Relevance of BFRs and thermal conditions on the formation pathways of brominated and brominated-chlorinated dibenzodioxins and dibenzofurans

The widespread use of brominated flame-retarded products in the last two decades has resulted in an increasing presence of bromine in thermal processes such as waste combustion and accidental fires. Brominated and brominated-chlorinated dibenzodioxins and dibenzofurans (PBDDs/PBDFs, PXDDs/PXDFs) are micropollutants of concern arising from such processes. The present review aims to evaluate the relevance of these compound classes in actual thermal processes. Four categories of thermal processes are discussed in this respect according to their potential for PBDD/PBDF and PXDD/PXDF generation: thermal stress, pyrolysis/gasification, insufficient combustion conditions and controlled combustion conditions. Under thermal stress situations, as they may occur in production or recycling processes, PBDDs/PBDFs precursors like polybrominated diphenylethers (PBDE) can have a relevant potential for PBDD/PBDF formation via a simple elimination. Under insufficient combustion conditions as they are present in, e.g. accidental fires and uncontrolled burning as well as gasification/pyrolysis processes, considerable amounts of PBDDs/PBDFs can be formed from BFRs, preferably via the precursor pathway. In contrast, under controlled combustion conditions, BFRs and PBDDs/PBDFs can be destroyed with high efficiency. The relevance of de novo synthesis of PXDDs/PXDFs is discussed for this condition.Providing a basis for the understanding of PXDD/PXDF formation in actual thermal processes, the present paper also summarises the formation pathways of brominated and brominated-chlorinated PXDDs/PXDFs from brominated flame retardants (BFRs) investigated during laboratory thermolysis experiments. Relevant mechanistic steps for PBDD/PBDF formation from brominated precursors are discussed including elimination reactions, condensation steps and debromination/hydrogenation reactions.In addition, chlorination/bromination and halogen exchange reactions are briefly discussed with respect for their relevance on the final distribution of PBDDs/PBDFs, mixed chlorinated PXDDs/PXDFs and PCDDs/PCDFs resulting from thermal processes.     

Screening of halogenated aromatic compounds in some raw material lots for an aluminium recycling plant

Four samples of scrap raw materials for an aluminium recycling plant were screened for the occurrence of persistent halogenated aromatic compounds. The samples contained waste from handling of electric and electronic plastics, filter dust from electronic crusher, cyclone dust from electronic crusher and light fluff from car shredder. In our screening analyses, brominated flame retardants were observed in all samples. Polybrominated diphenyl ethers (PBDE) were identified in all samples in amounts of 245-67450 ng/g. The major PBDE congeners found were decabromo- and pentabromodiphenyl ethers. 1,1-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, ethyl-pentabromobenzene, tetrabromobisphenol-A, pentabromotoluene and dimethyl tetrabromobenzene were observed in all scrap samples. The concentrations of PCBs, PCNs (polychlorinated naphthalenes) and nona- to undecachlorinated terphenyls in some of these scrap samples were remarkably high.     

PAH emission from the incineration of three plastic wastes

A batch-type, controlled-air incinerator was used for the treatment of polyvinyl chloride (PVC), high-density polyethylene (HDPE), and polypropylene (PP) plastic wastes. The concentration and composition of 21 individual polycyclic aromatic hydrocarbons (PAHs) in the raw wastes, flue gas (gas and particle phases), and ash were determined. Stack flue-gas samples were collected by a PAH stack-sampling system. Twenty-one individual PAHs were analyzed primarily by a gas chromatograph/mass spectrometer (GC/MS). The CO concentration correlated well with the total PAH (R2 > .89), and thus can be used as a surrogate indicator for PAH emission. Excess amounts of air supply in the incineration of plastic wastes could decrease not only the concentration of the PAHs in the bottom ash but also the emission factor (EF) of the total PAH in the stack flue gas. Of the three plastic wastes, HDPE was found to have the highest mean EF of the total PAHs (462.3 mg/kg waste) from the stack flue gas. Incinerating PVC would result in a higher EF of PAHs (195.4 mg/kg waste) in the bottom ash. When PVC plastic wastes were incinerated, higher-ringed PAHs constituted a larger percentage in the bottom ash as compared to those from PP and HDPE plastics. By judging the output and input (O/I) ratio of the PAHs from the incineration trials of plastic wastes, the PAHs involved in incineration of three plastic wastes were almost entirely destroyed; and a low residual amount between 0.00018 and 0.00032 remained in the emission.     

Flame retardants in indoor dust and air of a hotel in Japan

Occurrence of flame retardants (FRs) in the indoor environment of highly flame-retarded public facilities is an important concern from the viewpoint of exposure because it is likely that FRs are used to a greater degree in these facilities than in homes. For this study, brominated flame-retardants (BFRs) and organophosphate flame-retardants and plasticizers (OPs), and brominated dibenzo-p-dioxins/furans (PBDD/DFs) were measured in eight floor dust samples taken from a Japanese commercial hotel that was assumed to have many flame-retardant materials. Concentrations of polybrominated diphenylethers (PBDEs) and hexabromocyclododecanes (HBCDs) varied by about two orders of magnitude, from 9.8–1700 ng/g (median of 1200 ng/g) and from 72–1300 ng/g (median of 740 ng/g), respectively. Concentrations of the two types of BFRs described above were most dominant among the investigated BFRs in the dust samples. It is inferred that BFR and PBDD/DF concentrations are on the same level as those in house and office dust samples reported based on past studies. Regarding concentrations of 11 OPs, 7 OPs were detected on the order of micrograms per gram, which are equivalent to or exceed the BFR concentrations such as PBDEs and HBCDs. Concentrations of the investigated compounds were not uniform among dust samples collected throughout the hotel: concentrations differed among floors, suggesting that localization of source products is associated with FR concentrations in dust. Passive air sampling was also conducted to monitor BFRs in the indoor air of hotel rooms: the performance of an air cleaner placed in the room was evaluated in terms of reducing airborne BFR concentrations. Monitoring results suggest that operation of an appropriate air cleaner can reduce both gaseous and particulate BFRs in indoor air.     

An overview of commercially used brominated flame retardants,their applications,their use patterns in different countries/regions and possible modes of release

Brominated flame retardants (BFRs) are used in a variety of consumer products and several of those are produced in large quantities. These compounds have been detected in environmental samples, which can be attributed to the anthropogenic uses of these compounds. Brominated flame retardants are produced via direct bromination of organic molecules or via addition of bromine to alkenes; hence, an overview of the production and usage of bromine over the past three decades is covered. Production, application, and environmental occurrence of high production brominated flame retardants including Tetrabromobisphenol A, polybrominated biphenyls, Penta-, Octa-, Deca-brominated diphenyl ether (oxide) formulation and hexabromocyclododecane are discussed.     

The influence of resource strategies on childhood phthalate exposure—The role of REACH in a zero waste society

The present study aims to investigate how resource strategies, which intend to reduce waste and increase recycling, influence on human exposure to hazardous chemicals from material recycling. In order to examine the flows of hazardous chemicals in recycled material, a mass flow analysis of plastics and paper at European level, including the flow of phthalates, i.e. di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), and benzyl-butyl phthalate (BBP), has been performed. The result for the year 2012 shows that 26% of plastic wastes and 60% of paper consumed in Europe were recycled. This corresponds to the finding that approximately 4% of DEHP and BBP and 18% of DBP annual demands in Europe as raw material re-enter the product cycle with recycled plastics and paper. To examine the potential contribution of the phthalate exposure through recycled plastics and paper, a case study assessing the childhood exposures to phthalates from foods packed in recycled paper and plastics has been performed for 2-year-old children in Denmark. The result verifies that an increase in recycled paperboard and PET bottles in food packaging material causes a significant increase in childhood exposure to DBP corresponding to an additional exposure of 0.116–0.355 μg/kg bw/day; up to 18% of the total DBP exposure in Danish 2-year-olds. While most of the DEHP exposure can be explained, more than 50% of DBP and 70% of BBP exposure sources still remain to be identified. Finally, a conceptual framework for a circular economy based on sustainable and clean resource flows is proposed in order to increase material recycling without increasing adverse health effects.     

Playing with fire: the global threat presented by brominated flame retardants justifies urgent substitution

Few would now deny that the use of organobromine compounds to achieve fire retardancy in a diverse array of products and materials has led to contamination of the ecosphere on a widespread scale. This environmental prevalence and persistence of the brominated flame retardants, coupled with growing evidence of their potential for harm, present all too familiar parallels with the previous generation of persistent organic pollutants. Indeed, given the intrinsic properties of these brominated chemicals, the nature and extent of the current problem could well have been predicted in advance. The question is then whether we are prepared to let history repeat itself once more or to take precautionary action now to switch to more sustainable alternatives. The choice facing society is not between brominated flame retardants and unsafe products, but between fire safety leading to global contamination or fire safety achieved in less polluting ways. If we look beyond options for simple chemical-for-chemical substitution to alternative materials and designs, many of the solutions are already available. The remainder could undoubtedly be developed given the incentives to do so. However, a strong and clear policy approach, backed by legislative phase-outs within specified (and challenging) timeframes, will be necessary to break our current dependency on organobromine chemistry. This paper presents the justification for such an approach, reviews those initiatives already underway to replace brominated flame retardants and identifies pathways to the use of more sustainable products in the service of society.     

Mercury risk from fluorescent lamps in China: Current status and future perspective

Energy-efficient lighting is one of the key measures for addressing electric power shortages and climate change mitigation, and fluorescent lamps are expected to dominate the lighting market in China over the next several years. This review presents an overview on the emissions and risk of mercury from fluorescent lamps during production and disposal, and discusses measures for reducing the mercury risk through solid waste management and source reduction. Fluorescent lamps produced in China used to contain relatively large amounts of mercury (up to 40 mg per lamp) due to the prevalence of liquid mercury dosing, which also released significant amounts of mercury to the environment. Upgrade of the mercury dosing technologies and manufacturing facilities had significantly reduced the mercury contents in fluorescent lamps, with most of them containing less than 10 or 5 mg per lamp now. Occupational hygiene studies showed that mercury emissions occurred during fluorescent lamp production, particularly in the facilities using liquid mercury dosing, which polluted the environmental media at and surrounding the production sites and posed chronic health risk to the workers by causing neuropsychological and motor impairments. It is estimated that spent fluorescent lamps account for approximately 20% of mercury input in the MSW in China. Even though recycling of fluorescent lamps presents an important opportunity to capture the mercury they contain, it is difficult and not cost-effective at reducing the mercury risk under the broader context of mercury pollution control in China. In light of the significant mercury emissions associated with electricity generation in China, we propose that reduction of mercury emissions and risk associated with fluorescent lamps should be achieved primarily through lowering their mercury contents by the manufacturers while recycling programs should focus on elemental mercury-containing waste products instead of fluorescent lamps to recapture mercury from the waste stream cost-effectively.     

Potential release scenarios for carbon nanotubes used in composites

The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limited information is available about release of CNTs from actual products and articles. As a starting point for exposure assessment, exploring sources and pathways of release helps to identify relevant applications and situations where the environment and especially humans may encounter releases of CNTs. It is the aim of this review to identify various potential release scenarios for CNTs used in polymers and identify the greatest likelihood of release at the various stages throughout the life-cycle of the product. The available information on release of CNTs from products and articles is reviewed in a first part. In a second part nine relevant release scenarios are described in detail: injection molding, manufacturing, sports equipment, electronics, windmill blades, fuel system components, tires, textiles, incineration, and landfills. Release from products can potentially occur by two pathways; (a) where free CNTs are released directly, or more frequently (b) where the initial release is a particle with CNTs embedded in the matrix, potentially followed by the subsequent release of CNTs from the matrix.The potential for release during manufacturing exists for all scenarios, however, this is also the situation when exposure can be best controlled. For most of the other life cycle stages and their corresponding release scenarios, potential release of CNTs can be considered to be low, but it cannot be excluded totally. Direct release to the environment is also considered to be very low for most scenarios except for the use of CNTs in tires where significant abrasion during use and release into the environment would occur. Also the possible future use of CNTs in textiles could result in consumer exposure. A possibility for significant release also exists during recycling operations when the polymers containing CNTs are handled together with other polymers and mainly occupational users would be exposed.It can be concluded that in general, significant release of CNTs from products and articles is unlikely except in manufacturing and subsequent processing, tires, recycling, and potentially in textiles. However except for high energy machining processes, most likely the resulting exposure for these scenarios will be low and to a non-pristine form of CNTs. Actual exposure studies, which quantify the amount of material released should be conducted to provide further evidence for this conclusion.     

Determination of relative assay response factors for toxic chlorinated and brominated dioxins/furans using an enzyme immunoassay (EIA) and a chemically-activated luciferase gene expression cell bioassay (CALUX)

Determination of toxic activity requires knowledge of both the concentration and toxicity to evaluate the risk for adverse human health and environmental effects. A chemically-activated luciferase gene expression cell bioassay system (CALUX) and an antibody-based method enzyme immunoassay (EIA) were used to detect the dioxin-like response of several polybrominated, polychlorinated, and polybrominated/chlorinated dibenzo-p-dioxins/furans (PBDDs/Fs, PCDDs/Fs, and PBCDDs/Fs, respectively). It has been suggested that the biological activity of the brominated and mixed bromo/chloro compounds is similar to their chlorinated analogues (measured by binding to the Ah receptor). PBDD/F, PCDD/F, and PBCDD/F laboratory standards exhibited biological activity ranging over three orders of magnitude. The highest relative potency (REP) values from CALUX analysis, when compared to 2,3,7,8-TCDD, were 2,3,7,8-TBDD at 0.99 (± 0.07), 1,2,3,7,8-PeCDD at 0.69, and 2-Br-3,7,8-TriCDD at 0.72 (± 0.02). Cross-reactivities were calculated using EIA for several PBDDs/Fs and PBCDDs. The highest percent cross-reactivity was found for 2,3,7,8-TBDD at 138 (± 34%), and 2,3,7-TriBDD at 84 (± 36%).     

Tropical fruit trees as bioindicators of industrial air pollution in southeast Brazil

Psidium guajava L., Psidium cattleyanum Sabine and Mangifera indica L. were tested under field conditions as possible tropical bioindicators of industrial air pollution. The study was performed around the industrial complex of Cubat?o, SE Brazil, which comprises 23 industries, including fertilizer, cement, chemical, petrochemical, and steel plants, with 110 production units and 260 emission sources of pollutants. Saplings were exposed to environmental conditions during four periods of 16 weeks each (September 1994-September 1995), at four different sites in the coastal mountains near the industrial complex: the Valley of Pil?es River (VP), the reference area; the Valley of Mogi River (VM), with high contamination of particulate matter, fluorides (F), sulfur (S) and nitrogen (N) compounds; Caminho do Mar (CM1, CM2), mainly affected by organic pollutants, S and N compounds, and secondary pollutants; and Paranapiacaba (PP), affected by secondary pollutants, such as ozone. M. indica did not adapt to the climatic conditions at the exposure sites. In the two Psidium species, the presence of visible symptoms, root/shoot ratio, foliar contents of F, S and N, amounts of ascorbate (AA) and water-soluble thiols (-SH), as well as peroxidase activity (POD) were determined. P. guajava showed higher foliar accumulation of F, S and N, more pronounced alterations of biochemical indicators, and less visible leaf injury than P. cattleyanum. P. guajava may be used as an accumulative indicator in tropical climates, while further studies will be needed before P. cattleyanum might be applied as a sensitive species in biomonitoring programs.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans pollution in China: sources, environmental levels and potential human health impacts

This review represents an assessment of the pollution status of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in China (the mainland, Hong Kong and Taiwan). During the past decades, seven PCDD/Fs pollution hotspots have been found: (a). Ya-er Lake, Hubei Province, with 'total PCDD/Fs' level reaching 177,427 pg g(-1) (dry weight) in lake sediments; (b). Chinese Schistosomiasis affected areas of Jiangxi Province with 33,660 pg g(-1) in soil; (c). e-waste recycling area of Yangtze River Delta, with 2726 pg g(-1) in paddy soil; (d). e-waste recycling area of Guiyu (eastern part of Guangdong Province), with 967,500 pg g(-1) in mixture of burnt residue and soil (the highest level among all hotspots); (e). Pearl River Delta with 2630 pg g(-1) in coastal sediment. (f). Kwun Tong, Victoria Harbour, Hong Kong with 10,999 pg g(-1) in coastal sediment; and (g). southern Taiwan with 606,000 pg g(-1) in soil near the vicinity of a pentachlorophenol manufacturing factory. The main sources of PCDD/Fs in China were formed from impurities during the production of polychlorophenol, hexachlorobenzene, polychlorinated biphenyls, organic chlorinated pesticide and triclosan. In addition, sources of PCDD/Fs included municipal waste incineration, mineral fuel usage, open burning of electronic waste and crop residues, industrial waste discharge and vehicle exhaust emission. Due to potential human health risks from long-term exposure to PCDD/Fs at these hotspots, body loadings of these contaminants should be monitored.     

Recovery of copper from small grain size fractions of municipal solid waste incineration bottom ash by means of density separation

Small grain size fractions of municipal solid waste incineration (MSWI) bottom ash (BA) contain elemental and chemically bonded metals in appreciable amounts, especially copper. Investigations with a centrifugal concentrator were carried out using samples, which had been treated with different impact devices. Partly the impacts of single devices were visible in outlines, but mostly the surfaces of the metals were still covered with mineral residues. To generate copper rich fractions, parameters of the separation process should ensure mass yields <2%, best between 0.5 and 1%. The density of the concentrates is then generally >3.2 g/cm³. Best results were achieved with material from a special treatment train which is adapted to grain sizes <2 mm. Reliable copper contents between 20 and 40% (single runs >50%) could be realised. However, considering the required mass yields, referred to this subset only 150–170 g copper would be recovered from 1 Mg MSWI BA. Furthermore, this copper is only in parts present in elemental form. A dependable added value of such treatment step seems to be given only, if that enables a recycling of the mineral aggregates (tailings) in parallel to avoid landfill costs.     

高炉渣资源化生产绿色建材的环境效益评估——基于生命周期的视角

高炉渣是钢铁厂高炉炼铁产生的矿渣,具有较高的资源化价值,可用于生产多种绿色建材产品。熔融高炉渣经水急冷后形成的粒化高炉矿渣,粉磨成矿渣微粉可作为水泥混合材和混凝土掺合料。以高炉渣资源化过程为研究对象,采用生命周期清单分析方法,并基于GaBi 4软件平台,对我国某建材企业综合利用高炉渣生产矿渣硅酸盐水泥和商品混凝土全过程的能源消耗、原材料消耗和温室气体排放进行了分析,进而从节能、降耗和碳减排三方面评估其环境效益。结果表明,与普通硅酸盐水泥相比,矿渣硅酸盐水泥可分别实现节约能源1 911 MJ/t(节能26%),降低原材料消耗1 158 kg/t(降耗27%),减少碳排放236 kg/t(碳减排26%);与复合硅酸盐水泥相比,矿渣硅酸盐水泥可实现节约能源352 MJ/t(节能6%),降低原材料消耗278 kg/t(降耗8%),减少碳排放47 kg/t(碳减排7%)。与不掺加矿粉的普通商品混凝土比较,掺矿粉的商品混凝土可实现节约能源97 MJ/m3(节能5%),降低原材料消耗7 kg/m3(降耗0.3%),减少碳排放12 kg/m3(碳减排5%)。高炉渣资源化生产矿渣硅酸盐水泥和商品混凝土具有明显的环境效益。     

循环经济的核心内涵是资源循环利用--兼论循环经济概念的科学运用

本文通过对循环经济与可持续发展相互关系的阐析，提出了循环经济作为一种可持续经济运行形态的基本概念和四个基本特征。并着重指出：循环经济的核心内涵是资源循环利用。最后。本文对国内出现的循环经济概念泛化与误用现象以及发展循环经济应把握的几个相关问题进行了分析说明。     

Radioactive discharges from an alkaline pulp mill located in the south of Spain

Artificial and natural radionuclides present in environmental samples (Eucalyptus wood and bark) can be transferred in an alkaline pulp mill and concentrated in the recycling process. Some part of the radionuclides can be released into the environment associated with the discharges from such a factory. An alkaline pulp mill located in the South of Spain was extensively sampled during 1993 and different radionuclides analysed in the collected samples. Thus the concentrations and fluxes of natural (40K, 226Ra, 228Ra and 228Th) and artificial (137Cs and 90Sr) radionuclides associated with the samples collected along the pulp production process are presented. It is shown that radium and thorium radionuclides behave similarly to strontium and calcium and, consequently, concentrate within the Ca-cycle. Furthermore, 40K and 137Cs are concentrated during the Na-cycle. Finally, the results obtained by the authors are compared with the levels found in similar factories, though situated in the North of Europe, by other researchers.     

Pollution prevention in the pharmaceutical industry

The pharmaceutical industry traditionally uses complex batch-type processes in the manufacture of medicines, although the production of specific medicines by continuous processes is currently envisaged. Due to the diversity of these processes, it is difficult to define a general set of waste prevention guidelines that would apply to all drug manufacturing. The most applicable methods of prevention can, however, be delineated for each of the five steps in the pharmaceutical manufacturing, i.e. (i) research and development, (ii) chemical synthesis, (iii) natural product extraction, (iv) fermentation and (v) product formulation. Waste streams generally arise from cleaning and sterilising equipment, chemical spills, rejected by-products and the processes themselves. Prevention mainly involves waste reduction by materials substitution, process modification/optimisation, waste stream segregation and solvent waste recycling. These measures are assessed and lead to guidelines for waste minimisation methods according to the waste streams under scrutiny.     

广义物质循环模型及对循环经济的政策内涵

在传统经济增长模式下。我国资源开采、生产、消费及消费末端各个环节的环境问题都十分突出。然而传统的物质循环并不能从根本上解决我国经济增长与生态环境之间的矛盾。在总结传统物质循环的特点与局限性的基础之上。提出了旨在提高经济系统全过程资源效率与环境绩效的广义物质循环的概念及理论模型；剖析了广义物质循环的资源与环境政策内涵，并据此提出我国资源环境的生命周期政策途径；最后以广义物质循环的内涵及基本原则为指导。深入探讨了我国循环经济发展的资源政策与环境政策。本文认为。建立与发展以广义物质循环为核心的循环经济增长模式。是我国实现经济与环境持续协调发展的根本途径。     

Life cycle sustainability assessments (LCSA) of four disposal scenarios for used polyethylene terephthalate (PET) bottles in Mauritius

Improper disposal of post-consumer Polythylene Terephthalate (PET) bottles constitutes an eyesore to the environmental landscape and gives rise to numerous environmental and health-related nuisances. These problems impact negatively on the flourishing tourism industry in Mauritius. The present study was therefore undertaken to determine a sustainable disposal method among four selected disposal alternatives of post-consumer PET bottles in Mauritius. The disposal scenarios investigated were: 100 % landfilling (scenario 1); 75 % incineration with energy recovery and 25 % landfilling (scenario 2); 40 % flake production (partial recycling) and 60 % landfilling (scenario 3); and 75 % flake production and 25 % landfilling (scenario 4). Environmental impacts of the disposal alternatives were determined using ISO standardized life cycle assessment (LCA) and the SimaPro 7.1 software. Cost-effectiveness was determined using Life cycle costing (LCC) as described by the recent Code of Practice on LCC. An excel-based model was constructed to calculate the various costs. Social impacts were evaluated using Social Life Cycle Assessment (S-LCA) based on the UNEP/SETAC Guidelines for Social Life Cycle Assessment. For this purpose, a new and simple social life cycle impact assessment method was developed for aggregating inventory results. Finally, Life Cycle Sustainability Assessment (LCSA) was conducted to conclude the sustainable disposal route of post-consumer PET bottles in Mauritius. The methodology proposed to work out LCSA was to combine the three assessment tools: LCA, LCC and S-LCA using the Analytical Hierarchy Process. The results indicated that scenario 4 was the sustainable disposal method of post-consumer PET bottles. Scenario 1 was found to be the worst scenario.     

Dioxins sources and current remediation technologies--a review

Dioxins are highly toxic and ubiquitous compounds that are unintentional by-products of several chemical processes on earth. According to the earth pollutant terminology, they are next to the nuclear catastrophes. It is because of their concerns over adverse health effects, a number of countries have introduced stringent emission standards. The present review focuses on entire sources of dioxins present in the environment. They are broadly classified into four major categories such as, incineration, combustion, industrial and reservoir sources. State-of-the-art remediation technologies available for reducing dioxins formation and emission from the important sources such as, flue gas, fly ash and soil were described in detail. Further, in order to get a comprehensive perception about the dioxins subject, topics such as, dioxins transfer in the environment, their mode of action, toxicity equivalence factor, exposure and health risk assessment were highlighted in brief in the introduction. A future prospects based on the findings of the review was discussed at the end.