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Estimation of health and economic benefits based on ozone exposure level with high spatial-temporal resolution by fusing satellite and station observations Texte intégral
2019
Liang, Shuang | Li, Xiaoli | Teng, Yu | Fu, Hongchen | Chen, Li | Mao, Jian | Zhang, Hui | Gao, Shuang | Sun, Yanling | Ma, Zhenxing | Azzi, Merched
In recent years, ozone pollution has become more and more serious in China. Several epidemiological studies have demonstrated the correlation between short-term ozone exposure and several health risks including all-cause mortality, cardiovascular mortality, and respiratory mortality. In this study, the daily ozone exposure levels with 10 km × 10 km resolution were estimated based on satellite data derived from Ozone Monitoring Instrument (OMI) and the monitoring data. The health impacts for potential decrease in the daily ozone concentration and the corresponding economic benefits in 2016 were estimated by applying the environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) model. By reducing the daily maximum 8-h average concentration of ozone to 100 μg/m³, the estimated avoided all-cause mortalities were 120 × 10³ (95% confidence interval (CI): 67 × 10³, 160 × 10³) cases and the correspondingly economic benefits ranged from 36 to 64 billion CNY using amended human capital (AHC) and willingness to pay (WTP) method in 2016. If the daily maximum 8-h average concentration of ozone were rolled back to 70 μg/m³, the estimated avoided all-cause mortalities were 160 × 10³ (95% CI: 98 × 10³, 230 × 10³) cases and economic benefits ranged from 54 to 95 billion CNY based on AHC and WTP methods.
Afficher plus [+] Moins [-]Occurrence of neonicotinoids and fipronil in estuaries and their potential risks to aquatic invertebrates Texte intégral
2019
Hano, Takeshi | Ito, Katsutoshi | Ohkubo, Nobuyuki | Sakaji, Hideo | Watanabe, Akio | Takashima, Kei | Satō, Taku | Sugaya, Takuma | Matsuki, Kosuke | Onduka, Toshimitsu | Ito, Mana | Somiya, Rei | Mochida, Kazuhiko
This study aimed to evaluate and qualify field-based potential risks of seven neonicotinoid and phenylpyrazole (fipronil) insecticides on aquatic invertebrates, including estuary-resident marine crustaceans. One hundred and ninety-three estuarine water samples, with salinity ranging from 0.5 to 32.7, were collected from four estuarine sites in the Seto Inland Sea of Japan, in 2015–2018 and the insecticide levels were measured. Five neonicotinoid and fipronil insecticides were successfully identified, and their occurrence varied temporally. Marine crustaceans were simultaneously harvested every month from one of the estuarine water sampling sites in 2015–2017. Three predominant crustacean species, kuruma prawn (Penaeus japonicus), sand shrimp (Crangon uritai), and mysid (Neomysis awatschensis), were captured and their seasonal presence was species independent. A 96-h laboratory toxicity study with the insecticides using kuruma prawn, sand shrimp, and a surrogate mysid species (Americamysis bahia) indicated that fipronil exerted the highest toxicity to the three crustaceans. Using both toxicity data and insecticide occurrence in estuarine water (salinity ≥10, n = 169), the potential risks on the three marine crustaceans were quantified by calculating the proportion of mixture toxicity effects (Pₘᵢₓ). The Pₘᵢₓ of seven neonicotinoids on the crustaceans was less than 0.8%, which is likely to be too low to indicate adverse effects caused by the insecticides. However, short temporal detection of fipronil (exclusively in June and July) significantly affected the Pₘᵢₓ, which presented the maximal Pₘᵢₓ values of 21%, 3.4%, and 72% for kuruma prawn, sand shrimp, and mysid, respectively, indicating a significant effect on the organisms. As for estuarine water (salinity <10), some water samples contained imidacloprid and fipronil exceeding the freshwater benchmarks for aquatic invertebrates. The present study provides novel insights into the seasonally varying risks of insecticides to estuarine crustaceans and highlights the importance of considering whether ecological risk periods coincide with crustacean presence.
Afficher plus [+] Moins [-]Jumping on the bed and associated increases of PM10, PM2.5, PM1, airborne endotoxin, bacteria, and fungi concentrations Texte intégral
2019
Yen, Yu-Chuan | Yang, Chun-Yuh | Mena, Kristina Dawn | Cheng, Yu-Ting | Yuan, Chung-Shin | Chen, Pei-Shih
Jumping on the bed is a favorite behavior of children; however, no study has investigated the increased air pollutants resulting from jumping on the bed. Therefore, we aimed to investigate the elevated concentrations of particulate matter (PM) and bioaerosols from jumping on the bed and making the bed. Simulation of jumping on the bed and making the bed was performed at sixty schoolchildren's houses in Taiwan. PM10, PM2.5, PM1 (PM with aerodynamic diameter less than 10, 2.5, and 1 μm, respectively) and airborne bacteria, fungi and endotoxin concentrations were simultaneously measured over simulation and background periods. Our results show the increase of PM10, PM2.5, PM1, airborne bacteria and fungi through the behavior of jumping on the bed (by 414 μg m-3, 353 μg m-3, 349 μg m-3, 6569 CFU m-3 and 978 CFU m-3, respectively). When making the bed, the PM10, PM2.5, PM1, airborne bacteria and fungi also significantly increased by 4.69 μg m-3, 4.09 μg m-3, 4.15 μg m-3, 8569 CFU m-3, and 779 CFU m-3, respectively. Airborne endotoxin concentrations significantly increased by 21.76 EU m-3 following jumping on the bed and making the bed. Moreover, when jumping on the bed, higher PM2.5 and PM1 concentrations in houses with furry pets rather than no furry pets, and less airborne fungi in apartments than in townhouses were found. For making the bed, lower airborne fungi was found in houses using essential oils rather than no essential oils using. The airborne endotoxin concentrations were positively associated with furry pets and smokers in the homes and negatively correlated to the home with window opening with a statistical significance during the periods of jumping on the bed and making the bed. In conclusion, significant increases of PM and bioaerosols during jumping on the bed and making the bed may need to be concerned.
Afficher plus [+] Moins [-]Impact of disinfectant on bacterial antibiotic resistance transfer between biofilm and tap water in a simulated distribution network Texte intégral
2019
Zhang, Junpeng | Li, Weiying | Chen, Jiping | Wang, Feng | Qi, Wanqi | Li, Yue
Bacterial antibiotic resistance (BAR) is profoundly important to human health, but the environmental reservoirs of resistance determinants are poorly understood. BAR of biofilm and tap water were analyzed by using a water distribution simulator where different doses of chlorine and chloramine were used in this study. The results revealed that the disinfectants (≥2 mg/L) suppressed antibiotic resistant bacteria (ARB) in tap water and biofilms, while disinfected water and biofilms had a high relative abundance of ARB. The difference of ARB concentration and ARB percentage between the samples obtained from a disinfected pipeline and a non-disinfected pipeline became smaller over time. Because the water supply system is a unidirectional process, it is unclear how planktonic bacteria in water transfer BAR over time, although biofilm is suspected to play a role in this process. Compared with the biofilm samples without disinfectant, the disinfected biofilm had lower ICC and HPC/ICC percentage, lower AOC and AOC/TOC percentage, indicating that the disinfectant inhibited the bacteria growth in biofilm, and the disinfected biofilm had high proportion of non-culturable bacteria and low biodegradability, which affected BAR in biofilms. High throughput sequencing showed that in biofilms, the relative abundance of genera (uncultured_f_Rhodocyclaceae, Brevundimonas, and Brevibacillus in chlorinated systems, and Brevundimonas, Brevibacillus in chloraminated systems) with multiple antibiotic resistance and high abundance (up to 78.5%), were positively associated with disinfectant concentration and ARB percentage. The major prevalent genera in biofilms were also detected in tap water, suggesting that biofilm growth or biofilm detachment caused by external environmental factors will allow the movement of biofilm clusters with higher ARB concentration and percentage into bulk water, thereby increasing the antibiotic resistance of bacteria in tap water.
Afficher plus [+] Moins [-]Low-dose cadmium exposure acts on rat mesenchymal stem cells via RANKL/OPG and downregulate osteogenic differentiation genes Texte intégral
2019
Lv, Ying-Jian | Wei, Qin-Zhi | Zhang, Yang-Cong | Huang, Rui | Li, Bai-Sheng | Tan, Jian-Bin | Wang, Jing | Ling, Hai-Tuan | Wu, Shi-Xuan | Yang, Xing-Fen
Chronic cadmium (Cd) toxicity is a significant health concern, and the mechanism of long-term low-dose Cd exposure on bone has not been fully elucidated till date. This study aimed to assess the association between rat mesenchymal stem cells (MSCs) and long-term Cd exposure through 38-week intake of CdCl2 at 1 and 2 mg/kg body weight (bw). Increased gene expression of receptor activator of NF-κB ligand (RANKL) and decreased gene expression of osteoprotegerin (OPG) were observed. Fold change of RANKL gene expression (fold change = 1.97) and OPG gene expression (fold change = 1.72) showed statistically significant differences at dose 2 mg/kg bw. Decreased expression of key genes was observed during the early osteogenic differentiation of MSCs. The gene expression of Osterix in 1 mg/kg bw group was decreased by 3.70-fold, and the gene expressions of Osterix, Osteopontin, collagen type I alpha 2 chain (COL1a2) and runt-related transcription factor 2 (RUNX2) in 2 mg/kg bw group were decreased by 1.79, 1.67, 1.45 and 1.35-folds, respectively. Exposure to CdCl2 induced an increase in the renal Cd load, but only an adaptive response was observed, including increased expression of autophagy-related proteins LC3B and Beclin-1, autophagy receptor p62, and heme oxygenase 1 (HO-1), which is an inducible isoform that releases in response to stress. There were no significant changes in the urinary low molecular weight proteins including N-acetyl-b-D-glucosaminidase (NAG), β2-microglobulin and albumin (U-Alb). Urinary calcium (Ca) excretion showed no increase, and no obvious renal histological changes. Taken together, these results indicated that the chronic CdCl2 exposure directly act on MSCs through RANKL/OPG pathway and downregulate the key genes involved in osteogenic differentiation of MSCs. The toxic effect of Cd on bone may occur in parallel to nephrotoxicity.
Afficher plus [+] Moins [-]Partitioning of chemical contaminants to microplastics: Sorption mechanisms, environmental distribution and effects on toxicity and bioaccumulation Texte intégral
2019
Tourinho, Paula S. | Kočí, Vladimír | Loureiro, Susana | van Gestel, Cornelis A.M.
There is an increasing awareness of the threats posed by the worldwide presence of microplastics (MPs) in the environment. Due to their high persistence, MPs will accumulate in the environment and their quantities tend to increase with time. MPs end up in environments where often also chemical contaminants are present. Since the early 2000s, the number of studies on the sorption of chemicals to plastic particles has exponentially increased. The objective of this study was to critically review the literature to identify the most important factors affecting the sorption of chemical contaminants to MPs. These factors include the physicochemical properties of both the MPs and the chemical contaminants as well as environmental characteristics. A limited number of studies on soil together with an increased notion of the importance of this compartment as a final sink for MPs was observed. Therefore, we assessed the distribution of model chemicals (two PCBs and phenanthrene) in the soil compartment in the presence of MPs using a mass balance model. The results showed a high variation among chemicals and microplastic types. Overall, a higher partitioning to MPs of chemical contaminants in soil is expected in comparison to aquatic environments. As sorption to a large extent determines bioavailability, the effects of combined exposure to chemicals and MPs on the toxicity and bioaccumulation in biota are discussed. Finally, some considerations regarding sorption and toxicity studies using MPs are given.
Afficher plus [+] Moins [-]Oiling of the continental shelf and coastal marshes over eight years after the 2010 Deepwater Horizon oil spill Texte intégral
2019
Turner, R Eugene | Rabalais, Nancy N. | Overton, Edward B. | Meyer, Buffy M. | McClenachan, Giovanna | Swenson, Erick M. | Besonen, Mark | Parsons, Michael L. | Zingre, Jeffrey
We measured the temporal and spatial trajectory of oiling from the April, 2010, Deepwater Horizon oil spill in water from Louisiana's continental shelf, the estuarine waters of Barataria Bay, and in coastal marsh sediments. The concentrations of 28 target alkanes and 43 target polycyclic aromatic hydrocarbons were determined in water samples collected on 10 offshore cruises, in 19 water samples collected monthly one km offshore at 13 inshore stations in 2010 and 2013, and in 16–60 surficial marsh sediment samples collected on each of 26 trips. The concentration of total aromatics in offshore waters peaked in late summer, 2010, at 100 times above the May, 2010 values, which were already slightly contaminated. There were no differences in surface or bottom water samples. The concentration of total aromatics declined at a rate of 73% y−1 to 1/1000th of the May 2010 values by summer 2016. The concentrations inside the estuary were proportional to those one km offshore, but were 10–30% lower. The oil concentrations in sediments were initially different at 1 and 10 m distance into the marsh, but became equal after 2 years. Thus, the distinction between oiled and unoiled sites became blurred, if not non-existent then, and oiling had spread over an area wider than was visible initially. The concentrations of oil in sediments were 100–1000 times above the May 2010 values, and dropped to 10 times higher after 8 years, thereafter, demonstrating a long-term contamination by oil or oil residues that will remain for decades. The chemical signature of the oil residues offshore compared to in the marsh reflects the more aerobic offshore conditions and water-soluble tendencies of the dissolved components, whereas the anaerobic marsh sediments will retain the heavier molecular components for a long time, and have a consequential effect on the ecosystems.
Afficher plus [+] Moins [-]Azo dye biotransformation mediated by AQS immobilized on activated carbon cloth in the presence of microbial inhibitors Texte intégral
2019
Castañon, Daniel | Alvarez, Luis H. | Peña, Karen | García-Reyes, Refugio B. | Martinez, Claudia M. | Pat-Espadas, Aurora
In this work, anthraquinone-2-sulfonate (AQS) was covalently immobilized onto activated carbon cloth (ACC), to be used as redox mediator for the reductive decolorization of reactive red 2 (RR2) by an anaerobic consortium. The immobilization of AQS improved the capacity of ACC to transfer electrons, evidenced by an increment of 3.29-fold in the extent of RR2 decolorization in absence of inhibitors, compared to incubations lacking AQS. Experiments conducted in the presence of vancomycin, an inhibitor of acidogenic bacteria, and with 2-bromoethane sulfonic acid (BES), an inhibitor of methanogenic archaea, revealed that acidogenic bacteria are the main responsible for RR2 biotransformation mediated by immobilized AQS. Nonetheless, the results also suggest that some methanogens are able to maintain their capacity to use immobilized AQS as an electron acceptor to sustain the decolorization process, even in the presence of BES.
Afficher plus [+] Moins [-]Transport and retention of reduced graphene oxide materials in saturated porous media: Synergistic effects of enhanced attachment and particle aggregation Texte intégral
2019
Xia, Tianjiao | Ma, Pengkun | Qi, Yu | Zhu, Lingyan | Qi, Zhichong | Chen, Wei
The increasing production and use of graphene-based nanomaterials (e.g., graphene oxide (GO) and reduced graphene oxide (RGO)) will lead to their environmental release. To date, transport of RGOs in saturated porous media is poorly understood. Here, we examined the transport behaviors of three RGO materials obtained by reducing a GO product with commonly used reducing agents – N₂H₄, NaBH₄ and L-ascorbic acid (referred to as N₂H₄-RGO, NaBH₄-RGO and VC-RGO, respectively). When the dominant background cation was Na⁺, K⁺ or Mg²⁺, the mobility of the RGOs and GO in saturated quartz sand correlated well with their surface C/O ratio. Interestingly, the lower mobility of the more reduced materials (the ones with higher C/O values) was not only the results of their less negative surface charges and larger particle sizes, but also the outcome of their greater hydrophobicity, in line with the calculated extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) profiles. Counterintuitively, when the background cation was Ca²⁺, the least reduced material among the three RGOs, VC-RGO, exhibited the lowest mobility. Analysis of electrophoretic and aggregation properties, as well as pH-effect experiments, indicated that the surprisingly low mobility of VC-RGO was attributable to the strong cation-bridging effect (primarily Ca²⁺-bridging between RGO and quartz sand) associated with this material, as VC-RGO contained the highest amount of surface carboxyl group (a strong metal-binding moiety). Notably, enhanced attachment (due to increased hydrophobic effect and cation-bridging) and particle aggregation appeared to work synergistically to increase RGO retention, as the attachment of large RGO aggregates significantly enhanced particle straining by narrowing the flow path. These observations reveal a largely overlooked link between the mobility of graphene-based materials and their key physicochemical properties.
Afficher plus [+] Moins [-]A survey and risk assessment of neonicotinoids in water, soil and sediments of Belize Texte intégral
2019
Bonmatin, Jean-Marc | Noome, Dominique A. | Moreno, Heron | Mitchell, Edward A.D. | Glauser, Gaëtan | Soumana, Oumarou S. | Bijleveld van Lexmond, Maarten | Sánchez-Bayo, Francisco
Usage of neonicotinoids is common in all agricultural regions of the world but data on environmental contamination in tropical regions is scarce. We conducted a survey of five neonicotinoids in soil, water and sediment samples along gradients from crops fields to protected lowland tropical forest, mangroves and wetlands in northern Belize, a region of high biodiversity value. Neonicotinoid frequency of detection and concentrations were highest in soil (68%) and lowest in water (12%). Imidacloprid was the most common residue reaching a maximum of 17.1 ng/g in soil samples. Concentrations in soils differed among crop types, being highest in melon fields and lowest in banana and sugarcane fields. Residues in soil declined with distance to the planted fields, with clothianidin being detected at 100 m and imidacloprid at more than 10 km from the nearest applied field. About half (47%) of the sediments collected contained residues of at least one compound up to 10 km from the source. Total neonicotinoid concentrations in sediments (range 0.014–0.348 ng/g d. w.) were about 10 times lower than in soils from the fields, with imidacloprid being the highest (0.175 ng/g). A probabilistic risk assessment of the residues in the aquatic environment indicates that 31% of sediment samples pose a risk to invertebrate aquatic and benthic organisms by chronic exposure, whereas less than 5% of sediment samples may incur a risk by acute exposure. Current residue levels in water samples do not appear to pose risks to the aquatic fauna. Fugacity modeling of the four main compounds detected suggest that most of the dissipation from the agricultural fields occurs via runoff and leaching through the porous soils of this region. We call for better monitoring of pesticide contamination and invertebrate inventories and finding alternatives to the use of neonicotinoids in agriculture.
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