Wetlands are hotspots for production of toxic methylmercury (MeHg) that can bioaccumulate in the food web. The objective of this study was to determine whether the application of zero-valent iron (ZVI) or granular activated carbon (GAC) to wetland sediment could reduce MeHg production and bioavailability to benthic organisms. Field mesocosms were installed in a wetland fringing Hodgdon Pond (Maine, USA), and ZVI and GAC were applied. Pore-water MeHg concentrations were lower in treated compared with untreated mesocosms; however, sediment MeHg, as well as total Hg (THg), concentrations were not significantly different between treated and untreated mesocosms, suggesting that smaller pore-water MeHg concentrations in treated sediment were likely due to adsorption to ZVI and GAC, rather than inhibition of MeHg production. In laboratory experiments with intact vegetated sediment clumps, amendments did not significantly change sediment THg and MeHg concentrations; however, the mean pore-water MeHg and MeHg:THg ratios were lower in the amended sediment than the control. In the laboratory microcosms, snails (Lymnaea stagnalis) accumulated less MeHg in sediment treated with ZVI or GAC. The study results suggest that both GAC and ZVI have potential for reducing MeHg bioaccumulation in wetland sediment.

Although phosphorus (P) is an essential element needed for all lives, excess P can be harmful to the environment. The objective of this study aims to determine P flows in the fisheries sector of Thailand consisting of both sea and freshwater activities of captures and cultures. Currently, the annual fisheries catch averages 3.44 ± 0.50 Mt. Most comes from marine capture 1.95 ± 0.46 Mt, followed by coastal aquaculture 0.78 ± 0.09 Mt, freshwater aquaculture 0.49 ± 0.05 Mt, and inland capture 0.22 ± 0.01 Mt. Of this total, about 11% is contained in fresh products directly sold in local markets for consumption, while 89% is sent to processing factories prior to being sold in local markets and exported. The quantities of P entering the fisheries sector come from captures, import of fisheries products and feed produced from agriculture. This P input to the fisheries sector is found to average 28,506 t P.y−1 based on the past ten-year records. Of this total, P input from captures accounts for 76%; while, 11% represents aquatic feeds from agriculture and animal manures. About 13% is obtained from the imports of fishery products. Coastal and freshwater aquacultures are found to be P consumers because their feeds are almost all produced from agricultural crops grown inland. Moreover, these activities cause most of P losses, approximately 10,188 t P·y−1, which account for 89% of the total P loss from the fisheries sector. Overall, P in the fisheries sector is found to mobilize through three channels: (a) 44% is consumed within the country; (b) about 16% is exported; and, (c) 40% is lost from the ecosystem. Based on the results of this work it is recommended that future research be directed on ways to minimize P loss and maximize P recycle in Thailand's fisheries sector as to enhance its food security and curtail water pollution.

The interaction of pollutants with Cultural Heritage materials leads to artworks and materials degradation and loss, causing an unpriceless damage. This works aims to estimate the impacts of air pollution and meteorological conditions on limestone, copper and bronze and represents the European risk assessment for corrosion of Cultural Heritage materials. The measures and policies for atmospheric pollution reduction have cut off the SO2 concentration and consequently its impact on materials is drastically reduced. Indeed, in 1980 the number of UNESCO sites in danger was extremely high (94% for limestone, 54% for copper and 1% for bronze) while in 2010 these sites did not exceed the tolerable value of surface recession and corrosion. However, some problem related to air pollution persists. In particular, Random Forest Analysis (RFA), highlights PM10 as the main responsible for materials corrosion, in 2010. Two scenarios in 2030 have been tested, highlighting that the corrosion levels of limestone, copper and bronze exceed the tolerable limits only in the Balkan area and Turkey. Our results show the importance in the air quality modelling as a powerful tool for the UNESCO sites conservation.

Antibiotics entering the soil likely disturb the complex regulatory network of the soil microbiome, which is closely associated with soil quality and ecological function. This study investigated the effects of tetracycline (TC), sulfamonomethoxine (SMM), ciprofloxacin (CIP) and their combination (AM) on the bacterial community in a soil-microbe-plant system and identified the main bacterial responders. Antibiotic effects on the soil microbiome depended on antibiotic type and exposure time. TC resulted in an acute but more rapidly declining effect on soil microbiome while CIP and SMM led to a delayed antibiotic effect. The soil exposed to AM presented a highly similar bacterial structure to that exposed to TC rather than to SMM and CIP. TC, SMM and CIP had their own predominantly impacted taxonomic groups that include both resistance and sensitive bacteria. The antibiotic sensitive responders predominantly distributed within the phylum Proteobacteria. The potential bacteria resistant to each antibiotic exhibited phyla preference to some extent, particularly those resistant to TC. CIP and SMM resistance in soil was increased with exposure time while TC resistance gave the opposite result. Overall, the work extended the understanding of antibiotic effects on soil microbiome after introduced into the soil during greenhouse vegetable cultivation.

With the increasing usage of titanium dioxide nanoparticles (NPs), their release into the environment makes it important to understand their transport, fate and behaviour in natural waters. In this study, aggregation and deposition of TiO2 NPs were studied during a 3-h period by using a dynamic light scattering instrument and a UV–vis spectrophotometer, respectively. TiO2 NPs were spiked in 34 lake and 5 brackish water samples at an initial concentration of 10 mg L−1. Depending on the physicochemical properties of the natural waters, TiO2 NPs exhibited different colloidal stability. In brackish waters with high salinity, TiO2 NPs were prone to aggregate and settled rapidly. Whereas under conditions of humic and humus-poor lake waters, TiO2 NPs were suspended in water column for a longer time without remarkable change in particle size and concentration. Deposition likely occurred in nutrient-rich lakes which had high amount of nitrogen and phosphorus accompanied by high values of conductivity, alkalinity, pH and turbidity. Linear regression analysis revealed the statistically significant relationships (p ≤ 0.008) between the TiO2 NPs stability and these water properties. Our study makes a better understanding of the water properties that control the aggregation and deposition of TiO2 NPs in complex natural waters.

The objective of this study was to determine the prevalence of Staphylococcus in urban wastewater treatment plants (UWTP) of La Rioja (Spain), and to characterize de obtained isolates. 16 wastewater samples (8 influent, 8 effluent) of six UWTPs were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base for staphylococci and methicillin-resistant Staphylococcus aureus recovery. Antimicrobial susceptibility profile was determined for 16 antibiotics and the presence of 35 antimicrobial resistance genes and 14 virulence genes by PCR. S. aureus was typed by spa, agr, and multilocus-sequence-typing, and the presence of immune-evasion-genes cluster was analyzed. Staphylococcus spp. were detected in 13 of 16 tested wastewater samples (81%), although the number of CFU/mL decreased after treatment. 40 staphylococci were recovered (1–5/sample), and 8 of them were identified as S. aureus being typed as (number of strains): spa-t011/agr-II/ST398 (1), spa-t002/agr-II/ST5 (2), spa-t3262/agr-II/ST5 (1), spa-t605/agr-II/ST126 (3), and spa-t878/agr-III/ST2849 (1). S. aureus ST398 strain was methicillin-resistant and showed a multidrug resistance phenotype. Virulence genes tst, etd, sea, sec, seg, sei, sem, sen, seo, and seu, were detected among S. aureus and only ST5 strains showed genes of immune evasion cluster. Thirty-two coagulase-negative Staphylococcus of 12 different species were recovered (number of strains): Staphylococcus equorum (7), Staphylococcus vitulinus (4), Staphylococcus lentus (4), Staphylococcus sciuri (4), Staphylococcus fleurettii (2), Staphylococcus haemolyticus (2), Staphylococcus hominis (2), Staphylococcus saprophyticus (2), Staphylococcus succinus (2), Staphylococcus capitis (1), Staphylococcus cohnii (1), and Staphylococcus epidermidis (1). Five presented a multidrug resistance phenotype. The following resistance and virulence genes were found: mecA, lnu(A), vga(A), tet(K), erm(C), msr(A)/(B), mph(C), tst, and sem. We found that Staphylococcus spp. are normal contaminants of urban wastewater, including different lineages of S. aureus and a high diversity of coagulase-negative species. The presence of multiple resistance and virulence genes, including mecA, in staphylococci of wastewater can be a concern for the public health.

In the present study, trace elements and persistent organic pollutants (POPs) were quantified from Magnificent frigatebirds (Fregata magnificens) breeding at a southern Atlantic island. Stable isotope ratio of carbon (δ13C) and nitrogen (δ15N) were also measured to infer the role of foraging habitat on the contamination. For another group from the same colony, GPS tracks were recorded to identify potential foraging areas where the birds may get contaminated. Fourteen trace elements were targeted as well as a total of 40 individual POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The concentration of Hg in the blood was up to 6 times higher in adults (5.81 ± 1.27 μg g−1 dw.) than in nestlings (0.99 ± 0.23 μg g−1 dw.). A similar pattern was found for POPs. ∑PCBs was the prevalent group both in adults (median 673, range 336–2801 pg g−1 ww.) and nestlings (median 41, range 19–232 pg g−1 ww.), followed by the sum of dichlorodiphenyltrichloroethanes and metabolites (∑DDTs), showing a median value of 220 (range 75–2342 pg g−1 ww.) in adults and 25 (range 13–206 pg g−1 ww.) in nestlings. The isotope data suggested that the accumulation of trace elements and POPs between adults and nestlings could be due to parental foraging in two different areas during incubation and chick rearing, respectively, or due to a shift in the feeding strategies along the breeding season. In conclusion, our work showed high Hg concentration in frigatebirds compared to non-contaminated seabird populations, while other trace elements showed lower values within the expected range in other seabird species. Finally, POP exposure was found generally lower than that previously measured in other seabird species.

We sampled landlocked Arctic char (Salvelinus alpinus) from four lakes (Small, 9-Mile, North, Amituk) in the Canadian High Arctic that span a gradient of mercury contamination. Metals (Hg, Se, Tl, and Fe) were measured in char tissues to determine their relationships with health indices (relative condition factor and hepatosomatic index), stable nitrogen isotope ratios, and liver histology. A subcellular partitioning procedure was employed to determine how metals were distributed between potentially sensitive and detoxified compartments of Arctic char livers from a low- and high-mercury lake (Small Lake and Amituk Lake, respectively). Differences in health indices and metal concentrations among char populations were likely related to differences in feeding ecology. Concentrations of Hg, Se, and Tl were highest in the livers of Amituk char, whereas concentrations of Fe were highest in Small and 9-Mile char. At the subcellular level we found that although Amituk char had higher concentrations of Tl in whole liver than Small Lake char, they maintained a greater proportion of this metal in detoxified fractions, suggesting an attempt at detoxification. Mercury was found mainly in potentially sensitive fractions of both Small and Amituk Lake char, indicating that Arctic char are not effectively detoxifying this metal. Histological changes in char livers, mainly in the form of melano-macrophage aggregates and hepatic fibrosis, could be linked to the concentrations and subcellular distributions of essential or non-essential metals.

Tributyltin (TBT) and other organotin compounds have been restricted for use on leisure boats since 1989 in the EU. Nonetheless, release of TBT is observed from leisure boats during hull maintenance work, such as pressure hosing. In this work, we used a handheld X-ray Fluorescence analyser (XRF) calibrated for antifouling paint matrixes to measure tin, copper and zinc in antifouling paints coated on leisure boats in Sweden. Our results show that over 10% of the leisure boats (n = 686) contain >400 μg/cm2 of tin in their antifouling coatings. For comparison, one layer (40 μm dry film) of a TBT-paint equals ≈ 800 μg Sn/cm2. To our knowledge, tin has never been used in other forms than organotin (OT) in antifouling paints. Thus, even though the XRF analysis does not provide any information on the speciation of tin, the high concentrations indicate that these leisure boats still have OT coatings present on their hull. On several leisure boats we performed additional XRF measurements by progressively scraping off the top coatings and analysing each underlying layer. The XRF data show that when tin is detected, it is most likely present in coatings close to the hull with several layers of other coatings on top. Thus, leaching of OT compounds from the hull into the water is presumed to be negligible. The risk for environmental impacts arises during maintenance work such as scraping, blasting and high pressure hosing activities. The data also show that many boat owners apply excessive paint layers when following paint manufacturers recommendations. Moreover, high loads of copper were detected even on boats sailing in freshwater, despite the more than 20 year old ban, which poses an environmental risk that has not been addressed until now.

To study the effects of long-term mining activities on the agricultural soil quality of Mengnuo town in Yunnan province, China, the heavy metal and soil enzyme activities of soil samples from 47 sites were examined. The results showed that long-term mining processes led to point source heavy metal pollution and Pb, Cd, Zn and As were the primary metal pollutants. Polyphenoloxidase was found the most sensitive soil enzyme activity and significantly correlated with almost all the metals (P < 0.05). Amylase (for C cycling), acid phosphatase (for P cycling) and catalase (for redox reaction) activities showed significantly positive correlations (P < 0.05) with Pb, Cd, Zn and As contents. The correlations between soil enzymes activities and Cd, Pb and Zn contents were verified in microcosm experiments, it was found that catalase activity had significant correlations (P < 0.05) with these three metals in short-term experiments using different soils under different conditions. Based on both field investigation and microcosm simulation analysis, oxidoreductases activities (rather than a specific enzyme activity) were suggested to be used as “core enzyme”, which could simply and universally indicate the heavy metal pollution degrees of different environments. And hydrolases (for C, N, P and S recycling) could be used as a supplement to improve correlation accuracy for heavy metal indication in various polluted environments.