Evidence for cometabolic transformation of weathered toxaphene under aerobic conditions using camphor as a co-substrate.

AIMS: Toxaphene is a persistent organic pollutant, composed of approximately 1000 highly chlorinated bicyclic terpenes. The purpose of this study was to evaluate if camphor, a structural analogue of toxaphene, could stimulate aerobic biotransformation of weathered toxaphene. METHODS AND RESULTS: Two enrichment cultures that degrade camphor as the sole carbon source were established from contaminated soil and biosolids. These cultures were used to evaluate aerobic transformation of weathered toxaphene. Only the biosolids culture could transform compounds of technical toxaphene (CTTs) in the presence of camphor, while no transformation was observed in the presence of glucose or with toxaphene as a sole carbon source. The transformed toxaphene had lower concentration of CTTs with longer retention times, and higher concentration of compounds with lower retention times. Gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS) showed that aerobic biotransformation mainly occurred with Cl8 - and Cl9 -CTTs compounds. The patterns of Cl6 - and Cl7 -CTTs were also simplified albeit to a much lesser extent. Seven camphor-degrading bacteria were isolated from the enrichment culture but none of them could degrade toxaphene. CONCLUSION: Camphor degrading culture can aerobically transform CCTs via reductive pathway probably by co-metabolism using camphor as a co-substrate. SIGNIFICANCE AND IMPACT OF THE STUDY: Since camphor is naturally produced by different plants, this study suggests that stimulation of aerobic transformation of toxaphene may occur in nature. Moreover plants, which produce camphor or similar compounds, might be used in bioremediation of contaminated soils.

Chlorinated paraffins (CPs) in salmon sold in southern Germany: Concentrations, homologue patterns and relation to other persistent organic pollutants.

Chlorinated paraffins (CPs) are complex mixtures of persistent contaminants present throughout the aquatic food web. In this study 122 farmed and 11 wild salmon samples were collected over the course of four years (2014-2017). The ratio of short-chain CP and medium-chain CP and the corresponding homologue patterns were determined by means of gas chromatography (GC) with high resolution, accurate mass Orbitrap mass spectrometry (MS) technology. Characteristic patterns were observed, enabling differentiation between European and non-European (Chilean) samples. Concentration ranges of short-chain CPs (0.97-170 ng/g ww) and medium-chain CPs (1.1-79 ng/g ww) were similarly widespread over three orders of magnitude. Yet, both the mean and median concentrations of MCCPs were usually higher than those of the SCCP. CP levels were generally higher than those of marker polychlorinated biphenyls (PCBs) and hexabromocyclododecanes (HBCDDs). An age- and gender-dependent estimated intake range of 4.6-35 ng/kg bw/week for short and medium-chain CPs via the consumption of salmon was calculated for adults in Germany.

Occurrence of halogenated natural products in highly consumed fish from polluted and unpolluted tropical bays in SE Brazil.

Natural compounds from the metabolism of marine organisms have been detected at high concentrations in environmental samples which are not the producers of these compounds. These natural substances are known as halogenated natural products (HNPs). HNPs are possibly toxic halogenated compounds analogous to POPs that may bioaccumulate and biomagnify along the food web and pose a further risk to human and environmental health. The present study analyzed the occurrence of HNPs in the edible muscle of the three most consumed commercial fish species in the state of Rio de Janeiro: sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri) and mullet (Mugil liza) from the highly polluted Guanabara Bay (GB) and the less polluted Ilha Grande Bay (IGB). The analytical steps included Soxhlet extraction, clean-up step and injection in a gas chromatography system coupled to a mass spectrometer operated in the electron-capture negative ion mode (GC/ECNI-MS). The compounds 2,4,6-TBP, 2,4,6-TBA, MHC-1, Q1, 6-MeO-BDE 47 and 2'-MeO-BDE 68 were found in the analyzed fish from both studied areas. Q1, 6-MeO-BDE 47 and 2'-MeO-BDE 68 showed the highest concentrations in samples. Q1 concentrations in the sardines from IGB were higher than the sardines from GB (p < 0.05) and higher than the other IGB species (p < 0.05). The differences found among the species may be related to their characteristic habitat and diet. It is noteworthy that most of these compounds do not have any toxicological reference value. Moreover, the HNPs are being detected in species of low trophic level and since this study has worked only with commercial species, these fish may be considered as a source for human exposure to these natural compounds.

Halogenated Natural Products in Dolphins: Brain-Blubber Distribution and Comparison with Halogenated Flame Retardants.

Halogenated natural products (MHC-1, TriBHD, TetraBHD, MeO-PBDEs, Q1, and related PMBPs) and halogenated flame retardants (PBDEs, HBB, Dec 602, Dec 603, and DP) in blubber and brain are reported from five Alboran Sea delphinids (Spain). Both HNPs and HFRs were detected in brain, implying that they are able to surpass the blood-brain barrier and reach the brain, which represents a new finding for some compounds, such as Q1 and PMBPs, MHC-1, TriBHD, TetraBHD, or Dec 603. Moreover, some compounds (TetraBHD, BDE-153, or HBB) presented higher levels in brain than in blubber. This study evidence the high concentrations of HNPs in the marine environment, especially in top predators. It shows the importance of further monitoring these natural compounds and evaluating their potential toxicity, when most studies focus on anthropogenic compounds only. While no bioaccumulation was found for ∑HNPs, ∑HFRs increased significantly with body size for both common and striped dolphins. Studies evaluating BBB permeation mechanisms of these compounds together with their potential neurotoxic effects in dolphins are recommended.

Persistent organohalogen contaminant burdens in Antarctic krill (Euphausia superba) from the eastern Antarctic sector: a baseline study.

A baseline for persistent organohalogen compound (POC) accumulation in the Antarctic keystone species, Antarctic krill (Euphausia superba) has been established for a 50 degrees longitudinal range of the eastern Antarctic sector. Samples of adult krill, caught from 12 sites distributed between 30 degrees and 80 degrees E (60-70 degrees S), were analysed for >100 organohalogen compounds including chlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated organic compounds and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs). Organochlorine pesticides dominated measured krill contaminant burdens with hexachlorobenzene (HCB) as the single most abundant compound quantified. Krill HCB concentrations were comparable to those detected at this trophic level in both the Arctic and temperate northwest Atlantic, lending support for the hypothesis that HCB will approach global equilibrium at a faster rate than other POCs. Para, para'-dichlorodiphenylethene (p,p'-DDE) was detected at notable concentrations. Measurements of DDT and its degradation products provide an important baseline for monitoring the temporal and geographical influence of renewed, DDT usage for malaria-control in affected southern hemisphere countries. In contrast to the Arctic, PCBs did not feature prominently in contaminant burdens of Antarctic krill. The major commercial polybrominated diphenyl ether (PBDE) congeners -99 and -47 were quantified at low background levels with clear concentration spikes observed at around 70 degrees E , in the vicinity of modern, active research stations. The likelihood that local anthropogenic activities are supplementing low PBDE levels, delivered otherwise primarily via long range environmental transport, is discussed. The suspected naturally occurring brominated organic compound, 2,4,6-tribromoanisole (TBA), was a ubiquitous contaminant in all samples whereas the only PCDD/Fs quantifiable were trace levels of octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,7,8/1,2,3,4,7,9-hexachlorodibenzofuran (HxCDF). With the aims of; i) Generating a robust and broadly applicable POC auditing platform for the scarcely studied eastern Antarctic sector; ii) Determining the compounds accumulating in Antarctic krill for further toxicity evaluation studies and iii) Establishing a baseline for Antarctic predator exposure to POCs, this study represents one of the most comprehensive reports of POC contamination of the Antarctic food web to date.

[Prevalence of overweight and obesity in Swiss adolescents]. / Prävalenz von Ubergewicht und Adipositas bei Kantonsschülerlnnen in St. Gallen.

Overweight and obesity are the most important modulators in the development of chronic diseases. Body weight status in adulthood is often already determined in childhood and adolescence. In this study we evaluate possible threats and the prevalence of overweight and obesity among students of the Kantonsschule Burggraben in St.Gallen. Different anthropometric parameters (e.g. size, weight, circumference of waist and hip, body composition by BIA) were assessed among 552 students and different life-style factors as well as risk factors were assessed with a self-administered questionnaire. Using the IOTF-definitions between 6.12-8.18% of students were overweight and 1.08-2.23% were obese. Male students with the highest media consumption (MC) (around 4 h/d) had a higher BMI (kg/m2) than students with lower MC (around 2 h/d) or the lowest level of MC (approximately 1 h/d) (22.83 +/- 0.46 kg/m2 vs. 21.51 +/- 0.21 kg/m2 and 21.60 +/- 0.39 kg/m2; ANOVA p = 0.008). Similarly body composition was affected: students with the highest media consumption had the highest amount of body-fat mass: 12.69 +/- 0.66% vs. 11.05 +/- 0.34% and 10.69 +/- 0.62% (ANOVA p = 0.026) compared to medium and low MC, respectively. There was no correlation between the BMI, the body fat mass and the MC among female students. According to the level of activity male students with a high level showed a significant lower BMI than students with a lower level of physical activity (21.70 +/- 0.21 kg/m2 vs. 22.05 +/- 0.33 kg/m2; p = 0.016). The body fat mass was also lower for higher levels of physical activity (9.57 +/- 0.65% vs. 12.69 +/- 0.86%). Among female students the level of physical activity modulated the body fat mass (high level 20.66 +/- 0.52% vs. low level 23.53 +/- 0.58; p = 0.005) but had no effect on the BMI. Risk factors for obesity such as physical activity patterns are established in childhood and early adolescence. Preventive strategies have to be implemented as early as possible.

[Epidemiology of over- and underweight in Swiss college students]. / Prävalenz von Uber- und Untergewicht in einer Mittelschulpopulation.

Overweight and obesity rates are increasing worldwide. In this study 409 adolescents and young adults (age range 15-22 years) in a Swiss college were studied. The prevalence of overweight was 6.13% in the girls and 5.95% in the boys. 9.52% of the boys and 16.51% of the girls were underweight (BMI < 18.5 kg/m2). 16.98% of the girls had a fat mass > 30%. 2.98% of the boys had a fat mass of > 20%. Male adolescents with a fat mass > 15% judged their physical activity on a visual analogue scale (VAS) significantly lower than male adolescents with a fat mass of < 15% (mean +/- SD VAS score: 4.49 +/- 2.08 vs. 6.00 +/- 2.08, p = 0.03). The same was found in female adolescents: girls with a fat mass > 30% reported a lower physical activity level than females with a fat mass < 30% (mean +/- SD VAS score: 4.84 +/- 1.74 vs. 5.68 +/- 1.82, p = 0.04). Obesity and fatness, but also underweight, is a serious problem in Swiss adolescents. Well chosen public health strategies to address both sides of the energy balance equation are strongly needed.