines. The apparent absorption of DBT was 27.3% and was mainly found in liver, kidney, and intestines. However, a large proportion of the found DBT is formed from the degradation of TBT (approximately 40% of the found DBT in liver is degraded TBT). The apparent absorption of MBT was found to be 12.5%, and the originally administered MBT was mainly recovered in the feces. However, MBT was clearly detected in liver, kidney, stomach, intestines, and urine as degradation products of DBT and TBT. Although a significant variability from rat to rat is expected to be obtained, the analytical variability provided by this methodology is small enough to yield meaningful biological results. The results obtained demonstrate that the developed methodology is able to follow qualitatively, quantitatively, and simultaneously the specific metabolic pathways of different species of a given element.

Animals↗

Organotin implications in anticarcinogenesis. Effects of several organotins on tumour growth rate in mice.

Several cohorts of cancerous mice were continuously dosed with 2,2'-bipyridyl dibutyltin dichloride, 1,10-phenanthroline dibutyltin and histidine dibutyltin; presented at 1 ppm and 10 ppm in drinking water. Tumour growth rates were significantly reduced. Tributyltin fluoride (TBTF) applied dermally, using dimethyl sulfoxide (DMSO) as the carrier, over the tumour site was ineffective. Variation in thymus and spleen weight between controls and tin-exposed mice indicates a lymphatic involvement. Analysis of mouse tissue for total tin content showed high tin concentrations in the thymus and spleen.

Animals↗

Effects of organotin compounds on maximal electroshock seizure (MES) responsiveness in mice. II. Tricyclohexyltin and triphenyltin.

Male mice (25-30 g) were injected (ip) with either 0, 3.5 X 10(-6), 17.5 X 10(-6), or 26.25 X 10(-6) mol/kg of either tricyclohexyltin bromide (TCT) or triphenyltin acetate (TPhT) in a corn-oil vehicle. The mice were tested for maximal electroshock seizure (MES) at 0.5, 4, 24, and 96 h following exposure to the organotin compounds, and the durations of seizure phases were measured and used to assess seizure severity. No significant changes in seizure-grade distribution, as compared to controls, were observed in any of the TCT- or TPhT-treated groups at any of the time points examined. No significant changes in the duration of seizure phases, as compared to controls, were observed in animals dose with 3.5 X 10(-6) mol/kg of TCT or TPhT at any of the time points evaluated. At 0.5 h following exposure, the mice dosed with the two higher levels of TCT or TPhT exhibited increases in MES severity. At 4 and 24 h following exposures, the mice exposed to the two higher dose levels of TPhT exhibited decreases in MES severity, followed by a recovery of normal seizure severity at 96 h. Conversely, the animals dosed with the higher dose levels of TCT exhibited at increased MES severity at 4, 24, and 96 h following exposure. These results, in combination with those in the preceeding paper (Doctor and Fox, 1982), reveal that at equimolar doses TCT And TPhT possess a different spectrum of action than the tri-n-alkyltins.

Animals↗

Effect of alkyltins on rabbit articular and growth-plate chondrocytes in monolayer culture.

The effect of four different alkyltins (trimethyltin, triethyltin, dibutyltin, and dioctyltin) on the metabolism of rabbit articular and growth-plate chondrocytes was investigated using a monolayer cell-culture system. In most instances the compounds tested exhibited a general cytotoxic effect on these cells, inhibiting the synthesis of both DNA and sulfated proteoglycans. The effect of these compounds on proteoglycan synthesis was both quantitative and qualitative, as demonstrated by CsCl isopycnic density gradient centrifugation and gel exclusion chromatographic techniques. However, certain tin compounds tested, at specific concentrations, exerted a stimulatory effect on chondrocyte proliferation. Regarding DNA synthesis, growth-plate chondrocytes were more sensitive to the effect of the triethyltin, dibutyltin, and dioctyltin than were articular chondrocytes. The data are discussed in relation to the possible effects of the alkyltins on skeletal growth and development as well as the mechanism of action of the alkyltins at the molecular level.

Animals↗

Allyl-based groups for side-chain protection of amino-acids.

Allyl and allyloxycarbonyl groups are used for the side-chain protection of amino acids. The protecting groups may be selectively cleaved using the reagent HSnBu3 under palladium catalysis. The preparation of Boc and Fmoc series of protected amino acids is described.

Allyl Compounds↗

Occurrence of imposex in Thais haemastoma: possible evidence of environmental contamination derived from organotin compounds in Rio de Janeiro and Fortaleza, Brazil.

There are indications that the widespread use of organotin compounds (TBT and TPT) as antifoulings, as stabilizers in plastic and as pesticides, has severely affected several species of marine organisms. The most striking effect of TBT and TPT as hormonal disruptors is the development of male organs in females of gastropods, currently denominated imposex. This syndrome can lead to the sterilization and death of affected organisms. The present work gives an overview of the present state of knowledge on imposex occurrence and reports results of a survey conducted in Guanabara Bay, Rio de Janeiro and in several sites along the coast of Fortaleza, Ceará State. Different stages of imposex development were verified in this survey, however, the most prominent levels appeared associated to known spot sources of TBT and TPT.

Animals↗

[Method-performance studies of notified analytical method for fenbutatin oxide and cyhexatin].

Method-performance studies were conducted for the notified revised analytical method of fenbutatin oxide (FBTO) and cyhexatin (CHT). FBTO and CHT spiked into rice, soybeans, spinach, orange, tea powder and tea extract at the level of 0.5 microgram/g for FBTO and 0.1 microgram/g for CHT were analyzed in replicate in 6 laboratories. Means recoveries of FBTO were 85.2-96.5% and those of CHT were 83.5-89.2% except from soybeans (46.5%). Repeatability relative standard deviation values of FBTO and CHT in each crop were in the ranges of 2.3-9.4% and 3.2-6.3%, respectively. Reproducibility relative standard deviations were 3.9-12.6% for FBTO and 8.3-12.9% for CHT. Detection limits were 0.015-0.05 microgram/g for FBTO and 0.005-0.02 microgram/g for CHT.

Food Analysis↗

[Effects of organonitrogen, carbamate pesticides and others on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)].

There have been very few reports of the effect of pesticides on immediate allergy. In the previous report, the effect of pyrethroid pesticides and organophosphorus pesticides on immediate allergic reaction was investigated. Subsequently, 12 organonitrogen pesticides, 14 carbamate pesticides and 4 other pesticides were investigated for their effects on the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from rat basophilic leukemia cells (RBL-2H3). Two organonitrogen pesticides, bitertanol and pyridaben, and two organotin pesticides, cyhexatin and fenbutatin oxide, were found to promote beta-hexosaminidase release. Bitertanol non-specifically caused the promotion of chemical mediator release, while the release-promotive action of pyridaben was related to IgE antibody and those of cyhexatin and fenbutatin oxide to cell injury. On the other hand, two organonitrogen pesticides, propiconazole and triadimenol, and imazalil showed release-inhibitory action. These data suggested that some pesticides can affect immediate allergy.

Animals↗

Toxicity of tributyltin and triphenyltin to early life-stages of Paracentrotus lividus (Echinodermata: Echinoidea).

Sperm cell and embryo toxicity tests using the Mediterranean sea urchin Paracentrotus lividus were performed to assess the toxicity of tributyltin chloride, bis(tributyltin)oxide, triphenyltin acetate, and triphenyltin hydroxide. Toxicity values (mean effective concentration [EC50]) ranged from 2.97 to 18.5 microg/L for sperm cells and from 1.11 to 2.62 microg/L for embryos. For sperm cells, the toxicity of the two tributyl compounds was significantly greater than that of two triphenyl compounds; for embryos, the triphenyl compounds appeared to be more toxic. Study of embryotoxic effects highlighted closely concentration-dependent damages, the most sensitive stages corresponding to the crucial phases of differentiation (gastrula and prisma). Both EC50 and no-observed-effect concentration values for the four organotin compounds are similar to those reported in the literature for early life stages of other marine organisms.

Animals↗

Asia-Pacific mussel watch: monitoring of butyltin contamination in coastal waters of Asian developing countries.

Butyltin compounds (BTs) including mono-, di-, and tributyltin and total tin (sigmaSn), were determined in green mussels (Perna viridis) from various Asian developing countries, such as Cambodia, China (Hong Kong and southern China), Malaysia, India, Indonesia, the Philippines, and Vietnam, to elucidate the contamination status, distribution, and possible sources and to assess the risks on aquatic organisms and humans. Butyltin compounds were detected in green mussels collected from all the sampling location investigated, suggesting widespread contamination of BTs along the coastal waters of Asian developing countries. Among butyltin derivatives, tributyltin (TBT) was the predominant compound, indicating its ongoing usage and recent exposures in Asian coastal waters. Higher concentrations of BTs were found in mussels collected at locations with intensive maritime activities, implying that the usage of TBT as a biocide in antifouling paints was a major source of BTs. In addition, relatively high concentrations of BTs were observed in mussels from aquaculture areas in Hong Kong and Malaysia, as it has been reported in Thailand. With the recent improvement in economic status in Asia, it is probable that an increase in TBT usage will occur in aquaculture. Although contamination levels were generally low in mussel samples from most of the Asian developing countries, some of those from polluted areas in Hong Kong, India, Malaysia, the Philippines, and Thailand revealed levels comparable to those in developed nations. Furthermore, the concentrations of TBT in some mussels from polluted areas exceeded the threshold for toxic effects on organisms and estimated tolerable average residue levels as seafoods for human consumption. A significant correlation was observed between the concentrations of sigmaBTs and sigmaSn in mussels, and sigmaBTs were made up mostly 100% of sigmaSn in mussels taken from locations having intensive maritime/human activities. This suggests that anthropogenic BTs represent the major source of tin accumulation in mussels. To our knowledge, this is a first comprehensive report on butyltin pollution monitoring in developing countries in the Asia-Pacific region.

Animals↗

Acute toxicity studies of tri-n-butyltin and triphenyltin acetates in rats.

Two organotin compounds, tri-n-butyltin acetate (TBTA) and triphenyltin acetate (TPTA), that have antifungal potentials and are intended for use on yam root crops to prevent rot were evaluated for acute mammalian toxicity in rats. The median lethal doses po were 297.54 mg TBTA/kg and 402.38 mg TPTA/kg. Both compounds produced significant central nervous system and respiratory depressions at single doses of 200 mg TBTA/kg or 300 mg TPTA/kg. The histopathological findings due to TBTA included pulmonary, hepatic and renal congestion, brain hemorrhages, and destruction of the intestinal mucosa. TPTA produced brain congestion, and hepatic and pulmonary petechial and generalized hemorrhages.

Animals↗

Organotin compounds induce calcium overload and apoptosis in PC12 cells.

We examined the effects of four tri-substituted organotin compounds on intracellular Ca2+ and survival in PC12 cells. Treatment with micromolar concentrations of tributyltin and triphenyltin caused a rapid increase in the cytosolic free Ca2+ concentration ([Ca2+]i). This was due to enhanced Ca2+ influx and release from intracellular stores. When the [Ca2+]i elevation was maintained for over 30 min, internucleosomal DNA cleavage typical of apoptotic cell death followed. In contrast, when the increase in [Ca2+]i was transient, cells did not show internucleosomal DNA cleavage and retained their viability. Triethyltin modified [Ca2+]i only slightly, whereas trimethyltin had no effect. The latter two agents did not modify cell viability. Our data suggest that the toxicity of organotins in PC12 cells is linked to their ability to promote intracellular Ca2+ overload, which triggers apoptosis.

Animals↗

A flow cytometric method for measurement of intracellular chloride concentration in lymphocytes using the halide-specific probe 6-methoxy-N-(3-sulfopropyl) quinolinium (SPQ).

A flow cytometry method using the halide-specific fluorescent dye, 6-methoxy-N-(3-sulfopropyl) quinolinium (SPQ), has been developed to measure intracellular chloride concentration in single cells. Collisions with chloride quench the fluorescence of SPQ, making it possible to relate the measured fluorescence intensity to chloride concentration with a Stern-Volmer equation. To demonstrate the method, porcine lymphocytes were loaded in vitro, using a hypotonic method, with 5 mM SPQ. Fluorescence excitation was provided by a UV laser and the fluorescence emission intensity at 485 nm was recorded. Calibration was performed by using 7 microM nigericin (a K/H antiporter) and 10 microM tributyltin (a Cl/OH antiporter) to equilibrate the concentrations of intracellular and extracellular chloride. Calibration measurements were made for chloride concentrations between 0 mM and 140 mM. The calibration produced a Stern-Volmer quenching constant of 16.2 M(-1) which was used to relate measured cell fluorescence to intracellular chloride concentration. The intracellular chloride concentration for fresh porcine lymphocytes was determined to be 56.2 +/- 3.3 mM. Stable loading of cells with 5 mM SPQ was accomplished in 15 minutes, leakage of SPQ from the cells was minimal, and over 95% of the cells remained viable after loading.

Animals↗

Role of hydrophobic and hydrophilic interactions of organotin and organolead compounds with model lipid membranes.

The present study was conducted to clarify the mechanism of toxicity of organic compounds using lipid model membranes (liposomes and planar lipid membranes). The compounds studied were trialkyltin and trialkyllead chlorides, dialkyltin dichlorides and some inorganic forms of those metals. Two different (anionic and cationic) detergents were also used in the experiments to change the surface properties of liposomes. As a measure of interaction between the compounds studied and model membranes were the release of liposome bound praseodymium and the change in stability of planar membranes under the influence of those compounds. On the basis of the results obtained it was postulated that the mechanism of interaction between tin- and leadorganics and model lipid membranes is a combination of different factors featuring interacting sides. The most important properties determining the behaviour of organic compounds in the interaction were lipophilicity and polarity of different parts of the organics and the steric arrangement they can take in the medium. On the other hand, the surface potential of the lipid bilayer and the environment of the lipid molecules, that play a significant role in the availability of the lipid bilayer to the organics, were important factors in the interaction.

Lead↗