Showing papers in "Environmental Science and Pollution Research in 2017"
TL;DR: Because of the recent threat of microplastics to marine biota as well as on human health, it is important to control excessive use of plastic additives and to introduce certain legislations and policies to regulate the sources of plastic litter.
Abstract: Human populations are using oceans as their household dustbins, and microplastic is one of the components which are not only polluting shorelines but also freshwater bodies globally. Microplastics are generally referred to particles with a size lower than 5 mm. These microplastics are tiny plastic granules and used as scrubbers in cosmetics, hand cleansers, air-blasting. These contaminants are omnipresent within almost all marine environments at present. The durability of plastics makes it highly resistant to degradation and through indiscriminate disposal they enter in the aquatic environment. Today, it is an issue of increasing scientific concern because these microparticles due to their small size are easily accessible to a wide range of aquatic organisms and ultimately transferred along food web. The chronic biological effects in marine organisms results due to accumulation of microplastics in their cells and tissues. The potential hazardous effects on humans by alternate ingestion of microparticles can cause alteration in chromosomes which lead to infertility, obesity, and cancer. Because of the recent threat of microplastics to marine biota as well as on human health, it is important to control excessive use of plastic additives and to introduce certain legislations and policies to regulate the sources of plastic litter. By setup various plastic recycling process or promoting plastic awareness programmes through different social and information media, we will be able to clean our sea dustbin in future.
528 citations
TL;DR: Dust emission and deposition between atmosphere, land surface, and aquatic environment were associated with the transportation of microplastics, and adhering particles, grooves, pits, fractures, and flakes were the common patterns of degradation.
Abstract: Microplastic pollution has exhibited a global distribution, including seas, lakes, rivers, and terrestrial environment in recent years. However, little attention was paid on the atmospheric environment, though the fact that plastic debris can escape as wind-blown debris was previously reported. Thus, characteristics of microplastics in the atmospheric fallout from Dongguan city were preliminarily studied. Microplastics of three different polymers, i.e., PE, PP, and PS, were identified. Diverse shapes of microplastics including fiber, foam, fragment, and film were found, and fiber was the dominant shape of the microplastics. SEM images illustrated that adhering particles, grooves, pits, fractures, and flakes were the common patterns of degradation. The concentrations of non-fibrous microplastics and fibers ranged from 175 to 313 particles/m2/day in the atmospheric fallout. Thus, dust emission and deposition between atmosphere, land surface, and aquatic environment were associated with the transportation of microplastics.
518 citations
TL;DR: A growing body of evidence demonstrates that persistent, low levels of neonicotinoids can have negative impacts on a wide range of free-living organisms.
Abstract: Neonicotinoid pesticides were first introduced in the mid-1990s, and since then, their use has grown rapidly. They are now the most widely used class of insecticides in the world, with the majority of applications coming from seed dressings. Neonicotinoids are water-soluble, and so can be taken up by a developing plant and can be found inside vascular tissues and foliage, providing protection against herbivorous insects. However, only approximately 5% of the neonicotinoid active ingredient is taken up by crop plants and most instead disperses into the wider environment. Since the mid-2000s, several studies raised concerns that neonicotinoids may be having a negative effect on non-target organisms, in particular on honeybees and bumblebees. In response to these studies, the European Food Safety Authority (EFSA) was commissioned to produce risk assessments for the use of clothianidin, imidacloprid and thiamethoxam and their impact on bees. These risk assessments concluded that the use of these compounds on certain flowering crops poses a high risk to bees. On the basis of these findings, the European Union adopted a partial ban on these substances in May 2013. The purpose of the present paper is to collate and summarise scientific evidence published since 2013 that investigates the impact of neonicotinoids on non-target organisms. Whilst much of the recent work has focused on the impact of neonicotinoids on bees, a growing body of evidence demonstrates that persistent, low levels of neonicotinoids can have negative impacts on a wide range of free-living organisms.
386 citations
TL;DR: The present review elucidates various mechanisms that have been exerted by biofertilizers in order to promote plant growth and also provides protection against different plant pathogens as well as discusses the important roles and applications of biof fertilizer in different sectors including agriculture, bioremediation, and ecology.
Abstract: The worldwide increase in human population raises a big threat to the food security of each people as the land for agriculture is limited and even getting reduced with time. Therefore, it is essential that agricultural productivity should be enhanced significantly within the next few decades to meet the large demand of food by emerging population. Not to mention, too much dependence on chemical fertilizers for more crop productions inevitably damages both environmental ecology and human health with great severity. Exploitation of microbes as biofertilizers is considered to some extent an alternative to chemical fertilizers in agricultural sector due to their extensive potentiality in enhancing crop production and food safety. It has been observed that some microorganisms including plant growth promoting bacteria, fungi, Cyanobacteria, etc. have showed biofertilizer-like activities in the agricultural sector. Extensive works on biofertilizers have revealed their capability of providing required nutrients to the crop in sufficient amounts that resulted in the enhancement of crop yield. The present review elucidates various mechanisms that have been exerted by biofertilizers in order to promote plant growth and also provides protection against different plant pathogens. The aim of this review is to discuss the important roles and applications of biofertilizers in different sectors including agriculture, bioremediation, and ecology.
374 citations
TL;DR: This review highlights both the potential of biochar in alleviating drought and salt stress in plants and future prospect of the role of bio char under drought and Salt Stress in plants.
Abstract: Drought and salt stress negatively affect soil fertility and plant growth. Application of biochar, carbon-rich material developed from combustion of biomass under no or limited oxygen supply, ameliorates the negative effects of drought and salt stress on plants. The biochar application increased the plant growth, biomass, and yield under either drought and/or salt stress and also increased photosynthesis, nutrient uptake, and modified gas exchange characteristics in drought and salt-stressed plants. Under drought stress, biochar increased the water holding capacity of soil and improved the physical and biological properties of soils. Under salt stress, biochar decreased Na+ uptake, while increased K+ uptake by plants. Biochar-mediated increase in salt tolerance of plants is primarily associated with improvement in soil properties, thus increasing plant water status, reduction of Na+ uptake, increasing uptake of minerals, and regulation of stomatal conductance and phytohormones. This review highlights both the potential of biochar in alleviating drought and salt stress in plants and future prospect of the role of biochar under drought and salt stress in plants.
323 citations
TL;DR: The long-run estimates obtained from the ARDL model indicate that increases in renewable energy consumption mitigate environmental degradation whereas increases in non-renewable energy consumption contribute to CO2 emissions.
Abstract: The objective of this study is to explore the influence of the real income (GDP), renewable energy consumption and non-renewable energy consumption on carbon dioxide (CO2) emissions for the United States of America (USA) in the environmental Kuznets curve (EKC) model for the period 1980-2014. The Zivot-Andrews unit root test with a structural break and the Clemente-Montanes-Reyes unit root test with a structural break report that the analyzed variables become stationary at first-differences. The Gregory-Hansen cointegration test with a structural break and the bounds testing for cointegration in the presence of a structural break show CO2 emissions, the real income, the quadratic real income, renewable and non-renewable energy consumption are cointegrated. The long-run estimates obtained from the ARDL model indicate that increases in renewable energy consumption mitigate environmental degradation whereas increases in non-renewable energy consumption contribute to CO2 emissions. In addition, the EKC hypothesis is not valid for the USA. Since we use time-series econometric approaches that account for structural break in the data, findings of this study are robust, reliable and accurate. The US government is advised to put more weights on renewable sources in energy mix, to support and encourage the use and adoption of renewable energy and clean technologies, and to increase the public awareness of renewable energy for lower levels of emissions.
304 citations
TL;DR: Street dust is a potentially important source of microplastic contamination in the urban environment and control measures are required, especially during outdoor activities and workspaces with high abundant microplastics as acute exposure.
Abstract: Environmental pollutants such as microplastics have become a major concern over the last few decades. We investigated the presence, characteristics, and potential health risks of microplastic dust ingestion. The plastic load of 88 to 605 microplastics per 30 g dry dust with a dominance of black and yellow granule microplastics ranging in size from 250 to 500 μm was determined in 10 street dust samples using a binocular microscope. Fluorescence microscopy was found to be ineffective for detecting and counting plastic debris. Scanning electron microscopy, however, was useful for accurate detection of microplastic particles of different sizes, colors, and shapes (e.g., fiber, spherule, hexagonal, irregular polyhedron). Trace amounts of Al, Na, Ca, Mg, and Si, detected using energy dispersive X-ray spectroscopy, revealed additives of plastic polymers or adsorbed debris on microplastic surfaces. As a first step to estimate the adverse health effects of microplastics in street dust, the frequency of microplastic ingestion per day/year via ingestion of street dust was calculated. Considering exposure during outdoor activities and workspaces with high abundant microplastics as acute exposure, a mean of 3223 and 1063 microplastic particles per year is ingested by children and adults, respectively. Consequently, street dust is a potentially important source of microplastic contamination in the urban environment and control measures are required.
301 citations
TL;DR: The review shows that the intensification of human activities and the associated impacts on groundwater quality in China, especially in western China, has made groundwater quality research increasingly important, and has caught the attention of local, national, and international agencies and scholars.
Abstract: Groundwater quality research is extremely important for supporting the safety of the water supply and human health in arid and semi-arid areas of China. This review article was constructed to report the latest research progress of groundwater quality in western China where groundwater quality is undergoing fast deterioration because of fast economic development and extensive anthropogenic activities. The opportunities brought by increasing public awareness of groundwater quality protection were also highlighted and discussed. To guide and promote further development of groundwater quality research in China, especially in western China, ten key groundwater quality research fields were proposed. The review shows that the intensification of human activities and the associated impacts on groundwater quality in China, especially in western China, has made groundwater quality research increasingly important, and has caught the attention of local, national, and international agencies and scholars. China has achieved some progress in groundwater quality research in terms of national and regional laws, regulations, and financial supports. The future of groundwater quality research in China, especially in western China, is promising reflected by the opportunities highlighted. The key research fields proposed in this article may also inform groundwater quality protection and management at the national and international level.
282 citations
TL;DR: Results showed a positive monotonic relationship between income and CO2 emissions and all models do not support the EKC hypothesis which assumes an inverted U-shaped relationship betweenincome and environmental degradation.
Abstract: This study attempts to empirically examine the impact of financial development, income, trade openness, and urbanization on carbon dioxide emissions for the panel of emerging economies using the time series data over the period 1990-2013. Results showed a positive monotonic relationship between income and CO2 emissions. All models do not support the EKC hypothesis which assumes an inverted U-shaped relationship between income and environmental degradation. Financial development has a long-run negative impact on carbon emissions, implying that financial development minimizes environmental degradation. This means that financial development can be used as an implement to keep the degradation environmental clean by introducing financial reforms. The urbanization decreases the CO2 emissions; therefore, it is important for the policymakers and urban planners in these countries to slow the rapid increase in urbanization.
281 citations
TL;DR: This special issue of Environmental Science and Pollution Research highlights selected papers whose results have been obtained in the course of the COMBITOX project, an interdisciplinary research project aiming at conceiving an inline multiparametric device for the surveillance of water networks using biosensors.
Abstract: This special issue of Environmental Science and Pollution Research highlights selected papers whose results have been obtained in the course of the COMBITOX project. COMBITIOX is an interdisciplinary research project funded by the French National Research Agency (ANR) aiming at conceiving an inline multiparametric device for the surveillance of water networks using biosensors. This device is not intended to fully replace chemical methods, but when compared to analytical chromatographic methodologies, biological sensors can offer rapid and on-site monitoring of even trace levels of targeted compounds (Sun et al. 2015) and can quickly raise the alarm in the event of an accidental or intentional pollution. Numerous developments have been published to improve the sensitivity, specificity, and time response of various biosensors in laboratory conditions (Xiong et al. 2012) (der Meer et al. 2010), but their actual transfer into technological devices for the surveillance of water networks remains at a conceptual level. Thus, the challenge here is to go a step beyond and validate biosensors under real-life field conditions by incorporating them in a single inline detector. During the course of COMBITOX, we could define the interface between the biosensors and a common light detector as well as the physical conditioning of the bioreagents and usage protocol. Our resulting prototype allow the detection of bioavailable toxic compounds as well as microorganisms, impacting human health through the drinking water network or interfering with the biological process of modern wastewater treatment plants. We also plan to propose this system to meet the emerging threats such as bioterrorism. COMBITOX focuses on three families of Bobjects^ to detect: metals (cadmium, mercury, arsenic, nickel, etc.), environmental and/or food toxins, and pathogenic microorganisms. Whole-cell biosensors based on reporter gene under the control of an inducible promoter are used to detect various metals (Hynninen and Virta 2010), the antibody/antigen interaction for toxins (Makaraviciute and Ramanaviciene 2013), and the specific infection of bacteria by bacteriophages for pathogenic microorganisms (Smartt et al. 2012) (Vinay et al. 2015). In all cases, the signal measured is photochemical (fluorescence, bioluminescence, or chemo-luminescence): such a method to transduce the biological recognition is very sensitive and a single photodetector can be used for all biosensors included in the device. The challenge here rather lies in the design and the optimization of the different biological compounds for their use in the field while maintaining a high sensibility and robustness. As a consequence, the different articles presented in this special issue focus on original strategies for the optimization and the adaptation of the three types of biosensors for their use in a semi-autonomous inline water analyzer. In the case of whole-cell biosensors, improvement of the dose-responses Responsible editor: Philippe Garrigues
273 citations
TL;DR: The results indicate that except green purchasing, rests of the four independent variables have been found statistically significant to predict organizational performance and the eco-design of green practices followed by green information systems has revealed the greatest impact on organizational performance.
Abstract: This article investigates the impact of five determinants of the green supply chain practices on organizational performance in the context of Pakistan manufacturing firms A sample of 218 firms was collected from the manufacturing industry The green supply chain practices were measured through five independent variables including green manufacturing, green purchasing, green information systems, cooperation with customers, and eco-design By using exploratory factor and simultaneous regression analysis, the results indicate that except green purchasing, rests of the four independent variables have been found statistically significant to predict organizational performance However, the eco-design of green practices followed by green information systems has revealed the greatest impact on organizational performance Therefore, the managers of the manufacturing firms should not only implement eco-design in their supply chain but also concentrate on proper monitoring and implementation of green information systems to increase their firms’ performance A main contribution of this research from theoretical side is that it is possible to notice a negative effect of “green purchasing” towards organizational performance particularly in the scenario of Pakistan manufacturing industry Another valuable result is that green purchasing is an important antecedent of firms economic performance in the US manufacturing firms (Green et al 2012), although not significantly related to organizational performance in our study In addition, we also discussed research limitations, areas for future research, and implications for practitioners
TL;DR: It is observed that the EKC hypothesis is valid in France and the positive effect of the energy consumption on CO2 emissions is obtained, and a higher economic complexity suppresses the level ofCO2 emissions in the long run.
Abstract: This paper reanalyzes the determinants of the CO2 emissions in France. For this purpose, it considers the unit root test with two structural breaks and a dynamic ordinary least squares estimation. The paper also considers the effects of the energy consumption and the economic complexity on CO2 emissions. First, it is observed that the EKC hypothesis is valid in France. Second, the positive effect of the energy consumption on CO2 emissions is obtained. Third, it is observed that a higher economic complexity suppresses the level of CO2 emissions in the long run. The findings imply noteworthy environmental policy implications to decrease the level of CO2 emissions in France.
TL;DR: To improve knowledge on the nutritive benefits versus health risks associated with cassava consumption, further research is necessary to compare cassava cultivars and precisely study the influence of preparation methods.
Abstract: Due to its high adaptability, cassava (Manihot esculenta Crantz) is one of the world’s most cultivated and
consumed plants after maize and rice. However, there are relatively few scientific studies on this important crop. The objective of this review was therefore to summarize and discuss the available information on cassava cropping in order to promote sustainable practices in terms of production and consumption. Cassava cultivation has been expanding recently at the global scale and is widely consumed in most regions of South America, Africa, and Asia. However, it is also characterized by the presence in its roots of potentially toxic hydrocyanic acid. Furthermore, cassava can also absorb pollutants as it is currently cultivated near roads or factories and generally without consideration for potential sources of soil, water, or atmospheric pollution. Careful washing, peeling, and
adequate preparation before eating are therefore crucial steps for reducing human exposure to both environmental pollutants and natural hydrocyanic acid. At present, there is not enough precise data available on this staple food crop. To improve our knowledge on the nutritive benefits versus health risks associated with cassava consumption, further research is necessary to compare cassava cultivars and precisely study the influence of preparation methods.
TL;DR: Low density plastic debris probably recirculates between beach sediments and seawater in a greater extent than higher density debris and may be underestimated using current methods due to too small size of the debris, which influences also the findings of qualitative research of microplastics which provide the basis for conclusions about the sources ofmicroplastics in the marine environment.
Abstract: Microplastics’ (particles size ≤5 mm) sources and fate in marine bottom and beach sediments of the brackish are strongly polluted Baltic Sea have been investigated. Microplastics were extracted using sodium chloride (1.2 g cm−3). Their qualitative identification was conducted using micro-Fourier-transform infrared spectroscopy (μFT-IR). Concentration of microplastics varied from 25 particles kg−1 d.w. at the open sea beach to 53 particles kg−1 d.w. at beaches of strongly urbanized bay. In bottom sediments, microplastics concentration was visibly lower compared to beach sediments (0–27 particles kg−1 d.w.) and decreased from the shore to the open, deep-sea regions. The most frequent microplastics dimensions ranged from 0.1 to 2.0 mm, and transparent fibers were predominant. Polyester, which is a popular fabrics component, was the most common type of microplastic in both marine bottom (50%) and beach sediments (27%). Additionally, poly(vinyl acetate) used in shipbuilding as well as poly(ethylene-propylene) used for packaging were numerous in marine bottom (25% of all polymers) and beach sediments (18% of all polymers). Polymer density seems to be an important factor influencing microplastics circulation. Low density plastic debris probably recirculates between beach sediments and seawater in a greater extent than higher density debris. Therefore, their deposition is potentially limited and physical degradation is favored. Consequently, low density microplastics concentration may be underestimated using current methods due to too small size of the debris. This influences also the findings of qualitative research of microplastics which provide the basis for conclusions about the sources of microplastics in the marine environment.
TL;DR: These findings can have policy implications including the imposition of a “polluter pays” mechanism, such as the implementation of a carbon tax for pollution trading, to raise the urban population’s awareness about the importance of adopting renewable energy and to support clean, environmentally friendly technology.
Abstract: This study investigates the environmental Kuznets curve (EKC) hypothesis for the case of Turkey from 1960 to 2013 by considering energy consumption, trade, urbanization, and financial development variables Although previous literature examines various aspects of the EKC hypothesis for the case of Turkey, our model augments the basic model with several covariates to develop a better understanding of the relationship among the variables and to refrain from omitted variable bias The results of the bounds test and the error correction model under autoregressive distributed lag mechanism suggest long-run relationships among the variables as well as proof of the EKC and the scale effect in Turkey A conditional Granger causality test reveals that there are causal relationships among the variables Our findings can have policy implications including the imposition of a “polluter pays” mechanism, such as the implementation of a carbon tax for pollution trading, to raise the urban population’s awareness about the importance of adopting renewable energy and to support clean, environmentally friendly technology
TL;DR: This review will focus on the current understanding of NO interplay with phytohormones and other plant growth regulators under abiotic stress conditions.
Abstract: Nitric oxide (NO) is a free radical molecule involved in an array of functions under physiological and adverse environmental conditions As other free radical molecules, NO biological action depends on its cellular concentration, acting as a signal molecule when produced at low concentration or resulting in cellular damage when produced at sufficiently high levels to trigger nitro-oxidative stress Over the last decade, significant progress has been made in characterizing NO metabolism and action mechanism, revealing that diverse biosynthetic routes can generate this free radical in plants and its action mainly occurs through posttranslational modification (nitration and S-nitrosylation) of target proteins Intricate crosstalk networks between NO and other signaling molecules have been described involving phytohormones, other second messengers, and key transcription factors This review will focus on our current understanding of NO interplay with phytohormones and other plant growth regulators under abiotic stress conditions
TL;DR: The results support the existence of hypothetical EKC and indicate that trade openness negatively and significantly affects emissions, while real GDP and energy do positive effects of emissions and feedback linkages of emissions, real GDP, and trade are revealed.
Abstract: This paper examines whether the hypothetical environmental Kuznet curve (EKC) exists or not and investigates how trade openness affects CO2 emissions, together with real GDP and total primary energy consumption. The study sample comprises ten newly industrialized countries (NICs-10) from 1971 to 2013. The results support the existence of hypothetical EKC and indicate that trade openness negatively and significantly affects emissions, while real GDP and energy do positive effects of emissions. Moreover, the empirical results of short-run causalities indicate feedback hypothetical linkage of real GDP and trade, unidirectional linkages from energy to emissions, and from trade to energy. The error correction terms (ECTs) reveal in the long run, feedback linkages of emissions, real GDP, and trade openness, while energy Granger causes emissions, real GDP, and trade, respectively. The study recommendations are that our policymakers should encourage and expand the trade openness in these countries, not only to restrain CO2 emissions but also to boost their growth.
TL;DR: It has been concluded that more information regarding the types and quantities of antibiotics used by Chinese fish farmers is required and studies about the contribution of antibiotic usage in aquaculture to environmental levels in surface water, their potential risks on environment and human health, and the existence and spread of antibiotic resistance genes in Aquaculture are needed.
Abstract: China contributes to more than 60 % of the global aquaculture production, and its aquaculture industry has become one of the main players in food security. A large amount of antibiotics is believed to be used in fish cultivation for ensuring adequate production. The use of antibiotics as disease control agents and growth promoter in aquaculture in China has raised significant concerns recently because of the potential threats to human health. The extensive use of antibiotics in aquaculture may result in water and sediment contamination and the development of antibiotic resistance genes. In this review, the role of aquaculture in antibiotic contamination of the environment as well as the emerging concern of antibiotic resistance genes in China is discussed. Based on this review, it has been concluded that more information regarding the types and quantities of antibiotics used by Chinese fish farmers is required. Studies about the contribution of antibiotic usage in aquaculture to environmental levels in surface water, their potential risks on environment and human health, and the existence and spread of antibiotic resistance genes in aquaculture are needed.
TL;DR: The results suggest that anthropogenic activities, especially mining and smelting, have caused severe contamination of Cd, Pb, Zn, and Cu and posed very high potential ecological risk in the Xiangjiang River.
Abstract: Here, we aim to determine the distribution, ecological risk and sources of heavy metals and metalloids in the surface sediments of the Xiangjiang River, Hunan Province, China. Sixty-four surface sediment samples were collected in 16 sites of the Xiangjiang River, and the concentrations of ten heavy metals and metalloids (Mn, Zn, Cr, V, Pb, Cu, As, Ni, Co, and Cd) in the sediment samples were investigated using an inductively coupled plasma mass spectrometer (ICP-MS) and an atomic fluorescence spectrophotometer (AFS), respectively. The results showed that the mean concentrations of the ten heavy metals and metalloids in the sediment samples followed the order Mn > Zn > Cr > V > Pb > Cu > As ≈ Ni >Co > Cd. The geoaccumulation index (I geo), enrichment factor (EF), modified degree of contamination (mCd), and potential ecological risk index (RI) revealed that Cd, followed by Pb, Zn, and Cu, caused severely contaminated and posed very highly potential ecological risk in the Xiangjiang River, especially in Shuikoushan of Hengyang, Xiawan of Zhuzhou, and Yijiawan of Xiangtan. The Pearson's correlation coefficient (PCC) analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA) indicated that the ten heavy metals and metalloids in the sampling sediments of the Xiangjiang River were classified into three groups: (1) Cd, Pb, Zn, and Cu which possibly originated from Shuikoushan, Xiawan, and Yijiawan clustering Pb-Zn mining and smelting industries; (2) Co, V, Ni, Cr, and Al from natural resources; and (3) Mn and As. Therefore, our results suggest that anthropogenic activities, especially mining and smelting, have caused severe contamination of Cd, Pb, Zn, and Cu and posed very high potential ecological risk in the Xiangjiang River.
TL;DR: An overview on the impact of biochar on the chemical characteristics (greenhouse gas emissions, nitrogen loss, decomposition and humification of organic matter) and microbial community structure during composting of organic wastes and related mechanisms is provided.
Abstract: Biochar is produced by pyrolysis of biomass residues under limited oxygen conditions. In recent years, biochar as an amendment has received increasing attention on composting and soil remediation, due to its unique properties such as chemical recalcitrance, high porosity and sorption capacity, and large surface area. This paper provides an overview on the impact of biochar on the chemical characteristics (greenhouse gas emissions, nitrogen loss, decomposition and humification of organic matter) and microbial community structure during composting of organic wastes. This review also discusses the use of biochar for remediation of soils contaminated with organic pollutants and heavy metals as well as related mechanisms. Besides its aging, the effects of biochar on the environment fate and efficacy of pesticides deserve special attention. Moreover, the combined application of biochar and compost affects synergistically on soil remediation and plant growth. Future research needs are identified to ensure a wide application of biochar in composting and soil remediation.
TL;DR: This review provides a critical view of factors that affect absorption and translocation of POPs in plants and the limitations that plant have to deal with during the remediation of POPS.
Abstract: High toxicity, bioaccumulation factor and widespread dispersal of persistent organic pollutants (POPs) cause environmental and human health hazards. The combined use of plants and bacteria is a promising approach for the remediation of soil and water contaminated with POPs. Plants provide residency and nutrients to their associated rhizosphere and endophytic bacteria. In return, the bacteria support plant growth by the degradation and detoxification of POPs. Moreover, they improve plant growth and health due to their innate plant growth-promoting mechanisms. This review provides a critical view of factors that affect absorption and translocation of POPs in plants and the limitations that plant have to deal with during the remediation of POPs. Moreover, the synergistic effects of plant–bacteria interactions in the phytoremediation of organic pollutants with special reference to POPs are discussed.
TL;DR: Judicious use of water, management of soil, antagonistic effects of various inorganic plant-nutrients to As should be considered in rice cultivated areas to mitigate the building up of As in human food chain and with minimum negative impact to the environment.
Abstract: Arsenic (As) is a toxic metalloid. Serious concerns have been raised in literature owing to its potential toxicity towards living beings. The metalloid causes various water- and food-borne diseases. Among food crops, rice contains the highest concentrations of As. Consuming As-contaminated rice results in serious health issues. Arsenic concentration in rice is governed by various factors in the rhizosphere such as availability and concentration of various mineral nutrients (iron, phosphate, sulfur and silicon) in soil solution, soil oxidation/reduction status, inter-conversion between organic and inorganic As compounds. Agronomic and civil engineering methods can be adopted to decrease As accumulation in rice. Agronomic methods such as improving soil porosity/aeration by irrigation management or creating the conditions favorable for As-precipitate formation, and decreasing As uptake and translocation by adding a inorganic nutrients that compete with As are easy and cost effective techniques at field scale. This review focuses on the factors regulating and competing As in soil-plant system and As accumulation in rice grains. Therefore, it is suggested that judicious use of water, management of soil, antagonistic effects of various inorganic plant-nutrients to As should be considered in rice cultivated areas to mitigate the building up of As in human food chain and with minimum negative impact to the environment.
TL;DR: Impaired health impacts attributed to particulate matter less than 10 μg/m3 (PM10), nitrogen dioxide (NO2), and ozone (O3) in Kermanshah City (Iran) are assessed and immediate policies and actions are needed.
Abstract: Air pollution is emerging as a risk factor for human health like cancer and other health outcomes in developing countries, especially Iran where air pollutant concentrations are elevated. Additionally, some of the crucial environmental problems are caused by air pollution. Nevertheless, the data on health effects of air pollution are limited. The main objective of this study was to assess the health impacts attributed to particulate matter less than 10 μg/m3 (PM10), nitrogen dioxide (NO2), and ozone (O3) in Kermanshah City (Iran). The diurnal averages of PM10 and NO2 levels and 1-h averages of O3 concentrations were applied to assess the cardiovascular mortality due to exposure to these pollutants during the years 2014 and 2015. The excess number of cardiovascular mortality was estimated by relative risk (RR) and baseline incidence (BI) defined by the World Health Organization (WHO). The excess in mortality risk for cardiovascular diseases is of 188 premature deaths related to PM10, 33 related to NO2, and 83 related to O3, respectively. The results indicate that a 10-μg/m3 change in PM10, NO2, and O3 generates a relative risk of 1.066, 1.012, and 1.020, respectively. The excess of relative risk is of 6.6, 1.2, and 2.0%, respectively. Immediate policies and actions are needed to reduce the various sources of these pollutants from transport and energy manufacture facilities in Kermanshah.
TL;DR: The persistence of contaminants in the Arctic from distant sources first came to light in the late 1970s when pesticides were found in polar bear fat tissue and the reality of atmospheric POPs and their effects on wildlife and human health then became evident.
Abstract: Since the Second World War, scientists have identified certain chemical contaminants that exhibit toxic characteristics and are persistent in the environment, bioaccumulative, prone to long-range atmospheric transboundary migration and deposition, and expected to impose serious health effects on humans, wildlife, and marine biota adjacent to and distant from their origin of emission. These chemical pollutants are referred to as persistent organic pollutants (POPs) (Ashraf et al. 2015).
POPs have long half-lives in soils, sediments, air and biota. No consensus exists on how long the half-life in a given medium should be for the word “persistent� to be applicable; nevertheless, the half-life of a POP might be years or decades in soil/sediment and a number of days in the atmosphere. Several thousand POP chemicals are known. Many of them are members of a definite series or “families� of chemicals. For instance, 209 diverse groups of polychlorinated biphenyls have been identified; they differ from each other by the level of chlorination and the substitution position (Jones and Voogt 1999). The carbon-chlorine bond is very stable toward hydrolysis and larger numbers of chlorine substitution and/or functional groups lead to greater resistance to biological and photolytic degradation. Because POPs break down very slowly, they will be present in the environment for a long time, even if all new sources are immediately eliminated (Chu et al. 2006).
POPs in the environment are transported at low concentrations by movement of fresh and marine waters; in addition, because they are semi-volatile, POPs are transported over long distances in the atmosphere. The result is widespread distribution of POPs across the globe, including regions where they have never been used (Buccini et al. 2003). The POP levels observed in the Arctic region are surprising to many people because some of these pollutants have been banned from the USA and Canada for many years. POPs travel toward colder areas such as Alaska and then sink because of the colder temperatures. The settled contaminants remain in the area for a long period because the temperature does not allow them to easily breakdown. Consequently, they move from the air and water to soil and plants and then to animals and humans with ease. The persistence of contaminants in the Arctic from distant sources first came to light in the late 1970s when pesticides were found in polar bear fat tissue. The reality of atmospheric POPs and their effects on wildlife and human health then became evident. In addition to the Arctic, researchers have begun to search for evidence of airborne POPs in other cold ecosystems and mountain environments (Zhao et al. 2007).
POPs are usually hydrophobic (i.e., “water-hating�) and lipophilic (i.e., “fat-loving�) chemicals. In marine and terrestrial systems, they bind strongly to solids, particularly organic matter, evading the aqueous segment. They also enter the lipids of organisms more easily than the inside of the aqueous medium of cells and are stockpiled in fatty tissue. This stockpiling in fatty tissue allows the compounds to persevere in biota, where the metabolism rate is low. Consequently, POPs may climb the food chain. POPs tend to move in the gas phase under environmental temperatures. Therefore, they may volatilize from soils, vegetation, and aquatic systems into the air and, because of their resistance to breakdown reactions in air, migrate long distances before being re-deposited. The sequence of volatilization and condensation can be repeated frequently; as a consequence, POPs are detected in regions far removed from where they were used or discharged. POPs can partition between particles and aerosols in the air and are reliant on ambient temperature and the physico-chemical characteristics of the substances. In summary, the combination of permanency and the tendency to form a gas under suitable environmental conditions causes POPs to migrate long-range atmospheric distances. The combined effects of confrontation, metabolism, and lipophilicity result in the accumulation of POPs in food chains (Jones and Voogt 1999).
TL;DR: The potential causes of compaction and its consequences that have been published in last two decades are reviewed and various morphological and physiological alterations in plant as result of soil compaction have been discussed.
Abstract: Soil compaction causes substantial reduction in agriculture productivity and has always been of great distress for farmers. Intensive agriculture seems to be more crucial in causing compaction. High mechanical load, less crop diversification, intensive grazing, and irrigation methods lead to soil compaction. It is further exasperated when these factors are accompanied with low organic matter, animal trampling, engine vibrations, and tillage at high moisture contents. Soil compaction increases soil bulk density and soil strength, while decreases porosity, aggregate stability index, soil hydraulic conductivity, and nutrient availability, thus reduces soil health. Consequently, it lowers crop performance via stunted aboveground growth coupled with reduced root growth. This paper reviews the potential causes of compaction and its consequences that have been published in last two decades. Various morphological and physiological alterations in plant as result of soil compaction have also been discussed in this review.
TL;DR: The BT model showed that pollutants transported from the mainland of Indo-China and the marine region in the South China Sea were responsible for the high pollution event in the study area.
Abstract: Open biomass burning in Peninsula Malaysia, Sumatra, and parts of the Indochinese region is a major source of transboundary haze pollution in the Southeast Asia. To study the influence of haze on rainwater chemistry, a short-term investigation was carried out during the occurrence of a severe haze episode from March to April 2014. Rainwater samples were collected after a prolonged drought and analyzed for heavy metals and major ion concentrations using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. The chemical composition and morphology of the solid particulates suspended in rainwater were examined using a scanning electron microscope coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). The dataset was further interpreted using enrichment factors (EF), statistical analysis, and a back trajectory (BT) model to find the possible sources of the particulates and pollutants. The results show a drop in rainwater pH from near neutral (pH 6.54) to acidic (
TL;DR: This review focuses on recent research on the use of biochar for the adsorption of inorganic nitrogen (ammonium and nitrate) and phosphorus (phosphate) from water, especially for the main influence factors and mechanisms for nitrogen and phosphorus adsorbent on biochar.
Abstract: Biochar is the solid product of biomass pyrolysis that can be used for carbon sequestration, soil amendment, and pollution remediation. The use of biochar as an adsorbent for the removal of water contaminants has elicited increasing interest due to the multifunctional properties of this material. The application of biochar in the adsorption of inorganic nutrients from eutrophic water has not been reviewed. This review focuses on recent research on the use of biochar for the adsorption of inorganic nitrogen (ammonium and nitrate) and phosphorus (phosphate) from water, especially for the main influence factors and mechanisms for nitrogen and phosphorus adsorption on biochar.
TL;DR: The recent advances in the nanomaterials used for dye removal via adsorption, photocatalytic degradation, and biological treatment are reviewed and the modification methods for improving the effectiveness are highlighted.
Abstract: Organic dyes are one of the most commonly discharged pollutants in wastewaters; however, many conventional treatment methods cannot treat them effectively. Over the past few decades, we have witnessed rapid development of nanotechnologies, which offered new opportunities for developing innovative methods to treat dye-contaminated wastewater with low price and high efficiency. The large surface area, modified surface properties, unique electron conduction properties, etc. offer nanomaterials with excellent performances in dye-contaminated wastewater treatment. For examples, the agar-modified monometallic/bimetallic nanoparticles have the maximum methylene blue adsorption capacity of 875.0 mg/g, which are several times higher than conventional adsorbents. Among various nanomaterials, the carbonaceous nanomaterials, nano-sized TiO2, and graphitic carbon nitride (g-C3N4) are considered as the most promising nanomaterials for removing dyes from water phase. However, some challenges, such as high cost and poor separation performance, still limit their engineering application. This article reviewed the recent advances in the nanomaterials used for dye removal via adsorption, photocatalytic degradation, and biological treatment. The modification methods for improving the effectiveness of nanomaterials are highlighted. Finally, the current knowledge gaps of developing nanomaterials on the environmental application were discussed, and the possible further research direction is proposed.
TL;DR: The aim of this paper is to review the current state of knowledge on the behaviour of cyanide in the environment and its impact on the health and human life.
Abstract: Cyanide toxicity and their environmental impact are well known Nevertheless, they are still used in the mining, galvanic and chemical industries As a result of industrial activities, cyanides are released in various forms to all elements of the environment In a natural environment, cyanide exists as cyanogenic glycosides in plants seeds Too much consumption can cause unpleasant side effects However, environmental tobacco smoke (ETS) is the most common source of cyanide Live organisms have the ability to convert cyanide into less toxic compounds excreted with physiological fluids The aim of this paper is to review the current state of knowledge on the behaviour of cyanide in the environment and its impact on the health and human life
TL;DR: Except for some cases, GO and its derivatives show excellent adsorption capacities for PhAs, which is crucial for their applications in the environmental pollution cleanup.
Abstract: In this review paper, the ill effects of pharmaceuticals (PhAs) on the environment and their adsorption on graphene oxide (GO) and graphene oxide-based (GO-based) nanomaterials have been summarised and discussed. The adsorption of prominent PhAs discussed herein includes beta-blockers (atenolol and propranolol), antibiotics (tetracycline, ciprofloxacin and sulfamethoxazole), pharmaceutically active compounds (carbamazepine) and analgesics such as diclofenac. The adsorption of PhAs strictly depends upon the experimental conditions such as pH, adsorbent and adsorbate concentrations, temperature, ionic strength, etc. To understand the adsorption mechanism and feasibility of the adsorption process, the adsorption isotherms, thermodynamics and kinetic studies were also considered. Except for some cases, GO and its derivatives show excellent adsorption capacities for PhAs, which is crucial for their applications in the environmental pollution cleanup.