Search Results (49)

Commercial smooth-hound sharks of the genus Mustelus are commonly landed and consumed in Mediterranean fisheries, raising concerns about potential human exposure to persistent contaminants. This study investigated the occurrence of organochlorine compounds (OCs), including hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and its metabolites, and polychlorinated biphenyls (PCBs), together with per- and polyfluoroalkyl substances (PFAS), in muscle and liver tissues of Mustelus mustelus and Mustelus punctulatus collected in the waters of the Egadi Archipelago (central Mediterranean Sea). OCs were detected in all analyzed samples, with total PCB concentrations reaching higher values in liver compared to muscle tissues, reflecting tissue-specific accumulation and detoxification processes. PFAS were detected in all analyzed muscle samples (1.10–58.5 ng/g w.w.), with PFOS, PFOA and PFNA generally below current European regulatory thresholds, although isolated exceedances were observed. Stable isotope analysis (δ¹³C and δ¹⁵N) highlighted differences in trophic ecology between the two species and suggested that feeding habitat and trophic position may influence contaminant exposure patterns, particularly in M. punctulatus. The human health risk assessment, conducted as a screening-level evaluation, indicated potential concern associated with PCB concentrations in liver tissue, while risks associated with muscle consumption were generally lower. Overall, the integration of contaminant analysis and stable isotopes provides insights into organismal exposure pathways and supports the use of smooth-hound sharks as sentinels of contaminant presence in Mediterranean coastal ecosystems. Full article

A manganese dioxide-modified carboxylated graphene oxide (MnO₂@CGO) nanocomposite was fabricated and utilized as a solid nanosorbent for extracting six organochlorine pesticides from environmental water samples. The target compounds, Hexachlorobenzene (HCB), β-Hexachlorocyclohexane (β-HCH), Heptachlor, Aldrin, Dieldrin, and o,p-Dichlorodiphenyltrichloroethane (o,p-DDT), were determined by micro-solid phase extraction (µ-SPE) coupled with gas chromatography–mass spectrometry (GC-MS) in selective ion monitoring mode. Key experimental factors influencing the extraction performance, such as sample pH, sorbent dosage, type and volume of eluting solvent, and time for desorption, were systematically optimized. Under the optimized conditions, the method showed good linearity (R² = 0.998–1.000) within the concentration range of 0.1–5 ng L⁻¹. The developed procedure was successfully applied to Nile River, agricultural wastewater, and groundwater samples, achieving recoveries between 87.1% and 101.2% with RSDs below 4.0%. The detection limits were 0.005–0.010 mg L⁻¹ at a signal-to-noise ratio of 3.0. Overall, the MnO₂@CGO-based µ-SPE method offers a sensitive, reliable, and straightforward approach for monitoring trace levels of organochlorine pesticides in environmental waters. Full article

Many common chemicals are known or suspected to harm brain development, and children are particularly vulnerable, yet research on their long-term effects on mental health is limited. This study investigated the associations of early childhood exposure to endocrine disrupting and neurotoxic chemicals with the development of internalizing, externalizing, and attention-deficit/hyperactivity disorder (ADHD) symptoms from early childhood through adolescence in 387 children from the Rhea cohort in Crete, Greece. At age 4, serum concentrations of 3 organochlorine pesticides and 14 polychlorinated biphenyls, and urinary concentrations of 7 phthalate metabolites and 6 dialkyl phosphate metabolites were measured. Children’s symptoms were assessed via maternal reports at ages 4, 6, 11 and 15 years. Using generalized estimating equation models, the study found that early exposure to hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (DDE) was associated with increased externalizing symptoms across ages in girls [beta (95% CI): 0.20 (0.04, 0.37) and 0.11 (0.01, 0.21), respectively]. Among girls, low molecular weight (LMW) phthalates were also linked to elevated internalizing and externalizing symptoms, as well as ADHD-related difficulties [beta (95% CI): 0.15 (0.04, 0.26), 0.13 (0.01, 0.25), and 0.13 (0.02, 0.24), respectively]. Additionally, exposure to organophosphate pesticides was associated with increased externalizing and ADHD symptoms [beta (95% CI): 0.13 (0.04, 0.22) and 0.12 (0.04, 0.20), respectively]. The findings suggest that early childhood exposure to environmental chemicals may have long-term effects on emotional and behavioral development, with pronounced effects observed only in girls. Full article

This study investigates the dual catalytic inhibition mechanisms of chlorobenzene (CBz) formation during combustion using N- and S-modified layered double hydroxides (LDHs). The metal hydroxide layers in these LDHs primarily suppress lower-chlorinated CBzs (e.g., trichlorobenzene-dichlorobenzene) under inert conditions by inhibiting direct chlorination, achieving inhibition rates above 80%. In contrast, N/S functional groups, particularly thioacetamide, enhance catalytic inhibition efficiency under air, increasing it from 17.8% to 77.3% in the solid phase by controlling catalytic chlorination and limiting highly chlorinated CBzs (e.g., pentachlorobenzene–hexachlorobenzene). These findings highlight the complementary roles of metal hydroxide layers and N/S functional groups in reducing CBz formation, offering insights for developing efficient, multifunctional inhibitors for waste incineration pollution control. While promising, the scaling up of the application of LDH-based inhibitors may face challenges related to synthesis complexity and cost, requiring further research to provide a theoretical foundation for their large-scale application. Full article

Groundwater pollution in landfill-adjacent regions presents a critical environmental and public health issue. This study evaluates groundwater quality in Xiangyang City, focusing on drinking water sources and key pollution points near landfill sites. The investigation involved a comprehensive field survey, systematic sampling, and laboratory analysis to determine pollutant types, sources, and concentrations. A total of 13 landfill sites were examined, with 178 groundwater samples analyzed for physical, chemical, and biological indicators during both wet and dry seasons. The findings reveal that 27.0% of groundwater samples meet Class I standards, while 46.1% and 27.0% fall into Class IV and V categories, respectively, indicating a significant prevalence of poor-quality groundwater. Seasonal variations were observed, with both wet and dry seasons showing consistent distributions of Class I, IV, and V samples. Heavy metals such as lead and arsenic, along with organic pollutants like polychlorinated biphenyls and pesticides (e.g., hexachlorobenzene), were significant contaminants in several sites. Key indicators such as nitrate, ammonia nitrogen, manganese, and total hardness consistently exceeded standard limits, with the most affected sites including L4 and L5 in Xiangyang. This study identifies leachate infiltration as the primary cause of pollution, exacerbated by geological and agricultural non-point sources. Based on these findings, a robust framework for monitoring and controlling groundwater pollution is proposed, emphasizing stricter regulations, advanced monitoring systems, and cross-regional coordination. The results underscore the urgency of immediate intervention to safeguard groundwater quality in landfill-adjacent regions. Full article

Hexachlorobenzene (HCB) is a persistent organic pollutant (POP) commonly detected in milk and dairy products. These compounds pose a serious threat to the health of consumers due to their considerable bioaccumulation potential, high stability, and toxicity. (2) Methods: The study evaluated the potential of Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus probiotic cultures to reduce HCB residues in fermented goat milk beverages during 21-day refrigerated storage. HCB content was determined by gas chromatography coupled with mass spectrometry (GC/MS). (3) Results: A strong negative correlation was found between HCB concentration in fermented milk and storage time. After 21 days, a 75–78% reduction in HCB content was observed, with L. plantarum showing greater efficiency in reducing hexachlorobenzene levels than L. rhamnosus. (4) Conclusions: The use of probiotic cultures contributed to a significant reduction in the HCB content of fermented goat milk. Our findings support the hypothesis that the lactic acid bacteria Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus can lower hexachlorobenzene levels in fermented products Full article

Environmental chemical exposure has been rising over the past few decades but its impact on fertility remains uncertain. We assessed exposures to 23 common chemicals across a range of sociodemographic characteristics and their relationship with self-reported infertility. The analytic sample was non-pregnant women aged 18–49 years without a history of hysterectomy or oophorectomy (n = 2579) from the National Health and Nutrition Examination Survey (2013–2016). Environmental chemical exposure was assessed with biospecimens and dichotomized as high and low levels of exposure based on the median. Logistic regression models estimated the adjusted odds ratio (aOR) and 95% confidence intervals (CIs) for the association between high levels of exposure and infertility, adjusted for age, race, education level, family income, and smoking status. We observed associations between infertility and cadmium [aOR: 1.88; 95% CI: 1.02–3.47] and arsenic [aOR: 1.88 (1.05–3.36)]. Two pesticides hexachlorobenzene [OR: 2.04 (1.05–3.98)] and oxychlordane [OR: 2.04 (1.12–3.69)] were also associated with infertility in unadjusted analyses. There were negative associations with two Per- and polyfluoroalkyl substances with n-perfluorooctanoic acid [aOR: 0.51: (0.30–0.86)] and n-perfluorooctane sulfonic acid [aOR: 0.51: (0.26–0.97). Specific chemicals may contribute to infertility risk, highlighting the need for targeted public health strategies to mitigate exposure. Full article

The Santiago-Guadalajara River Basin (SGRB), located in western Mexico, is one of the most polluted rivers in the country. A pesticide monitoring program was carried out from January 2022 to September 2022, during which time water samples collected at 25 sites in the main stem and tributaries revealed the presence of 13 of the 24 pesticides analyzed, including α-BHC, β-BHC, γ-BHC (Lindane), γ-Chlordane, Hexachlorobenzene, Heptachlor, Aldrin, α-Endosulfan, DDT, -4,4, Methoxychlor, Chlorpyrifos-methyl, Endosulfan sulfate, and Dicofol. A high level of correlation was found between the identified pesticides, which could mean that several of these pesticides reached a stable level within the monitored water bodies. Most of the identified pesticides are classified as high environmental risk according to the Stockholm Convention because of their persistence and high degree of toxicity to the environment and human health. A Pesticide Toxicity Index (PTI) was applied to identify the streams considered to be of concern due to the presence of pesticides exceeding the threshold limits established by national and international guidelines. Performing a calculation for the entire Santiago-Guadalajara River Basin, the PTI reached a value of 0.833, which, according to the criteria of this method, classifies it as a “Moderate” level of risk for aquatic life. Increased regulatory and surveillance measures by state and federal authorities are required to prevent the use of these pesticides, which have been restricted globally. Full article

Hexachlorobenzene (HCB) is one of the most persistent environmental pollutants of global concern. Ni/Fe nanoparticles, with their small particle size, large surface area, and high reactivity, are a promising candidate for HCB degradation. In this work, we investigated the kinetics and products of the dechlorination of HCB by Ni/Fe nanoparticles and how the presence of heavy metal ions Cd(Ⅱ) and Zn(Ⅱ) influences the reaction. It is found that 400 μg/L HCB can be rapidly removed by 7.5 g/L Ni/Fe nanoparticles and the removal percentage reaches 99% in 48 h. The removal is facilitated by adsorption and sequential dechlorination of HCB, producing PCB, 1,2,3,4-TeCB, and 1,2,3-TCB as the main products, with 1,2,3,5/1,2,4,5-TeCB, 1,2,4-TCB, and 1,2-DCB as the minor products. The addition of heavy metal ions Cd(Ⅱ) and Zn(Ⅱ) does not significantly affect the removal rate of HCB but hinders the adsorption and degradation of the byproducts through competitive adsorption. Additionally, the concentration of both Cd(Ⅱ) and Zn(Ⅱ) decreases rapidly and achieves over 98% removal in 4 h. Our study reveals that Ni/Fe nanoparticles can remove HCB and heavy metals Cd(Ⅱ) and Zn(Ⅱ) concurrently, with the extent of HCB dechlorination reduced compared to that without heavy metal. These findings may inform the application of Ni/Fe nanoparticles in the treatment of water bodies and soil contaminated by both halogenated aromatics and heavy metal. Full article

The aim of this study was to evaluate contamination levels and the frequency of detection of organochlorine (OCPs) and organophosphate pesticides (OPPs), pyrethroids, carbamates and polychlorinated biphenyls (seven PCB congeners) in a total of 534 samples of cow’s, sheep’s and goat’s milk and dairy products from Croatia. Concentrations above the limit of quantification (LOQ) were measured for fourteen OCPs, nine OPPs, six pyrethroids, one carbamate and PCBs with a total of 172 results, and no concentrations exceeded the maximal residue levels defined by the European Union. The mean concentrations of pesticides and the sum of seven PCBs were determined in the ranges 0.92–17.4 μg/kg and 1.38–2.74 μg/kg. Pesticides were quantified in 27% of samples, and seven PCBs were quantified in 5.23% of samples. Among the three pesticide groups, the highest numbers of quantified results were found for OCPs (12.1–20.8%). The highest frequencies of detection were found for the sum of 4,4’-dichlorodiphenyltrichloroethane and its isomers (DDTs), hexachlorobenzene and seven PCBs. The sum of seven PCBs was quantified within the range of 3.3–6.67% of samples per milk type and dairy products. Among the OPPs, the highest frequency of detection was found for chlorpyrifos in cow’s milk. Based on the estimated daily intakes, chronic risk characterisation showed no risk for adults or ten-year-old children for the consumption of cow’s milk and dairy products. Full article

Pesticides and polychlorinated biphenyls (PCBs) are persistent environmental pollutants. When entering the food chain, they can represent a public health problem due to their negative effects on health. In this study, concentrations of organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), pyrethroids, carbamates, and PCBs—a total 73 compounds—were determined in a total of 2268 samples of fat tissues (beef, pork, sheep, goat, poultry, game, horse, rabbit) and processed fat, meat, and processed meat products collected in Croatia during an 8-year period. In fatty tissues, 787 results exceeded the limits of quantification (LOQ): 16 OCPs, eight OPPs, six pyrethroids, one carbamate, and seven PCBs. The most positive results in fat samples were found for OCPs, with a frequency of quantification in the range of 57.5–87.5%. Hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (DDE) were quantified in the highest percentages, in the ranges of 5.5–66.7% and 5.4–55.8%. Concentrations above the MRL values were determined for chlorpyrifos in pork fat and for resmethrin in six fat samples and one pâté. In 984 samples of meat and meat products, only 62 results exceeded the LOQ values. The highest frequency of quantification was determined for OCPs (25 samples), of which 40% were DDT isomers (60% DDE). Frequency quantifications of PCBs in fat samples were between 7.23 and 36.7%. An evaluation of the health risk assessment showed that the consumption of fat, meat, and meat products does not pose a threat to consumer health, since all EDI values were well below the respective toxicological reference values. Full article

(1) Background: Hexachlorobenzene (HCB) is a persistent organic pollutant that is possibly carcinogenic to humans. It is still found in the environment, humans and animals, and in foods, including milk and dairy products; (2) Methods: The influence of the probiotic cultures Lacticaseibacillus rhamnosus LCR and Lactiplantibacillus plantarum subsp. plantarum LP on the possibility of effecting the biodegradation of HCB in dairy products fermented from mare milk was investigated, taking into account the product storage time (maximum 21 days). HCB content was determined using the GC/MS method; (3) Results: A strong negative Pearson correlation (p < 0.05) was found between HCB concentration and the refrigeration storage time of the fermented beverages. The highest HCB reduction was observed in milk fermented with both Lacticaseibacillus rhamnosus LCR and Lactiplantibacillus plantarum subsp. plantarum LP (78.77%), while the lowest was noted when only Lactiplantibacillus plantarum subsp. plantarum LP was used (73.79%); (4) Conclusions: This pilot study confirmed that probiotics commonly used to give products health-promoting properties can also contribute to reducing the content of undesirable substances, and the bacterial cultures used might provide an alternative method for reducing HCB residues in fermented drinks. Full article

Being a famous hometown of vegetables in China, Shouguang City has a long history of vegetable cultivation and is a comprehensive national commodity base for vegetables and fruits. In recent decades, with the expansion of agricultural production, the use of pesticides is increasing. Although organochlorine pesticides (OCPs) have been banned, there are still some residues in soil, groundwater and other media. The study on the migration of the OCPs in soil and groundwater is of great importance for the maintenance of food security. Using methods of hydrogeological survey, laboratory testing and numerical simulation, the spatial distribution characteristics, sources and pollution degree of OCPs in soil and groundwater were analyzed, and the migration and transformation of OCPs in soil–groundwater was dynamically simulated and predicted. The study showed that there were many kinds of OCPs residual in the soil environment. The hexachlorocyclohexane (HCHs) in the topsoil of the study area were mainly due to the use of lindane, and the main source of dichlorodiphenyltrichloroethane (DDTs) in soil was the use of DDTs in history. The contents of HCHs, DDTs and hexachlorobenzene in the topsoil of the study area were at a low level, while the content of endosulfan metabolite endosulfan sulfate was comparatively higher. In recent years, the content of organochlorine pesticides in soil has generally decreased. The indexes of OCPs in groundwater can meet the Standards for Drinking Water quality of China. It was predicted that the HCH pollutants would mainly be distributed in Gucheng Street, Shangkou Town, and its south area where the concentration exceeds 3 ng/L exceeds that of 240 km². DDT pollutants would mainly be distributed in the east and north of Shouguang City, where the concentration beyond 0.6 ng/L exceeds that of 200 km². Endosulfan sulfate pollutants would mainly be distributed in the Gucheng Street Office, Shangkou Town, and its south area where the concentration exceeds 1.5 ng/L will exceed that of 150 km². Hexachlorobenzene (HCB) pollutants would mainly be distributed in Fengcheng in the west of Shouguang City and Nancha River in the northeast, where the concentration exceeds 0.2 ng/L will exceed that of 200 km². The study enriched the monitoring data of OCPs in agricultural planting areas and provided reference for source analysis, migration prediction, and pollution prevention of OCPs. Full article

Occupational and environmental chemical exposure have been associated with adverse reproductive consequences. This study investigates the relationship between spontaneous abortion and blood pesticide and polychlorinated biphenyl (PCB) levels. A survey was conducted, and blood samples were collected from 200 patients, consisting of 100 cases with spontaneous abortion and 100 cases with normal deliveries. A total of 150 different pesticides, including organophosphates, organochlorines, carbamates, and pyrethroids, were screened in the collected blood samples and analyzed quantitatively using Tandem mass spectrometry—specifically in combination with liquid chromatography and gas chromatography–tandem mass spectrometry methods. Eight types of PCBs were analyzed with the gas chromatography-tandem mass spectrometry method. The groups were compared based on these analyses. The mean age of the participants was 28.09 ± 4.94 years. In 59% of the spontaneous abortion group, 5.05 ± 1.97 chemicals were detected in different amounts. (p < 0.05). Analysis of the samples identified the presence of β-Hexachlorocyclohexane (β-HCH), delta-hexachlorocyclohexane (δ HCH), Hexachlorobenzene (HCB), Pentachlorobiphenyl-28 (PCB-28), Pentachlorobiphenyl-52 (PCB-52), o,p′-Dichlorodiphenyldichloroethylene (o,p′-DDE), p,p′-Dichlorodiphenyldichloroethylene (p,p’DDE), o,p′-Dichlorodiphenyldichloroethane (o,p′-DDD), p,p′-Dichlorodiphenyldichloroethane (p,p′-DDD), Pentachlorobiphenyl-118 (PCB-118), Pentachlorobiphenyl-101 (PCB-101), Pentachlorobiphenyl-153 (PCB-153), Pentachlorobiphenyl-138 (PCB-138), Pentachlorobiphenyl-202 (PCB-202), Pentachlorobiphenyl-180 (PCB-180) as well as Fibronil, Buprimate, Acetoclor, Acemiprid, Pentimanthalin, and Triflokystrobin. The spontaneous abortion group had significantly higher exposure to PCB-101, PCB-52, PCB-138, and δ-HCH (p < 0.05). Women included in the study had high pesticide and PCB exposure rates. Many of the blood samples contained multiple pesticides with endocrine-disrupting effects. Higher exposure to organochlorine compounds in the serum was identified in the group with spontaneous abortions. Full article

We investigated the occurrence of organochlorine pollutants (OCs) in the muscle of brown trout and evaluated their potential modulation of parasite infection. The toxicological risk for consumer health was assessed, too. Trout were collected from the Sila National Park (Calabria region, South of Italy). The highest concentrations emerged for the sum of the 6 non-dioxin-like (ndl) indicator polychlorinated biphenyls (Σ6ndl-PCBs), followed by the 1,1,1-trichloro-2,2-di(4-chlorophenyl)-ethane (DDT), dioxin-like PCBs, hexachlorobenzene (HCB), and dieldrin. Measured on lipid weight (LW), the mean value of Σ6ndl-PCBs amounted to 201.9 ng g⁻¹, that of ΣDDTs (the sum of DDT-related compounds) to 100.2 ng g⁻¹, with the major contribution of the DDT-metabolite p,p’-DDE which was detected in all sample units (97.6 ng g⁻¹ on average). Among dioxin-like congeners, PCB 118 showed the highest mean concentration (21.96 ng g⁻¹ LW) and was detected in all sample units. Regression analysis of intestinal parasites on OC concentration was performed, controlling for two potential confounding factors, namely sex and sexual stage. The results evidenced the existence of interactions between the dual stressors in the host-parasite system in the wild. A negative and statistically significant correlation was estimated, suggesting that OCs may decrease parasite infection degree. Regarding the toxicological risk evaluation, OC concentrations were consistently below the current European Maximum Residue Limits. Full article