Polychlorinated Dibenzo-p-dioxins Research Articles (Page 1)

Persistent organic pollutants in food systems: A comparative study across four contrasting socio-ecosystems: Portugal, Senegal, French Guiana, and Guadeloupe.

While many studies on the health effects of PM2.5 exist, the risks of PM2.5 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 PM2.5 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.

Abstract Polychlorinated dibenzo-p-dioxins and dibenzofurans are highly toxic pollutants that persist in the environment, bioaccumulate, and pose serious risks to human health and ecosystems. Their widespread presence, linked to cancer, endocrine disruption, and immune system impairment, required the knowledge of their long-term effects and mitigation approaches, which has led to the investigation of their toxicities. This review provides an overview of research progress, challenges, state-of-the-art control technologies, and future perspectives in the field of toxicology. Toxicological studies emerged from Asia, Europe, and North America, with most studies from the USA. Epidemiological studies have linked exposure to PCDD/Fs with adverse health outcomes, such as cancer, developmental abnormalities, and immune system disorders. Various techniques have been developed among others to remediate PCDD/Fs, including electrokinetic treatment, thermal desorption, vitrification, and supercritical water for soil and sediment. Biological methods are frequently preferred because they are more economical and environmentally advantageous. Eliminating persistent organic pollutants pollution sources for soils as well as controlling, securing, and remediating polluted sites and reservoirs are urgently needed measures to limit exposure and ensure food safety. In terms of control technologies, significant progress has been made in the development of state-of-the-art approaches for mitigating PCDD/F contamination. The development of cheaper and faster analytical methods to accurately measure these compounds in environmental and biological matrices is encouraged.

The term "dioxins" encompasses a group of chlorinated organic pollutants, including polychlorinated dibenzo-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), which impact human health, affecting immunological, neurological, endocrine, and reproductive systems. Activities like burning fuels, waste incineration, landfill fires, and certain industrial processes are major sources of dioxin emissions. There has been much debate on the quantity of dioxins released by waste incinerators but considerably less debate has been carried out on the dioxin emissions of landfill fires. Thus, this study evaluates dioxin emissions changes in countries that have transitioned from landfill to waste-to-energy (WTE) in a specific period. This study analyzes data from selected countries, including the UK, Austria, Poland, Ireland, Norway, Lithuania, Finland, and China, and applies parametric estimation methods to determine changes in dioxin emissions during the transition from landfill to WTE. The results of this study indicate that reducing landfilling leads to a significant decrease in dioxin emissions. In the studied countries, dioxin emissions decreased in the range of 27% and 94% per mass unit of waste treated by WTE and landfill methods. This reduction emphasizes the potential of WTE to increase environmental sustainability compared to traditional landfilling. Also, it confirms that the reduction of landfill fires is the main factor in the reduction of dioxin emissions. The study's insights may serve as guidance for underdeveloped and developing regions seeking to mitigate dioxins and other pollution through modernized waste treatment infrastructure.

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.

Elucidating the correlation between polychlorinated dibenzo-p-dioxins and prostate cancer progression: Insights from gene expression and molecular docking.

Chemically modified silicon carbide nanotubes by indium mono-doping and doping with antimony, tin, and tellurium as sensors for polychlorinated dibenzo dioxins (PCDDs): Outlook from a computational perspective

This study investigated the impact of oral dioxin and PCB exposure on Holstein cows during negative (NEB) and positive (PEB) energy balance. Nine cows were divided into control (CON, n=4) and exposed (EXP, n=5) groups. The EXP group received 278/266pg dioxin-like (dl)-PCB TEQ/kg BW/day and 75/72ng non-dl-PCBs/kg BW/day for 28 days during both NEB and PEB. Inner exposure and health parameters were assessed. Cholesterol levels increased faster in the EXP group during NEB (p=0.049). During PEB, CD4+ cell proportion and mean fluorescence intensity (MFI), along with CD8+ cell MFI, decreased in the EXP group while increasing in the CON group (p=0.004, p=0.05, and p=0.023, respectively). AHR-signaling mRNA expression was unaffected in subcutaneous adipose tissue, spleen, and peripheral blood mononuclear cells. However, approximately 100 days post-exposure, hepatic AHR and ARNT mRNA expression remained elevated in the EXP group (p=0.023 each) and correlated positively with liver dioxin and PCB residues (r2=0.43-0.75). Overall, dioxin and PCB effects on the examined endpoints were minor. The long-term implications of the observed T-cell and hepatic AHR-signaling changes require further investigation.

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.

Dioxin and PCB levels in sea trout with ulcerative disease syndrome.

Atmospheric wet deposition monitoring of PCDD/Fs in an urban site: Fluxes, rain concentrations and washout ratios.

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.

Association between dietary intake estimated levels of PCDD/Fs and human sperm quality.

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCB), polychlorinated dibenzo-p-dioxins (PCDD), and polychlorinated dibenzofurans (PCDF), are a class of chemical compounds with high persistence that can accumulate in living organisms, mainly in fatty tissues. In addition, exposure to them can cause a wide variety of health problems and adverse effects on humans and wildlife. Therefore, this work aimed to assess the occurrence, distribution, and levels of PCB, PCDD and PCDF in fish samples from the Antioquia region, Colombia. In total, 90 samples of different fish species were evaluated. The levels of the six indicator PCBs were in a range between 26.6 pg·g−1 w.w (1.33 ng·g−1 fat) and 4550 pg·g−1 w.w (236.0 ng⋅g−1 fat), the mean value was 395 pg·g−1 w.w (16.7 ng⋅g−1 fat) and the median was 186 pg·g−1 w.w (8.24 ng⋅g−1 fat). The levels of dioxin-like PCBs were between 3.09 pg·g−1 w.w (0.135 ng⋅g−1 fat) and 567 pg·g−1 w.w (33.9 ng⋅g−1 fat), the mean value was 47.2 pg·g−1 w.w (2.30 ng⋅g−1 fat) and the median was 15.5 pg·g−1 w.w (0.811 ng⋅g−1 fat). The mean and median of the PCB toxic equivalent values were 46.6 fg·TEQ·g−1 w.w and 12.0 fg·TEQ·g−1 w.w, respectively. In all cases, PCDD/PCDF were below the analytical method quantification limits. In summary, PCB and PCDD/PCDF levels in selected fish corresponded to background levels and no hot spots were observed. Finally, this study provided an overview of the current situation regarding the presence of these types of pollutants in the region, which could support future research.Graphical abstract

Pollution from past industrial activities can remain unnoticed for years or even decades because the pollutant has only recently gained attention or been identified by measurements. Modeling the emission history of pollution is essential for estimating population exposure and apportioning potential liability among stakeholders. This paper proposes a novel approach for reconstructing the history of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) pollution from municipal solid waste incinerators (MSWIs) with unknown past emissions. The proposed methodology relies on the search for technical and operational data on the pollution source in archives, the extraction of representative data from the scientific literature, and the use of kinetic models of the formation and decomposition of PCDD/Fs within combustion chambers. This new methodological tool allows to estimate any MSWI’s stack emission and relative profile of seventeen PCDD/F congeners over time. The approach is validated through a case study of an MSWI in Switzerland. The modeled congener profile achieved a Pearson correlation coefficient of 0.98 with measurements in fly ash washwater. Additionally, the simulated soil quantity (1,115–1,419 gTEQ WHO-2005 or 1,283–1,698 gTEQWHO-2022) agrees in order of magnitude with the estimated quantity from measurements (371 gTEQ WHO-2005 or 425 gTEQ WHO-2022).Graphical Supplementary InformationThe online version contains supplementary material available at 10.1007/s00244-025-01150-9.

Base-catalyzed hydrolysis mechanism of polychlorinated dibenzo-p-dioxins based on quantitative structure-activity relationship.

Investigation of the effect of chlorine in different additives on dioxin formation during high temperature processing of iron ore

The widespread consumption of roasted plantain and fish (Bolle), a common delicacy in Bayelsa State has raised concerns over potential health risks associated with food processing contaminants such as acrylamides, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). The roasted plantain and fish are usually prepared by placing the peeled plantain and the dressed fish on a wired gauze and placed over a burning charcoal. The subacute toxicity study of this diet was investigated using twenty adult male rats averagely weighing 117.22 \(\pm\) 4.48 g. The rats were divided into four groups of five rats per group. Group A (Control), was fed with the standard rat chow, Group B; was fed with only the roasted plantain, Group C; was fed with only the roasted fish, and Group D; was fed with a combination of the roasted plantain and fish. The rats were given free access to the feed and portable water ad-libitum throughout the experimental protocol. Body/organ weight data were recorded before and after the completion of the experimental protocol. On day 15th of the experimental protocol, the rats were euthanized and blood specimens were obtained by cardiac puncture for biochemical analysis. The liver, kidney and heart were dissevered instantaneously and weighed. Findings from the study showed that the roasted plantain-fed group had significantly reduced body weight gain, and increased liver and kidney to body weight ratio (p>0.05). The plasma enzyme activity (AST, ALT and ALP) of the plantain-fed group were also significantly increased (p<0.05) while other groups showed non-significant differences (p>0.05) with the control group. The antioxidant status (CAT, SOD and GPx), haematological parameters (RBC, PCV, Hb, MCV, MCH, MCHC and platelet) of the plantain-fed groups were also significantly decreased (p<0.05) while other groups had non-significant changes (p>0.05) when compared to the control group. Malondialdehyde levels in the roasted plantain-fed group were also significantly increased (p<0.05).

ABSTRACT This study aims to identify the occurrence and characteristics of PCDD/Fs in soil and sediment samples from secondary copper and aluminum villages in northern Vietnam using the HRGC/MS system. Additionally, it assesses the impact of PCDD/Fs on human health and the potential ecological risks they pose. The residual concentrations of PCDD/Fs in soil and sediment samples collected from the secondary copper Dai Bai village and secondary aluminum Man Xa village were as follows: 0.37 ± 0.29 ng TEQ/kg d.w. (ranging from 0.06 to 0.63 ng TEQ/kg d.w.); 4.88 ± 0.51 ng TEQ/kg d.w. (ranging from 0.512 to 12.17 ng TEQ/kg d.w.); 11.2 ± 5.31 ng TEQ/kg d.w. (ranging from 5.12 to 15.2 ng TEQ/kg d.w.); and 21 ± 12.7 ng TEQ/kg d.w. (ranging from 0.37 to 31.6 ng TEQ/kg d.w.), respectively. The distribution of PCDD/Fs indicated Octa- and Hepta-CDD/Fs as the dominant congeners with high chlorine content. The TEQ levels of PCDD/Fs in all soil and sediment samples were found to be below the allowable limit according to Vietnamese regulations, with the top contributor being 2,3,4,7,8-PeCDF. Samples collected near the production areas exhibited higher levels of PCDD/Fs compared to those collected farther away. The UNEP toolkit was utilized to determine the permissible dioxin TEQ concentrations suitable for livestock farming. The lifetime average daily doses (LADD) of PCDD/Fs via soil ingestion in Man Xa and Dai Bai were calculated as 0.04 × 10−3 and 1.54 × 10−3 pg TEQ/kg d.w. respectively. The relative cancer risks for humans were estimated at 0.05 × 10−12 and 2.05 × 10−12. Furthermore, the ecological risk assessment method indicates that dioxin in all soil and sediment samples near the aluminum recycling craft village had a negative impact on the ecosystem. In contrast, sediment samples taken away from the aluminum recycling craft village and all sediment soil samples in the bronze casting village did not show negative impacts on the ecosystem.

Biomass plays a pivotal role in global energy production, with a significant share allocated for industrial heat and power generation. The combustion of biomass generates biomass ash, which is widely utilized as a fertiliser. However, concerns arise regarding the presence of dioxins in biomass ash, which may limit its continued use. Dioxins are toxic compounds listed under the Stockholm Convention due to their persistence and detrimental effects on human health and the environment. This study investigates the dioxin content in biomass ashes produced in various combustion plants with a capacity of 1-50MWth in Estonia, where biomass is widely used for heating and power production. The research encompassed samples from nine biomass combustion plants with varying technical parameters considering both bottom and fly ash. Dioxin concentrations were determined for 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), and 12 dioxin-like PCBs (PCBs). The results indicate that dioxin TEQ content in all samples was well below the European Union's (EU) POP Regulation limit of 5µg TEQ/kg, with most values being at least tenfold lower. However, some samples failed to meet the EU Fertilising Products Regulation's threshold of 20ng TEQ/kg. Notably, fly ash exhibited higher dioxin concentrations than bottom ash. While PCBs were in significant concentrations, PCDDs dominated the overall dioxin TEQ content. This study provides essential insights into the dioxin content in biomass ash and its correlation with current EU regulatory limits. It also highlights the complex distribution of dioxin congeners, particularly PCBs, within biomass ash, emphasizing the continued research's importance.