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Enhanced organic contaminants accumulation in crops: Mechanisms, interactions with engineered nanomaterials in soil Texto completo
2018
Wu, Xiang | Wang, Wei | Zhu, Lizhong
The mechanism of enhanced accumulation of organic contaminants in crops with engineered nanomaterials (ENMs) were investigated by co-exposure of crops (Ipomoea aquatica Forsk (Swamp morning-glory), Cucumis sativus L. (cucumber), Zea mays L. (corn), Spinacia oleracea L. (spinach) and Cucurbita moschata (pumpkin))to a range of chemicals (polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polybrominated diphenyl ether (PBDE)) and ENMs (TiO2, Ag, Al2O3, graphene, carbon nanotubes (CNTs)) in soil. Induced by 50 mg kg−1 graphene co-exposure, the increase range of BDE-209, BaP, p,p′-DDE, HCB, PYR, FLU, ANT, and PHEN in the plants were increased in the range of 7.51–36.42, 5.69–32.77, 7.09–59.43, 11.61–66.73, 4.58–57.71, 5.79–109.07, 12.85–109.76, and15.57–127.75 ng g−1, respectively. The contaminants in ENMs-spiked and control soils were separated into bioavailable, bound and residual fractions using a sequential ultrasonic extraction procedure (SUEP) to investigate the mechanism of the enhanced accumulation. The bioavailable fraction in spiked soils showed no significant difference (p > 0.05) from that in the control, while the bound fraction increased in equal proportion (p > 0.05) to the reduction in the residual fraction. These results implied that ENMs can competitively adsorbed the bound of organic contaminants from soil and co-transferred into crops, followed by a portion of the residual fraction transferred to the bound fraction to maintain the balance of different fractions in soils. The mass balance was all higher than 98.5%, indicating the portion of degraded contaminants was less than 1.5%. These findings could expand our knowledge about the organic contaminants accumulation enhancement in crops with ENMs.
Mostrar más [+] Menos [-]Temporal trends in dioxin-like polychlorinated biphenyl concentrations in serum from the general population of Shandong Province, China: A longitudinal study from 2011 to 2017 Texto completo
2018
Lin, Mu | Ma, Yulong | Yuan, Haodong | Luo, Xinghua | Wang, Qinghua | Liu, Anming | Wang, Ying | Jin, Jun
Temporal changes in the concentrations of dioxin-like (DL) polychlorinated biphenyls (PCBs) in environmental and biological matrices in China are not well understood. We determined the DL-PCB concentrations in pooled serum samples from the general population of Weifang City, Shandong Province, China in 2011 (n = 305) and 2017 (n = 495). The total DL-PCB concentration was 3.48 ± 1.31 ng/g lipid (mean ± standard deviation) in 2011 and 2.82 ± 1.73 ng/g lipid (19% lower) in 2017, but the difference was not statistically significant (p = 0.347). The DL-PCB concentrations and toxic equivalent concentrations were much lower in the serum from Weifang residents than have been found in serum from the inhabitants of other parts of the world. The concentrations of most of the DL-PCB congeners followed different downward temporal trends, but the PCB-118 concentration was higher in 2017 than in 2011. The temporal changes in the PCB concentrations and compositions in the samples from the general population of Weifang indicated that there may a new source of unintentionally produced PCBs in Weifang.
Mostrar más [+] Menos [-]Long-term exposure to ambient particulate matter (PM2.5) is associated with platelet counts in adults Texto completo
2018
Zhang, Zilong | Chan, Ta-Chien | Guo, Cui | Chang, Ly-yun | Lin, Changqing | Chuang, Yuan Chieh | Jiang, Wun Kai | Ho, Kin Fai | Tam, Tony | Woo, Kam S. | Lau, Alexis K.H. | Lao, Xiang Qian
The prothrombotic effects of particulate matter (PM) may underlie the association of air pollution with increased risks of cardiovascular disease. This study aimed to investigate the association between long-term exposure to PM with an aerodynamic diameter ≤2.5 μm (PM2.5) and platelet counts, a marker of coagulation profiles.The study participants were from a cohort consisting of 362,396 Taiwanese adults who participated in a standard medical examination program between 2001 and 2014. Platelet counts were measured through Complete Blood Count tests. A satellite-based spatio-temporal model was used to estimate 2-year average ambient PM2.5 concentration at each participant's address. Mixed-effects linear regression models were used to investigate the association between PM2.5 exposure and platelet counts.This analysis included 175,959 men with 396,248 observations and 186,437 women with 397,877 observations. Every 10-μg/m3 increment in the 2-year average PM2.5 was associated with increases of 0.42% (95% CI: 0.38%, 0.47%) and 0.49% (95% CI: 0.44%, 0.54%) in platelet counts in men and women, respectively. A series of sensitivity analyses, including an analysis in participants free of cardiometabolic disorders, confirmed the robustness of the observed associations. Baseline data analyses showed that every 10-μg/m3 increment in PM2.5 was associated with higher risk of 17% and 14% of having elevated platelet counts (≥90th percentile) in men and women, respectively.Long-term exposure to PM2.5 appears to be associated with increased platelet counts, indicating potential adverse effects on blood coagulability.
Mostrar más [+] Menos [-]Fractionation and mobility of thallium in areas impacted by mining-metallurgical activities: Identification of a water-soluble Tl(I) fraction Texto completo
2018
Cruz-Hernández, Yusniel | Ruiz-García, Mismel | Villalobos, Mario | Romero, Francisco Martin | Meza-Figueroa, Diana | Garrido, Fernando | Hernández-Alvarez, Elizabeth | Pi-Puig, Teresa
Mining and metallurgy generate residues that may contain thallium (Tl), a highly toxic metal, for which it is currently not feasible to determine its geochemical speciation through X-ray absorption spectroscopy due to a combination of very low contents and the interference of accompanying high arsenic contents. Therefore, fractionation studies in residues and soils are required to analyze the mobility and bioavailability of this metal, which in turn provide information to infer its speciation. For this purpose, in this work a modification of the BCR procedure was applied to residues and contaminated soils from three mining zones of Mexico and two mining zones of Spain, spanning samples with acidic to alkaline pH values.The Tl extraction procedure consisted of the following fractions: (1) water-extractable, (2) easily exchangeable and associated to carbonates, associated to (3) poorly-crystalline and (4) crystalline Fe and Mn oxyhydroxides, and (5) associated to organic matter and sulfides; and finally a residual fraction as associated to refractory primary and other secondary minerals. The extracted contents were analyzed by Inductively-Coupled Plasma with Mass Spectrometry.Surprisingly, water-soluble, in Tl(I) oxidation state, was detected in most areas, regardless of the pH, a fact that has not been reported before in these environments, and alerts to potential health risks not previously identified. Most of the samples from a metallurgy area showed high levels of Tl in non-residual fractions and a strong correlation was obtained between extracted Mn and Tl in the third fraction, suggesting its association to poorly crystalline manganese oxides. In the majority of samples from purely mining environments, most of the Tl was found in the residual fraction, most probably bound to alumino-silicate minerals. The remaining Tl fractions were extracted mainly associated to the reducible mineral fractions, and in one case also in the oxidizable fraction (presumably associated to sulfides).Capsule: Soluble Tl(I) was found in all soil samples contaminated with either mining or metallurgical wastes. Additionally, in those affected by metallurgical wastes a very strong Tl-Mn correlation was found.
Mostrar más [+] Menos [-]Composted biosolids and treated wastewater as sources of pharmaceuticals and personal care products for plant uptake: A case study with carbamazepine Texto completo
2018
Ben Mordechay, Evyatar | Tarchitzky, Jorge | Chen, Y. (Yona) | Shenker, Moshe | Chefetz, Benny
Irrigation with treated wastewater (TWW) and application of biosolids to arable land expose the agro-environment to pharmaceuticals and personal care products (PPCPs) which can be taken up by crops. In this project, we studied the effect of a carrier medium (e.g., biosolids and TWW) on plant (tomato, wheat and lettuce) uptake, translocation and metabolism of carbamazepine as a model for non-ionic PPCPs. Plant uptake and bioconcentration factors were significantly lower in soils amended with biosolids compared to soils irrigated with TWW. In soils amended with biosolids and irrigated with TWW, the bioavailability of carbamazepine for plant uptake was moderately decreased as compared to plants grown in soils irrigated with TWW alone. While TWW acts as a continuous source of PPCPs, biosolids act both as a source and a sink for these compounds. Moreover, it appears that decomposition of the biosolids in the soil after amendment enhances their adsorptive properties, which in turn reduces the bioavailability of PPCPs in the soil environment. In-plant metabolism of carbamazepine was found to be independent of environmental factors, such as soil type, carrier medium, and absolute amount implemented to the soil, but was controlled by the total amount taken up by the plant.
Mostrar más [+] Menos [-]Using cell phone location to assess misclassification errors in air pollution exposure estimation Texto completo
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.
Mostrar más [+] Menos [-]Association between organohalogenated pollutants in cord blood and thyroid function in newborns and mothers from Belgian population Texto completo
2018
Dufour, Patrice | Pirard, Catherine | Seghaye, Marie-Christine | Charlier, Corinne
The last decades have seen the increasing prevalence of thyroid disorders. These augmentations could be the consequence of the increasing contamination of the environment by chemicals that may disrupt the thyroid function. Indeed, in vitro studies have shown that many chemicals contaminating our environment and highlighted in human serum, are able to interfere with the thyroid function. Given the crucial importance of thyroid hormones on neurodevelopment in fetus and newborns, the influence of these pollutants on newborn thyroid homeostasis is a major health concern. Unfortunately, the overall evidence for a deleterious influence of environmental pollutants on thyroid remains poorly studied. Therefore, we assessed the contamination by polychlorinated biphenyls (PCBs), organochlorine pesticides and perfluorinated compounds (PFC) in 221 cord blood samples collected in Belgium between 2013 and 2016. Our results showed that compared to previous studies performed on newborns recruited in Belgium during the two last decades, the present pollutant contamination is declining. Multivariate statistical analyses pointed out a decrease of thyroid stimulating hormone (TSH) level in male newborns with detectable level of 4,4′- dichlorodiphenyldichloroethylene (4,4′-DDE) in comparison with those with no detectable level (p = 0.025). We also highlighted a negative association between perfluorononanoic acid (PFNA) concentration and TSH in male newborns (p = 0.018). Logistic regression showed increased odds ratio for presentation of hypothyroid in mother for each one unit augmentation of log natural concentration of PFOA (OR = 2.30, [1.18–4.5]) and PFOS (OR = 2.03 [1.08–3.83]). Our findings showed that the residual contamination by PFCs and organochlorine pollutants in cord blood are correlated with thyroid hormone in the newborns and the risk of hypothyroid in mothers.
Mostrar más [+] Menos [-]Seasonal and annual variations in removal efficiency of perfluoroalkyl substances by different wastewater treatment processes Texto completo
2018
Chen, Shuqin | Zhou, Yunqiao | Meng, Jing | Wang, Tieyu
Municipal wastewater treatment plants (WWTPs) are important in the migration and transformation of perfluoroalkyl substances (PFASs) in water bodies. Six municipal WWTPs located in the upper reaches of the Guanting reservoir, along the Yanghe River, were sampled from November 2016 to July 2017. Influents, effluents, and activated sludge solutions were sampled and the concentrations of 17 PFASs were analyzed. Perfluorobutanoic acid (PFBA), Perfluorooctanoic acid (PFOA), Perfluorohexanoic acid (PFHxA), Perfluoropentanoic acid (PFPeA), Perfluorobutane sulfonat (PFBS) and Perfluorooctane sulfonate (PFOS) accounted for more than 90% of these. Seasonal variations in PFASs in influent directly influenced concentrations in supernatant and effluent. The annual average PFAS concentrations were 46.4, 45.1, and 38.5 ng L⁻¹ in influent, supernatant, and effluent, respectively, indicating that WWTPs do not efficiently remove PFASs from wastewater. Annual average PFAS removal efficiencies differed among WWTPs, were influenced primarily by the treatment process used at each, and followed the order Cyclic Activated Sludge System (CASS, 32.2%) > Orbal Oxidation Ditch (OD, 17.5%) > Anaeroxic–Anoxic–Oxic (A²/O, −1.49%). Short-chain PFASs were removed significantly more efficiently in the CASS compared to the other systems. These results can show how traditional wastewater treatment plants can help remove PFASs from the environment.
Mostrar más [+] Menos [-]Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile Texto completo
2018
Jorquera, Héctor | Barraza, Francisco | Heyer, Johanna | Valdivia, Gonzalo | Schiappacasse, Luis N. | Montoya, Lupita D.
Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile Texto completo
2018
Jorquera, Héctor | Barraza, Francisco | Heyer, Johanna | Valdivia, Gonzalo | Schiappacasse, Luis N. | Montoya, Lupita D.
Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however, little is known about the indoor air quality in this region. A field measurement campaign at 63 households in the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoor and outdoor (24-hr) PM2.5 and its elemental composition were measured and compared. Infiltration parameters and outdoor/indoor contributions to indoor PM2.5 were also determined. A statistical evaluation of how various air quality interventions and household features influence indoor PM2.5 was also performed.This study determined median indoor and outdoor PM2.5 concentrations of 44.4 and 41.8 μg/m3, respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species. Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM2.5 concentrations were then estimated as 12.5 and 26.5 μg/m3, respectively; therefore, 68% of indoor PM2.5 comes from outdoor infiltration. This high percentage is due to high outdoor pollution and relatively high household air exchange rates (median: 1.06 h−1).This study found that S, Br and Rb were dominated by outdoor contributions, while Si, Ca, Ti, Fe and As originated from indoor sources. Using continuous indoor and outdoor PM2.5 measurements, a median indoor source strength of 75 μg PM2.5/min was estimated for the diurnal period, similar to literature results. For the evening period, the median estimate rose to 135 μg PM2.5/min, reflecting a more intense wood burning associated to cooking and space heating at night.Statistical test results (at the 90% confidence level) support the ongoing woodstove replacement program (reducing emissions) and household weatherization subsidies (reducing heating demand) for improving indoor air quality in southern Chile, and suggest that a cookstove improvement program might be helpful as well.
Mostrar más [+] Menos [-]Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile
Interactive responses of primary producers and grazers to pollution on temperate rocky reefs Texto completo
2018
Fowles, Amelia E. | Stuart-Smith, Rick D. | Hill, Nicole A. | Thomson, Russell J. | Strain, Elisabeth M.A. | Alexander, Timothy J. | Kirkpatrick, James | Edgar, Graham J.
Macroalgal beds provide important habitat structure and support primary production for rocky reef communities, but are increasingly degraded as a result of human pressures. Various sources of pollution can have both direct and interactive effects on stressed ecosystems. In particular, interactions involving invertebrate grazers could potentially weaken or strengthen the overall impact of pollution on macroalgal beds. Using a paired impact-control experimental design, we tested the effects of multiple pollution sources (fish farms, marinas, sewerage, and stormwater) on translocated and locally established algal assemblages, while also considering the influence of invertebrate grazers. Marinas directly affected algal assemblages and also reduced densities of amphipods and other invertebrate mesograzers. Fish farms and sewerage outfalls tended to directly increase local establishment of foliose and leathery algae without any indication of changes in herbivory. Overall, pollution impacts on algae did not appear to be strongly mediated by changes in grazer abundance. Instead, mesograzer abundance was closely linked to availability of more complex algal forms, with populations likely to decline concurrently with loss of complex algal habitats. Macrograzers, such as sea urchins, showed no signs of a negative impact from any pollution source; hence, the influence of this group on algal dynamics is probably persistent and independent of moderate pollution levels, potentially adding to the direct impacts of pollution on algal beds in urbanised environments.
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