Occurrence, source diagnosis, and biological effect assessment of DDT and its metabolites in various environmental compartments of the Pearl River Delta, South China: A review

This review summarizes and analyzes available data in the literature (mostly after 2000) on the occurrence of dichlorodiphenyltrichloroethane (DDT) and its main metabolites, dichlorodiphenyldichloroethane (DDD) and chlorodiphenyldichloroethylene (DDE), in the environment of the Pearl River Delta (PRD), South China. Generally, the concentration levels of the sum of DDT, DDD, and DDE, designated as DDTs thereafter, have not significantly declined since 1983. However, the composition of DDTs residues has changed with time. DDTs in soil, freshwater sediment and freshwater fish species were mainly residues from chronological use. There is evidence that new point sources, such as dicofol and anti-fouling paint, may have contributed DDTs to various environmental compartments. Risk assessment against existing criteria indicated that the levels of DDTs in water and some fish species may pose adverse effects to humans or wildlife, and those in sediment/soil may also cause negative impacts to the eco-environment of the PRD.     

A comprehensive review of hydrophobic silica and composite aerogels: synthesis,properties and recent progress towards environmental remediation and biomedical applications

Environmental Science and Pollution Research - The hydrophobicity of silica and composite aerogels has enabled them to acquire applications in a variety of fields. With remarkable structural,...     

Phosphorus flame retardants: properties, production, environmental occurrence, toxicity and analysis

Since the ban on some brominated flame retardants (BFRs), phosphorus flame retardants (PFRs), which were responsible for 20% of the flame retardant (FR) consumption in 2006 in Europe, are often proposed as alternatives for BFRs. PFRs can be divided in three main groups, inorganic, organic and halogen containing PFRs. Most of the PFRs have a mechanism of action in the solid phase of burning materials (char formation), but some may also be active in the gas phase. Some PFRs are reactive FRs, which means they are chemically bound to a polymer, whereas others are additive and mixed into the polymer. The focus of this report is limited to the PFRs mentioned in the literature as potential substitutes for BFRs. The physico-chemical properties, applications and production volumes of PFRs are given. Non-halogenated PFRs are often used as plasticisers as well. Limited information is available on the occurrence of PFRs in the environment. For triphenyl phosphate (TPhP), tricresylphosphate (TCP), tris(2-chloroethyl)phosphate (TCEP), tris(chloropropyl)phosphate (TCPP), tris(1,3-dichloro-2-propyl)phosphate (TDCPP), and tetrekis(2-chlorethyl)dichloroisopentyldiphosphate (V6) a number of studies have been performed on their occurrence in air, water and sediment, but limited data were found on their occurrence in biota. Concentrations found for these PFRs in air were up to 47 μg m(-3), in sediment levels up to 24 mg kg(-1) were found, and in surface water concentrations up to 379 ng L(-1). In all these matrices TCPP was dominant. Concentrations found in dust were up to 67 mg kg(-1), with TDCPP being the dominant PFR. PFR concentrations reported were often higher than polybrominated diphenylether (PBDE) concentrations, and the human exposure due to PFR concentrations in indoor air appears to be higher than exposure due to PBDE concentrations in indoor air. Only the Cl-containing PFRs are carcinogenic. Other negative human health effects were found for Cl-containing PFRs as well as for TCP, which suggest that those PFRs would not be suitable alternatives for BFRs. TPhP, diphenylcresylphosphate (DCP) and TCP would not be suitable alternatives either, because they are considered to be toxic to (aquatic) organisms. Diethylphosphinic acid is, just like TCEP, considered to be very persistent. From an environmental perspective, resorcinol-bis(diphenylphosphate) (RDP), bisphenol-A diphenyl phosphate (BADP) and melamine polyphosphate, may be suitable good substitutes for BFRs. Information on PFR analysis in air, water and sediment is limited to TCEP, TCPP, TPhP, TCP and some other organophosphate esters. For air sampling passive samplers have been used as well as solid phase extraction (SPE) membranes, SPE cartridges, and solid phase micro-extraction (SPME). For extraction of PFRs from water SPE is recommended, because this method gives good recoveries (67-105%) and acceptable relative standard deviations (RSDs) (<20%), and offers the option of on-line coupling with a detection system. For the extraction of PFRs from sediment microwave-assisted extraction (MAE) is recommended. The recoveries (78-105%) and RSDs (3-8%) are good and the method is faster and requires less solvent compared to other methods. For the final instrumental analysis of PFRs, gas chromatography-flame photometric detection (GC-FPD), GC-nitrogen-phosphorus detection (NPD), GC-atomic emission detection (AED), GC-mass spectrometry (MS) as well as liquid chromatography (LC)-MS/MS and GC-Inductively-coupled plasma-MS (ICP-MS) are used. GC-ICP-MS is a promising method, because it provides much less complex chromatograms while offering the same recoveries and limits of detection (LOD) (instrumental LOD is 5-10 ng mL(-1)) compared to GC-NPD and GC-MS, which are frequently used methods for PFR analysis. GC-MS offers a higher selectivity than GC-NPD and the possibility of using isotopically labeled compounds for quantification.     

Ion-imprinted polymers for environmental monitoring of inorganic pollutants: synthesis, characterization, and applications

Ion imprinting has become one of the fast-growing technologies that have gained a lot of attention recently especially in the area of materials science. One of them is called the ion-imprinted polymers (IIPs). The IIPs are synthesized on the principles of enzyme phenomenon whereby a polymer is altered by a polymerization that takes place in the presence of a template that will be later removed to create cavities that will recognize only the analyte of interest. This specific and selective affinity for the target species decreases the chances of competition with other different types of ions. The imprinting technique started with the discovery of the bulk polymerization method where by the monomer, initiator, crosslinker, and template are mixed together and allowed to polymerize, and then the resulting polymer is ground and sieved to get particles with sizes suitable for the polymer's application. The IIPs have got some attractive qualities for use in environmental applications which include their stability and inexpensiveness and have a wide range of synthesis options with each suiting a certain unique application. Apart from environmental work, IIPs have applications in many other areas such as in membranes, in drug delivery, and in biosensors as alternatives to antibodies just to mention a few. This review focuses on the synthesis, types of imprinting, characterization, and applications of IIPs.     

Rapid assays for environmental and biological monitoring

Abstract

Rapid, inexpensive, sensitive, and selective enzyme‐linked immunosorbent assays (ELISAs) now are utilized in environmental science. In this laboratory, many ELISAs have been developed for pesticides and other toxic substances and also for their metabolites. Compounds for which ELISAs have recently been devised include insecticides (organophosphates, carbaryl, pyrethroids, and fenoxycarb), herbicides (s‐triazines, arylureas, triclopyr, and bromacil), fungicides (myclobutanil), TCDD, and metabolites of naphthalene and toluene. New rapid assays have been developed for mercury.     

Nanoscale zero-valent metals: a review of synthesis,characterization, and applications to environmental remediation

Engineered nanoscale zero-valent metals (NZVMs) representing the forefront of technologies have been considered as promising materials for environmental remediation and antimicrobial effect, due to their high reducibility and strong adsorption capability. This review is focused on the methodology for synthesis of bare NZVMs, supported NZVMs, modified NZVMs, and bimetallic systems with both traditional and green methods. Recent studies have demonstrated that self-assembly methods can play an important role for obtaining ordered, controllable, and tunable NZVMs. In addition to common characterization methods, the state-of-the-art methods have been developed to obtain the properties of NZVMs (e.g., granularity, size distribution, specific surface area, shape, crystal form, and chemical bond) with the resolution down to subnanometer scale. These methods include spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), electron energy-loss spectroscopy (EELS), and near edge X-ray absorption fine structure (NEXAFS). A growing body of experimental data has proven that nanoscale zero-valent iron (NZVI) is highly effective and versatile. This article discusses the applications of NZVMs to treatment of heavy metals, halogenated organic compounds, polycyclic aromatic hydrocarbons, nutrients, radioelements, and microorganisms, using both ex situ and in situ methods. Furthermore, this paper briefly describes the ecotoxicological effects for NZVMs and the research prospects related to their synthesis, modification, characterization, and applications.     

A review about COVID-19 in the MENA region: environmental concerns and machine learning applications

Environmental Science and Pollution Research - Coronavirus disease 2019 (COVID-19) has delayed global economic growth, which has affected the economic life globally. On the one hand, numerous...     

Occurrence and environmental implications of pharmaceuticals in Chinese municipal sewage sludge

The presence of pharmaceuticals in aquatic environment has become a topic of concern because of their potential adverse effects on human health and wildlife species. A total of 45 dewatered sewage sludge samples were collected throughout China and analyzed for 30 commonly consumed pharmaceutical residues. Ofloxacin was found to be the dominant contaminant with concentrations up to 24 760 μg kg⁻¹, followed by oxytetracycline (5280 μg kg⁻¹), norfloxacin (5280 μg kg⁻¹) and ketoprofen (4458 μg kg⁻¹). The concentration of pharmaceutical residues varied greatly depending on the operation conditions of wastewater treatment plants and sampling locations. Poor agreement was found between the predicted (calculation based on the annual consumption and coefficient of sludge water partition) and detected concentrations of the pharmaceuticals indicating that the occurrence of pharmaceutical residues was affected by various factors such as loading rates, sewage properties and the chemical properties such as the contribution from polar groups. National wide fate and ecotoxicity study is required for the development of control strategies.     

Chlorophenols and other related derivatives of environmental concern: properties, distribution and microbial degradation processes

Chlorophenols are chlorinated aromatic compound structures and are commonly found in pesticide preparations as well as industrial wastes. They are recalcitrant to biodegradation and consequently persistent in the environment. A variety of chlorophenols derivatives compounds are highly toxic, mutagenic and carcinogenic for living organisms. Biological transformation by microorganisms is one of the key remediation options that can be exploited to solve environmental pollution problems caused by these notorious compounds. The key enzymes in the microbial degradation of chlorophenols are the oxygenases and dioxygenases. These enzymes can be engineered for enhanced degradation of highly chlorinated aromatic compounds through directed evolution methods. This review underscores the mechanisms of chlorophenols biodegradation with the view to understanding how bioremediation processes can be optimized for cleaning up chloroaromatic contaminated environments.     

Water toxicants: a comprehension on their health concerns,detection, and remediation

Environmental Science and Pollution Research - Water is an essential moiety for the human use since a long time. Availability of good-quality water is very essential, as it is used in almost all...     

Occurrence and congener profiles of polybrominated diphenyl ethers (PBDEs) in environmental samples from coastal British Columbia, Canada

Environmental levels and detailed congener profiles (31 congeners and 3 coeluting congener groups) of polybrominated diphenyl ethers (PBDEs) were assessed in a number of biota samples taken over a large geographic range covering harbours and industrial sites on Canada's West Coast. Additionally, PBDE congener profiles were determined using semipermeable membrane devices (SPMDs) deployed in the Fraser River, the river in Western Canada with the largest industrial activity. PBDE levels detected in biota were between 4 and 2300 ng/g lipid and these levels were compared with those reported in selected European biota to provide a wider perspective on PBDE contamination on Canada's West Coast. Thirteen-congener PBDE patterns in the environmental samples were examined using principal component analysis (PCA), and additionally, comparisons were made between the PBDE profiles in the sample groups and commercially used PBDE technical mixtures (e.g., Bromkals) on a percent composition basis. PCA on congener specific data revealed that PBDE patterns are remarkably similar over a wide geographical range in Western Canada, however, the general pattern in environmental samples varies significantly from those of the predominant technical mixtures. Finally, correlations between PBDE and other persistent and toxic co-occurring contaminants found in Dungeness crab were determined.     

A synthesis of convergent reflections,tensions and silences in linking gender and global environmental change research

This synthesis article joins the authors of the special issue “Gender perspectives in resilience, vulnerability and adaptation to global environmental change” in a common reflective dialogue about the main contributions of their papers. In sum, here we reflect on links between gender and feminist approaches to research in adaptation and resilience in global environmental change (GEC). The main theoretical contributions of this special issue are threefold: emphasizing the relevance of power relations in feminist political ecology, bringing the livelihood and intersectionality approaches into GEC, and linking resilience theories and critical feminist research. Empirical insights on key debates in GEC studies are also highlighted from the nine cases analysed, from Europe, the Americas, Asia, Africa and the Pacific. Further, the special issue also contributes to broaden the gender approach in adaptation to GEC by incorporating research sites in the Global North alongside sites from the Global South. This paper examines and compares the main approaches adopted (e.g. qualitative or mixed methods) and the methodological challenges that derive from intersectional perspectives. Finally, key messages for policy agendas and further research are drawn from the common reflection.     

Occurrence of arsenic in brown rice and its relationship to soil properties from Hainan Island, China

The acquaintance of arsenic concentrations in rice grain is vital in risk assessment. In this study, we determined the concentration of arsenic in 282 brown rice grains sampled from Hainan Island, China, and discussed its possible relationships to the considered soil properties. Arsenic concentrations in the rice grain from Hainan Island varied from 5 to 309 μg/kg, with a mean (92 μg/kg) lower than most published data from other countries/regions and the maximum contaminant level (MCL) for As_i in rice. The result of correlation analysis between grain and soil properties showed that grain As concentrations correlated significantly to soil arsenic speciation, organic matter and soil P contents and could be best predicted by humic acid bound and Fe-Mn oxides bound As fractions. Grain arsenic rises steeply at soil As concentrations lower than 3.6 mg/kg and gently at higher concentrations.     

The nexus between environmental regulations,economic growth,and environmental sustainability: linking environmental patents to ecological footprint reduction in South Asia

Environmental Science and Pollution Research - Environmental sustainability has become a major concern for policymakers across the globe. In this regard, understanding the factors responsible for...     

PTFE-coated non-stick cookware and toxicity concerns: a perspective

PTFE is used as an inner coating material in non-stick cookware. This unique polymer coating prevents food from sticking in the pans during the cooking process. Such cookware is also easy to wash. At normal cooking temperatures, PTFE-coated cookware releases various gases and chemicals that present mild to severe toxicity. Only few studies describe the toxicity of PTFE but without solid conclusions. The toxicity and fate of ingested PTFE coatings are also not understood. Moreover, the emerging, persistent, and well-known toxic environmental pollutant PFOA is also used in the synthesis of PTFA. There are some reports where PFOA was detected in the gas phase released from the cooking utensils under normal cooking temperatures. Due to toxicity concerns, PFOA has been replaced with other chemicals such as GenX, but these new alternatives are also suspected to have similar toxicity. Therefore, more extensive and systematic research efforts are required to respond the prevailing dogma about human exposure and toxic effects to PTFE, PFOA, and GenX and other alternatives.     

Pharmaceuticals in the Environment in Italy: Causes, Occurrence, Effects and Control

- DOI: http://dx.doi.org/10.1065/espr2006.01.004 Background, Aim and Scope Environmental contamination by pharmaceuticals is an emerging issue. Until recently, information on medicinal substances released into the environment was scant, but several studies have now been published. Data are, however, usually scattered and a systematic approach to this subject is generally lacking. Moreover, because of differences in the prevalence of diseases, treatment habits and options, or simply for market reasons, the pollution profile can differ significantly in different countries. The aim of this work is to review the papers dealing with environmental contamination by pharmaceuticals in Italy, with the aim of providing a comprehensive view on a national scale. Methods Papers related to environmental contamination by pharmaceuticals in Italy were reviewed, in order to offer a comprehensive view of this subject. Topics included analysis, occurrence, monitoring, modelling, treatment, control of the emissions, and ecotoxicological effects of pharmaceuticals in the environment. Results and Conclusion The literature suggests that pharmaceuticals are widespread contaminants, entering the environment from a myriad of scattered points. Patients, in case of drugs for human use, or animals for veterinary drugs, are the main sources of contamination. Pharmaceuticals can be ranked according to environmental loads, predicted by multiplying sales figures by the rate of metabolism in man or animals. Priority pharmaceuticals, i.e. the molecules of concern for the environment, can be measured in waste and surface water by liquid chromatography-tandem mass spectrometry, and the loads detected are generally comparable to the predicted ones. Pharmaceuticals are designed to stimulate a response in humans and animals at low doses, with a very specific target, so the implications for human health and the environment need to be assessed. In vitro and in vivo studies suggest that pharmaceutical principles, taken singularly or in combinations, and concentrations close to those detected in the environment, may have ecotoxicological effects. The sewage system is an important point in the control of contamination, but sewage treatment plants are not able efficiently to abate a substantial part of water-borne pharmaceuticals. Several variables play a role, however, in the processes of waste water treatment, and could be specifically adjusted to improve the efficiency of drug abatement, mitigating the potential environmental hazards. Recommendation and Perspective Pharmaceuticals in the environment are becoming a subject of global concern, with potential environmental consequences. Further knowledge of the causes, occurrence and effects of drugs as environmental pollutants is necessary for a better understanding of this ecological issue, as well as to improve abatement strategies, and to mitigate subtle environmental consequences.     

Recent trends in microbial nanoparticle synthesis and potential application in environmental technology: a comprehensive review

Environmental Science and Pollution Research - Microbial technology comprising environment in various aspects of pollution monitoring, treatment of pollutants, and energy generation has been put...     

Monofluorinated analogues of polychlorinated biphenyls (F-PCBs): synthesis using the Suzuki-coupling, characterization, specific properties and intended use

An improved method, a palladium-catalyzed cross-coupling reaction the so-called Suzuki-coupling, was used to synthesize 19 monofluorinated analogues (F-PCBs) of polychlorinated biphenyls (PCBs), including analogues of PCBs 28, 52 and 81. The coupling of chlorinated and/or fluorinated isomers of aryl boronic acids with bromo- and/or iodobenzenes gave the desired F-PCB congeners in good to excellent yields. The self-coupling product of the aryl boronic acids was the major impurity, but this limitation could be minimized. The influence of ortho-substitution by chlorine on the reaction time was studied in detail. The F-PCBs were characterized by means of ¹H and ¹⁹F NMR and mass spectrometry (MS). F-PCBs show remarkably similar characteristics in many aspects to those of the corresponding non-fluorinated parent PCBs. Since fluorine is generally resistant to degradation, once incorporated into a substrate it functions as an indelible label that can be used to monitor structures and dynamics. F-PCBs may prove their usefulness as markers and tracers in mechanistic and toxicological studies. The aim of further research will be to test the suitability of fluorine as a sensitive probe in a broad range of applications, including synthesis, analytical, mechanistic and toxicological studies.