Search Results (76)

To date, dust storms and haze episodes have rarely been compared with pollution characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and particulate matter, as well as human health risks due to a lack of efficient data. In this study, we selected dust storms and haze episodes in East China during 2023, monitored the concentrations of PCDD/Fs in ambient air, further revealed the main characteristic variations in PCDD/Fs toxic equivalent (TEQ) concentration and congener distribution in ambient air, and assessed the human health risk posed by dust storms and haze episodes. The results show that the TEQ concentration of PCDD/Fs in ambient air was 147.6 fg-TEQ/m³ in haze episodes compared with 48.7 fg-TEQ/m³ for dust storms and 25.8 fg-TEQ/m³ for a good weather day. This indicates that the concentration for PCDD/Fs and PM_2.5 in haze episodes was 3.03 times and 0.733 times, respectively, compared with dust storms. Moreover, the variations for particulate matter of air pollution during 2022–2023, as well as the relationship between PCDD/Fs and PM_2.5 in East China was also systematically revealed. The results reveal that the concentration of PM_2.5 shows a positive correlation with PCDD/Fs. Furthermore, the human health risk of dust storms was also compared with haze episodes. Accordingly, this study could fill the knowledge gap of dust storms and haze episodes on the transmission of PCDD/Fs in the ambient air of East China and provide a scientific reference for monitoring and early warning of PCDD/Fs. Full article

While many studies on the health effects of PM_2.5 exist, the risks of PM_2.5 species remain largely unexplored in Middle Eastern and North African countries. This study assesses, for the first time, the carcinogenic and non-carcinogenic health risks for elements, polycyclic aromatic hydrocarbons (PAHs), phthalates, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) bound to PM_2.5 in the Greater Cairo Area. A total of 59 samples were collected from an urban site in Dokki (November 2019–January 2020). Chemical analysis showed higher concentrations of PCDFs (5418 fg/m³) than PCDDs (1469 fg/m³), with DL-PCBs being the most abundant (6577 fg/m³). Health risk assessment for inhalation showed non-carcinogenic risks for all age groups, especially for newborns. Manganese (Mn) and lead (Pb) posed the highest elemental non-carcinogenic risk, while the hazard quotient (HQ) for PAHs exceeded 1 across all ages. PCDDs, PCDFs, and DL-PCBs showed an estimated cancer risk reaching 10⁻⁶ in adults, indicating a significant health concern. Key contributors to cancer risk included arsenic (As), chromium (Cr(VI)), and vanadium (V), which accounted for over 80% of the total elemental cancer risk. Major and trace elements posed the highest lifetime cancer risk, nearly 37 times the acceptable level. Full article

With the acceleration of global urbanization, polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), as a by-product of solid waste incineration, have attracted more and more attention for their environmental pollution and health hazards. By describing the generation and transformation mechanism of PCDD/Fs, this review focuses on the methods to control the generation of PCDD/Fs and reduce their environmental pollution. Initially, the study analyzes the formation mechanisms of PCDD/Fs, and it emphasizes that variations in incineration conditions, feedstock compositions, and technological approaches substantially influence PCDD/F formation. Subsequently, the review examines existing PCDD/F control technologies—including optimization technology of high-temperature pyrolysis and incineration, photocatalytic degradation technology, supercritical water oxidation technology and biodegradation—and evaluates their respective advantages and limitations. The current challenges and future research directions, such as the development of novel monitoring technologies, the development of industry standards, and the enhancement of policy support, are finally presented. Effective PCDD/F control requires advanced real-time monitoring (e.g., AI-enhanced mass spectrometry), unified global standards, and policy support (e.g., subsidies, phased regulations). Future solutions lie in multiscale modeling, international collaboration, and adaptive technologies for sustainable risk reduction. Full article

Urban soils are often affected by long-term deposition of persistent organic pollutants, including polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). This study evaluated the biodegradation potential of indigenous bacterial strains isolated from chronically contaminated soils in Lausanne, Switzerland. Using selective enrichment techniques, five strains were isolated, with no biosafety concerns for human health and environmental applications. These isolates were screened for their ability to degrade dibenzofuran (DBF) and 2,7-dichlorodibenzo-p-dioxin (2,7-DD) under mineral medium conditions. A simplified two-strain consortium (Acinetobacter bohemicus and Bacillus velezensis) and a broader five-strain co-culture were then applied to real soil microcosms over a 24-week period. This work provides the first experimental evidence that A. bohemicus and B. velezensis can degrade DBF and 2,7-DD under controlled conditions. Dioxin concentrations were monitored at 4, 8, and 24 weeks using a Gas Chromatography Mass Spectrometry (GC-MS). In laboratory conditions, co-cultures showed enhanced degradation compared to individual strains, likely due to metabolic complementarity. In soil, the simplified two-strain consortium performed better at dioxin degradation, especially at earlier time points. Although no statistically significant reductions were observed due to high variability and limited sample size, consistent trends emerged, particularly at the most contaminated site. These findings support the relevance of testing bioremediation strategies under realistic environmental conditions. Full article

The main objective of this study was to select indigenous fungal species suitable for the potential mycoremediation of the soils polluted by organic pollutants. As a sampling area, Litvínov City (North Bohemia, Czech Republic) was selected. The city is characterized by intensive coal mining, coal processing, and the chemical industry, predominantly petrochemistry. The elevated contents of persistent organic pollutants (POPs) such as polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were identified in urban soils due to the long-term industrial pollution. The results confirmed elevated contents of PAHs in all the analyzed soil samples with high variability ranging between 0.5 and 23.3 mg/kg regardless of the position of the sampling area on the city map. PCBs and PCDD/Fs exceeded the detection limits in the soil at the sampling points, and several hotspots were revealed at some locations. All the sampling points contained a diverse community of saprotrophic and mycorrhizal fungi, as determined according to abundant basidiomycetes. Fungal species with a confirmed ability to degrade organic pollutants were found, such as species representing the genera Agaricus from the Agaricaceae family, Coprinopsis from the Psathyrellaceae family, Hymenogaster from the Hymenogasteraceae family, and Pluteus from the Pluteaceae family. These species are accustomed to particular soil conditions as well as the elevated contents of the POPs in them. Therefore, these species could be taken into account when developing potential bioremediation measures to apply in the most polluted areas, and their biodegradation ability should be elucidated in further research. The results of this study contribute to the investigation of the potential use of fungal species for mycoremediation of the areas polluted by a wide spectrum of organic pollutants. Full article

A bioassay for dioxin analysis of human samples has the advantages of cost effectiveness and requiring only a small sample volume. Using a DR-EcoScreen bioassay, we measured the biological equivalency (BEQ) levels in serum samples from 32 men exposed to dioxins in Bien Hoa and 32 unexposed men in Hanoi, Vietnam. For the Bien Hoa men, the World Health Organization toxic equivalent (WHO-TEQ) levels of dioxins had already been measured by instrumental analysis. The difference in fat-based BEQ levels between exposed and unexposed men was greater than for crude BEQ levels, with a strong correlation between fat-based BEQ and WHO-TEQ levels. The fat-based BEQ levels in Bien Hoa men with longer residency but lower WHO-TEQ levels were significantly higher than those in unexposed men and Bien Hoa men with shorter residency but higher WHO-TEQs, suggesting that fat-based BEQ may be an effective marker of dioxin-like activity. Additionally, comparisons of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and TEQs between shorter- and longer-residency groups indicated that higher levels of polychlorinated dibenzo-p-dioxins (PCDDs), particularly TCDD, contribute to increased BEQ levels. Taken together, the DR-EcoScreen bioassay may be useful to analyze dioxin-like activity associated with WHO-TEQs of men in a dioxin contamination hotspot originating from Agent Orange in Vietnam. Full article

Municipal Solid Waste Incinerators (MSWIs) are facilities designed to burn municipal solid waste to reduce its volume and mass and generate energy. A significant concern related to MSWIs is the emission of toxic and carcinogenic pollutants, including polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), heavy metals, and particulate matter. This review synthesizes global epidemiological and exposure assessment studies investigating cancer risks associated with residential proximity to MSWIs. Findings reveal a complex relationship: older incinerators with high emissions correlate with elevated risks of non-Hodgkin lymphoma (NHL), soft-tissue sarcoma (STS), and liver cancer in some studies, particularly in Europe. However, results remain inconsistent due to methodological limitations such as exposure misclassification, latency periods, and confounding factors like socioeconomic status. Modern facilities equipped with advanced pollution control technologies demonstrate reduced risks, often within regulatory thresholds. Key challenges include accurately quantifying historical exposures and disentangling MSWI-specific risks from other environmental or lifestyle factors. While advancements in dispersion modeling and biomonitoring have improved risk assessments, geographical and temporal variations in findings underscore the need for continued research. The review concludes that while historical evidence suggests potential cancer risks near older MSWIs, stricter emissions regulations and technological improvements have mitigated health impacts, although vigilance through long-term monitoring remains essential to safeguard public health. Full article

The removal of polychlorinated dibenzo-p-dioxins (PCDDs) via advanced oxidation processes (AOPs) poses a significant challenge due to their high toxicity and chemical stability. In this study, a series of well-dispersed cobalt nanoparticles supported on carbon nitrides (xCoCNs) was synthesized to activate peroxymonosulfate (PMS) for 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD) degradation under visible light. The catalysts prepared were characterized using SEM, XPS, photoluminescence (PL), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). Among them, 2CoCN with an optimal Co content exhibited the highest photocatalytic efficiency, achieving 90.5% degradation of 2,8-DCDD within 160 min under visible light/persulfate oxidation (Vis+PMS+2CoCN system). Compared with other catalysts, 2CoCN exhibited superior optical performance and a narrower bandgap, enabling efficient excitation under visible light (Vis). Notably, all xCoCNs demonstrated pH adaptability, achieving complete degradation of 2,8-DCDD under neutral conditions (pH = 7) without additional acid/alkali adjustment. Through rigorous free radical capture experiments, it was demonstrated that SO₄^•−, ^•OH and ¹O₂ were the primary reactive oxygen species (ROS) in the Vis+PMS+2CoCN system. The catalyst exhibited excellent reusability, with stable activity retained over five cycles. Based on these findings, degradation pathways and mechanisms of 2,8-DCDD in the 2CoCN+Vis+PMS system were proposed. This study presents an effective approach for PCDD abatement in wastewater treatment applications. Full article

Selective catalytic reduction of nitrogen oxides with NH₃ (NH₃-SCR) was investigated deeper and deeper with poisoning factors such as H₂O, SO₂, heavy metals, etc. In order to remove the reheating process before the SCR reactor, the application trend of NH₃-SCR technology in the non-power industry is concentrated on the condition of low temperature even ultra-low temperature. The present study summarizes the research process of SO₂ and H₂O resistance of NH₃-SCR catalysts under low temperatures related to the working conditions of municipal solid waste incineration plants. In detail, the effects of a high content of H₂O and low concentration of SO₂ are reviewed. Other factors such as heavy metals, alkali, or alkaline earth metals in the reaction system, synergistic removal of NO_x, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are addressed. Finally, the catalytic performance of assembled monolithic catalysts and pilot-scale experiments are also analyzed for the possibility of industrial application. Hopefully, in view of the questions outlined in this study, valuable insights could be taken into consideration for the development of NH₃-SCR in waste incineration. Full article

Polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emissions during the roasting of green Arabica coffee and coffee formulations containing alcohol, sugar, and honey were investigated in this study. Fast and slow roasting methods, which took 5.62 and 9.65 min to achieve a light roast, respectively, were used to evaluate the emissions. The concentrations in the flue gas during the fast roasting of green coffee (0.0296 ng Nm⁻³ and 0.00364 ng WHO-TEQ Nm⁻³) were 13.9% and 70.5% higher than during slow roasting, respectively. However, this was only the trend for some formulations, and no significant differences in concentrations were found between the methods at p = 0.05. Thus, the slow roasting method might not necessarily reduce formation when additives are included. The emission factors were 2.86 ng kg⁻¹ and 0.352 ng WHO-TEQ kg⁻¹, and 4.17 ng kg⁻¹ and 0.176 ng WHO-TEQ kg⁻¹ for the fast and slow roasting of green coffee, respectively. Further investigations are warranted to understand the formation mechanism, assess potential health risks, and explore mitigation strategies. These findings have implications for both coffee processing industries and regulatory bodies, as understanding the impact of roasting methods and additives could inform the development of cleaner production practices and targeted emission reduction policies. Full article

The open burning of sugarcane residue is commonly used as a low-cost and fast method during pre-harvest and post-harvest periods. However, this practice releases various pollutants, including dioxins. This study aims to predict polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs or dioxins) emissions using the grey model (GM (1,1)) and to map the annual flux spatial distribution at the provincial level from 2023 to 2028. An annual emission inventory at the provincial level was developed using the activity rate of dry crop residue from national agencies and literature, following the guidelines set by the United Nations Environment Programme (UNEP). Emission distributions from 2016 to 2022 were then mapped. The average PCDD/F emission values show significant variation among the provinces, averaging 309 pg TEQ/year. Spatially, regions with intensive sugarcane production, such as Lampung and East Java consistently show high emissions, often exceeding 400 pg/m². Emissions calculated using the UNEP emission factor tend to be higher compared to other factors, due to its generic nature and lack of regional specificity. Emission predictions using GM (1,1) indicate that North Sumatra is expected to experience a steady increase in PCDD/Fs emissions, whereas South Sumatra and Lampung are projected are projected to see a slight decline. This forecast assumes no changes in regional intervention strategies. Most regions in Java Island show a gradual increase in emissions, except for East Java, which is predicted to have a slight decline from 416 pg/year in 2023 to 397 pg/year in 2028. Additionally, regions such as Gorontalo and parts of East Java are projected to remain ‘hotspots’ with consistently high emissions, highlighting the need for targeted interventions. To address emission hotspots, this study emphasizes the need for cleaner agricultural practices, enhanced enforcement of environmental regulations, and the integration of advanced monitoring technologies to mitigate the environmental and health impacts of PCDD/F emissions in Indonesia. Future studies should consider developing monthly emissions profiles to better account for local agricultural practices and seasonal conditions. The emission data generated in this study, which include both spatial and temporal distributions, are valuable for air quality modeling studies and can help assess the impact of current and future emissions on ambient air quality. Full article

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) are a group of organic chemicals containing three-ring structures that can be substituted with one to eight chlorine atoms, leading to 75 dioxin and 135 furan congeners. As endocrine-disrupting chemicals (EDCs), they can alter physiological processes causing a number of disorders. In this study, quantitative structure–toxicity relationship (QSTR) studies were used to determine the correlations between the PCDD/Fs’ molecular structures and various toxicity endpoints. Strong QSTR models, with the coefficients of determination (r²) values greater than 0.95 and ANOVA p-values less than 0.0001 were established between molecular descriptors and the endpoints of bioconcentration, fathead minnow LC50, and Daphnia magna LC50. The ability of PCDD/Fs to bind to several nuclear receptors was investigated via molecular docking studies. The results show comparable, and in some instances better, binding affinities of PCDD/Fs toward the receptors relative to their natural agonistic and antagonistic ligands, signifying possible interference with the receptors’ natural biological activities. These studies were accompanied by the molecular dynamics simulations of the top-binding PCDD/Fs to show changes in the receptor–ligand complexes during binding and provide insights into these compounds’ ability to interfere with transcription and thereby modify gene expression. This introspection of PCDD/Fs at the molecular level provides a deeper understanding of these compounds’ toxicity and opens avenues for future studies. Full article

The current research paper presents the results of the first regional assessment of sediment contamination by dioxins (polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs)) in the south-eastern part of the Baltic Sea (Lithuanian and Polish marine areas) during the periods of 2014 and 2019–2020. In total, 143 surface and core sediment samples were taken of existing offshore dredged-soil-disposal sites in the area of the former shipyard in the Port of Gdynia (Poland), as well as in a profile from the nearshore to the deeps of the Gdansk basin, following the natural pattern of sediment migration in the region. The obtained results indicated wide variation in both the total content of the investigated compounds as well as the profiles of congeners, indicating the likely sources of their origin. Based on the obtained concentration characteristic profiles of the congeners, we determined the amount of dioxins and the likely sources of their origin in the Gdansk Basin. The profiles showed elevated contents of octa- and hepta-chlorodibenzodioxins (OCDD and HpCDD) in the sediments, while the fractions of most other toxic congeners were considerably lower. The domination of OCDF in the spectrum of the studied PCDFs suggests the possible contribution of industrial processes. The obtained results have filled the gaps in our knowledge while providing a perfect background for more detailed discussions concerning the accumulation of dioxins in surface sediments from the south-eastern part of the Baltic Sea. Full article

Excess female births (lower sex ratio at birth) associated with paternal exposure to 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) have been reported in Italy. However, no significant effects of maternal TCDD exposure on the sex ratio were reported. We investigated the effects of maternal TCDD exposure and the toxic equivalent quantity of polychlorinated dibenzo-p-dioxins/dibenzofurans (TEQ-PCDD/Fs) on the sex ratio at birth in 576 Vietnamese infants from three birth cohorts. TCDD and TEQ-PCDD/Fs in breast milk were stratified (low, mild, moderate, and high) as maternal exposure markers. Logistic regression analysis was used to investigate associations between female birth and dioxin exposure groups after adjusting for confounders. In sprayed and unsprayed areas, adjusted odds ratios (ORs) of female birth (reference: low-TCDD group) were 2.11 in the moderate-TCDD group and 2.77 in the high-TCDD group, which were significantly associated with increased TCDD exposure. In sprayed areas, a significantly increased OR in the high-TCDD group was observed. No significant associations, however, were found between having a girl and TEQ-PCDD/F levels. These results suggest that maternal TCDD exposure may alter the sex ratio at birth among Vietnamese residents of areas with high dioxin contamination. Full article

Using a trace polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) stabilizing generator, an experimental study related to the influence of temperature (150, 165, and 180 °C) and activated carbon (AC) dosage (0.10, 0.15, and 0.20 g) on the adsorption effect of gas-phase PCDD/Fs via coal-based AC was conducted. Increasing the AC dosage is the most efficient method to improve the PCDD/Fs adsorption efficiency from 65.8% (0.10 g) to 93.0% (0.20 g) at 150 °C in an exponential trend. Both the polychlorinated-ρ-dibenzodioxins (PCDD)/polychlorinated dibenzofurans (PCDF) ratio and the Cl-PCDD/Fs value showed positive correlations, with the AC dosage under the same temperature. Increasing adsorption temperature declined the adsorption capacity of AC, resulting in the exponentially decreased average I-TEQ value adsorbed per gram of AC, from 131.3 ng TEQ/Nm³ (150 °C) to 55.9 ng TEQ/Nm³ (180 °C). The coal-based AC used in this study preferred to adsorb lower chlorinated PCDD/Fs, tetrachlorianted dibenzo-p-dioxin and dibenzofurans (TCDD/Fs), and pentachlorianted dibenzo-p-dioxin and dibenzofurans (PeCDD/Fs) than highly chlorinated PCDD/Fs, heptachlorianted dibenzo-p-dioxin and dibenzofurans (HpCDD/Fs), hexachlorinated dibenzo-p-dioxin and dibenzofurans (HxCDD/Fs), and octachlorianted dibenzo-p-dioxin and dibenzofurans (OCDD/Fs), which was aggravated by the increasing temperature. The characterization of the surface properties of AC revealed that slight oxidation occurred on the AC surface during the adsorption process, introducing oxygen to the competitive adsorption. In addition, it was found in this study that an increased temperature led to a higher content of hydrophilic carboxyl and anhydride groups and weakened π-π interactions, which were also partly responsible for the negative impact of the increasing temperature on the AC adsorption capacity. The results of this study can contribute to the operation optimization for controlling PCDD/F emissions from municipal solid waste incineration (MSWI). Full article