Assessment of PCDD/F and dioxin-like PCB levels in environmental and food samples in the vicinity of IZAYDAS waste incinerator plant (WIP): from past to present

Concentrations of persistent organic pollutants in long-finned pilot whales (Globicephala melas) sampled in a mass stranding event (MSE) on the Irish coast

On 6 November 2010, a mass stranding event (MSE) occurred on Rutland Island, Co Donegal involving 33 long-finned pilot whales (Globicephala melas). While the cause of the stranding remains unknown, the event enabled the collection of a large number of tissue samples for opportunistic quantification of Persistent Organochlorine Pollutants (POP) and from across a spectrum of age-classes, maturity, and sexes. The concentrations of 24 Polychlorinated Biphenyls (PCBs), 15 Organochlorine Compounds (OCs), 5 Brominated Flame Retardants (BFRs) and 17 Polychlorinated-dibenzo-dioxins/furans (PCDD/Fs) were investigated in blubber samples via lipid extraction and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS). Concentrations ranged from, 48.03 ng/g lw-46,860.76 ng/g lw for ΣPCBs, 1585.40 ng/g to 558,833.71 ng/g for ΣOCs, 3.24 ng/g lw-134.82 ng/g lw for ΣBFRs and 0.008 ng/g lw-0.0518 ng/g lw for ΣPCDD/Fs. Concentrations of POPs quantified were consistent with those reported in previous studies with the exclusion of organochlorine compounds which were found to have significantly higher total concentrations. With high levels of such legacy pollutants posing potentially severe implications for the health and reproductive abilities of this species and marine mammals, the continual monitoring of POPs concentrations in animals across multiple demographics remains vital.

The development of a novel, green, efficient, and eco-friendly GC-MS/MS analytical method for the reliable and rapid determination of dl-PCBs, and PCDD/Fs using hydrogen as a carrier gas and a modified ion source

The polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) are worldwide contaminants, and they tend to accumulate in wide variety of matrices. Therefore, due to the highest accumulation rate and recalcitrancy, their precise quantification makes significant concern about their toxicological effects on both humans and organisms. The objective of the study is that using hydrogen carrier gas instead of helium in gas chromatography with triple quadrupole (GC-MS/MS) systems could contribute to improvements on the analysis of dl-PCBs and PCDD/Fs in environmental matrices. The study evaluates the performance of the analysis time under the desired chromatographic resolution criteria for PCDD/Fs analysis, monitoring the plausible mass spectrum/fragmentation ratio changes, and finally the quantification limits of the targeted most toxic persistent organic compound congeners. The main advantage of using H2 carrier gas is that the analysis time was drastically reduced (∼2.5 times) along with improved resolution due to an increase in peak widths in ∼0.6-0.7 factor. This study emphasized that the resolution was remarkably affected by the hexa congeners of PCDD/Fs; nearly baseline separation was observed. However, the sensitivity was slightly reduced (∼6-7 fold), which affected the calibration starting concentrations (0.8-3.2 pg/μl). The acquired mass spectra indicated that the lower fragment enhancement was noticeable, particularly on higher chlorinated ones (hexa, hepta, and octa congeners). The calculated ortho-effect values (1-58) in this study are consistent with the previous results in the literature (1-66 and 1-83) and supports the conclusion about the observations of lower fragment enhancement. Despite non-detection of hydrogenation, there is a significant difference in the quant/qual ion ratios in the studied compounds between helium and hydrogen carrier gas. The finalized methodology was examined, and the performance of the hydroinert® ion source was assessed over a three-month analysis period with a real sample analysis (RSD ≤17.8 %). The results indicate that hydrogen is a potential and reliable GC-MS/MS carrier gas in dl-PCBs and PCDD/Fs for environmental matrices.

Urban air PCDD/Fs: Atmospheric concentrations, temporal changes, gas/particle partitioning, possible sources and cancer risks

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) are pollutants of concern due to their toxic effects. No active sampling study on PCDD/Fs has been conducted in Bursa. This study aimed to fill this gap by measuring PCDD/F levels in the region. Accordingly, the samples were collected from an urban area in Bursa, covering four seasons between June 2022 and April 2023. The total (gas+particulate) ambient air concentrations were between 312.23 and 829.80 fg/m3 (mean: 555.05 ± 173.62 fg/m3). In terms of toxic equivalents (TEQ), the average concentration was 43.29 ± 9.18 fg WHOTEQ/m3. Based on the concentration values obtained, cancer and non-carcinogenic risk values of PCDD/Fs were calculated for three different age groups. The results indicated negligible health risks for all age groups. In addition, a seasonal assessment was also made and it was observed that PCDD/F concentration values varied with the ambient air temperatures. In general, higher values were measured in colder months compared to warmer months. This was probably due to the additional sources and adverse meteorological conditions. Moreover, the gas/particle partitioning of PCDD/Fs was investigated in detail. The average gas and particulate phase concentrations for PCDD/Fs were 101.81 ± 20.77 and 453.24 ± 172.50, respectively. It was found that an equilibrium state was not reached in the gas/particle partitioning. Two different gas/particle partition models based on adsorption and absorption mechanisms were compared, and the absorption model gave more consistent predictions. The Principal Component Analysis (PCA) was employed to identify the possible PCDD/F sources. The results indicated that the region was influenced by vehicle emissions, residential heating, organized industrial zones and metal recycling facilities. In addition, 72-hour backward air mass trajectory analyses were performed to understand the long-range transported air masses. However, it was found that the transported air masses did not significantly affect the concentration values measured in the sampling site.

Evaluation of hexabromocyclododecane (HBCD), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) outflows during the destruction of HBCD wastes in a hazardous waste incinerator

This paper presents an evaluation of hexabromocyclododecane (HBCD), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) outflows during the destruction of HBCD waste stockpiles in IZAYDAS Hazardous Waste Incinerator (HWI) in Kocaeli, Türkiye. HBCD wastes containing 100 % pure HBCD were in 25 kg packages with 63 % Br content were co-incinerated in a 3-day test burn with average feed rate of 26 kg/h. HBCD, PBDD/Fs and PCDD/Fs were measured in the outlet streams to quantify the amount of unintended POPs releases associated with the processing of HBCD waste and to observe the POP removal performance of air pollution control equipment (APCE) of the incinerator. Total mass outflow rate of HBCDs is calculated as 2.6 g/day, corresponding to destruction efficiency of 99.9996 %. Total toxicity of the brominated dioxins was measured as 0.00044 ng TEQ/Nm3 on average, while highly brominated congeners are dominant. PCDD/F concentrations in the outflow streams during HBCD test burns are produced similar congener distributions with those given in the previous studies, with the dominance of 7,8-chlorinated congeners. Mass flows in the outlet streams indicated that the efficiency of ESP and wet scrubbers for the removal of PCDD/Fs and HBCDs. Flue gas concentrations of PCDD/Fs, HBCDs and PBDD/Fs obtained in HBCD burn test indicated that burning HBCD wastes cause no significant emissions as operational parameters and total halogen content in the menu are kept within the incinerator limits.

Levels, patterns and risk assessment of PCDD/Fs and dl-PCBs through dietary exposure in the Valencian Region (Spain)

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCBs) levels were measured in representative vegetable oils and animal origin foodstuffs collected in a Total Diet Study carried out in the Valencian Region (Spain). A total amount of 3,300 food samples were collected and grouped into 5 main food groups: vegetable oils, meat and meat products, eggs, milk and dairy products and fish and sea products. The samples were analysed using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS). The food group which presented the highest concentration in wet weight (ww) for the sum of PCDD/Fs and dl-PCBs was fish and sea products (0.5 pg TEQ g-1 ww), whereas meat and meat products (0.6 pg TEQ g-1 lipid) showed the highest levels expressed in lipid terms. Occurrence data of PCDD/F and dl-PCBs were combined with consumption data to estimate the dietary exposure of adults (>15 years) and children (6-15 years). Finally, the estimated weekly intake (EWI) was calculated using a deterministic approach and considering the food consumption of the population, with fish and sea products being the main food group contributor. Likewise, considering the worst-case scenario (Upper Bound, UB), average EWI were 1.8 and 3.4 pg TEQ kg-1 body weight (bw) week-1 for adults and children, respectively. For children, the average EWI was almost twice above the tolerable weekly intake (TWI) of 2 pg TEQ kg-1 bw week-1 set by EFSA in 2018. In terms of risk characterisation, the overall obtained results showed that 19 % of adults and 43 % of children may exceed the TWI when using UB.

Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review

Endocrine-disrupting chemicals (EDCs) are a growing public health concern worldwide. Consumption of foodstuffs is currently thought to be one of the principal exposure routes to EDCs. However, alternative ways of human exposure are through inhalation of chemicals and dermal contact. These compounds in food products such as canned food, bottled water, dairy products, fish, meat, egg, and vegetables are a ubiquitous concern to the general population. Therefore, understanding EDCs' properties, such as origin, exposure, toxicological impact, and legal aspects are vital to control their release to the environment and food. The present paper provides an overview of the EDCs and their possible disrupting impact on the endocrine system and other organs.

Characterization of PCDD/F and dl-PCB levels in air in Gipuzkoa (Basque Country, Spain)

This research examines the levels and trends of pollutants, specifically 17 congeners of PCDD/Fs and 12 dl-PCBs, in the air measured in the province of Gipuzkoa (Basque Country, Spain). The study used PCDD/Fs, dl-PCB, and the sum of dioxin-like compounds as separate response variables. A total of 113 air samples were collected and analyzed using the method described in the European Standard (EN-1948:2006) from two industrial areas. The results were analyzed using non-parametric test to assess the variability of these pollutants based on different factors (year, season and day of the week) and General Linear Models to assess the weight of each factor. The study found that the toxic equivalents (TEQs) for PCDD/Fs were 12.29 fg TEQm^-3 and for dl-PCBs were 1.63 fg TEQm^-3, which were in a similar range or lower than those observed in other national and international studies in industrial areas. The results showed temporal variations, with higher levels of PCDD/Fs in autumn-winter than in spring-summer and higher levels of PCDD/Fs and dl-PCBs during weekdays than on weekends. The industrial area where the energy recovery plant (ERP) will be located had higher levels of air pollutants due to the presence of two PCDD/Fs emitting industries nearby, as indicated by the Spanish Registry of Polluting Emission Sources. Both industrial areas showed similar profiles of PCDD/Fs and dl-PCBs, with the PCDD/F profiles dominated by OCDD, 1,2,3,4,6,7,8-HpCDD, and 1,2,3,4,6,7,8-HpCDF in terms of concentrations and 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF, and 2,3,7,8-TCDD in terms of TEQs. The dl-PCB profiles were dominated by PCB 118, PCB 105, and PCB 77 in terms of concentrations and PCB 126 in terms of TEQs. The findings of this study can serve as an indicator of the potential impact of ERP on the health of the resident population and the environment.

A comprehensive assessment, source input determination and distribution of persistent organic pollutants (POPs) along with heavy metals (HMs) in reservoir lake sediments from Çanakkale province, Türkiye

This study presents the distribution of persistent organic pollutants (POPs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in the sediments from four dams and two ponds in the Çanakkale city, Türkiye. The total concentration varied from 41.47 to 145.45 ng/g d.w. for PAHs; 1.40-14.96 ng/g d.w. for organochlorine pesticides (OCPs) and 0.13-3.31 ng/g d.w. for polychlorinated biphenyls (PCBs). The total polychlorinated dibenzo-p-dioxins/furans (∑PCDD/Fs) concentrations varied between 7.35 and 63.46 pg/g d.w. The HM distribution in sediments ranged from 9.41 to 21.13 mg/kg d.w. for As; 0.20-0.39 mg/kg d.w. for Cd; 19.4-281.68 mg/kg d.w. for Cr; 23.50-118.25 mg/kg d.w. for Pb and 118.9-374.82 mg/kg d.w. for Zn. This paper also elucidates possible sources of POP and HMs in sediment by using diagnostic ratios. The calculated ratios were shown that anthropogenic input is the source of these pollutants in sediments. Principal component analysis showed that the low molecular weight of POPs is considerably related and correlated, while high molecular weight pollutants have made another group and highly correlated with each other. The results indicated that anthropogenic pollution is mainly related to atmospheric input. Anthropogenic pollutants are more apparent at Atikhisar and Bakacak dams close to urbanized locations. Rather than the anthropogenic impact, based on the measured data interpretation, the global climate change effect was seen in Bakacak dam. The overall concentration of all pollutants revealed that Atikhisar and Bakacak sediments are high-level polluted areas according to several types of sediment guidelines.

Zr-MOF-Induced Smart Accumulation Enables Surface-Enhanced Raman Spectroscopic Detection of Dioxin at ppt Level in Food Samples

The fast and economical detection of trace polychlorinated dibenzo-p-dioxins (PCDDs) in food samples by current mass spectrum-based methods is hindered by tedious sample preparation and bulky & expensive analytical instruments. Surface-enhanced Raman spectroscopy (SERS) successfully detects many organic pollutants in foods but not dioxins because the employed metal nanoparticles weakly adsorb hydrophobic PCDDs. Herein, we report the detection of PCDDs in milk with SERS for the first time using a bifunctional substrate consisting of Au nanoparticles embedded in a zirconium-based metal-organic framework shell (AuNP/Zr-MOF). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), as the most toxic PCDD, is detected as low as 1.2 parts per trillion (ppt) in real milk samples with massive interfering substances in 30 min, which is the lowest among all reported methods. The aromatic rings of Zr-MOF promote the smart accumulation of TCDD through π-π interactions, and Au-Cl interactions drive TCDD onto Au surfaces. Zr-MOF shells with pore sizes of 12.7 and 20 Å block the accessibility of larger interfering molecules. A one-step apparatus and protocol are established to be superior to traditional methods in terms of time and cost. This work provides new insight into a rational screening method for the detection of persistent organic pollutants in a real sample matrix.

Determination of PCDD/F and DL-PCB pollution levels, source appointment and risk assessment of surface sediments in dam lakes in Istanbul, Türkiye

The current situation of the water resources of Istanbul, which is one of the important metropolises of Europe, should be known and constantly monitored by the reasons of the rapid increase in the city population, the acceleration of production-related industrial activities, the expansion of the city with construction activities, and the decrease in precipitation. The purpose of this study was to reveal the situations of surface sediments collected from Istanbul water reservoirs in terms of PCDD/Fs and DL-PCBs, to identify possible sources, and to conduct their ecological risk assessment. Total PCDD/Fs and DL-PCBs concentrations varied between 28.13 and 457.4 pg/g (average 136.8 pg/g) and 12.19-340.1 pg/g (average 72.09 pg/g). The corresponding TEQ values of PCDD/Fs and DL-PCBs were between 0.53 and 5.37 pg TEQ/g (average 2.23 pg TEQ/g) and 0.02-0.44 pg TEQ/g (average 0.12 pg TEQ/g), respectively. Octachlorodibenzo-p-dioxin (OCDD) is the dominant congener by constituting about 75% of the total PCDD/Fs on average, while congener distributions of DL-PCBs showed the dominance of PCB-118 and PCB-105. The sediments taken from Kazandere dam have the lowest pollution levels for both PCDD/Fs and DL-PCBs. The highest PCDD/F and DL-PCB amounts were measured in sediments of Alibey and Elmalı dams (closest to highly populated settlements of Istanbul), which are most affected by the air pollution caused by the traffic, commercial/industrial combustion (like waste incineration facility) and combustion for residential heating. Almost all the sediments have total dioxin-like toxicity levels higher than the safe threshold level (with two exceptions) of 0.85 pg TEQ/g dw, proposed for ecological risk. Health risk assessment shows that levels of dioxin-like compounds would result in a total intake of 0.33 pg TEQ/kg bw/day even in the worst-case scenario, not exceeding the tolerable daily intake value of 1 pg TEQ/kg bw/day. Among exposure pathways, consumption of fish constitutes almost all the total intake, while contributions of other pathways are minimal.

A bibliometric analysis of pre- and post-Stockholm Convention research publications on the Dirty Dozen Chemicals (DDCs) in the African environment

Persistent organic pollutants (POPs) are toxic chemicals that stay in the environment for a long time. To address the toxicity issues, global nations, including 53 African countries, ratified the Stockholm Convention to minimize or eliminate the production of 12 POPs known as the "Dirty Dozen". However, these Dirty Dozen Chemicals (DDCs) still exist in significant concentration in the African environment, prompting numerous research to investigate the level of their occurrences. Here, we conducted a bibliometric analysis to examine the publication trends in DDCs-related research in Africa using articles published between 1949 and 2021 from the Web of Science and Scopus databases. A total of 884 articles were published within the survey period, with a publication/author and author/publication ratio of 0.36 and 2.76, respectively. South Africa ranked first in terms of number of publications (n = 133, 15.05%), and total citations (n = 3115), followed by Egypt (n = 117), Nigeria (n = 77), USA (n = 40), and Ghana (n = 38). Research collaboration was relatively high (collaboration index = 2.88). The insignificant difference between the theoretical and observed Lotka's distribution indicates Lotka's law does not fit the DDC literature. An annual growth rate of 0.57% implies that a substantial increase of articles in years to come is not expected. More research programs should be established in other African countries to measure up to South Africa's supremacy. This is critical in order to provide a basis for effective compliance to the Stockholm Convention on POPs in Africa.

In vitro effects of polychlorinated biphenyls and their hydroxylated metabolites on the synthesis and metabolism of iodothyronines in the chicken (Gallus domesticus) thyroid gland

To assess the effect of polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (OH-PCBs) on thyroid hormone [TH: thyroxine (T₄) and triiodothyronine (T₃)] secretion, the concentrations of iodothyronine deiodinases (DIO1, DIO2, DIO3), and mRNA expression of genes involved in TH synthesis (TSHR, NIS, TPO, TG), metabolism (DIO1, DIO2, DIO3), and transport (OATP1C1, MCT8, MCT10, LAT1), chicken thyroid explants were incubated in medium supplemented with TSH (250 mU/ml), PCB118, PCB153, 4-OH-PCB107, and 3-OH-PCB153 (0.5 × 10^-8 M), and TSH together with each PCB and OH-PCB. The results of the in vitro experiment revealed that, except for 4-OH-PCB107, all applied PCBs and OH-PCBs inhibited basal and TSH-stimulated T₄ secretion. Moreover, they increased basal and reduced TSH-stimulated T₃ secretion. PCBs and OH-PCBs decreased the TSH-stimulated TSHR expression. Following PCB and OH-PCB exposure, significant changes in mRNA expression of NIS, TPO, and TG were observed. PCBs and OH-PCBs affected DIO1 and DIO3 transcript levels and protein abundances of each DIO. Furthermore, PCB-dependent effects on OATP1C1, MCT8, and MCT10 mRNA expression were found. In conclusion, both PCB118 and PCB153 and their OH-PCBs affect TH synthesis and deiodination processes in the chicken thyroid gland and influence TH transport across the thyrocyte membrane. In addition, the effects of PCBs and OH-PCBs depended mainly on the type of PCB congener and the exposure time. These results indicate that not only parental PCBs but also OH-PCBs are hazardous for the thyroid gland and may disrupt its endocrine function. Further studies are necessary to explain a mechanism of PCB and OH-PCB action in the avian thyroid gland.

Study on site selection of municipal solid waste incineration plant based on swarm optimization algorithm

In this paper, based on an improved swarm optimization algorithm, a new site selection model of a municipal solid waste (MSW) incineration plant is proposed. First, the whale optimization algorithm and particle swarm optimization algorithm are combined according to certain rules to improve the performance of the hybrid algorithm. Through a verification of the single and multi-peak functions, the results show that the algorithm achieves a good performance. The location model of the MSW incineration plant is based on many factors, including the economy, environmental protection, population scale, and operation cost. Finally, based on a sample analysis, a new location model of an MSW incineration plant is used to select the location of an Anshan MSW incineration plant, and a reasonable location is obtained.

Qualitative and quantitative changes in traffic and waste incineration PCDD/Fs in urban air and soils under different seasonal conditions (Metropolitan Area of Barcelona)

A sampling and analysis scheme was implemented to discriminate between inputs of polychlorodibenzo-p-dioxins and polychlorodibenzofurans (PCDD/Fs) at low concentrations in urban areas. Ambient air and soils were sampled and analyzed in five stations in the Metropolitan area of Barcelona (2018-2019); one located in a reference urban traffic site and four in the area of influence of an integrated waste management facility (IWMF) that included a solid waste incinerator. Seasonality was the main factor determining the PCDD/F composition, and involved lower values in the warmer months. This seasonal effect was related to enhanced photooxidation of PCDDs compared to PCDFs and faster depletion of the less chlorinated congeners due to volatility at higher ambient temperature; consistent with the compounds' octanol-air partition coefficients. The ratio 2,3,7,8-tetrachlorobenzofuran/1,2,3,4,6,7,8-heptachlorobenzofuran allowed, for the first time, identifying cases of preferential contributions of IWMF and traffic inputs, i.e. values of 0.06 and 0.32, respectively. Combination of this ratio with the airborne PCDD/F levels illustrated that the quantitative PCDD/F levels were not a useful criterion for elucidation between IWMF and traffic inputs. PCDD/Fs levels in soils ranged between 9.0 and 22 pg WHO-TEQ/g in the two sites closest to the IWMF, while the other sites, including the traffic site, showed values between 0.8 and 1.9 pg WHO-TEQ/g. The levels in the former group were higher than those observed in other urban areas and above 5 pg WHO-TEQ/g, which is a limit reference value in several European countries. The C₇ and C₈ observed congener distributions in all soils examined were different from those in the air samples and similar to those reported in sewage sludge from waste water treatment plants, not showing influences from IWMF or traffic PCDD/F inputs.

Impact of municipal and industrial waste incinerators on PCBs content in the environment

Polychlorinated biphenyls (PCBs) have been withdrawn from the market due to their toxicity, bioaccumulation capacity, and persistence. PCBs have been observed to potentially form in combustion processes under appropriate conditions and in the presence of precursors containing chlorine. The study covered a municipal waste incineration plant and an industrial waste incineration plant. The objective of the study was to assess the effect of these objects on PCB accumulation in soil and plants taking into account the distance from the emission object and wind direction. Soil samples were collected from layers: 0-5, 5-10, 10-20, and 20-30 cm. Test plants were collected from the same areas as the soil samples. The highest accumulation of PCBs was found in plants with large leaf area. Around the municipal waste incineration plant, these were Tanacetum vulgare leaves (12.45 ng/g), and around the industrial waste incineration plant–grasses (4.3 ng/g). In the case of soils, the accumulation of PCBs for both kind waste incinerators was similar, reaching approximately 3 ng/g. As the distance from the municipal waste incinerator and industrial waste incinerator increased, the accumulation of PCBs in the soil decreased. For municipal waste incinerator, no effect of wind direction on PCB accumulation in the soil was observed. In the majority of cases, the accumulation of PCBs in soils taken from the leeward side of the industrial waste incinerator was higher than that in soils from the windward side. In soils around the municipal waste incinerator, PCB compounds moved deep into the soil and reached the highest accumulation in the soil layer of 10-20 cm or 20-30 cm. In soils around the industrial waste incinerator, the highest accumulation of PCBs occurred in the soil layer of 0-5 cm.