Dioxin Concentrations Research Articles

Development of Environmentally Friendly Technologies for Pyrolysis of Organic Compounds

One of the priority scientific areas for many years at the Krzhizhanovsky Power Engineering Institute (ENIN) has been studying the processing of low-grade solid fuels with the production of valuable lighter hydrocarbons in demand in the energy and chemical industries. From 1970–1990 with the direct participation of the institute’s staff, a technology was developed and mastered on an industrial scale for the processing of oil shale using solid coolant. The article shows that ENIN created a serious scientific basis and developed methods for studying the thermal decomposition of low-grade fuels in their various modifications, which allows them to be used for experimental studies into the processing of a wide range of organic materials. Information is provided on the results of studies at the ENIN full-scale experimental stand on the creation of a new technology based on the pyrolysis of organic compounds (low-grade fuels) with the rationale for its use for solving the urgent task of class B and C waste disposal. The circuit diagram is described in detail and the experimental stand’s main components playing a key role in the technological process of environmentally friendly disposal of medical waste (MW) are described. Much attention is paid to the issue of quenching (high-speed cooling) of exhaust gases, which plays a major role in preventing the secondary formation of dioxins. Calculation of the quenching device in the ANSYS Fluent software environment is verified using experimental data. The results of the experiments showed that the measured concentration of dioxins and furanes in the exhaust gases obtained at the ENIN experimental stand during its operation on a typical model mixture of medical waste without the use of special gas purification agents amounted to 0.03 I-TEQ (I‑TEQ—dioxin equivalent) under normal conditions at a concentration of O2 equal to 11%, which is lower than the European standard (0.1 I-TEQ).

Simple and rapid determination of dioxin in fish and sea food using a highly sensitive reporter cell line, CBG 2.8D

Food, especially animal origin food is the main source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (dl-PCBs) for human exposure. So, a simple, rapid and cheap bioassay method is needed for determination of dioxins in food samples. In this study, we used a new highly sensitive reporter cell line to determine the concentration of dioxins in 33 fish and seafood samples. The samples were extracted by shaking with water/isopropanol (1:1 v/v) and hexane and cleaned-up by a multi layered silica gel column and an alumina column, then analyzed using CBG 2.8D cell line. We compared the results obtained from the CBG 2.8D cell assay to those obtained from conventional High-Resolution Gas Chromatography–High Resolution Mass Spectrometry (HRGC–HRMS) analysis. Good correlations were observed between these two methods (r2=0.93). While the slope of regression line was 1.76, the bioanalytical equivalent (BEQ) values were 1.76 folds higher than WHO-TEQ values and the conversion coefficient was 0.568 (the reciprocal of 1.76). In conclusion, CBG 2.8D cell assay was an applicable method to determine dioxins levels in fish and sea food samples.

Characteristics of fly ash from waste-to-energy plants adopting grate-type or circulating fluidized bed incinerators: a comparative study

ABSTRACT Although the pressure of waste siege was reduced by the development of waste-to-energy (WTE) plants, every year million tons of toxic municipal solid waste incineration (MSWI) fly ash is produced which is regarded as a hazardous waste. In this paper, ten MSWI fly ash samples were collected to analyze the composition, physical properties, leachability of heavy metals, and toxicity of dioxins to obtain a comprehensive evaluation, which has not been discussed in the previous studies. The analysis and comparison of fly ash is based on the main type of incinerators applied nowadays. Due to differences in the incinerator types, there were significant differences observed in the size distribution, microstructure, element content, and crystalline structure of fly ash, which are related to the heavy metal leachability and dioxin toxicity. The heavy metal leaching toxicity of nine fly ash samples failed to meet the requirements of the landfill regulations. The main heavy metals above an unacceptable level are Pb (4.271 mg/L) in the grate-type fly ash and Cd (1.035 mg/L) in the circulating fluidized bed (CFB) fly ash. Furthermore, the I-TEQ concentrations of dioxins of two CFB fly ash (3.207 and 3.212 ng I-TEQ/g) exceeded the limit value. The main contribution to the dioxin concentrations of the fly ash is from OCDD (18.7–64.3%), and the main contributor to the I-TEQ (international toxicity equivalent quantity) value is 23478-PeCDF (range 33.0 to 43.2%). In addition, correlation between compositional analysis and toxicity indexes was discussed carefully. The findings in this work can provide directions for the disposal and utilization of the fly ash from different incinerators, which can be beneficial for MSWI fly ash management.

Serum metabolic changes associated with dioxin exposure in a Chinese male cohort

Dioxins, a group of persistent organic pollutants, have been proved to correlate with ranges of diseases by activating the aryl hydrocarbon receptor (AhR). However, previous dioxin toxicity studies primarily focused on the activation of AhR with signaling pathways at gene and protein levels. The investigation of underlying mechanisms at the metabolic level is still necessary. In this study, serum samples of 48 and 47 healthy participants with the highest and lowest dioxin levels based on quartile distribution of the serum dioxin concentrations of 215 male adults were selected for metabolomics analysis by using liquid chromatography coupled with orbitrap high-resolution mass spectrometry to investigate dioxin-related metabolic responses. The identified potential biomarkers included acylcarnitines, fatty acids and derivatives, glycerophospholipids, etc. suggested that metabolic pathways such as fatty acid β-oxidation, essential fatty acid metabolism, arachidonic acid metabolism, glycerophospholipid and sphingolipid metabolism and purine metabolism were disturbed by dioxin exposure. The results indicated that people with high dioxin exposure levels were at the potential health risks of inflammation, liver and cardiovascular diseases. The metabolic findings may help understand the link between dioxin exposure and the diseases.

The relationship between perinatal exposure to dioxins and serum steroid hormone levels in preschool-aged children at an e-waste region in China.

Perinatal exposure to dioxins affects steroid hormone synthesis. The purpose of the present study was to evaluate the associations between perinatal exposure to dioxins and serum steroid hormone levels in preschool-aged children from an e-waste recycling region in China. In the present study, we enrolled 50 pairs of mothers and infants from the Taizhou, Luqiao region in 2015. Of the 50 pairs of mothers and infants, 42 pairs participated in this study when the children were 4 years old. We measured breast milk dioxin concentrations using high-resolution gas chromatography/mass spectrometry. Additionally, we used liquid chromatography-tandem mass spectrometry to measure the concentrations of progesterone, testosterone, androstenedione (A-dione), and dehydroepiandrosterone (DHEA) in serum samples from the 4-year-old children. We used multivariate linear regressions to assess the associations between dioxin congeners and steroid hormones. Results were reported as beta estimates and 95% confidence intervals by bootstrapping. We observed sex-related differences between breast milk dioxins and serum steroid hormone levels in 4-year-old children. An increase in breast milk dioxins was associated with a decrease in testosterone in serum samples from boys. Similarly, an increase in breast milk dioxins was associated with a decrease in progesterone levels in serum samples from girls. However, dioxins were not associated with changes in the levels of testosterone, DHEA, or A-dione in girls. Based on these results, we conclude that perinatal exposure to dioxins modifies steroidogenesis in preschool-aged children. However, the long-term impact of dioxins requires further large-scale studies to assess these effects in school-going children and adolescents.

Актуальність проблеми визначення діоксинів і поліхлорованих біфенілів (ПХБ) у продуктах для дитячого харчування

The Aim of the Article. Analysis of the current state of the problem of the dioxins and polychlorinated biphenyls (PCBs) determination in baby food products and the development of sample preparation methods for determining these xenobiotics in food products for infants and young children. Dioxins form a group of structurally and chemically related chlorinated tricyclic oxygen-containing aromatic compounds (congeners), which includes 75 polychlorinated dibenzo-para-dioxins (PCDDs) and 135 polychlorinated dibenzofurans (PCDFs). The most toxic congeners of dioxins, in which chlorine atoms along with other positions are necessarily in 2,3,7,8 positions of benzene rings. Their total number is 17:7 PCDD congeners and 10 PCDF congeners. A group of polychlorinated biphenyls (PCBs) – chlorinated bicyclic aromatic compounds, which consists of 209 different congeners, 12 of which have a spatial and electronic structure and exhibit toxicological properties similar to dioxins, therefore, they are called dioxin-like PCBs (DL-PCBs). In addition, when monitoring food products as a marker, a group of 6 PCBs was selected that did not exhibit dioxin-like toxicity and therefore did not belong to dioxin-like PCBs (NDL-PCBs). Thus, of the total number of 419 PCDDs, PCDFs and PCBs, only 35 are toxicologically significant, therefore, these compounds are subject to control in baby food products. To control the content of the amount of dioxins, the amount of dioxins and DL-PCBs and the amount of NDL-PCBs in foods for infants and children from one to three years in Ukraine, the maximum levels of these compounds on the basis of the order of the Ministry of Health of Ukraine No. 368 of 05/13/2013 were harmonized with the maximum allowable levels in foods for infants and young children in accordance with Commission Regulation (EU) No. 1259/2011. Methods for the analysis of dioxins and PCBs. Two instrumental analysis methods are used to determine dioxins and dioxin-like PCBs in foods for baby food: 1) a combination of high-resolution (capillary) gas chromatography with high-resolution mass spectrometry (GC/MS); 2) a combination of GCHR with tandem mass spectroscopy (GC/MS/MS). High-resolution (capillary) gas chromatography is used to determine non-dioxin-like (marker) PCBs. The stage of sample preparation, including the stages of extraction and purification, is key in determining dioxins and PCBs. Conclusions. The stage of sample preparation using automatic devices (liquid extraction under pressure, an automated extract purification system) and chromatographic columns was developed to further determine the mass concentration of dioxins and PCBs in baby food products. The developed procedures using devices for the automatic extraction and purification of the obtained extracts from baby food samples will make it possible in the future to determine PCDDs/PCDFs, ortho-unsubstituted, mono-ortho-substituted and marker PCBs in one sample. Key Words: dioxins, polychlorinated biphenyls, baby food.

Influence of xenobiotic detoxication gene polymorphisms and experience on the level of accumulation of dioxins in Emercom of Russia employees

Relevance. Occupational activities of firefighters are considered extreme. Toxic combustion products are the most dangerous. Among these products, dioxins and dioxin-like compounds are particularly dangerous due to their ability to accumulate in the body.Intention is to analyze the content of toxic combustion products in atmospheric air during and after fires of various locations, as well as to evaluate dioxin concentrations in the blood plasma of employees of the Federal Firefighting Service of the Emercom of Russia, depending on the polymorphic variants of xenobiotic detoxification genes and professional experience.Methodology. To assess accumulation of dioxins in the body of firefighters with different polymorphic variants of xenobiotic detoxification genes, atmospheric air at different locations of fires was assessed for toxic combustion products. Accumulation of dioxins in the body of firefighters was analyzed depending on the polymorphisms of xenobiotic detoxification genes and work experience. 350 employees of the Federal Firefighting Service of the Emercom of Russia were examined, of them there were 234 firefighters and 116 supervisory staff involved in the investigations at the fire sites. The control group consisted of 82 rescue workers who were not directly involved in fire fighting. The examined individuals aged (32.2 ± 9.5) years.Results and Discussion. The data obtained indicate that high concentrations of dioxins in surface air at the fire site persist for more than 2 weeks, while the maximum permissible concentration is increased 4.5-10-fold. The highest concentration of dioxins is observed during fires in industrial enterprises and in residential buildings. According to the analysis of the dioxins in the blood of the Federal Firefighting Service employees and the control group, concentrations of individual chemical compounds among the employees of the Federal Firefighting Service were 2–7 times higher and 15 times higher in terms of the dioxin equivalent compared to the control group (p <0.05). High concentrations of dioxins were also revealed in the blood of supervisory staff. Analysis of the dioxins in the blood of the staff of the Federal Firefighting Service, EMERCOM of Russia showed that increased length of service correlated with dioxin concentrations in the blood: variations in chemical compounds reached 2.3–6.8 times (p <0.05) between those with 0–1 year vs 6 years or more experience and 1.3–1.7 times (p <0.05) between those with 2–5 years vs 6 years and more experience. Concentrations of dioxins in the blood plasma of employees of the Federal Firefighting Service of the Emercom of Russia were assessed depending on the polymorphic variants of xenobiotic detoxification genes and professional experience. A group of individuals carrying the combination of the EPHX1 Tyr / Tyr, CYP1A1 A / A, GSTT1 I / I, GSTM1 I / I, GSTP1 A / A, GSTP1 C / C genotypes was revealed: their dioxin concentrations in the blood were as low as 25% of that among other groups despite length of service.Conclusion Genotyping of firefighters will help arrange timely measures to detoxify dioxins, especially in carriers of minor alleles of xenobiotic biotransformation genes, in order to reduce morbidity and increase professional longevity.

Baseline characterization of sediments and marine biota near industrial effluent discharge in Northumberland Strait, Nova Scotia, Canada

A bleached kraft pulp mill operating in Nova Scotia, Canada has discharged effluent into a former tidal estuary known as Boat Harbour since 1967. After treatment in Boat Harbour, effluent is discharged into Northumberland Strait. Contaminated sediments in Boat Harbour are slated for remediation following cessation of effluent discharge. A review of historical documents to identify contaminants in marine biota in Northumberland Strait found insufficient data to properly assess baseline conditions prior to remediation. This study measured metal, methylmercury, dioxin and furan concentrations in surficial sediments and American lobster (Homarus americanus), rock crabs (Cancer irroratus) and blue mussels (Mytilus edulis) in Northumberland Strait. When compared to Canadian Council of Ministers of the Environment sediment quality guidelines and Canadian Food Inspection Agency tissue guidelines results indicated limited contamination in sediments and biota, posing low risk to marine biota. Long-term monitoring is recommended to verify effectiveness of remediation.

High inter-species differences of 12378-polychlorinated dibenzo-p-dioxin between humans and mice

Although huge interspecies differences in the response to dioxins have been acknowledged, toxic equivalency factors derived from rodent studies are often used to assess human health risk. To determine interspecies differences, we first developed a toxicokinetic model in humans by measuring dioxin concentrations in environmental and biomonitoring samples from Southern China. Significant positive correlations between dioxin concentrations in blood and age were observed for seven dioxin congeners, indicating an age-dependent elimination rate. Based on toxicokinetic models in humans, the half-lives of 15 dioxin congeners were estimated to be 1.60–28.55 years. In consideration that the highest contribution to total toxic equivalency in blood samples was by 12378-polychlorinated dibenzo-p-dioxin (P5CDD), this study developed a physiologically based pharmacokinetic (PBPK) model of 12378-P5CDD levels in the liver, kidney, and fat of C57/6J mice exposed to a single oral dose, and the half-life was estimated to be 26.1 days. Based on estimated half-lives in humans and mice, we determined that the interspecies difference of 12378-P5CDD was 71, much higher than the default usually used in risk assessment. These results could reduce the uncertainty human risk assessment of 12378-P5CDD, and our approach could be used to estimate the interspecies differences of other dioxin congeners.

Brazilian medical waste program as an intent to reduce costs and air release of carcinogens.

e19128 Background: Hospital waste management is a current sustainability challenge. The proper waste separation is principally recommended in most protocols, despite not always performed. Potentially infectious, sharp and chemical residues must be properly incinerated. Incineration increases the cost of waste management and releases hazardous gases into the atmosphere, such as dioxins. Dioxins are extremely stable compounds with an estimated half-life of 7 to 9 years in humans. As an important compound of air pollution, they have been classified as a class I human carcinogen by the International Agency for Research on Cancer. The dioxin carcinogenicity evolves action on transcriptional activation and inhibition of apoptosis. A higher serum concentration of dioxins is found in individuals who live near incinerators or who consume food produced near them.Furthermore, studies showed a 3 to 4 times higher risk of developing cancer in inhabitants of the neighborhood of waste incinerators and an association of serum concentration of dioxins and mortality from different types of cancer. Some neoplasms related to this exposure are lung cancer, soft tissue sarcomas and Non-Hodgkin Lymphoma. Methods: We present the impact of adequate division of medical waste from an institution in the Federal District - Brazil with data collected for 8 years. The residues were separated into two groups, the first being formed of residues that should be incinerated (potentially infectious, sharps and chemicals); and the second for regular garbage, which could be recyclable or non-recyclable. Results: By training the team and establishing appropriate protocols for proper segregation of materials, we achieved a saving of 66% from what would have been incinerated waste, equivalent to 76 tons, of which 71.9 tons correspond to recyclable waste. Also, the incineration cost was five times higher than the adequate disposal of regular waste. If the waste separation protocol had not been implemented, the biohazardous and chemical material would have contaminated the rest of the residues, making incineration as a final destination mandatory for all the waste, resulting in the release of more gases after incineration and a 64% higher cost. Conclusions: Despite the barriers to the classification of residues such as non-standardization and inadequate training of hospital teams, this low-cost implementation procedures significantly reduces the cost of waste management and the air release of human carcinogens.

Resource utilization of municipal solid waste incineration fly ash in iron ore sintering process: A novel thermal treatment

High calcium in the municipal solid waste incineration (MSWI) fly ash made it a potential material for replacing part of the calcium flux used in iron ore sintering process. The results show that the sintering indexes were not negative affected but improved slightly as MSWI fly ash added, which is mainly because the ultra-fine material helped to obtain a better granulation and produced liquid phase under high temperature. Removal rates of harmful elements were improved as the increased content of chlorine brought in by the MSWI fly ash, which means that the residual contents of K, Na, Pb and Zn in the finished sinter were not increased significantly. 93.03% of the dioxins in the MSWI fly ash was degraded due to the fast heating rate and high temperature during sintering process, both of which are favorable factors for the degradation of dioxins. Although the addition of the MSWI fly ash made the concentration of SO2 and dioxins in the flue gas increased, standardized discharge can still be realized through conventional activated carbon system for flue gas purification. Therefore, the resource utilization and harmless disposal of MSWI fly ash can be realized through iron ore sintering process.

Hygienic assessment of the quality of water used in industrial manufacture

Phenols of natural and industrial origin were found in the Priangarya reservoirs in concentrations exceeding MAC. After chlorination, there was a marked increase in the content of chlorophenols and dioxins with a maximum concentration of the last 68 pg / l. Drinking water of this quality in combination with harmful factors of the working environment can be a risk factor for the health of workers.

Health effects of nutrients and environmental pollutants in Baltic herring and salmon: a quantitative benefit-risk assessment

BackgroundHealth risks linked with dioxin in fish remain a complex policy issue. Fatty Baltic fish contain persistent pollutants, but they are otherwise healthy food. We studied the health benefits and risks associated with Baltic herring and salmon in four countries to identify critical uncertainties and to facilitate an evidence-based discussion.MethodsWe performed an online survey investigating consumers’ fish consumption and its motivation in Denmark, Estonia, Finland, and Sweden. Dioxin and methylmercury concentrations were estimated based on Finnish studies. Exposure-response functions for several health endpoints were evaluated and quantified based on the scientific literature. We also quantified the infertility risk of men based on a recent European risk assessment estimating childhood dioxin exposure and its effect on sperm concentration later in life.ResultsBaltic herring and salmon contain omega-3 fatty acids and vitamin D, and the beneficial impact of these fishes on cardiovascular diseases, mortality, and the risk of depression and cancer clearly outweighs risks of dioxins and methylmercury in people older than 45 years of age and in young men. Young women may expose their children to pollutants during pregnancy and breast feeding. This study suggests that even in this critical subgroup, the risks are small and the health benefits are greater than or at least similar to the health risks. Value of information analysis demonstrated that the remaining scientific uncertainties are not large. In contrast, there are several critical uncertainties that are inherently value judgements, such as whether exceeding the tolerable weekly intake is an adverse outcome as such; and whether or not subgroup-specific restrictions are problematic.ConclusionsThe potential health risks attributable to dioxins in Baltic fish have more than halved in the past 10 years. The new risk assessment issued by the European Food Safety Authority clearly increases the fraction of the population exceeding the tolerable dioxin intake, but nonetheless, quantitative estimates of net health impacts change only marginally. Increased use of small herring (which have less pollutants) is a no-regret option. A more relevant value-based policy discussion rather than research is needed to clarify official recommendations related to dioxins in fish.

Switching Coal-Fired Thermal Power Plant to Composite Fuel for Recovering Industrial and Municipal Waste: Combustion Characteristics, Emissions, and Economic Effect

Combustion characteristics were studied experimentally for single droplets of fuel slurries based on wet coal processing waste with municipal solid waste components (cardboard, plastic, rubber, and wood) and used turbine oil. We established the ignition delay time for three various groups of fuel compositions in motionless air at 600–1000 °C. The minimum values are 3 s, and the maximum ones are 25 s. The maximum temperatures in the droplet vicinity reach 1300 °C during fuel combustion for compositions with 10% of used oil. The combustion temperatures of fuel compositions without oil are 200–300 °C lower. The concentrations of anthropogenic emissions in flue gases do not exceed those from dry coal combustion. Adding used oils to composite fuels reduces the concentrations of dioxins and furans in flue gases when municipal solid waste in the fuel burns out due to high combustion temperatures. Based on the experimental research findings, we have elaborated a strategy of combined industrial and municipal waste recovery by burning it as part of composite fuels, as illustrated by three neighboring regions of the Russian Federation with different industrial structures and levels of social development. This strategy suggests switching three typical coal-fired thermal power plants (one in each of the regions) to composite liquid fuel. It will reduce the hazard of waste to the environment and decrease the consumption of high-quality coals for power generation. Implementing the developed strategy for 25 years will save 145 Mt of coal and recover 190–260 Mt of waste. The positive economic effect, considering the modernization of fuel handling systems at thermal power plants and the construction of a fuel preparation plant, will make up 5.7 to 6.9 billion dollars, or 65–78%, respectively, of the main costs of three thermal power plants operating on coal within the identical period.

Risk Factors for Environmental Pollution with Dioxin-Containing Compounds

Introduction. It has been demonstrated that the use of 2,4-D herbicide contaminates the environment with polychlorinated compounds, including dioxins. Additional risk factors for population health and the environment include climatic conditions of Siberia, processes of translocation of compounds from soil to plants, their ability to reach the human body along trophic chains and to have a toxic effect. The objective of this study was to analyze the behavior of the 2,4-D herbicide and dioxins in the environment and to justify health risk factors. Materials and methods. We used the method of gas chromatography-mass spectrometry that combines high efficiency of separation of impurities, the possibility of determining their molecular composition, selectivity of recording, and high sensitivity. We used a chromatographic method to determine residual amounts of the 2,4-dichlorophenoxyacetic acid amine salt (2,4-D) in soil, feed, and food of plant and animal origin. The calculation of average and statistical errors of indicators was performed using t-test in MS Excel. Results. Contamination of water of open reservoirs of the Irkutsk Region with the 2,4-D herbicide amine salt was found in concentrations as high as 7.7 μg/L with a positive sample count of 49%. In spring and summer, the water of open reservoirs is also polluted. In soils, the 2,4-D amine salt is immobile, concentrated in the surface layer at the level of 0.42–0.37 mg/kg. The maximum total soil concentration of dioxins reached 1,479 ng/kg exceeding the maximum permissible soil concentration of dioxins by 306 times. The maximum concentration of dioxins in feed was found at the end of the growing season (317–322 ng/kg). Dioxins accumulate in fat-containing food; thus, measured dioxin concentrations in butter averaged 680.6 ng/kg demonstrating a 10-fold excess of the permissible level. The estimated daily intake of dioxins with food can be as high as 26.2 pg/kg, which is 2.6 times higher than the permissible daily dose. We conducted the environmental and medico-hygienic analysis of outcomes of using the effective herbicide that poses a serious danger to human health due to the possibility of dioxin formation. We identified risk factors and substantiated the daily dose of dioxins for humans as a temporary value.

Chloracne and Hyperpigmentation Caused by Exposure to Hazardous Aryl Hydrocarbon Receptor Ligands

Dioxins and dioxin-like compounds are environmental pollutants that are hazardous to human skin. They can be present in contaminated soil, water, and air particles (such as ambient PM2.5). Exposure to a high concentration of dioxins induces chloracne and hyperpigmentation. These chemicals exert their toxic effects by activating the aryl hydrocarbon receptor (AHR) which is abundantly expressed in skin cells, such as keratinocytes, sebocytes, and melanocytes. Ligation of AHR by dioxins induces exaggerated acceleration of epidermal terminal differentiation (keratinization) and converts sebocytes toward keratinocyte differentiation, which results in chloracne formation. AHR activation potently upregulates melanogenesis in melanocytes by upregulating the expression of melanogenic enzymes, which results in hyperpigmentation. Because AHR-mediated oxidative stress contributes to these hazardous effects, antioxidative agents may be potentially therapeutic for chloracne and hyperpigmentation.

The Environmental Significance of Sediment Surface Area as a Controlling Factor in the Preservation of Polychlorinated Dibenzo-P-Dioxins and Dibenzofurans (PCDD/PCDF) in Sediments Adjacent to Woodfibre Pulp Mill, Howe Sound, British Columbia

A sediment core was retrieved from an area adjacent to a Pulp and Paper Mill in Howe Sound, British Columbia, in order to examine the accumulation dioxins (PCDDs) and furans (PCDFs). Downcore distribution of TOC in the bulk samples is relatively uniform (0.5–1.7 wt. %). Bulk PCDD/F concentration shows selective enrichment and depletion at specific sediment horizons, and a low to moderate correlation with surface area (r2 = 0.23–0.54). TOC in size fractionated sediments ranges from 0.3–11 wt. % and shows a moderate correlation with surface area (r2 = 0.51). The relationship between PCDD/Fs and surface area is congener specific, ranging from no significant correlation (TCDD; r2 = 0.05), to a good correlation (i.e., OCDF; r2 = 0.74). Results indicate that both dioxin and furan concentrations are related to organic matter concentration, molecular chlorination and sediment surface area.

Industrial disposal processes for treatment of polychlorinated dibenzo-p-dioxins and dibenzofurans in municipal solid waste incineration fly ash.

Hazardous waste disposal is a serious environmental concern in China. Therefore, in this study, industrial trials were conducted in a low-temperature thermal degradation facility, a tunnel kiln, and a shaft kiln to effectively treat dioxins in municipal solid waste incineration (MSWI) fly ash. The results indicated that the low-temperature thermal degradation facility efficiently decomposed polychlorinated dibenzo-p-dioxins and dibenzofurans in the MSWI fly ash. Additionally, the concentrations of dioxins in the treated fly ash and exhaust gas were lower than the suggested standard limits and the degradation ratio of dioxins was ∼99%. Therefore, treated fly ash characterized by acceptable dioxin risks could be utilized for the production of non-fired building materials. The results from the tunnel kiln indicated complete decomposition of the dioxins in the firing and insulating sections. However, the addition of fly ash in the tunnel kiln increased the concentration of dioxins in the flue gas. This can be primarily attributed to the heterogeneous catalytic synthesis reaction in the low-temperature section of the tunnel kiln. The results from the shaft kiln indicated degradation of at least 22% of the dioxins in the ash. The dioxin concentration in the flue gas was lower than the national standard while that in the clinker was within a reasonable limit. Furthermore, the environmental risks were significantly reduced at fly ash addition ratios lower than 3%.

Cytochrome P450 1A2 activity and incidence of thyroid disease and cancer after chronic or acute exposure to dioxins.

Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD) is the most toxic congener of a family of structurally and mechanistically related persistent organic pollutants whose effects are mediated through the aryl hydrocarbon receptor (AhR). Induction of CYP1A1/2 by TCDD through the AhR depends on the magnitude and the duration of exposure. We aimed to assess CYP1A2 activity after acute and chronic exposure to TCDD. The Maincy cohort is a sample population from Melun in the Val-de-Seine region in France that lived for at least 5years close to a waste incinerator emitting polluted vapours (1974-2002) with high concentrations of dioxins (up to 2000 times the maximal recommended values). Acute exposure to TCDD (Viktor Yushchenko) has been described elsewhere by Sorg et al (Toxicol. Sci. 2012; 125:310-317). Both are rare cases of well-identified source of chronic and acute exposure to TCDD. All subjects underwent a full medical history and physical examination and had a cutaneous examination, and a retro-auricular skin biopsy was taken. A questionnaire was designed and used regarding demographic, personal, environmental and occupational characteristics. CYP1A2 activity was assessed 2hours after the ingestion of a drink containing caffeine through measurement of the metabolic ratio of paraxanthine (17X) over caffeine (137X) by LC-MS/MS or LC-UV. CYP1A1 expression in skin biopsies was determined by immunohistochemical analysis. Forty-seven exposed subjects (age 11-78) and 31 controls were included in the study. Eleven exposed subjects had a history of thyroid disease (23.4%), and 7 (14.8%) had a cancer vs none and 1, respectively, in controls. Nodular skin lesions were found in 13 exposed subjects (27.7%) vs none in controls. Mean CYP1A2 activity of the exposed population was modestly elevated as compared to controls (17X/137X metabolic ratio of 0.475 vs 0.374, P=.051). CYP1A2 was, however, induced (17X/137X, metabolic ratio >0.5) in 27.6% of the exposed cases vs 6.4% of the controls. In contrast, acute dioxin exposure was associated with a strong induction (mean 17X/137X, metabolic ratio of 1.9) still present 29months after the acute exposure. CYP1A1 was expressed in 59.6% of the skin biopsies (highly expressed in 31.9%) of the Maincy cohort. No correlation between CYP1A2 activity, CYP1A1 expression and clinical manifestations (thyroid disease, cancer, skin lesions) could be demonstrated. Higher frequencies of dysthyroidism and cancer were detected in the population exposed chronically to dioxins from a waste incinerator. CYP1A2 was induced in 27.6% of the exposed population, while the magnitude of induction was fourfold higher after acute exposure in the case of Yushchenko.

THE MATHEMATICAL APPROACH OF THE ASSESSMENT OF ECOLOGICAL RISKS ON THE EXAMPLE OF TOXINS

The article analyses the actual research and the meaning of assessment of ecological risks on the example of a non-threshold toxins. This question is very urgent from the point of using of a great amount of harmful substances, which get into the environmental and as a result into the food links, the users of which is a man. In this study it is examined the results of negative influence carcinogens on the health on the example vinyl chloride, arsenic, dioxins, which get into the organism of man via the using of water, polluted by these toxins. The article gives a short characteristic of selected harmful substances the main sources and the ways of getting into the environment and to the organism of man. To define certain risks, it was taken into consideration corresponding suitable, factors of risks, permissible concentration of carcinogens in the water, the rate of getting water into the organism of man, average time of possible harmful influence. On the basis of done calculations it was determined that the most amount of dioxins can get with water and the least amount of arsenic, the main risk for the mans health gives vinyl chloride. More over it exceeds the volume of permissible risk , which is rather dangerous for the person health. At present it is observed the simultaneous availability of many carcinogens both in air and in water. So it was examined the additive model of accounting of risks that foresees the consideration of some harmful factors. But the negative impact and available risks can be not only added but they can intensify a harmful influence of one factor on another. In this case it is observed such a phenomenon as a synergism, that also must be taken into consideration while calculating the risks. That′s why calculating such risks a coefficient of synergism was used. The study found out that the content carcinogens in water can be rather dangerous. The most danger is the content of dioxins in water in spite of the fact that they dissolve in water very bad.The article analyses the actual research and the meaning of assessment of ecological risks on the example of a non-threshold toxins. This question is very urgent from the point of using of a great amount of harmful substances, which get into the environmental and as a result into the food links, the users of which is a man. In this study it is examined the results of negative influence carcinogens on the health on the example vinyl chloride, arsenic, dioxins, which get into the organism of man via the using of water, polluted by these toxins. The article gives a short characteristic of selected harmful substances the main sources and the ways of getting into the environment and to the organism of man. To define certain risks, it was taken into consideration corresponding suitable, factors of risks, permissible concentration of carcinogens in the water, the rate of getting water into the organism of man, average time of possible harmful influence. On the basis of done calculations it was determined that the most amount of dioxins can get with water and the least amount of arsenic, the main risk for the mans health gives vinyl chloride. More over it exceeds the volume of permissible risk , which is rather dangerous for the person health. At present it is observed the simultaneous availability of many carcinogens both in air and in water. So it was examined the additive model of accounting of risks that foresees the consideration of some harmful factors. But the negative impact and available risks can be not only added but they can intensify a harmful influence of one factor on another. In this case it is observed such a phenomenon as a synergism, that also must be taken into consideration while calculating the risks. That′s why calculating such risks a coefficient of synergism was used. The study found out that the content carcinogens in water can be rather dangerous. The most danger is the content of dioxins in water in spite of the fact that they dissolve in water very bad.