PCDD/Fs and Dioxin-like PCBs in Chicken Eggs and Soils in Dong Nai Province, Southern Vietnam: Impacts of Raising Methods and Nearby Pollution Sources

Dioxins and Related Compounds in Sediment and Soil from Craft Villages and Industrial Areas in Northern Vietnam

This study focuses on the determination of dioxins and related compounds (DRCs) in sediment and soil samples gathered from craft villages and industrial zones in Bac Ninh province, northern Vietnam. The PCDD/Fs and DL-PCBs levels in sediment samples ranged from 8.34 to 1302 pg/g and 34.5 to 3186 pg/g, respectively, and total equivalent toxicity (TEQ) of DRCs ranged from 0.596 to 88.1 pgTEQ/g. The total mass concentration of DRCs in the soil samples varied from 14.2 to 4857 pg/g, with corresponding total TEQ values ranging from 0.387 to 2.61 pgTEQ/g. Risk assessment based on sediment quality guideline indicators shows that DRCs at paper recycling village had moderate adverse biological effect. Some soil samples collected in industrial clusters have total carcinogenic risk (CR) values close to the threshold (1.0 × 10-6). Based on the results, it is necessary to continue monitoring and evaluating DRC compounds in craft village and industrial cluster environments and have remediation solutions to reduce these contaminated compounds.

Spatial distributions and source identification of PCDD/Fs and PCBs in soils and pine needles in the multi-industrial city of Ulsan, South Korea

The spatial distribution and contamination patterns of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in soil and pine needles from the multi-industrial city of Ulsan, South Korea were assessed. The mean concentrations of Σ17 PCDD/Fs, Σ12 dl-PCBs, and Σ7 I-PCBs were 78 pg/g dw, 90 pg/g dw, and 453 pg/g dw in the soil and 6 pg/g ww, 31 pg/g ww, and 166 pg/g ww in the pine needles, respectively. The mean concentrations of PCDD/Fs, dl-PCBs, and I-PCBs in the soil at industrial sites (138, 184, and 453 pg/g dw) were significantly higher than those at urban (47, 33, and 186 pg/g dw) and suburban sites (48, 49, and 234 pg/g dw). In the pine needles, although PCDD/F and PCB levels were higher at several industrial sites, mean concentrations at the industrial (6, 31, and 166 pg/g ww), urban (4, 29, and 143 pg/g ww), and suburban (4, 31, and 169 pg/g ww) sites were comparable, indicating that atmospheric transport plays a crucial role in spreading contamination throughout the study area. Higher chlorinated PCBs were predominant in the soils, while PCDFs and lower chlorinated PCBs were more common in the pine needles, reflecting the distinct physicochemical properties and interactions of these chemicals with each medium. Principal Component Analysis (PCA) revealed industrial combustion as the main source of PCDD/Fs and PCBs, with Aroclors identified as an additional source of PCBs. Suburban areas were influenced by both local sources and pollutants transported from urban and industrial areas. This study highlights that industrial activities and atmospheric transport significantly contribute to the widespread contamination of PCDD/Fs and PCBs in Ulsan.

Levels of PCDD/Fs, PCBs, metals and rare earth elements in eggs and vegetables from areas with different environmental contamination impacts in the Campania region (Southern Italy)

Studying the links between environmental pollution and the levels of contamination in food is an important challenge to ensure human health. Matched samples of eggs from free-range hens and vegetables were analysed to investigate the bioaccumulation of PCDD/Fs, PCBs, metals and rare earth elements. Only two egg samples resulted above the limit fixed for PCDD/Fs and the action level set for DL-PCBs. The highest concentrations were found in the eggs from an area situated in a big city affected by strong urbanisation. Although eggs and vegetables were subjected to the same environmental pollution, the PCDD/F and PCB bioaccumulation that occurred in the eggs was much higher than those in vegetables (p < 0.01). In vegetables, the highest PCDD/F and PCB concentrations were found in lettuce and potatoes grown on contaminated soil. Higher bioaccumulation of Fe and Zn occurred in eggs compared to vegetables; La, Pr, Nd, Sm and Eu were found only in lettuce samples. The results of this study may provide important data useful in the risk assessment of human exposure through diet in accidents involving dangerous chemicals. Furthermore, the estimated weekly intakes calculated for PCDD/Fs and PCBs highlighted that, although vegetables accumulate very low concentrations of these contaminants, they contribute more than eggs to human exposure.

2,3,7,8-tetrachlorodibenzo-p-dioxin induces multigenerational testicular toxicity and biosynthetic disorder of testosterone in BALB/C mice: Transcriptional, histopathological and hormonal determinants

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent environmental contaminant, is an endocrine disrupter with a proven reproductive toxicity in mammals. However, its effects on male fertility across generations are still elusive. The current work evaluates the toxicity of dioxin on male reproductive system in two separate groups of BALB/C mice; a group of pubertal males directly exposed to TCDD (referred to as DEmG), and a group of indirectly exposed males (referred to as IDEmG) comprises of F1, F2 and F3 males born from TCDD-exposed pregnant females. Both groups were exposed to 25 μg TCDD/kg body weight for a week. Our data show that males of TCDD-DEmG exhibited significant alterations in the expression of certain genes involved in the detoxification of TCDD and the biosynthesis of testosterone. This was accompanied with testicular pathological symptoms, including a sloughing in the germinal epithelium and a congestion of blood vessels in interstitial tissue with the presence of multinuclear cells into seminiferous tubule, with a 4-fold decline in the level of serum testosterone and reduced sperm count. Otherwise, the male reproductive toxicity across F1, F2 and F3 generations from TCDD-IDEmG was mainly characterized by: i) a reduce in body and testis weight. ii) a decrease in gene expression of steriodogenesis enzyme, e.g., AhR, CYP1A1, CYP11A1, COX1, COX2, LOX5 and LOX12. iii) a remarked and similar testicular histopathology that found for DEmG, iv) a serious decline in serum testosterone. v) a decreased male-to-female ratio. vi) a low sperm count with increasing abnormalities. Thus, pubertal or maternal exposure to TCDD provokes multigenerational male reproductive toxicity in mice, ultimately affecting the spermatogenesis and suggesting that the hormonal alternation and sperm abnormality are the most marked effects of the indirect exposure of mammalian male to TCDD.

Developing an Improved Strategy for the Analysis of Polychlorinated Dibenzo-p-Dioxins/Furans and Dioxin-like Polychlorinated Biphenyls in Contaminated Soils Using a Combination of a One-Step Cleanup Method and Gas Chromatography with Triple Quadrupole Mass Spectrometry

Soils contaminated with polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and dioxin-like (dl) polychlorinated biphenyls (PCBs), known as persistent organic pollutants (POPs), have garnered global attention because of their toxicity and persistence in the environment. The standard method for target analytes has been used; however, it is an obstacle in large-scale sample analysis due to the comprehensive sample preparation and high-cost instrumental analysis. Thus, analytical development of inexpensive methods with lower barriers to determine PCDDs/Fs and dl-PCBs in soil is needed. In this study, a one-step cleanup method was developed and validated by combining a multilayer silica gel column and Florisil micro-column followed by gas chromatography with triple quadrupole mass spectrometry (GC-QqQ-MS/MS). To optimize the separation and quantification of 17 PCDDs/Fs and 12 dl-PCBs in soils, the sample cleanup and instrumental conditions were investigated. For quantification method validation, spiking experiments were conducted to determine the linearity of the calibration, recovery, and method detection limit of PCDDs/Fs and dl-PCBs using isotopic dilution GC-QqQ-MS/MS. The applicability of the simultaneous determination of PCDDs/Fs and dl-PCBs was confirmed by the recovery of native target congeners and labeled surrogate congeners spiked into the quality-control and actual soil samples. The results were in good agreement with the requirements imposed by standard methods. The findings in this work demonstrated the high accessibility of the sample cleanup and analysis methods for the efficient determination of PCDDs/Fs and dl-PCBs in contaminated soils.

PCDD/Fs and PCBs in hen eggs from a contaminated area in Italy: a 9 years spatio-temporal monitoring study

Eggs can represent a food susceptible to contamination, with bioaccumulation potential for POPs. The Province of Taranto, Southern Italy, is of particular relevance in this context because of the presence of industrial sources of PCDD/Fs and PCBs. The aim of this study was to analyze and report the levels of these contaminants in hen eggs sampled in farms located within a radius of 20 km from the industrial area of Taranto. Between 2013 and 2021, 227 hen eggs were collected, according to a special monitoring plan of the Prevention Department. Samples were analyzed by the National Reference Laboratory for Halogenated POPs in Feed and Food. Median (IQR) values were: 0.28 (0.59) pg WHO-TEQ/g fat for PCDD/Fs, 0.89 (1.70) pg WHO-TEQ/g fat for PCDD/Fs + DL-PCBs, 0.57 (1.16) pg WHO-TEQ/g fat for DL-PCBs, 2.24 (5.51) ng/g fat for NDL-PCBs. Samples not-compliant (Reg. 1881/2006/EC and amendments) for at least one contaminant were 17 (7.5%). No contaminants values or exceedances showed a statistically significant correlation with distance from industrial area (p > 0.05). Higher PCDD/Fs values were observed in first and second quarters (p < 0.05). All contaminants' values pairwise combinations showed significant (p < 0.0001) strong (ρ > 0.7) correlation. According to our epidemiological investigations, the exceedances are to be attributed to factors mainly related to farmers' wrong habits. These results confirmed the importance of the monitoring of contaminants' levels in the matrices at risk as well as to focus on enhancing good management practices on eggs-producing farms.

Polychlorinated dibenzo-p-dioxins/dibenzofurans and mercury in vegetable of the contaminated Ya-Er Lake area: Concentrations, sources, and health risk

The Ya-Er Lake is a seriously polychlorinated dibenzo-p-dioxins/dibenzo-furans (PCDD/Fs) and mercury (Hg)-contaminated lake by pesticide and chlor-alkali plants in China. The oxidation pond method has been conducted to control pollution, moreover, the contaminated sediment was dredged and stacked, becoming a sediment stack yard for vegetable cultivation. To assess effects of oxidation pond method and dredging programme on pollution management and long-term risks of PCDD/Fs and Hg, the concentrations of PCDD/Fs, total Hg (THg), and methylmercury (MeHg) in soil and vegetable sampled from the sediment stack yard were measured and analyzed. Significantly positive relationships between concentrations of PCDD/Fs (p < 0.01), THg, and MeHg (p < 0.05) in edible parts of vegetable and soil were found, suggesting that bioaccumulation from contaminated soil derived from sediment dredging is important sources of PCDD/Fs and Hg in vegetable. Much higher PCDD/Fs (12 ± 9 pg/g dw) and Hg (THg, 0.14 ± 0.23 μg/g dw; MeHg,12.63 ± 13.31 ng/g dw) levels in vegetable were found compared with those from other contaminated regions, indicative of serious PCDD/Fs and Hg pollution in vegetable harvested from contaminated soil. Finally, the calculated provisional tolerable daily intake (PTDI) values showed higher health risk of PCDD/Fs and Hg exposure to local residents through consumption of purple and white flowering stalk, and oilseed rape. Our study established a good model to evaluate the long-term risks of PCDD/Fs and Hg. Moreover, the results indicate that the oxidation pond method and dredging programme were not effective to remove PCDD/Fs and Hg in sediment, which shed new light on management strategy of PCDD/Fs and Hg pollution in contaminated regions.