Multi-decadal changes in tundra environments and ecosystems: synthesis of the International Polar Year-Back to the Future project (IPY-BTF)

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in subarctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies.     

Dietary exposure of rainbow trout to 8:2 and 10:2 fluorotelomer alcohols and perfluorooctanesulfonamide: Uptake, transformation and elimination

The bioaccumulation of perfluorooctanesulfonamide (PFOSA) and two fluorotelomer alcohols (8:2 FTOH, 10:2 FTOH) by rainbow trout (Oncorhynchus mykiss) through dietary exposure, including depuration rates and metabolism was investigated. Concentrations in the spiked feed ranged from 10.9 μg g⁻¹ wet weight (wet wt) for PFOSA and 6.7 μg g⁻¹ wet wt for 8:2 FTOH to 5.0 μg g⁻¹ wet wt for 10:2 FTOH. Trout was fed at 1.5% body weight per day for 30 d and depuration was followed for up to 30 d following previously published dietary exposure protocols. Perfluorooctanesulfonate (PFOS) was the major perfluoroalkylsulfonate (PFSA) detected in fish following dietary exposure to PFOSA. Half-lives of PFOS and PFOSA were 16.9 ± 2.5 and 6.0 ± 0.4 d, respectively. A biomagnification factor (BMF) of 0.023 was calculated for PFOSA which indicates that dietary exposure to PFOSA does not result in biomagnification in the rainbow trout. PFOS had a BMF of 0.08. The fluorotelomer saturated acids (8:2 FTCA, 10:2 FTCA) and fluorotelomer unsaturated acids (8:2 FTUCA, 10:2 FTUCA) were the major products detected in rainbow trout following dietary exposure to 8:2 FTOH and 10:2 FTOH, respectively. Half-lives were 3.7 ± 0.4, 2.1 ± 0.5, 3.3, and 1.3 d for 10:2 FTCA, 10:2 FTUCA, 8:2 FTCA, and 8:2 FTUCA, respectively. Small amounts of perfluorooctanoate (PFOA) and perfluorodecanoate (PFDA) were also detected in the FTOH exposed fish.     

Concentrations and sources of Dechlorane Plus in sewage sludge

Sewage sludge from 31 urban Spanish wastewater treatment plants (WWTP) was analyzed for the emerging halogenated flame retardant Dechlorane Plus (DP). Concentrations of the two major isomers in the technical mixture, syn and anti, ranged between 0.903-19.2 and 1.55-75.1 ng g⁻¹ dry weight, respectively. Overall, concentrations of DP were lower than those of polybrominated diphenyl ethers (PBDEs) (9.10-995 ng g⁻¹ dry weight) and this is likely related to the higher usage of brominated flame retardants. The average ratio of the syn isomer to total DP (f_syn) was 0.28 ± 0.05, which is similar to that of the commercial mixture. Comparing different wastewater treatment methods, we found lower concentrations in those using biological nitrogen and phosphorous elimination, suggesting that DP is susceptible to microbial degradation and that anti-DP is more so, given the enrichment of syn-DP in the sewage sludge. Principal components analysis revealed significant positive correlation (r = 0.619, p < 0.05) between total DP concentrations with the contribution of industrial input to waste streams. This implies release of DP is related to industrial activity, likely stemming from the use of the technical product during manufacture of consumer goods. However, use and disposal of products containing DP could not be dismissed. According to our knowledge, this is the first report on DP in WWTP sludge.     

Transfer functions for solid-solution partitioning of cadmium for Australian soils

To assess transport and ecotoxicological risks of metals, such as cadmium (Cd) in soils, models are needed for partitioning and speciation. We derived regression-based “partition-relations” based on adsorption and desorption experiments for main Australian soil types. First, batch adsorption experiments were carried out over a realistic range of dissolved Cd concentrations in agricultural soils in Australia. Results showed linear sorption relationships, implying the adequacy of using Kd values to describe partitioning. Desorption measurements were then carried out to assess in-situ Kd values and relate these to soil properties The best transfer functions for solid-solution partitioning were found for Kd values relating total dissolved Cd concentration to total soil Cd concentrations, accounting for the variation in pH, SOM contents and DOC concentrations. Model predictions compared well with measurements of an independent data set, but there was a tendency to underestimate dissolved Cd concentrations of highly polluted soils.     

Occupational exposure to formaldehyde in an institute of morphology in Brazil: a comparison of area and personal sampling

Background, aims, and scope

Formaldehyde (FA) is a harmful chemical, which is classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. Solutions of FA that are used to preserve cadavers in research and education morphological institutes represent a risk to occupational health of professionals and students. During the dissection of cadavers in the anatomy laboratories, FA vapors are emitted, resulting in the exposure of students and their instructors to elevated levels of FA. The World Health Organization recommends an air quality guideline value of 0.1 mg m^?3 for exposure to FA. The limit of occupational exposure adopted by the Brazilian legislation (2.3 mg m^?3) is markedly higher than those adopted by institutions of other countries around the world. The purpose of this study was to determine the levels of personal exposure and the area concentration of FA in the morphology department of the Federal Fluminense University, Brazil, and investigate and compare the relationship between them.

Methods

Four rooms distributed in the three floors of the Morphology Department were evaluated: the embalming laboratory, the anatomy laboratories, the corridor of the teachers?? rooms, and the entrance hall. Thirty-six samples in total were collected in the second semester of 2010 and first semester of 2011. The air sampling and FA analysis were performed according to the EPA TO-11A Protocol, using a diffusive sampling device for carbonyl compounds. Personal samples were collected from monitors using a sampling device pinned on each person??s lapel. The samples were analyzed using rapid resolution liquid chromatography with UV-DAD detection at 360 nm.

Results and discussion

The concentrations of FA ranged from 0.20 and 0.18 mg m^?3 in the corridor between the teachers?? rooms, 0.03 to 0.37 mg m^?3 in the entrance hall, 0.22 to 2.07 mg m^?3 in the anatomy laboratory, 2.21 to 2.52 mg m^?3, in the embalming room. The levels found in the corridor between the teachers?? rooms and in the entrance hall were lower than in other compartments because of their large distances to the sources of FA and better ventilation. The other rooms presented higher levels of FA because of the activities carried there (embalming and dissection procedures). Even in the rooms that showed the lowest levels of FA, the values found were higher than those established by all international guideline limits, except the Brazilian legislation limit, although, the concentration level in the embalming room was even greater than the Brazilian guideline. These concentrations are 100?C1,000-fold higher than those reported in an FA outdoor study. The exposure levels of monitors and students ranged from 1.89 to 4.82 mg m^?3, indicating that current practices at the Morphology Department at the university would represent a health risk. The simultaneous monitoring of area concentrations and personal exposure showed that the characteristics of classes and of cadavers?? parts, the number of students in the room and even the activities of the monitors influence the FA concentrations.

Conclusion

This study revealed that the concentration of FA was low in the ventilated areas of the Morphology Department, and that the personal exposure when the person was close to the cadavers during the dissection procedure was higher than the mean FA concentration. This should be considered in the risk assessment of FA during these activities without effective protection equipment. It is suggested that the Brazilian legislation of exposure to formaldehyde requires an urgent update considering international legislation.     

Sediment contact test with <Emphasis Type="Italic">Potamopyrgus antipodarum</Emphasis> in effect-directed analyses—challenges and opportunities

Background and scope  

Effect-directed analysis is increasingly used for the identification of key toxicants in environmental samples and there is a growing need for in vivo biotests as diagnostic tools. Within this study, we performed an in vivo sediment contact test, applicable on both native field samples and their extracts or fractions, in order to be able to compare the results from both field and laboratory studies.     

Deactivation and regeneration of ZSM-5 zeolite in catalytic pyrolysis of plastic wastes

In this work, a study of the regeneration and reuse of ZSM-5 zeolite in the pyrolysis of a plastic mixture has been carried out in a semi-batch reactor at 440 °C. The results have been compared with those obtained with fresh-catalyst and in non-catalytic experiments with the same conditions. The use of fresh catalyst produces a significant change in both the pyrolysis yields and the properties of the liquids and gases obtained. Gases more rich in C3-C4 and H₂ are produced, as well as lower quantities of aromatic liquids if compared with those obtained in thermal decomposition. The authors have proved that after one pyrolysis experiment the zeolite loses quite a lot of its activity, which is reflected in both the yields and the products quality; however, this deactivation was found to be reversible since after regeneration heating at 550 °C in oxygen atmosphere, this catalyst recovered its initial activity, generating similar products and in equivalent proportions as those obtained with fresh catalyst.     

Conductive-diamond electrochemical oxidation of chlorpyrifos in wastewater and identification of its main degradation products by LC-TOFMS

The electrochemical transformation of the organophosphorous insecticide chlorpyrifos (CPF) was investigated in wastewater. The oxidation of CPF was carried out in a single-compartment electrochemical flow cell working under batch operation mode, using diamond-based material as anode and stainless steel as cathode. In order to evaluate its persistence and degradation pathway, two different concentration levels (1.0 mg L⁻¹ and 0.1 mg L⁻¹) were studied. Liquid chromatography/mass spectrometry was used for evaluation of the initial and electrolyzed solutions. The identification of CPF transformation products was performed by liquid chromatography-time of flight-mass spectrometry (LC-TOFMS). Results showed that CPF is completely removed at the end of treatment time. Analysis by LC-TOFMS allowed the identification of six degradation products (with Mw 154, 170, 197, 305 321 and 333). Three of the identified intermediates (Mw 170, 305 and 321) were completely removed at the end of electrolysis time. Interestingly, the formation of diethyl 3,5,6-trichloropyridin-2yl phosphate (chlorpyrifos oxon) and 3,5,6-trichloropyridin-2-ol was also found in previous reported degradation pathways using different degradation technologies.