Evaluation of selected polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane (DDT) in fresh root and leafy vegetables using GC-MS

Investigation of organic micropollutant pollution in İzmit Bay: a comparative study of passive sampling and instantaneous sampling techniques

In this study, we used a comprehensive array of sampling techniques to examine the pollution caused by organic micropollutants in İzmit Bay for the first time. Our methodology contains spot seawater sampling, semi-permeable membrane devices (SPMDs) passive samplers for time-weighted average (TWA), and sediment sampling for long-term pollution detection in İzmit Bay, together. Additionally, the analysis results obtained with these three sampling methods were compared in this study. Over the course of two seasons in 2020 and 2021, we deployed SPMDs for 21 days in the first season and for 30 days in the second season. This innovative approach allowed us to gather sea water samples and analyze them for the presence of polycyclic aromatic hydrocarbons (Σ15 PAHs), polychlorinated biphenyls (Σ7 PCBs), and organochlorine pesticides (Σ11 OCPs). Using SPMD-based passive sampling, we measured micropollutant concentrations: PAHs ranged from 1963 to 10342 pg/L in 2020 and 1338 to 6373 pg/L in 2021; PCBs from 17.46 to 61.90 pg/L in 2020 and 8.37 to 78.10 pg/L in 2021; and OCPs from 269.2 to 8868 pg/L in 2020 and 141.7 to 1662 pg/L in 2021. Our findings revealed parallels between the concentrations of PAHs, PCBs, and OCPs in both SPMDs and sediment samples, providing insights into the distribution patterns of these pollutants in the marine ecosystem. However, it is worth noting that due to limited data acquisition, the suitability of spot sampling in comparison to instantaneous sampling remains inconclusive, highlighting the need for further investigation and data collection.

Development and application of a new QuEChERS-molecularly imprinted solid phase extraction (QuEChERS-MISPE) technique for analysis of DDT and its derivatives in vegetables

The current study synthesized a molecularly imprinted polymer, combined it with the QuEChERS method to form a new hybrid technique, the QuEChERS-MISPE as an alternative to the QuEChERS-dSPE for analysis of DDTs as model pesticides. Batch studies confirmed that the binding of the DDTs to the MIP cavities formed a monolayer formation through chemisorption resulting in an adsorption capacity of 429 ng g-1. A study of matrix effects indicated signal suppression for both techniques. However, the new QuEChERS-MISPE technique is less affected by matrix effects, has better sensitivity and recoveries compared to the conventional QuEChERS-dSPE technique. Application of the new QuEChERS-MISPE technique detected trace levels of DDTs in vegetables in South Africa. However, a health risk assessment indicated that potential risks for consumers was minimal. Although the risk is minimal, the detection of DDTs in vegetables in South Africa should be a concern and more constant monitoring is required.

Strategies for mitigation of pesticides from the environment through alternative approaches: A review of recent developments and future prospects

Chemical-based peticides are having negative impacts on both the healths of human beings and plants as well. The World Health Organisation (WHO), reported that each year, >25 million individuals in poor nations are having acute pesticide poisoning cases along with 20,000 fatal injuries at global level. Normally, only ∼0.1% of the pesticide reaches to the intended targets, and rest amount is expected to come into the food chain/environment for a longer period of time. Therefore, it is crucial to reduce the amounts of pesticides present in the soil. Physical or chemical treatments are either expensive or incapable to do so. Hence, pesticide detoxification can be achieved through bioremediation/biotechnologies, including nano-based methodologies, integrated approaches etc. These are relatively affordable, efficient and environmentally sound methods. Therefore, alternate strategies like as advanced biotechnological tools like as CRISPR Cas system, RNAi and genetic engineering for development of insects and pest resistant plants which are directly involved in the development of disease- and pest-resistant plants and indirectly reduce the use of pesticides. Omics tools and multi omics approaches like metagenomics, genomics, transcriptomics, proteomics, and metabolomics for the efficient functional gene mining and their validation for bioremediation of pesticides also discussed from the literatures. Overall, the review focuses on the most recent advancements in bioremediation methods to lessen the effects of pesticides along with the role of microorganisms in pesticides elimination. Further, pesticide detection is also a big challenge which can be done by using HPLC, GC, SERS, and LSPR ELISA etc. which have also been described in this review.

Endocrine disruptors: Unravelling the link between chemical exposure and Women's reproductive health

An Endocrine Disrupting Chemical (EDC) is any compound that disrupts the function of the endocrine system in humans and is ubiquitous in the environment either as a result of natural events or through anthropogenic activities. Bisphenol A, phthalates, parabens, pesticides, triclosan, polychlorinated biphenyls, and heavy metals, which are frequently found in the pharmaceutical, cosmetic, and packaging sectors, are some of the major sources of EDC pollutants. EDCs have been identified to have a deteriorating effect on the female reproductive system, as evidenced by the increasing number of reproductive disorders such as endometriosis, uterine fibroids, polycystic ovary syndrome, premature ovarian failure, menstrual irregularity, menarche, and infertility. Studying EDCs in relation to women's health is essential for understanding the complex interactions between environmental factors and health outcomes. It enables the development of strategies to mitigate risks, protect reproductive and overall health, and inform public policy decisions to safeguard women's well-being. Healthcare professionals must know the possible dangers of EDC exposure and ask about environmental exposures while evaluating patients. This may result in more precise diagnosis and personalized treatment regimens. This review summarises the existing understanding of prevalent EDCs that impact women's health and involvement in female reproductive dysfunction and underscores the need for more research. Further insights on potential mechanisms of action of EDCs on female has been emphasized in the article. We also discuss the role of nutritional intervention in reducing the effect of EDCs on women's reproductive health. EDC pollution can be further reduced by adhering to strict regulations prohibiting the release of estrogenic substances into the environment.

A Facile and Rapid Strategy for Quantifying PCBs in Cereals Based on Dispersive Solid-Phase Extraction and Gas Chromatography-Mass Spectrometry: A Reference for Safety Concerns in Sustainable Textiles

Cereals and their derivative products such as starch and cyclodextrin are significant natural materials for sustainable textile processing (e.g., sizing, dispersing, etc.). However, the contamination of cereals with polychlorinated biphenyls (PCBs) is often neglected, which has led to increasing concerns due to the adverse effects on end users. Therefore, monitoring PCBs in cereals is of great importance in preventing health risks. However, high starch, protein, and fat contents make cereals a complicated matrix and can challenge the analysis of PCBs in cereals. This work describes a facile and rapid strategy for quantifying 18 PCBs in cereals that included corn, wheat, and rice through dispersive solid-phase extraction and gas chromatography with mass spectrometry. Importantly, this was the first time that carboxyl-modified, multi-walled carbon nanotubes were incorporated in the detection of PCBs in cereals. The influences of several parameters on the extraction and clean-up efficiency were investigated; these included the type and volume of extraction solvent, sonication time, and the type and dosage of the adsorbent. The matrix effects on quantification were also evaluated. This approach exhibited a better clean-up performance. All the analytes showed weak matrix effects, and thus a solvent standard plot could be prepared for their quantification. Spiking experiments in the selected matrices at three concentration levels from 0.5 to 10 μg/kg resulted in satisfactory recoveries that ranged from 79.2% to 110.5% with relative standard deviations (RSDs; n = 6) less than 10.3%. The limits of detection (LODs) and quantification (LOQs) ranged from 0.04 to 0.1 μg/kg and 0.1 to 0.4 μg/kg, respectively. The practical application of this method was investigated by analyzing actual cereal samples, which demonstrated that the proposed approach was a facile and efficient strategy for PCB determination and provided a reference for the safety evaluation of sustainable textiles. The method also could be generalized to other troublesome samples for testing of multiple PCBs.

Application of insecticides on peppermint (Mentha × piperita L.) induces lignin accumulation in leaves by consuming phenolic acids and thus potentially deteriorates quality

Irrational use of pesticides may lead to physiological and metabolic disorders in different crops. However, there are limited investigations on impacts of insecticides on physiology and biochemistry, secondary metabolic pathways, and associated quality of medicinal plants such as peppermint (Mentha × piperita L.). In this study, target metabolites in peppermint were monitored following foliar spraying of five insecticides: imidacloprid, pyriproxyfen, acetamiprid, chlorantraniliprole, and chlorfenapyr. Compared with the control, all insecticide treatments caused a significant loss of soluble protein (decreased by 22.3-38.7%) in peppermint leaves. Insecticides induced an increase in the levels of phytohormones jasmonic acid and abscisic acid in response to these chemical stresses. Among them, imidacloprid increased jasmonic acid by 388.3%, and pyriproxyfen increased abscisic acid by 98.8%. The contents of phenylpropanoid metabolites, including rutin, quercetin, apigenin, caffeic acid, 4-hydroxybenzoic acid, ferulic acid, syringic acid, and sinapic acid showed a decreasing trend, with pyriproxyfen decreasing the levels of quercetin and 4-hydroxybenzoic acid by 78.8% and 72.6%, respectively. Combined with correlation analysis, the content of lignin in leaves shows different degrees of negative correlations with several phenolic acids. It could be inferred that insecticides may trigger plant defense mechanisms that accumulate lignin (increased by 24.6-49.1%) in leaves by consuming phenolic acids to barricade absorption of insecticides. Through constructing networks between phytohormones and secondary metabolites, peppermint may regulate the contents of caffeic acid, 4-hydroxybenzoic acid, and sinapic acid by the antagonistic effect between salicylic acid and abscisic acid in response to insecticidal stresses. Principal component analysis and systemic cluster analysis revealed that the most pronounced changes in physiological indexes and metabolites were caused by the pyriproxyfen treatment. In conclusion, this study improves our understanding of the mechanism by which insecticides affect plant physiological and metabolic processes, thus potentially altering the quality and therapeutic value of peppermint as an example.

Characteristics and Residual Health Risk of Organochlorine Pesticides in Fresh Vegetables in the Suburb of Changchun, Northeast China

In this study, eleven organochlorine pesticides (OCPs) in fresh vegetables in the Changchun suburb were investigated, and their potential health risks were evaluated. The average concentrations of OCPs in edible parts of vegetables were found in the following descending order: Σhexachlorocyclohexanes (ΣHCHs) (6.60 µg·kg^-1) > Σdichlorodiphenyltrichloroethanes (ΣDDTs) (5.82 µg·kg^-1) > ΣChlordanes (2.37 µg·kg^-1) > heptachlor (0.29 µg·kg^-1). Moreover, OCPs in different types of vegetables exceeded the maximum residue limits (MRLs), and the exceeding rates in various vegetables decreased in the following order: leafy vegetables (19.12%) > root vegetables (18.75%) > fruit vegetables (3.85%). The proportions of OCPs exceeding MRL in different vegetables were found in the following descending order: Welsh onion (22.50%) > radish (18.75%) > Chinese cabbage (14.29%) > pepper (6.90%) > cucumber (3.23%) > eggplant (2.94%) > tomato (2.78%). The sources' identification results showed that DDTs in vegetables came mainly from newly imported technical DDTs and dicofol, while HCHs originated mainly from lindane. For both adults and children, the average target hazard quotients (avg. THQ) were all less than 1, and the average hazard index (avg. HI) values were 0.043 and 0.036, respectively. There were no significant health risks associated with OCP exposure for the inhabitants of the study area.

Pesticides: Behavior in Agricultural Soil and Plants

This review considers potential approaches to solve an important problem concerning the impact of applied pesticides of various classes on living organisms, mainly agricultural crops used as food. We used the method of multi-residual determination of several pesticides in agricultural food products with its practical application for estimating pesticides in real products and in model experiments. The distribution of the pesticide between the components of the soil-plant system was studied with a pesticide of the sulfonylureas class, i.e., rimsulfuron. Autoradiography showed that rimsulfuron inhibits the development of plants considered as weeds. Cereals are less susceptible to the effects of pesticides such as acetamiprid, flumetsulam and florasulam, while the development of legume shoots was inhibited with subsequent plant death.

Polycyclic aromatic hydrocarbons (PAHs) in leafy vegetables consumed in southern Nigeria: concentration, risk assessment and source apportionment

Four commonly consumed leafy vegetables, obtained from four major cities in southern Nigeria, were analysed for their polycyclic hydrocarbon (PAH) content using gas chromatography coupled with mass spectrometry (GC-MS). The estimated daily intake (EDI), margin of exposure (MOE), hazard index (HI) and total cancer risk (TCR); principal component analysis (PCA) and diagnostic ratios (DRs) were respectively used for risk evaluation and source identification of the detected PAHs. The results showed that the mean concentration (µg kg^-1) of ∑16 PAHs in the vegetables ranged from 532 to 2261. The EDI values ranged from 459 to 4876, 1809 to 8378, 2733 to 13,036 and 4143 to 12,568 ng kg^-1 bw day^-1 for benzo[a]pyrene (BaP), PAH2, PAH4, and PAH8 for children exposure respectively, and from 115 to 1219, 452 to 2095, 683 to 3259 and 1036 to 3142 ng kg^-1 bw day^-1 for adult exposure respectively. The estimated MOE values were < 10,000, indicating that the vegetables were unsuitable for consumption. The HI values were < 1, suggesting that there were no potential non-carcinogenic risks, but the total cancer risk values (> 1 × 10^-6) designated carcinogenic risk of PAHs with consumption of these vegetables. The DR and PCA result showed that PAHs originated from high-temperature pyrogenic processes and vehicular emissions.

Pesticides: formulants, distribution pathways and effects on human health - a review

Pesticides are commonly used in agriculture to enhance crop production and control pests. Therefore, pesticide residues can persist in the environment and agricultural crops. Although modern formulations are relatively safe to non-target species, numerous theoretical and experimental data demonstrate that pesticide residues can produce long-term negative effects on the health of humans and animals and stability of ecosystems. Of particular interest are molecular mechanisms that mediate the start of a cascade of adverse effects. This is a review of the latest literature data on the effects and consequences of contamination of agricultural crops by pesticide residues. In addition, we address the issue of implicit risks associated with pesticide formulations. The effects of pesticides are considered in the context of the Adverse Outcome Pathway concept.

Human health risk assessment of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) pesticide residues in fruits and vegetables in Nigeria

The residues of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in forty-eight (48) composite fruit and vegetable samples (carrot, cucumber, tomato, and watermelon) were qualitatively and quantitatively determined using gas chromatography equipped with electron capture detector (GC-ECD). Safety indices such as the estimated average daily intake (EADI), cancer benchmark concentration (CBC), hazard quotient (HQ) and index (HI), and hazard ratio (HR) were also estimated. Results showed the predominance of HCH and its isomers in the fruits and vegetables as compared with the DDTs. The most predominant HCHs in all the fruits was α-HCH with mean concentrations of 2.704 ± 2.488 mg kg-1 (carrot), 1.536 ± 1.036 mg kg-1 (cucumber), 6.814 ± 2.967 mg kg-1 (tomato), and 9.241 ± 2.735 mg kg-1 (watermelon). The analysis showed that the levels of pesticide residues detected in 25 to 100% of the fruit and vegetable samples were above the UK/European Commission Maximum Residue Limits (MRLs). The non-carcinogenic health risk estimates showed that only α-HCH in tomatoes and watermelon had HQ > 1 which indicates the possibility of systemic health risk in children consumers. The carcinogenic health risk showed that only α-HCH and γ-HCH in children and α-HCH in adults had HR > 1 for tomato and watermelon which implies the possibility of carcinogenic health risk from its consumption. It is therefore paramount to institute a policy and regulatory framework for regular monitoring of pesticide residues in fruits and vegetables in Nigeria in order to ensure food safety for consumers and protect human health.

Occurrence of organic micropollutants and human health risk assessment based on consumption of Amaranthus viridis, Kinshasa in the Democratic Republic of the Congo

The contamination of water resource and food chain by persistent organic pollutants (POPs) constitutes a major environmental and human health concern worldwide. The aim of this study was to investigate the levels of POPs in irrigation water, soil and in Amaranthus viridis (A. viridis) from different gardening sites in Kinshasa to evaluate the potential environmental and human health risks. A survey study for the use of pesticides and fertilizers was carried out with 740 market gardeners. The levels of POPs (including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs)) were analyzed in irrigation water and 144 vegetable samples collected from different gardening sites. The assessment of potential human health risk was estimated by calculating daily intake and toxic equivalency to quantify the carcinogenicity. The results show highest PAH levels in A. viridis from all studied sites. The concentrations of the sum of seven PCBs (Σ7PCB_S) congeners in analyzed plants ranged between 15.89 and 401.36 ng g^-1. The distributions of OCPs in both water and A. viridis were congener specific, chlorpyrifos-ethyl and p,p'-DDE were predominantly detected. Among PBDEs, only BDE47 was quantified with noticeable concentration in A. viridis, while no PBDEs were detected in irrigation water. Higher estimated daily intake values indicate that consuming leafy vegetables might associate with increased human health risks. However, calculated incremental lifetime cancer risk values indicates no potential carcinogenic risk for the local population. The results of this study provide important information on A. viridis contamination by POPs and strongly recommend implementing the appropriate measures to control the use of chemicals used in studied gardening areas. Thus in Kinshasa, urban agriculture control programs for POPs and fertilizers is very important in order to protect the public health through direct and dietary exposure pathways.

Highly sensitive and selective detection of PCB 77 using an aptamer-catalytic hairpin assembly in an aquatic environment

Polychlorinated biphenyls (PCBs) are synthetic organic compounds that are extremely difficult to break down in water and can accumulate in human fat and organisms. However, methods that can be used to detect large amounts of PCBs remain unsatisfactory, as they are generally overly sensitive and involve complex operations. An aptamer-based catalytic hairpin assembly (aptamer-CHA) reaction for the selective detection of 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) was developed. It combines the advantages of aptamers and signal amplification reactions. The aptamer selectivity recognizes the target, PCB 77, which triggers the sensitive CHA reaction to produce a fluorescence signal. CHA is a sensitive enzyme-free signal amplification method suitable for on-site detection. Therefore, the identification aptamer is the basis for the quantitative detection of PCB 77, with a detection range of 0.01 μg L⁻¹ to 500 μg L⁻¹ and a detection limit of 0.01 μg L⁻¹. In this study, the aptamer was used to improve the selectivity of the reaction, and the CHA reaction improved the sensitivity of the detection system. Such high-sensitivity PCB detection capabilities with simplified procedures may be useful for real-time field detection and other monitoring tasks. This method can be used as a rapid fluorescence detection strategy for other targets in aquatic environments.

The fluorescence sensing strategy was used to detect PCB77 based on the aptamer-complex and catalytic hairpin assembly.

Cloning, overexpression, purification, characterization and structural modelling of a metabolically active Fe2+ dependent 2,6-dichloro-p-hydroquinone 1,2-dioxygenase (CpsA) from Bacillus cereus strain AOA-CPS_1

2,6-Dichloro-p-hydroquinone (DiCHQ) aromatic-ring cleavage by DiCHQ 1,2-dioxygenase (CpsA) is very crucial for complete transformation of pentachlorophenol (PCP) to 2-chloromaleylacetate in Bacillus cereus AOA-CPS_1 (BcAOA). The 978 bp gene (cpsA) was detected and amplified in the genome of BcAOA; cloned, overexpressed and purified to homogeneity. CpsA showed a single ≅36.9 kDa protein band on SDS-PAGE and exhibited optimum activity at 30 °C and pH 9.0. CpsA was stable between 20 °C and 40 °C, and also retained about 90% of its activity at 60 °C for 120 min. The enzyme retained about 90% activity between pH 9.0 and 11.5 and 60% activity at pH 13.0. CpsA was found to be Fe²⁺ dependent as about 90% increased activity was observed in the presence of FeSO₄. CpsA showed apparent v_max, K_m, k_cat and k_cat/K_m of 27.77 ± 0.9 μMs^-1, 0.990 ± 0.03 mM, 4.20 ± 0.04 s^-1 and 4.24 ± 0.03 s^-1 mM^-1, respectively at pH 9.0. Analysis of the reaction products via GC-MS confirmed 2-chloromaleylacetate as the ring-cleavage product. CpsA 3D structure revealed a conserved 2-His-1-carboxylate facial triad motif (His 9, His 244 and Thr 11), with Fe³⁺ at the centre. Findings from this study provide new insights into the involvement of this enzyme in PCP degradation and suggests alternate possible mechanism of ring-cleavage by dioxygenases.

Trophic Magnification of Legacy (PCB, DDT and Hg) and Emerging Pollutants (PFAS) in the Fish Community of a Small Protected Southern Alpine Lake (Lake Mergozzo, Northern Italy)

The biomagnification of mercury, polychlorobiphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs) and perfluoroalkyl acids substances (PFASs) was evaluated in the trophic web of Lake Mergozzo, a small and deep Italian subalpine lake, which has been chosen because it is a protected environment, and discharges into the lake are mostly avoided. Carbon source and relative trophic levels were calculated by using 13C and 15N stable isotopes, respectively, and trophic magnification factors (TMFs) were derived. Zooplankton and thirteen species of fish were collected and analyzed, and the results showed the elevated level of biota contamination from both legacy and emerging pollutants, even if direct discharges were avoided. Concentrations in biota, expressed as sums of compounds, ranged from 0.4 to 60 µg kg−1 wet weight (ww) for PFASs, from 16 to 1.3 104 µg kg−1 lipid content (lw) for DDTs, from 17 to 1.5 104 µg kg−1 lw for PCBs and from 20.0 to 501 µg kg−1 ww for mercury (Hg). TMFs of this deep, cold lake, with a prevalent pelagic trophic chain, were high and clearly indicated fish biomagnification, except for PFAS. The biomagnification capability of PFAS in a fish-only food web was discussed by using the biomagnification of Hg as a benchmark for assessing their bioaccumulation potential.

Magnetic ferroferric oxide and polydopamine molecularly imprinted polymer nanocomposites based electrochemical impedance sensor for the selective separation and sensitive determination of dichlorodiphenyltrichloroethane (DDT)

Dichlorodiphenyltrichloroethane (DDT) is a kind of broad-spectrum insecticides, which is potentially toxic and persistently threatens the safety of environment and food, due to their stability in nature and difficulty to degrade. For the first time, a novel impedance chemical sensor based on magnetic Fe₃O₄ and polydopamine molecularly imprinted polymer magnetic nanoparticles (PDA@Fe₃O₄ MIP MNPs) was designed. Bisphenol A (BPA) and dopamine were used as virtual template molecules and functional monomer for MIP synthesis, respectively. Recognition cavities formed in PDA layers could specifically recognize and effectively adsorb DDT molecules, with the help of virtual templates that had similar molecular structure to DDTs. The as-prepared PDA@Fe₃O₄-MIP MNPs could be used for specific adsorption and efficient extraction of target molecules 4,4'-DDT from food samples. The electrochemical impedance of the PDA@Fe₃O₄-MIP MNPs increased sensitively with the adsorption of 4,4'-DDT, the correlationship between of the electrochemical impedance response and the concentration of 4,4'-DDT were applied in the construction of electrochemical impedance sensors for the determination of 4,4'-DDT. The sensor showed a good linear relationship between the charge transfer resistance (R_ct) and the 4,4'-DDT concentration over a range from 1 × 10^-11 to 1 × 10^-3 mol L^-1 with a detection limit of 6 × 10^-12 mol L^-1. The sensor also exhibited excellent sensitivity and selectivity as well as high stability for the detection of pesticide residues and other environmentally harmful chemicals in various food samples.