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Resultados 1771-1780 de 7,921
A systematic review of the leaf traits considered to contribute to removal of airborne particulate matter pollution in urban areas
2021
Corada, Karina | Woodward, Huw | Alaraj, Hiba | Collins, C Matilda | de Nazelle, Audrey
Global urban planning has promoted green infrastructure (GI) such as street trees, shrubs or other greenspace in order to mitigate air pollution. Although considerable attention has been paid to understanding particulate matter (PM) deposition on GI, there has been little focus on identifying which leaf traits might maximise airborne PM removal. This paper examines existing literature to synthesize the state of knowledge on leaf traits most relevant to PM removal. We systematically reviewed measurement studies that evaluated particulate matter accumulated on leaves on street trees, shrubs green roofs, and green walls, for a variety of leaf traits. Our final selection included 62 papers, most from field studies and a handful from wind tunnel studies. The following were variously promoted as useful traits: coniferous needle leaves; small, rough and textured broadleaves; lanceolate and ovate shapes; waxy coatings, and high-density trichomes. Consideration of these leaf traits, many of which are also associated with drought tolerance, may help to maximise PM capture. Although effective leaf traits were identified, there is no strong or consistent evidence to identify which is the most influential leaf trait in capturing PM. The diversity in sampling methods, wide comparison groups and lack of background PM concentration measures in many studies limited our ability to synthesize results. We found that several ancillary factors contribute to variations in the accumulation of PM on leaves, thus cannot recommend that selection of urban planting species be based primarily on leaf traits. Further research into the vegetation structural features and standardization of the method to measure PM on leaves is needed.
Mostrar más [+] Menos [-]Environmental toxicology wars: Organ-on-a-chip for assessing the toxicity of environmental pollutants
2021
Yang, Sheng | Chen, Zaozao | Cheng, Yanping | Liu, Tong | Lihong Yin, | Pu, Yuepu | Liang, Geyu
Environmental pollution is a widespread problem, which has seriously threatened human health and led to an increase of human diseases. Therefore, it is critical to evaluate environmental pollutants quickly and efficiently. Because of obvious inter-species differences between animals and humans, and lack of physiologically-relevant microenvironment, animal models and in vitro two-dimensional (2D) models can not accurately describe toxicological effects and predicting actual in vivo responses. To make up the limitations of conventional environmental toxicology screening, organ-on-a-chip (OOC) systems are increasingly developing. OOC systems can provide a well-organized architecture with comparable to the complex microenvironment in vivo and generate realistic responses to environmental pollutants. The feasibility, adjustability and reliability of OCC systems make it possible to offer new opportunities for environmental pollutants screening, which can study their metabolism, collective response, and fate in vivo. Further progress can address the challenges to make OCC systems better investigate and evaluate environmental pollutants with high predictive power.
Mostrar más [+] Menos [-]Residential green space structures are associated with a lower risk of bipolar disorder: A nationwide population-based study in Taiwan
2021
Chang, Hao-Ting | Wu, Chih-Da | Wang, Jung-Der | Chen, Po-See | Su, Huey-Jen
Although many researchers have identified the potential psychological benefits offered by greenness, the association between green space structures and mental disorders is not well understood. The purpose of this study was to identify associations between green space structures and the incidence of bipolar disorder. To this end, we investigated 1,907,776 individuals collected from Taiwan’s National Health Insurance Research Database. After a follow-up investigation from 2005 to 2016, among those with no history of bipolar disorder, 20,548 individuals were further found to be diagnosed with bipolar disorder. A geographic information system and landscape index were used to quantify three indices of green space structures: mean patch area (area and edge), mean fractal dimension index (shape), and mean proximity index (proximity). Additionally, greenness indices, the normalized difference vegetation index, and the enhanced vegetation index were used to confirm the association between greenness and incidence of bipolar disorder. These five indices were used to represent the individual’s exposure according to the township of the hospital that they most frequently visited with symptoms of the common cold. Spearman’s correlation analysis was performed to select variables by considering their collinearity. Subsequently, the frailty model for each index was used to examine the specific associations between those respective indices and the incidence of bipolar disorder by adjusting for related risk factors, such as socioeconomic status, metabolic syndrome, and air pollution. A negative association was identified between the mean patch area and the mean proximity index, and the incidence of bipolar disorder. In contrast, a positive association was found between the mean fractal dimension index and the incidence of bipolar disorder. We observed similar results in sensitivity testing and subgroup analysis. Exposure to green spaces with a larger area, greater proximity, lower complexity, and greener area may reduce the risk of bipolar disorder.
Mostrar más [+] Menos [-]Effect of sea surface temperature and precipitation on annual frequency of harmful algal blooms in the East China Sea over the past decades
2021
Zhou, Yuntao | Yan, Weijin | Wei, Wenyu
Coastal harmful algal blooms (HABs) in China’s seas have attracted researchers’ attention for decades. Among the four seas of China, the HAB frequency is the highest in the East China Sea (ECS). The impact of climate change and anthropogenic dominant factors on HABs is not well quantified and the response of HABs to the changing climate is also not clear. Here, we compiled a time series of observation-based HAB events since the 1980s and performed a regional assessment to elucidate the dominant drivers of HAB events in the ECS. The results showed that the increase in the frequency of HAB events in the ECS between 2000 and 2003 was associated with increases in dissolved inorganic phosphorus and sea surface temperature anomalies as well as decreasing summer precipitation. The declining annual frequency in HAB events in the ECS after 2003 was associated with the two climatological factors, most notably, precipitation. Under the “business-as-usual” scenario, climate change will increase the annual HAB events in the ECS from the historical frequency (1985–2013) by more than five-fold by the end of 21st century. These findings demonstrated that management strategies based on reducing nutrient loading also need to consider the effects of climate change in the future.
Mostrar más [+] Menos [-]Polycyclic aromatic compounds (PACs) in the Canadian environment: Ambient air and deposition
2021
Tevlin, Alexandra | Galarneau, Elisabeth | Zhang, Tianchu | Hung, Hayley
Polycyclic aromatic compounds (PACs) in Canadian air and deposition were examined at the national scale for the first time in over twenty-five years. Air concentrations spanned four orders of magnitude, and were highest near industrial emitters and lowest in the Arctic. Declines in unsubstituted PAHs were observed at locations close to industrial facilities that had reduced emissions, but trends elsewhere were modest or negligible. Retene concentrations are increasing at several locations. Ambient concentrations of benzo[a]pyrene exceeded Ontario’s health-based guideline in many urban/industrial areas. The estimated toxicity of the ambient PAC mixture increased by up to a factor of six when including compounds beyond the US EPA PAHs. Knowledge of PAC deposition is limited to the Laurentian Great Lakes and Athabasca Oil Sands regions. The atmosphere remained a net source of PAHs to the Great Lakes, though atmospheric inputs were decreasing with halving times of 26–30 years. Chemical transport modelling substantially overestimated wet deposition, but model performance is unknown for dry deposition. Sources from Asia, Europe and North America contributed to Arctic and Sub-Arctic concentrations, whereas transboundary or long-range transport have not been assessed outside Canada’s north. Climate-related impacts from re-emission and forest fires were implicated in maintaining air concentrations in the high Arctic that were not consistent with global emissions reductions. Industrial emission decreases were substantial at the national scale, but their influence on the environment was limited to areas near relevant facilities. When examined through the lens of ambient levels at the local scale, evidence suggested that contributions from residential wood combustion and motor vehicles were smaller and larger, respectively, than those reported in national inventories. Future work aimed at characterizing PACs beyond the EPA PAHs, improving measurement coverage, elucidating deposition phenomena, and refining estimates of source contributions would assist in reducing remaining knowledge gaps about PACs in Canada.
Mostrar más [+] Menos [-]A model for population exposure to PM2.5: Identification of determinants for high population exposure in Seoul
2021
Guak, Sooyoung | Lee, Sang-Gyu | An, Jaehoon | Lee, Hunjoo | Lee, Kiyoung
Outdoor concentrations of particulate matter with an aerodynamic diameter of <2.5 μm (PM₂.₅) are often used as a surrogate for population exposure to PM₂.₅ in epidemiological studies. However, people spend most of their daily activities indoors; therefore, the relationship between indoor and outdoor PM₂.₅ concentrations should be considered in the estimation of population exposure to PM₂.₅. In this study, a population exposure model was developed to predict seasonal population exposure to PM₂.₅ in Seoul, Korea. The input data for the population exposure model comprised 3984 time-location patterns, outdoor PM₂.₅ concentrations, and the microenvironment-to-outdoor PM₂.₅ concentrations in seven microenvironments. A probabilistic approach was used to develop the Korea simulation exposure model. The determinants for the population exposure group were identified using a multinomial logistic regression analysis. Population exposure to PM₂.₅ varied significantly among the three seasons (p < 0.01). The mean ± standard deviation of population exposures to PM₂.₅ was 21.3 ± 4.0 μg/m³ in summer, 9.8 ± 2.7 μg/m³ in autumn, and 29.9 ± 10.6 μg/m³ in winter. Exposure to PM₂.₅ higher than 35 μg/m³ mainly occurred in winter. Gender, age, working hours, and health condition were identified as significant determinants in the exposure groups. An “unhealthy” health condition was the most significant determinant. The high PM₂.₅ exposure group was characterized as a higher proportion of males of a lower age with longer working hours. The population exposure model for PM₂.₅ could be used to implement effective interventions and evaluate the effectiveness of control policies to reduce exposure.
Mostrar más [+] Menos [-]Chronic pesticide exposure elicits a subtle carry-over effect on the metabolome of Aurelia coerulea ephyrae
2021
Olguín-Jacobson, Carolina | Pitt, Kylie A. | Carroll, Anthony R. | Melvin, Steven D.
Chemical pollutants, such as pesticides, often leach into aquatic environments and impact non-target organisms. Marine invertebrates have complex life cycles with multiple life-history stages. Exposure to pesticides during one life-history stage potentially influences subsequent stages; a process known as a carry-over effect. Here, we investigated carry-over effects on the jellyfish Aurelia coerulea. We exposed polyps to individual and combined concentrations of atrazine (2.5 μg/L) and chlorpyrifos (0.04 μg/L) for four weeks, after which they were induced to strobilate. The resultant ephyrae were then redistributed and exposed to either the same conditions as their parent-polyps or to filtered seawater to track potential carry-over effects. The percentage of deformities, ephyrae size, pulsation and respiration rates, as well as the metabolic profile of the ephyrae, were measured. We detected a subtle carry-over effect in two metabolites, acetoacetate and glycerophosphocholine, which are precursors of the neurotransmitter acetylcholine, important for energy metabolism and osmoregulation of the ephyrae. Although these carry-over effects were not reflected in the other response variables in the short-term, a persistent reduction of these two metabolites could have negative physiological consequences on A. coerulea jellyfish in the long-term. Our results highlight the importance of considering more than one life-history stage in ecotoxicology, and measuring a range of variables with different sensitivities to detect sub-lethal effects caused by anthropogenic stressors. Furthermore, since we identified few effects when using pesticides concentrations corresponding to Australian water quality guidelines, we suggest that future studies consider concentrations detected in the environment, which are higher than the water quality guidelines, to obtain a more realistic scenario by possible risk from pesticide exposure.
Mostrar más [+] Menos [-]Potential health risk assessment of HFRs, PCBs, and OCPs in the Yellow River basin
2021
Chen, Yiping | Zhao, Yan | Zhao, Meng M. | Wu, Jun-Hua | Wang, Kai-bo
The concentrations of PBDEs, NBFRs, DP, PCBs, and OCPs were analyzed in water samples of the Yellow River Basin (YRB) and in soil and maize samples collected from basin irrigation areas to understand the status of POPs and associated health risks. The results showed: (1) the congeners of eight PBDEs and seven NBFRs were detected in 10 tributaries, with average concentrations of 1575 and 4288 pg. L⁻¹. Thirty-three congeners of PCBs were detected, and the average concentration of PCB was 232 pg. L⁻¹. Five HCHs were the primary congeners among twenty-three congeners of OCPs in the ten tributaries, accounting for 79% of the total. The average concentration of OCPs was 8287 pg. L⁻¹. (2) Similar congeners of HFRs, PCBs, and OCPs were found in the trunk water. The ranking based on the HFR concentration was upstream > downstream > midstream, and that of the PCB and OCP concentration was downstream > upstream > midstream. (3) PCBs and OCPs in the trunk water of the YRB and in the soil and maize irrigated with river water pose potential carcinogenic and non-carcinogenic risks. The results indicate considerable organic pollution in the YRB, suggesting that national emission standards for POPs should be implemented soon.
Mostrar más [+] Menos [-]Treatment technologies to mitigate the harmful effects of recalcitrant fluoroquinolone antibiotics on the environ- ment and human health
2021
Mathur, Purvi | Sanyal, Doyeli | Callahan, Damien L. | Conlan, Xavier A. | Pfeffer, Frederick M.
Antibiotic proliferation in the environment and their persistent nature is an issue of global concern as they induce antibiotic resistance threatening both human health and the ecosystem. Antibiotics have therefore been categorized as emerging pollutants. Fluoroquinolone (FQs) antibiotics are an emerging class of contaminants that are used extensively in human and veterinary medicine. The recalcitrant nature of fluoroquinolones has led to their presence in wastewater, effluents and water bodies. Even at a low concentration, FQs can stimulate antibacterial resistance. The main sources of FQ contamination include waste from pharmaceutical manufacturing industries, hospitals and households that ultimately reaches the wastewater treatment plants (WWTPs). The conventional WWTPs are unable to completely remove FQs due to their chemical stability. Therefore, the development and implementation of more efficient, economical, convenient treatment and removal technologies are needed to adequately address the issue. This review provides an overview of the technologies available for the removal of fluoroquinolone antibiotics from wastewater including adsorptive removal, advanced oxidation processes, removal using non-carbon based nanomaterials, microbial degradation and enzymatic degradation. Each treatment technology is discussed on its merits and limitations and a comparative view is presented on the choice of an advanced treatment process for future studies and implementation. A discussion on the commercialization potential and eco-friendliness of each technology is also included in the review. The importance of metabolite identification and their residual toxicity determination has been emphasized. The last section of the review provides an overview of the policy interventions and regulatory frameworks that aid in retrofitting antibiotics as a central key focus contaminant and thereby defining the discharge limits for antibiotics and establishing safe manufacturing practices.
Mostrar más [+] Menos [-]C-offset and crop energy efficiency increase due industrial poultry waste use in long-term no-till soil minimizing environmental pollution
2021
Romaniw, Jucimare | de Moraes Sá, João Carlos | Lal, R. | de Oliveira Ferreira, Ademir | Inagaki, Thiago Massao | Briedis, Clever | Gonçalves, Daniel Ruiz Potma | Canalli, Lutécia Beatriz | Padilha, Alessandra | Bressan, Pamela Thaísa
Brazil is one of the major global poultry producers, and the organic waste generated by the chicken slaughterhouses can potentially be used as a biofertilizer in agriculture. This study was designed to test the hypothesis that continuous use of biofertilizer to the crops, substituting the use of mineral fertilizer promote C-offset for the soil and generate crop energy efficiency for the production system. Thus, the objectives of this study were to evaluate the effects of biofertilizer use alone or in combination with mineral fertilizer on soil organic carbon (SOC) stock, carbon dioxide (CO₂) mitigation, C-offset, crop energy efficiency and productivity, and alleviation of environmental pollution. The experiment was established in southern Brazil on a soil under 15 years of continuous no-till (NT). Experimental treatments were as follows: i) Control with no fertilizer application, ii) 100% use of industrial mineral fertilizer (Min-F); iii) 100% use of organic waste originated from poultry slaughterhouses and hereinafter designated biofertilizer (Bio-F), and iv) Mixed fertilizer equivalent to the use of 50% mineral fertilizer + 50% of biofertilizer (Mix-F). Effects of experimental treatments were assessed for the crop sequence based on bean (Phaseolus vulgaris), soybean (Glycine max) and corn (Zea mays) in the summer and wheat (Triticum aestivum) and black oat (Avena strigosaSchreb) in the winter composing two crops per year, as follow: bean/wheat-soybean/black oat-corn/wheat-soybean/black oat-corn/wheat-bean. The continuous use of Bio-F treatment significantly increased the index of crop energy efficiency. It was higher than that of control, and increased it by 25.4 Mg CO₂eq ha⁻¹ over that of Min-F treatment because of higher inputs of crop biomass-C into the system. Further, continuous use of Bio-F resulted in a significantly higher CO₂eq stock and offset than those for Min-F treatment. A positive relationship between the C-offset and the crop energy efficiency (R² = 0.71, p < 0.001) indicated that the increase of C-offset was associated with the increase of energy balance and the amount of SOC sequestered. The higher energy efficiency and C-offset by application of Bio-F indicated that the practice of crop bio fertilization with poultry slaughterhouse waste is a viable alternative for recycling and minimizing the environmental impacts.
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