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Using cell phone location to assess misclassification errors in air pollution exposure estimation Full text
2018
Yu, Haofei | Russell, Armistead | Mulholland, James | Huang, Zhijiong
Air pollution epidemiologic and health impact studies often rely on home addresses to estimate individual subject's pollution exposure. In this study, we used detailed cell phone location data, the call detail record (CDR), to account for the impact of spatiotemporal subject mobility on estimates of ambient air pollutant exposure. This approach was applied on a sample with 9886 unique simcard IDs in Shenzhen, China, on one mid-week day in October 2013. Hourly ambient concentrations of six chosen pollutants were simulated by the Community Multi-scale Air Quality model fused with observational data, and matched with detailed location data for these IDs. The results were compared with exposure estimates using home addresses to assess potential exposure misclassification errors. We found the misclassifications errors are likely to be substantial when home location alone is applied. The CDR based approach indicates that the home based approach tends to over-estimate exposures for subjects with higher exposure levels and under-estimate exposures for those with lower exposure levels. Our results show that the cell phone location based approach can be used to assess exposure misclassification error and has the potential for improving exposure estimates in air pollution epidemiology studies.
Show more [+] Less [-]First evaluation of the use of down feathers for monitoring persistent organic pollutants and organophosphate ester flame retardants: A pilot study using nestlings of the endangered cinereous vulture (Aegypius monachus) Full text
2018
Monclús, Laura | López Béjar, Manel | De la Puente, Javier | Covaci, Adrian | Jaspers, Veerle L.B.
Raptor feathers have been increasingly used to assess pollutants in ecotoxicological monitoring studies. However, the suitability of down feathers to detect pollutants has not yet been investigated. In this study, concentrations of persistent organic pollutants (POPs) and organophosphate ester flame retardants (OPEs) were assessed in down and juvenile contour feathers of Spanish cinereous vulture (Aegypius monachus) nestlings (circa 73 days old) and contaminant concentrations were compared between both types of feathers from the same individuals. Concentrations of polychlorinated biphenyls (PCBs: 1.30–6.16 ng g−1 dw feather), polybrominated diphenyl ethers (PBDEs: 0.23–1.35 ng g−1 dw feather), p,p'-dichlorodiphenyldichloroethylene (pp-DDE: 0.09–6.10 ng g−1 dw feather) and tris (1-chloro-2-propyl) phosphate (TCiPP: 0.86–48.96 ng g−1 dw feather) were significantly higher in down than in contour feathers. In contrast, contour feathers showed higher levels of the more volatile POP, lindane (0.25–3.12 ng g−1 dw feather). Concentrations of hexachlorobenzene (HCB) and OPEs (except TCiPP) were similar between the two types of feathers. By showing high accumulation of the most persistent POPs investigated, down feathers presented a contamination profile similar to that previously described in raptor eggs. As these feathers grow during the first days of a vulture chicks life, they probably reflect the contaminant burden of the chick due to maternal transfer to the egg. Overall, the present study provides the first indication that down feathers may be useful for biomonitoring studies. Further research is needed to confirm whether nestling down feathers reflect the concentrations in the egg.
Show more [+] Less [-]Retrospective study of foreign body-associated pathology in stranded cetaceans, Canary Islands (2000–2015) Full text
2018
Puig-Lozano, R. | Bernaldo de Quirós, Y. | Díaz-Delgado, J. | García-Álvarez, N. | Sierra, E. | Fuente, J. de la | Sacchini, S. | Suárez-Santana, CM. | Zucca, D. | Câmara, N. | Saavedra, P. | Almunia, J. | Rivero, M.A. | Martínez Fernández, Ángel | Arbelo, M.
Marine pollution, overrepresented by plastic, is a growing concern worldwide. However, there is little knowledge on occurrence and detrimental impacts of marine debris in cetaceans. To partially fill in this gap of knowledge, we aimed to investigate the occurrence and pathologies associated with foreign bodies (FBs) in a large cohort of cetaceans (n = 465) stranded in the Canary Islands. The Canary Islands shelter the greatest cetacean biodiversity in Europe, with up to 30 different species, of which nine are regularly present year around. We found at least one ingested FB in 36 out of 465 (7.74%) studied cetaceans, involving 15 different species, including eight out of the nine (80%) cetacean species present year-round in the Canary Islands. Risso's dolphin was the species most affected, followed by sperm whale, beaked whale and mysticetes. Plastic FB were the most common item found (80.56%). FB was directly associated with death in 13/36 (36.11%) animals. Poor body condition and deep diving behavior were found to be risk factors for FB ingestion, whereas the adult age was a protective factor. To the authors knowledge this is the first study that use statistical analysis to investigate risk and protective factors for FB ingestion. This study also provides insights of the potential impact caused by ingested FBs on the animal's health and mortality. This knowledge is critical to better understand and assess the impact of FB in cetaceans setting the scientific basis for prospective impact monitoring and future conservation policies.
Show more [+] Less [-]Effects of broadband sound exposure on the interaction between foraging crab and shrimp – A field study Full text
2018
Hubert, Jeroen | Campbell, James | van der Beek, Jordy G. | den Haan, Manon F. | Verhave, Rik | Verkade, Laura S. | Slabbekoorn, Hans
Aquatic animals live in an acoustic world in which they often rely on sound detection and recognition for various aspects of life that may affect survival and reproduction. Human exploitation of marine resources leads to increasing amounts of anthropogenic sound underwater, which may affect marine life negatively. Marine mammals and fishes are known to use sounds and to be affected by anthropogenic noise, but relatively little is known about invertebrates such as decapod crustaceans. We conducted experimental trials in the natural conditions of a quiet cove. We attracted shore crabs (Carcinus maenas) and common shrimps (Crangon crangon) with an experimentally fixed food item and compared trials in which we started playback of a broadband artificial sound to trials without exposure. During trials with sound exposure, the cumulative count of crabs that aggregated at the food item was lower, while variation in cumulative shrimp count could be explained by a negative correlation with crabs. These results suggest that crabs may be negatively affected by artificially elevated noise levels, but that shrimps may indirectly benefit by competitive release. Eating activity for the animals present was not affected by the sound treatment in either species. Our results show that moderate changes in acoustic conditions due to human activities can affect foraging interactions at the base of the marine food chain.
Show more [+] Less [-]Particulate mercury in ambient air in Shanghai, China: Size-specific distribution, gas–particle partitioning, and association with carbonaceous composition Full text
2018
Han, Deming | Zhang, Jiaqi | Hu, Zihao | Ma, Yingge | Duan, Yusen | Han, Yan | Chen, Xiaojia | Zhou, Yong | Cheng Jinping, | Wang, Wenhua
Mercury (Hg) has a complex atmospheric transformation cycle and acts as a global pollutant. Size-specific particle bound mercury (PBM) was implemented in different functional (industrial, urban and suburban) areas in Shanghai, China. The total concentration of 13-staged PBM (rang of 0.01–18.0 μm) varied of 99.0–611 pg/m3, with an average value of 318 ± 144 pg/m3. The Gaoqiao petrochemical industry (GQPI) site showed the highest concentrations, whereas the suburban Shanghai Jiao Tong University (SJTU) displayed the lowest. The PBM in nucleation, accumulation and coarse modes were 7.63–96.7, 69.5–455, and 9.43–176 pg/m3, respectively, and the fractions of 0.56–1.00 and 0.32–0.56 μm were the two most abundant. Both OC and EC displayed unimodal distribution patterns (peak of 0.56–1.00 μm) at GQPI, while bimodal distributions were observed at urban and suburban sites. Statistically positive correlations between the overall PBM and the corresponding PM and carbonaceous compounds (r = 0.38–0.54, p < 0.01), indicating their similar origins and OC/EC enhanced gaseous mercury forming PBM. The gas–particle partition model predicted gaseous oxidized mercury (GOM) were 253 ± 133, 237 ± 122, and 257 ± 144 pg/m3 for GQPI, SAES and SJTU, respectively. The particle proportions of divalent mercury in the fraction of 0.32–1.00 μm were substantial (>80%), but smaller (<50%) for nucleation and coarse modes. The fraction of 9.90–18.00 μm occupied nearly 50% of the overall dry deposition fluxes of mercury. These finding highlight the emissions from different mercury and OC/EC origins, caused different size-specific distributions of PBM, which further affect their gas-particle partitioning and dry deposition of mercury species.
Show more [+] Less [-]Modeling and evaluating spatial variation of polycyclic aromatic hydrocarbons in urban lake surface sediments in Shanghai Full text
2018
Yang, Jing | Yang, Yi | Chen, Rui-Shan | Meng, Xiang-Zhou | Xu, Jie | Qadeer, Abdul | Liu, Min
To explore the influence of rapid urbanization development on the accumulation of 16 priority PAHs in urban environment, thirty-three surface sediments from city lakes in different urbanized areas of Shanghai were collected to evaluate the occurrence characteristic and source apportionment of PAHs. The concentrations of Σ₁₆PAHs in lake surface sediments ranged from 55.7 to 4928 ng g⁻¹ with a mean value of 1131 ng g⁻¹ (standard deviation, 1228 ng g⁻¹), of which 4-, 5- and 6-ring PAHs were the dominant components. Spatial distribution of PAHs in lake surface sediments showed a significantly declining trend along with a decreasing urbanization gradient (one-way ANOVA, p < .05). Two hotspots of sediment PAHs were mainly distributed at highly urbanized areas with intensive population density and heavy traffic activities and at burgeoning industrial towns in the suburb. Source apportionment of total PAHs identified by a constrained positive matrix factorization model revealed that vehicle emission and combustion of coal, biomass and natural gas were the absolutely predominant sources, respectively accounting for 55.0% and 40.45% of total PAHs burden in lake sediments. Land use regression (LUR) models were successfully developed to evaluate spatial variation of PAHs contamination in urban sediments based on their significant correlations with residential land, commercial land, traffic variables, industrial sources, and population density. All PAH compounds showed strong associations with one or two source indicators (the traffic congestion index and the number of industrial sources), with the fitting R² varying from 0.529 to 0.984. Our findings suggest that energy consumption related to land use activities obviously promoted PAH accumulations in urban sediment environment during rapid development of urbanization and industrialization in Shanghai.
Show more [+] Less [-]The evil within? Systemic fungicide application in trees enhances litter quality for an aquatic decomposer-detritivore system Full text
2018
Newton, Kymberly | Zubrod, Jochen P. | Englert, Dominic | Lüderwald, Simon | Schell, Theresa | Baudy, Patrick | Konschak, Marco | Feckler, Alexander | Schulz, Ralf | Bundschuh, Mirco
Waterborne exposure towards fungicides is known to trigger negative effects in aquatic leaf-associated microbial decomposers and leaf-shredding macroinvertebrates. We expected similar effects when these organisms use leaf material from terrestrial plants that were treated with systemic fungicides as a food source since the fungicides may remain within the leaves when entering aquatic systems. To test this hypothesis, we treated black alder (Alnus glutinosa) trees with a tap water control or a systemic fungicide mixture (azoxystrobin, cyprodinil, quinoxyfen, and tebuconazole) at two worst-case application rates. Leaves of these trees were used in an experiment targeting alterations in two functions provided by leaf-associated microorganisms, namely the decomposition and conditioning of leaf material. The latter was addressed via the food-choice response of the amphipod shredder Gammarus fossarum. During a second experiment, the potential impact of long-term consumption of leaves from trees treated with systemic fungicides on G. fossarum was assessed. Systemic fungicide treatment altered the resource quality of the leaf material resulting in trends of increased fungal spore production and an altered community composition of leaf-associated fungi. These changes in turn caused a significant preference of Gammarus for microbially conditioned leaves that had received the highest fungicide treatment over control leaves. This higher food quality ultimately resulted in a higher gammarid growth (up to 300% increase) during the long-term feeding assay. Although the underlying mechanisms still need to be addressed, the present study demonstrates a positive indirect response in aquatic organisms due to systemic pesticide application in a terrestrial system. As the effects from the introduction of plant material treated with systemic fungicides strongly differ from those mediated via other pathways (e.g., waterborne exposure), our study provides a novel perspective of fungicide-triggered effects in aquatic detritus-based food webs.
Show more [+] Less [-]Uranium (VI) transport in saturated heterogeneous media: Influence of kaolinite and humic acid Full text
2018
Chen, Chong | Zhao, Kang | Shang, Jianying | Liu, Chongxuan | Wang, Jin | Yan, Zhifeng | Liu, Kesi | Wu, Wenliang
Natural aquifers typically exhibit a variety of structural heterogeneities. However, the effect of mineral colloids and natural organic matter on the transport behavior of uranium (U) in saturated heterogeneous media are not totally understood. In this study, heterogeneous column experiments were conducted, and the constructed columns contained a fast-flow domain (FFD) and a slow-flow domain (SFD). The effect of kaolinite, humic acid (HA), and kaolinite/HA mixture on U(VI) retention and release in saturated heterogeneous media was examined. Media heterogeneity significantly influenced U fate and transport behavior in saturated subsurface environment. The presence of kaolinite, HA, and kaolinite/HA enhanced the mobility of U in heterogeneous media, and the mobility of U was the highest in the presence of kaolinite/HA and the lowest in the presence of kaolinite. In the presence of kaolinite, there was no difference in the amount of U released from the FFD and SFD. However, in the presence of HA and kaolinite/HA, a higher amount of U was released from the FFD. The findings in this study showed that medium structure and mineral colloids, as well as natural organic matter in the aqueous phase had significant effects on U transport and fate in subsurface environment.
Show more [+] Less [-]Deep sequence analysis reveals the ovine rumen as a reservoir of antibiotic resistance genes Full text
2018
Hitch, Thomas C.A. | Thomas, Ben J. | Friedersdorff, Jessica C.A. | Ougham, Helen | Creevey, Christopher J.
Antibiotic resistance is an increasingly important environmental pollutant with direct consequences for human health. Identification of environmental sources of antibiotic resistance genes (ARGs) makes it possible to follow their evolution and prevent their entry into the clinical setting. ARGs have been found in environmental sources exogenous to the original source and previous studies have shown that these genes are capable of being transferred from livestock to humans. Due to the nature of farming and the slaughter of ruminants for food, humans interact with these animals in close proximity, and for this reason it is important to consider the risks to human health. In this study, we characterised the ARG populations in the ovine rumen, termed the resistome. This was done using the Comprehensive Antibiotic Resistance Database (CARD) to identify the presence of genes conferring resistance to antibiotics within the rumen. Genes were successfully mapped to those that confer resistance to a total of 30 different antibiotics. Daptomycin was identified as the most common antibiotic for which resistance is present, suggesting that ruminants may be a source of daptomycin ARGs. Colistin resistance, conferred by the gene pmrE, was also found to be present within all samples, with an average abundance of 800 counts. Due to the high abundance of some ARGs (against daptomycin) and the presence of rare ARGs (against colistin), we suggest further study and monitoring of the rumen resistome as a possible source of clinically relevant ARGs.
Show more [+] Less [-]Residential road traffic noise as a risk factor for hypertension in adults: Systematic review and meta-analysis of analytic studies published in the period 2011–2017 Full text
2018
Dzhambov, Angel M. | Dimitrova, Donka D.
Multiple cross-sectional studies indicated an association between hypertension and road traffic noise and they were recently synthetized in a WHO systematic evidence review. However, recent years have seen a growing body of high-quality, large-scale research, which is missing from the WHO review. Therefore, we aimed to close that gap by conducting an updated systematic review and meta-analysis on the exposure-response relationship between residential road traffic noise and the risk of hypertension in adults. Studies were identified by searching MEDLINE, EMBASE, the Internet, conference proceedings, reference lists, and expert archives in English, Russian, and Spanish through August 5, 2017. The risk of bias for each extracted estimate and the overall quality of evidence were evaluated using a list of predefined safeguards against bias related to different study characteristics and the Grading of Recommendations Assessment, Development and Evaluation system, respectively. The inverse variance heterogeneity (IVhet) model was used for meta-analysis. The possibility of publication bias was evaluated by funnel and Doi plots, and asymmetry in these was tested with Egger's test and the Luis Furuya-Kanamori index, respectively. Sensitivity analyses included leave-one-out meta-analysis, subgroup meta-analysis with meta-regressions, and non-linear exposure-response meta-analysis. Based on seven cohort and two case-control studies (n = 5 514 555; 14 estimates; Lden range ≈ 25–90 dB(A)), we found “low” evidence of RR per 10 dB(A) = 1.018 (95% CI: 0.984, 1.053), moderate heterogeneity (I2 = 46%), and no publication bias. In the subgroup of cohort studies, we found “moderate” evidence of RR per 10 dB(A) = 1.018 (95% CI: 0.987, 1.049), I2 = 31%, and no publication bias. In conclusion, residential road traffic noise was associated with higher risk of hypertension in adults, but the risk was lower than previously reported in the systematic review literature.
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