PCDDs/PCDFs and PCBs in water samples from the Three Gorge Reservoir

The Three Gorge Reservoir (TGR) is the largest reservoir in China and its water quality is an important health concern, we have determined the concentrations of PCDDs/PCDFs and PCBs in the water samples collected at three seasons: August 2004, January 2005 and August 2005. The results showed that the average WHO-TEQ of total dioxins-like compounds (PCDDs/PCDFs+PCBs) was 0.06558 pg l(-1), ranged from 0.0008 to 0.32439 pg l(-1), which are much lower than other reported water sources. The main dioxins (PCDDs/PCDFs) are hepta- and octa-chlorinated dibenzo-p-dioxins (CDDs) and chlorinated dibenzofurans (CDFs). Since the levels of dioxins may change after the last water-store stage, the present study provides important data to compare the water quality in the TGR in the future.     

Human exposure to dioxins through the diet in Catalonia,Spain: carcinogenic and non-carcinogenic risk

The main objectives of this study were to estimate the dietary intake of dioxins by the population of Catalonia, Spain, to determine which food groups showed the greatest contribution to this intake, and to assess the health risks potentially associated with the dietary dioxin intake. From June to August 2000, food samples were randomly acquired in seven cities of Catalonia. Dioxin concentrations were determined in 108 samples belonging to the following groups: vegetables, fruits, pulses, cereals, fish and shellfish, meats and meat products, eggs, milk and dairy products, and oils and fats. Estimates of average daily food consumption were obtained from recent studies. Total dietary intake of dioxins for the general population of Catalonia was estimated to be 95.4 pg WHO-TEQ/day (78.4 pg I-TEQ/day), with fish and shellfish (31%), diary products (25%), cereals (14%) and meat (13%) showing the greatest percentages of contribution to dioxin intake. The contribution of all the rest of food groups to the total dietary intake was under 20%. The non-carcinogenic risk index of dioxin intake through the diet was in the range 0.34-1.36, while the carcinogenic risk level was 1,360 excess cancer over a lifetime of 70 years. Our results corroborate the decreasing tendency in dietary intake of dioxins found in recent studies (2000-2001) from various countries.     

二恶英的生成及污染控制

介绍了二恶英的性质、毒性、污染源以及排放趋势,重点论述了二恶英的生成影响因素与污染排放控制技术.二恶英的生成影响因素主要有炭源、氯源、温度、催化剂和氧源等.二恶英的污染排放控制技术则介绍了传统的去除技术和一些降解技术.     

Historical trends of polychlorinated dibenzo-p-dioxins and dibenzofurans in three dated sediment cores from Mexico

This paper describes the first report of dioxins and furans (PCDDs/Fs) in sediment cores from Mexico. Sedimentation rates and vertical fluxes were estimated using ²¹⁰Pb dating. Two cores correspond to marine sediments and one to an endorheic lake. Concentrations of PCDDs/Fs found in the three sites are typical of non-impacted areas with low concentrations when compared to reference values. However the PCDDs/Fs sediment profiles show an increasing concentration trend in the upper core sections. This behavior is different from that found at many sites around the globe where diminishing concentrations have been reported. A strong predominance of OCDD was observed, and a comparison to typical composition profiles of industrial and other sources did not result in clear origin assignments for these measured compounds. We suggest that local sources may be responsible for the increase in concentration and, because these undetermined sources have not been curtailed, their importance is still growing.     

二恶英的生成及污染控制

介绍了二恶英的性质、毒性、污染源以及排放趋势,重点论述了二恶英的生成影响因素与污染排放控制技术.二恶英的生成影响因素主要有炭源、氯源、温度、催化剂和氧源等.二恶英的污染排放控制技术则介绍了传统的去除技术和一些降解技术.     

An evaluation of three empirical air-to-leaf models for polychlorinated dibenzo-p-dioxins and dibenzofurans

Three empirical air-to-leaf models for estimating grass concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (abbreviated dioxins and furans) from air concentrations of these compounds are described and tested against two field data sets. All are empirical in that they are founded on simplistic bioconcentration and related approaches which rely on field data for their parameterization. One of the models, identified as the EPA Model, partitions the total air concentration into vapor and particle phases, and separately models the impact of both. A second model addresses only the vapor phase; grass concentrations are modeled as a function of vapor deposition. For the third model, it is assumed that the grass plants "scavenge" a fixed volume of air of dioxins, and hence grass concentrations are modeled as a simple product of total air concentration and a constant scavenging coefficient. Field data from two sites, a rural and an industrial site in the United Kingdom, included concurrent measurements of dioxins in air and field grass, and dioxin and furan depositions, for one 6-week sampling period. Principal findings include: (1) the EPA Model underpredicted grass concentrations at the rural field site by a factor of 2, while the Scavenging Model underpredicted grass concentrations by a factor of 3.8, and the Vapor Deposition Model significantly underpredicted grass concentrations (by a factor greater than 10), (2) the presence of high soil concentrations for some of the dioxins and furans at the industrial site appears to have caused higher grass concentrations and confounded the air-to-plant modeling exercise, (3) the Scavenging Model could be calibrated to the data set; however, a key premise of this model that vapor and particle phase dioxins equally impact the plants, is not supported by the field data, (4) measured depositions are highly correlated to but systematically lower than modeled depositions, which could be due to modeling assumptions or a systematic measurement bias.     

Assessment of the emission of PCDD/Fs and dioxin-like PCBs from an industrial area over a nearby town using a selective wind direction sampling device

The development of new sampling devices or strategies to assess the concentration of persistent organic pollutants (POPs) in the environment has increased in the last two decades. In this study, a selective sampling device was used to evaluate the impact of potential local sources of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) emissions on the ambient air levels of such compounds in a town near an important industrial estate. Average concentrations of target compounds of up to 2.5 times for PCDD/Fs and 2 times for dl-PCBs were found to come from the industrial state confirming this area as the main responsible for the majority of such compounds reaching the town.This finding was supported by a PCDD/F and dl-PCB sample profile analysis and a principal component analysis (PCA), which established a direct link between the dioxin-like compounds found in the samples collected in the town and their source.     

The emission inventory of PCDD/PCDF in Taiwan

Establishment of a country or region-based dioxin inventory was considered a crucial step toward elimination of worldwide dioxins/POPs contaminations, although no harmonized method for the preparation of an inventory is available at present. In this study, we used limited data and information to generate an inventory of dioxin emissions from some major sources in Taiwan. A total of 67.25 g I-TEQ of dioxins released annually was estimated. Unlike most of the industrialized countries, municipal waste incineration is not the highest contributor for dioxins released into the atmosphere. In contrast, secondary copper smelting accounts for more than 39% of the total dioxin emissions, and is higher than those from all waste incinerators combined (23.7%). Cement kilns and electric arc furnaces for steels also produced significant portion (both >10%) of dioxins into the environment, followed by secondary aluminum smelting (6.53%), industrial oil combustion (5.02%) and power plants fueled by coal (5.01%). Other known sources are either insignificant with respect to their dioxin emissions or not included in this inventory due to lack of information or uncertainty of the results. Data presented in this report provide a general picture of dioxin emissions in Taiwan, but were mostly based on less reliable or representative information, especially with respect to emission factors from different emission sources. It is necessary to establish background information relative to our own environment at present. Upon available, the inventory should be updated accordingly for proper environmental management on dioxins.     

Dioxins in the Venice lagoon

Venice is famous around the world for its uniqueness and architectural splendours, arts and the history of the “Serenissima Repubblica”, as it was known in the past, but few are aware that Venice economy is strongly dependent on the industrial activities based mainly on the adjacent Porto Marghera area. For many years, the lagoon that physically separates the city from the dry land has avoided association between the concern connected with the pollution derived from these industrial activities and the public perception of Venice. Since 1995, dioxins have appeared as a lagoon contaminant, and their presence, at such a level requiring immediate “in depth” studies and interventions, has been fully realized for decades.     

Steps towards a European dioxin emission inventory

The results of a project aiming at collection and evaluation of information regarding the industrial and non-industrial emission sources for dioxins and furans (PCDD/PCDF) in 17 European Countries (EU 15, CH, N) are presented. An overview about national documents covering dioxin emission inventories for the period 1990-1995 is given. Some data on emissions associated with residual materials, waste and waste water are presented additionally. Based on the air emission data contained in these documents the most important emission sources were determined which are assumed to cover about 90% of the overall emissions. For the selected sources and for all 17 countries new estimates of the atmospheric PCDD/PCDF emissions were derived from average emission factors and statistical activity rates for the year 1994. As a result, on the European scale the largest annual PCDD/PCDF emission is assessed to be released from municipal waste incineration, quite closely followed by emissions from iron ore sintering. Considerable releases of dioxins and furans--based, however, on highly uncertain data--are further assessed for domestic burning, accidental fires and (former) use of contaminated wood preservatives (pentachlorophenol). A lower but still significant emission is further assigned to the sector of non-ferrous metal production; particular processes used in this branch proved to generate very high PCDD/PCDF flue gas concentrations.     

Status of PCDD/F-emission control in Germany on the basis of the current legislation and strategies for further action

The protection of environment from polychlorinated dibenzodioxin and -furan (PCDD/F) impacts, caused by a heterogeneous spectrum of thermal stationary sources and several others in chemical industry, bases on a comprehensive legislation in Germany. The results of this emission reduction strategy are presented by emission inventories for stationary, mainly industrial sources comparing in this paper data for emissions between 1994 and 2001. These results show that the implementation of best available techniques (BAT) at industrial sources for PCDD/F-reduction has been nearly fully exhausted at nearly all relevant sources and extensive overall emission reductions were achieved by the end of the 1990s. Further reductions for PCDD/F are needed for specific sources in metallurgical industries, especially sinter plants, and for domestic furnaces only. For coplanar PCBs (co-PCBs) almost no emission data are available from German sources; a few data from measurements of co-PCB have been published from two waste incineration plants. These measurements show that the emission limit value of 0.1 ng TEQ/m3 is not exceeded by co-PCBs in the waste gas in addition to the background PCDD/F concentration. As a consequence from the new appraisals for toxicity equivalences (TEQ) and tolerable daily intakes (TDI) of the World Health Organisation the Federal Environmental Agency in Germany discusses a level of 1 pg WHO TEQ/(kg(bw) d) as an acceptable limit value for adult's burden, taking into account, that this value is too much for children in the pre- and post-natal age and further action for PCDD/F- and co-PCB reduction is needed for the last sensitive group. As a summary can be reported that PCDD/F and co-PCB intakes into the nutrition chain could not have their origin from stationary industrial sources mainly. More attention should be given to more diffuse source such as residential combustion and others, which are more directly connected to the nutrition chain, like green food drying. Important effects could be expected by restrictions of PCDD/F impacts by regulations for control of feed, feed components and compounds feed for pigs and cattle.     

Levels of dioxins, dibenzofurans and selected other chlorinated organic compounds in food from Russia

Food is considered to be the main source of dioxins (PCDDs) and dibenzofurans (PCDFs) for human intake, but there are relatively few publications reporting the levels of dioxins and furans in food samples.^(1–4) Food samples from western to eastern Russia were collected during three recent trips by one of us (AS), and tested for dioxins and dibenzofurans to provide some indication of environmental contamination. The results show that in specific food samples there are more dioxins present than dibenzofurans, but in fish samples the opposite is true. We compare the levels found in Russian food with levels found in samples from other countries, on both wet weight and lipid basis. These Russian samples show ranges similar to but slightly lower than those seen in other industrial countries.     

Criteria for the evaluation of dioxins in the environment

In FRG and other countries unequivocal criteria for the limitation of dioxins (PCDD's/PCDF's) in food like vegetables and fruits are lacking. These have to be directly associated with the limitation of dioxins in the soil and the deposition of particulate matter as the two main pathways for plant contamination. Based on recent investigations in the vicinity of cable-waste incinerators in Northrhine-Westphalia with comparatively high contents of dioxins in garden plants and soils and other sources of dioxins, considerations are given for the establishment of the criteria urgently needed.     

Assessment of atmospheric metallic pollution in the metropolitan region of São Paulo, Brazil, employing Tillandsia usneoides L. as biomonitor

Tillandsia usneoides L. is an epiphytic bromeliad plant able to absorb water and nutrients directly from the air. For this reason this species was selected to carry out a monitoring study of air pollution in the metropolitan region of S?o Paulo, Brazil. Five consecutive transplantation experiments (8 weeks each) were performed in 10 sites of the city, submitted to different sources of air pollution (industrial, vehicular), using plants collected from an unpolluted area. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis. Traffic-related elements such as Zn and Ba presented high concentrations in exposure sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn and Co the highest contents were related to industrial zones and can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source.     

Assays of dioxins and dioxin-like compounds in actually contaminated soils using transgenic tobacco plants carrying a recombinant mouse aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic tobacco plant XD4V-26 showed a significant dose-dependent induced GUS activity when cultured on MS medium containing PCB126 [toxic equivalency factor (TEF) = 0.1]. In contrast, PCB169 and PCB180, which have 0.03 of TEF and unassigned TEF values, respectively, did not significantly induce GUS activity under the same conditions as with PCB126. When the tobacco plants were cultivated for up to 5 weeks on actually contaminated soils with dioxins and dioxin-like compounds collected from the periphery of an incinerator used for disposal of residential and industrial wastes, GUS activity in the leaves was dose-dependently increased. The plants clearly detected 360 pg-TEQ g^?1 of dioxins and dioxin-like compounds in this assay. There was a positive correlation between GUS activity and TEQ value of dioxins and dioxin-like compounds in the plants. This assay does not require any extraction and purification processes for the actually contaminated soil samples.     

An updated assessment of the exposure of Canadians to dioxins and furans

Dioxins and furans substituted in the 2,3,7, and 8 positions are highly toxic substances. The governments of Canada and Ontario have recently concluded that human exposure should not exceed 10 pg TEQ/kg bw/d. Updated estimates of average lifetime intakes by Canadian adults of dioxins and furans from all sources are under 10 pg TEQ/kg bw/d. The estimation of exposure calculated from current tissue concentrations in Canadian adults supports this finding. Excessive consumption of some highly contaminated fish and wildlife species may lead to intakes of dioxins and furans that approach or exceed the 10 pg TEQ/kg bw/d value and constitutes a danger to health.     

Dioxins, dioxin-like PCBs and chloroorganic contaminants in herring, Clupea harengus, from different fishing grounds of the Baltic Sea

The contaminant levels of dioxins, dioxin-like PCBs and a range of chloroorganic compounds have been determined in relation to various fishing grounds of the Baltic Sea. Sampling covered an area from the Skagerrak to the coast of Latvia. The data are compared with herring from fishing grounds in the North Sea and west of the British Isles. Also the temporal trend of the dioxin levels in the edible part of herring landed around the Island of Rügen is given from commercial samples collected between 1996 and 2004. A continuous increase of the dioxin concentrations was observed from west to east. Lowest concentrations of 0.199 ng WHO-PCDD/F-TEQ kg(-1)wet weight were found in herring fillets west of the British Isles. Highest level of 6.972 ng WHO-PCCD/F-TEQ kg(-1)w.w. was analysed in fillets off the coast of Latvia. Results showed also a spatial dependence of the WHO-TEQ ratio dioxins:dioxin-like PCBs and of the dioxin congener profile. Only the DDT group of various chloroorganic compounds determined, showed a dependence from the fishing ground. A clear temporal tendency could not be deduced from the data.     

Seasonal change of PCDDs/PCDFs/DL-PCBs in the water of Ayase River, Japan: pollution sources and their contributions to TEQ

In Japan, Ayase River is one of the most polluted rivers by PCDDs, PCDFs and dioxin-like PCBs, which are referred to as dioxins in this paper. The water samples of the river were collected once per month for a year, and dioxins were analyzed to examine the dioxin sources and their contributions to toxic equivalent (TEQ). The WHO-2006 TEQs ranged from 0.26 to 7.0 pg-TEQ L⁻¹ and the average was 2.7 pg-TEQ L⁻¹; eight of 12 samples exceeded the environmental quality standard in Japan (1.0 pg-TEQ L⁻¹). The TEQ value was high during the irrigation period from May to August. The most part of the dioxins in the river water existed in suspended solids (SS) and it seemed that the river received water with highly-dioxin-contaminated SS in the irrigation period. The homologue profiles of the water samples suggested that the dioxins were influenced by pentachlorophenol (PCP) and chlornitrofen (CNP) formulations which were widely used as herbicides for the paddy fields in Japan. According to TEQ apportionment estimated by using indicative congeners, the TEQ was mainly contributed by PCP. Moreover, it was also shown that the TEQ contributions of PCP and CNP formulations increased along with the increase of the total TEQ and the TEQ contribution was dominated by these herbicides during the irrigation period. Therefore, it was concluded that the herbicides-originated dioxins run off from the paddy fields into the river during the irrigation period and increased the dioxins level in the river water. The result from the principal component analysis was consistent with these conclusions.     

The war in Kosovo

During the operation “Allied Force” in the spring of 1999, the burning or damaging of industrial and military targets in the Former Republic of Yugoslavia resulted in the release of a large number of chemicals into the atmosphere. The releases contained not only conventional air pollutants, but also Semi-Volatile Organic compounds (SVOs) which are known to be hazardous to health. Under suitable meteorological conditions, these chemicals can be transported across borders over large distances. In this paper, an analysis of measurements and dispersion calculations is presented which provides evidence of pollutant transport from the conflict area to Greece. The measuring program was carried out in Xanthi, Greece and included aerosol sampling and subsequent analysis for the determination of the concentration of SVOs including dioxins, furans, PCBs (PolyChlorinated Biphenyls), PAHs (Polycyclic Aromatic Hydrocarbons) and organic phthalates. This paper focuses on two episodes of organic phthalates that were observed during the conflict period. Pollution measurements are interpreted by means of air trajectories and dispersion calculations. For this purpose, the HYSPLIT_4 (HYbrid Single-Particle Langrangian Integrated Trajectory) modeling system is used to calculate the dispersion of toxic substances.     

Human exposure to dioxins through diet in Italy

We have measured the content of polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (together defined as “dioxins”) in 269 samples of food of animal origin collected through the regional veterinary services, covering the national territory. Quantification of the dioxins was accomplished by isotope dilution method, and toxic equivalents (TEQ) were calculated. The average daily food intake was obtained from two main sources: national data collected by the National Institute of Nutrition, and data from an ongoing cohort study on diet and cancer including 40, 000 Italian subjects.

The mean value of dioxins measured in food of animal origin was 0.144 ± 0.266 pg-TEQ/g (range: 0.003–1.655 pg-TEQ/g). Fish was the item with the highest content. The estimated intake of dioxins with main food items of animal origin is presented. The major contribution to dioxins intake with food comes from cow milk and fish consumption. These results are in agreement with what observed in studies conducted in other countries, such as Germany, Finland, Japan, Spain, and are below the limits set by the European legislation.