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Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): Confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions 全文
2015
de Sá, Luís Carlos | Luís, Luís G. | Guilhermino, Lúcia
Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the prey selection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey. All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (up to 50%), while M-est fish did not, suggesting that developmental conditions may influence the prey selection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.
显示更多 [+] 显示较少 [-]Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication 全文
2015
Dunck, Bárbara | Lima-Fernandes, Eva | Cássio, Fernanda | Cunha, Ana | Rodrigues, Liliana | Pascoal, Cláudia
We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient.
显示更多 [+] 显示较少 [-]Natural soil mineral nanoparticles are novel sorbents for pentachlorophenol and phenanthrene removal 全文
2015
He, Yan | Zeng, Fanfeng | Lian, Zhenghua | Xu, Jianming | Brookes, Philip C.
Natural soil montmorillonite and kaolinite nanoparticles (NPs) were tested as efficient sorbents for organic contaminant (OC) removal through mimicking their natural environmental dispersive states. Sorption of both mineral NPs decreased with increasing pH with ionizable pentachlorophenol (PCP), but increased with pH with non-ionizable phenanthrene (PHE), within the pH range of 4–10. In contrast, sorption decreased consistently for both PCP and PHE, as a function of increasing ion concentration (0.001–0.1 mol L−1). Sorption differences were likely caused by the electrolytic conditions dependent upon surface chemistry of OCs and mineral NPs. The results confirmed that the highly dispersive soil mineral NPs would prevail over both engineered NPs and their regular μm-sized colloids for OC removal, due to their ecological advantages and higher sorption properties. This finding provided a realistic assessment of the environmental function of soil natural minerals in water once they are released from soil into OC polluted aqueous systems.
显示更多 [+] 显示较少 [-]Carcinogenic risk of chromium, copper and arsenic in CCA-treated wood 全文
2015
Ohgami, Nobutaka | Yamanoshita, Osamu | Thang, Nguyen Dinh | Yajima, Ichiro | Nakano, Chihiro | Wenting, Wu | Ohnuma, Shoko | Kato, Masashi
We showed that 2.1% of 233 pieces of lumber debris after the Great East Japan Earthquake was chromated copper arsenate (CCA)-treated wood. Since hexavalent chromium (Cr), copper (Cu) and pentavalent arsenic (As) in the debris may be diffused in the air via incineration, we exposed human lung normal (BEAS-2B) and carcinoma (A549) cells to Cr, Cu and As at the molar ratio in a representative CCA-treated wood. Co-exposure to 0.10 μM Cr and 0.06 μM As, which solely had no effect on colony formation, synergistically promoted colony formation in BEAS-2B cells, but not A549 cells, with activation of the PI3K/AKT pathway. Sole exposure and co-exposure to Cu showed limited effects. Since previous reports showed Cr and As concentrations to which human lungs might be exposed, our results suggest the importance to avoid diffusion of Cr and As in the air via incineration of debris including CCA-treated wood after the disaster.
显示更多 [+] 显示较少 [-]High concentrations of polycyclic aromatic hydrocarbons (naphthalene, phenanthrene and pyrene) failed to explain biochar's capacity to reduce soil nitrous oxide emissions 全文
2015
Alburquerque, J.A. | Sánchez-Monedero, M.A. | Roig, A. | Cayuela, M.L.
The presence of polycyclic aromatic hydrocarbons (PAHs) has been postulated as a mechanism by which biochar might mitigate N2O emissions. We studied whether and to what extent N2O emissions were influenced by the three most abundant PAHs in biochar: naphthalene, phenanthrene and pyrene. We hypothesised that biochars contaminated with PAHs would show a larger N2O mitigation capacity and that increasing PAH concentrations in biochar would lead to higher mitigation potentials. Our results demonstrate that the high-temperature biochar (550 °C) had a higher capacity to mitigate soil N2O emissions than the low-temperature biochar (350 °C). At low PAH concentrations, PAHs do not significantly contribute to the reductions in soil N2O emissions; while biochar stimulated soil N2O emissions when it was spiked with high concentrations of PAHs. This study suggests that the impact of biochar on soil N2O emissions is due to other compositional and/or structural properties of biochar rather than to PAH concentration.
显示更多 [+] 显示较少 [-]Impact of manufactured TiO2 nanoparticles on planktonic and sessile bacterial communities 全文
2015
Jomini, Stéphane | Clivot, Hugues | Bauda, Pascale | Pagnout, Christophe
In the present study, we conducted a 2 week microcosm experiment with a natural freshwater bacterial community to assess the effects of titanium dioxide nanoparticles (TiO2-NPs) at various concentrations (0, 1, 10 and 100 mg/L) on planktonic and sessile bacteria under dark conditions. Results showed an increase of planktonic bacterial abundance at the highest TiO2-NP concentration, concomitant with a decrease from that of sessile bacteria. Bacterial assemblages were most affected by the 100 mg/L TiO2-NP exposure and overall diversity was found to be lower for planktonic bacteria and higher for sessile bacteria at this concentration. In both compartments, a 100 mg/L TiO2-NPs exposure induced a decrease in the ratio between the Betaproteobacteria and Bacteroidetes. For planktonic communities, a decrease of Comamonadaceae was observed concomitant with an increase of Oxalobacteraceae and Cytophagaceae (especially Emticicia). For sessile communities, results showed a strong decrease of Betaproteobacteria and particularly of Comamonadaceae.
显示更多 [+] 显示较少 [-]Health impact of bioaccessible metal in lip cosmetics to female college students and career women, northeast of China 全文
2015
Gao, Peng | Liu, Sa | Zhang, Zhaohan | Meng, Ping | Lin, Nan | Lu, Binyu | Cui, Fuyi | Feng, Yujie | Xing, Baoshan
Actual measure-based studies have estimated ingestion rate of moderate and high daily use to female college students and career women in northeast of China. Sequential extraction analyses showed that total bioaccessible metals concentration in lipstick ranged from 2.103 to 31.103 μg/g and in lip balm ranged from 0.100 to 3.716 μg/g. The relationship between total bioaccessible metal concentrations and the cost of lip cosmetics showed a negative correlation. Lead was detected in all 30 products (100%), with an average concentration of 0.346 for lip balm and 0.407 μg/g for lipstick. With the exception of chromium content in three lipsticks, the estimated exposure in female college students and career women to target metals via lipstick and lip balm ingestion (calculated for moderate and high use) were much lower than the acceptable reference limits. The findings strongly emphasize the need to focus on the health risk of lip balm.
显示更多 [+] 显示较少 [-]Temporal trends of mercury, organochlorines and PCBs in northern gannet (Morus bassanus) eggs from Bonaventure Island, Gulf of St. Lawrence, 1969–2009 全文
2015
Champoux, Louise | Rail, Jean-François | Lavoie, Raphael A. | Hobson, Keith A.
Since 1969, northern gannet (Morus bassanus) eggs from Bonaventure Island, Québec, have been collected to monitor concentrations of contaminants. Levels of p,p′-DDE, which caused low breeding success of Bonaventure gannets in the 1960s, decreased by 99.4% from 1969 to 2009 (17.1–0.1 mg/kg ww), with concomitant improvement of hatching success. PCBs, most organochlorines and mercury also showed decreasing trends. Stable isotopes of carbon (δ13C) and nitrogen (δ15N) were measured to track the possible influence of diet changes on concentrations of contaminants over time. The confounding effect of the combustion of fossil fuels on baseline values of δ13C (the Suess effect) was taken into account. No temporal trends were observed in δ13C and δ15N values in gannet eggs. Hence trophic level or foraging area had a negligible influence on temporal trends of contaminants.
显示更多 [+] 显示较少 [-]Multi-generational effects of propranolol on Daphnia magna at different environmental concentrations 全文
2015
Jeong, Tae-Yong | Kim, Hyun Young | Kim, Sang-don
To evaluate the effects of propranolol on Daphnia magna (D. magna), we employed a multi-generational exposure period for eight generations and an environmentally relevant low concentration with 1.5 ng/L, 0.2 μg/L and 26 μg/L to reflect a realistic exposure scenario. Physiological endpoints were checked, including growth, number of neonates, heart rate, frequency of abdominal appendage movement and malformation rate of neonates. In the results, growth and abdominal appendage movement were affected by environmental concentration during several generations, and the responses showed consistent tendencies of response increase with concentration increase. Heart rate was the only endpoint affected throughout all exposure generations. Inhibitory and acceleratory effects on heart rate, growth and abdominal appendage movement suggest that it is necessary to cover sub-lethal endpoints of non-targeted organisms in eco-toxicity study because the physiological responses were detected at much lower concentrations than the results of traditional toxicity tests, including environmental concentration.
显示更多 [+] 显示较少 [-]Concentrations and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs (NPAHs) in the atmosphere of North China, and the transformation from PAHs to NPAHs 全文
2015
Lin, Yan | Qiu, Xinghua | Ma, Yiqiu | Ma, Jin | Zheng, Mei | Shao, Min
The occurrence of polycyclic aromatic hydrocarbons (PAHs) and nitrated derivatives (NPAHs), as well as their transformation may have significant health impacts on humans. To investigate the level, spatial distribution and the transformation process of PAHs and NPAHs in North China, we performed a gridded field passive air sampling campaign in summer of 2011. The median concentration of 25 PAH congeners and 13 NPAHs was 294 ng m−3 (or 26.7 μg sample−1) and 203 ng sample−1, respectively. Relative higher level of PAHs in Shanxi Province and NPAHs in megacities was observed. In North China, coal/biomass combustion and photochemical formation was the predominant source of PAHs and NPAHs, respectively. To investigate the relationship between these pollutants, a model incorporating NPAHs, PAHs and NO2 was established, and the result indicated that NO2 will promote the transformation processes from PAHs to NPAHs, which may increase the total toxicity of PAH–NPAH mixtures.
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