Pesticides in human milk collected from Jinhua, China: Levels, influencing factors and health risk assessment

Hitting two targets with one shot on pesticide genotoxicity assessment - Identifying risk while unveiling ex vivo approach as a throughput tool in gill-breathing animals

Pesticides in the environment often compromise the ecosystem, thus requiring reliable approaches to assess their effects. Commonly used approaches, such as in vivo, come with several disadvantages, namely in the light of the 3 R's policy. Seeking for accurate and ethical approaches, this study intended to validate the ex vivo technique as an alternative, and to assess the genotoxicity of chemically-based pesticides and a biopesticide. The ex vivo approach was applied to gill cells of Procambarus clarkii for 2, 4 and 8 h. Cell viability and DNA integrity were evaluated to determine the applicability of this approach. Crayfish gill cells only showed to be suitable for exposures of 2 h. Accordingly, genotoxicity was evaluated in gill cells exposed, for 2 h, to environmentally relevant concentrations of the chemically-based pesticides dimethoate (20 µg L-1), imazalil (160 µg L-1) and penoxsulam (23 µg L-1), as well as to the bioinsecticide Turex® (25, 50, 100, 200 and 400 µg L-1). Every chemically-based pesticide demonstrated to be genotoxic, despite not inducing oxidative DNA damage. On the other hand, Turex® showed no genotoxic effects. Overall, the ex vivo approach demonstrated to be possible and practical to implement, improving the number of outcomes with a lower number of organisms. The findings from the screening test suggest that biological pesticides may pose a lower risk to non-target organisms compared to chemically-based pesticides.

Review of scientific literature on available methods of assessing organochlorine pesticides in the environment

Organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) widely used in agriculture and industry, causing serious health and ecological consequences upon exposure. This review offers a thorough overview of OCPs analysis emphasizing the necessity of ongoing work to enhance the identification and monitoring of these POPs in environmental and human samples. The benefits and drawbacks of the various OCPs analysis techniques including gas chromatography-mass spectrometry (GC-MS), gas chromatography-electron capture detector (GC-ECD), and liquid chromatography-mass spectrometry (LC-MS) are discussed. Challenges associated with validation and optimization criteria, including accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ), must be met for a method to be regarded as accurate and reliable. Suitable quality control measures, such as method blanks and procedural blanks, are emphasized. The LOD and LOQ are critical quality control measure for efficient quantification of these compounds, and researchers have explored various techniques for their calculation. Matrix interference, solubility, volatility, and partition coefficient influence OCPs occurrences and are discussed in this review. Validation experiments, as stated by European Commission in document SANTE/11813/2017, showed that the acceptance criteria for method validation of OCP analytes include ≤20 % for high precision, and 70-120 % for recovery. This may ultimately be vital for determining the human health risk effects of exposure to OCP and for formulating sensible environmental and public health regulations.

The role of miRNA-26a-5p and target gene socs1a in flutolanil induced hepatotoxicity of zebrafish at environmental relevant levels

Flutolanil has been detected worldwide in aquatic environment and fish, which has become an undeniable stressor on ecosystem and human health. Flutolanil has been reported to be toxic to aquatic organisms. However, the pathophysiological and molecular mechanism behind the detrimental effects remains obscure. Here we reported hepatotoxicity induced by flutolanil in HepG2 cells and zebrafish, as revealed by toxicokinetic, HE staining, miRNAs-mRNAs sequencing, molecular dynamic simulations and dual luciferase reporter assays. Collectively, our results indicated that flutolanil could be absorbed by and accumulated in the liver of zebrafish, causing hepatic vacuolar degeneration, steatosis and nuclear condensation and abnormal liver function, where its exposure at environmental levels disrupted the expressions of miRNA-26a-5p and its target gene socs1a by mediating JAK-STAT signaling pathway, which was partially responsible for hepatotoxicity, correlated with oxidative stress, cell apoptosis, inflammation, cell cycle disorder and mitochondrial dysfunction. These findings suggest that miRNA-26a-5p/socs1a can serve as potential biomarkers of hepatotoxicity in zebrafish following exposure to flutolanil. This uncovered route will provide a new tool for the risk assessment of flutolanil and a guide to proper use of flutolanil and environmental remedy, and open up a new horizon for liver disease assessment.

Pesticides in the hydrogeo-environment: a review of contaminant prevalence, source and mobilisation in India

Chemical pesticides in the hydrogeological system are a global concern as they pose a severe threat to humans and other organisms. In agriculture, around 4.12 million tonnes of pesticides were used globally in 2018, which is 50% more than in the 1990s. Various pesticides detected in the hydrogeological system of India since the 1990s have been documented and reviewed to understand the prevalence, source, history and degradation pathways. This review contributes to a better understanding of existing pesticide pollution and the state of hydrogeological resource deterioration. Small to excess levels of pesticide residues were detected in groundwater, surface water, soil, and sediments. Pesticides that were most commonly and predominantly found in the hydrogeological system were HCHs, DDTs, endosulfan, heptachlor, drins (aldrin, dieldrin, endrin), chlordane etc. β and γ-HCH isomers among HCHs, whereas p,p'-DDT and p,p'-DDE among the DDTs were detected most prevalently. In many regions, pesticide residue levels in water have exceeded the maximum residue limits of WHO and BIS, while those in soils and sediments have exceeded the threshold effect level and probable effect level. Higher pesticide residues were detected in the water resources of rural agricultural areas compared to peri-urban or urban areas. A positive correlation of pesticide residues between water resources and soil has been observed in some regions, suggesting a similar contamination source. Diagnostic ratios of pesticides reveal their source, history and degradation pathways. Diagnostic ratios observed in various studies conducted in India suggest historical as well as recent use of banned pesticides. Strengthening current policies and regulations, monitoring pesticide use, changes in pesticide application practices, awareness among farmers, and the use of prominent removal techniques are necessary to tackle pesticide contamination in India.

Heavy metals in paired samples of hair and nails in China: occurrence, sources and health risk assessment

The occurrence of heavy metals including chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) was investigated in paired samples of hair and nails collected from 121 volunteers in 16 cities, China. Results showed that the mean concentrations of Zn, Cu, As, Pb, Cr, Ni and Cd were 205, 18.0, 7.79, 6.18, 3.54, 2.02, 0.533 μg g^-1 in hair and 103, 8.09, 0.760, 7.27, 6.07, 8.81, 0.485 μg g^-1 in nails, respectively. The concentrations of Zn, Ni, Cr, Cd and Pb were positively correlated in paired samples of hair and nails, whereas a negative correlation was found for Cu and As between hair and nails. Higher concentrations of heavy metals were found in northern China than southern China. The multivariate analysis of variance revealed that dwelling environment was the dominant factor influencing the levels of Cd in hair (p < 0.05), while age was the dominant factor influencing the levels of Cr in nails (p < 0.05). Moreover, industrial pollution and smoking were also the important factors leading to the accumulation of heavy metals in human body. Principal component analysis (PCA) showed that industrial pollution and decoration material immersion were the main factors for the high concentrations of Cr and Ni in hair, accounting for 62.9% of the total variation; As in hair was dominantly related to groundwater pollution. The concentrations of heavy metals were within the recommended ranges in nails from this study. However, the mean levels of Cr, Ni and As in hair exceeded their recommended reference values, indicating potential health risks from heavy metals for residents in China.

Occurrence and exposure risk assessment of organochlorine pesticides in two waterbird species from Honghu Lake Wetland, Central China

Monitoring and evaluating bird exposure to hazardous pollutants in wetlands are receiving considerable attention. In this study, the occurrence of 18 organochlorine pesticides (OCPs) in the muscle of bean geese (Anser fabalis) and common teals (Anas crecca) collected from Honghu Lake Wetland (HLW), Central China was studied. Additionally, an exposure risk assessment model was applied to obtain risk levels of OCPs to these birds through three oral routes (food intake, water drinking and soil ingestion). The results suggested that the most abundant OCPs detected in the muscle of waterbirds were DDTs (7.68-602 ng/g lipid weight), followed by HCHs (1.39-89.8 ng/g lipid weight). A significant difference (p < 0.05) existed between two species, but most of OCPs exhibited no statistically relationship with age or gender (p > 0.05). The compositional patterns of OCPs combined with ratios of certain metabolites to their parent compounds indicated that all OCPs in the HLW were largely from historical usage except heptachlor. The exposure risk assessment revealed that common teals with lighter weight had greater exposure risks than bean geese. Of the OCPs analyzed, DDTs could probably cause harm to target birds studied here. Exposure via food intake was identified to be significant while soil ingestion and water drinking contributed least, but they should still be concerned.

Assessment of endocrine disrupting chemicals in breast milk: Association with dietary habits and duration of lactation

The present study was aimed to assess infant safety associated with the presence of persistent organochlorine pesticides (OCPs) in breast milk, a possible route of transfer of endocrine-disrupting chemicals to newborns in North India. Colostrum and breast milk samples (n = 130) were collected at different stages of lactation. Pesticides analysis was performed using gas chromatography mass spectrometry (GC-MS). We observed that of all the samples analysed, OCPs concentration was higher in breast milk than in colostrum, suggesting pesticides contamination increases over lactation period. As far as OCPs are concerned, dieldrin [1196.64 ± 673.75 ng/g lipid weight (lw)], and β-HCH [1107.78 ± 1301.72 ng/g lw], were the predominant OCPs, followed by aldrin [977.09 ± 707.69 ng/g lw], α-HCH [948.04 ± 476.65 ng/g lw] and 1,1'-(2,2-Dichloroethene-1,1-diyl)bis(4-chlorobenzene) (p,p'DDE) [790.11 ± 399.35 ng/g lw]. The association between OCPs levels and women dietary habits were also explored, and all the OCPs were grouped and compared to each other by consumption level of fish, meat, sea foods, eggs, and dairy products. We found that women consuming non vegetarian food, like fish and meat, were exposed 3.5 times more to OCPs than women consuming vegetarian food. In addition, we also observed that factors like mother's age was positively (<0.005 - <0.001) correlated while gestational age and infant birth weight were negatively (<0.005) associated with the levels of OCPs in colostrum and breast milk, respectively. Unfortunately, neither any standards nor guidelines are available for the use of pesticides, therefore, it is suggested that careless use of OCPs should be checked and suitable remedial measures be taken to decrease human contamination. Moreover, further studies are warranted to elucidate relationship between pesticide residues in breast milk and the maternal and child health.

Uncovering the functions of plasma proteins in ulcerative colitis and identifying biomarkers for BPA-induced severe ulcerative colitis: A plasma proteome analysis

Ulcerative colitis (UC), a long-term inflammation of the colon, is a worldwide disease. Accumulating reports have suggested the contribution of environmental pollutants to UC development. As such, the identification of biomarkers to evaluate pollutant-induced UC could provide a better assessment on the world's pollution problem. In the present study, we applied the plasma proteome to profile the plasma protein changes in three models: dextran sulfate sodium (DSS)-induced colitis, bisphenol A (BPA), and BPA-severe colitis. We aimed to investigate the functional roles of plasma proteins related to colitis development and further understand the synergistic effect of BPA on colitis. In addition, we aimed to identify novel biomarkers for UC non-invasive diagnosis and assessment of BPA-induced colitis. Our results showed a significant dysregulation of plasma proteins in these three models. Bioinformatics analysis, including gene ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, and Ingenuity Pathway Analysis, highlighted the important effects of these dysregulated plasma proteins in immune and inflammatory responses through the regulation of CCR3 signaling in eosinophils, PI3K signaling in B lymphocytes, CD28 signaling in T helper cells, and leukocyte extravasation signaling in DSS-induced colitis model. Furthermore, our data suggested that BPA exposure altered the plasma proteins involved in lipid-related metabolic processes, leukocyte cell-cell adhesion and cytokine response. More importantly, we identified plasma proteins, ALB, APOA4, C3, CFB, DPEP1, HP, LTF, and Retnlg as biomarkers for assessing BPA-induced colitis.

Exposure patterns, chemical structural signatures, and health risks of pesticides in breast milk: A multicenter study in China

China is the world's largest pesticide user. These chemicals are bioaccumulative in the human body, and eventually could be transferred from the mother to the fetus/infant via placental and breastfeeding transport, which might pose developmental deficiency risks. In this study, human biomonitoring of legacy pesticides was conducted in three Chinese cities using 60 breast milk samples. The patterns, chemical structural signatures, and the estimated daily intake of pesticides were assessed. The median concentration of HCB (57.8 ng g^-1 lw, Interquartile range: 28.5-76.9 ng g^-1 lw) was the highest among all pesticides, whereas the HCHs, DDXs, TCVP, and heptachlor were also detected. A significantly different pattern of pesticides was found among three sampling cities: the Mianyang cases were mostly DDXs oriented while the Wuhan and Hangzhou cases were under HCB, HCHs, TCVP, and heptachlor influences. Maternal age and pre-pregnancy BMI were found to be the influencing factors for the pesticides in the breast milk, and dietary preferences were an important factor in the exposure scenario. Chemical structural signatures indicated that for HCHs and DDXs the exposure was mostly historical, while the lindane and dicofol exposure may exist among the volunteering mothers. The EF for chiral pesticides did not deviate significantly from the racemic value. The risk from breastfeeding was negligible according to the Chinese and UN standard, while some cases from Hangzhou and Wuhan exceeded the Canadian restrictions. Thus, the adverse health effects of chemical exposure by dietary intake for infants need to be closely monitored in future studies.

Determination of multi-class pesticides residues of cow and human milk samples from Iran using UHPLC-MS/MS and GC-ECD: A probabilistic health risk assessment

Raw, pasteurized, powdered cow milk and human milk samples from Tehran, Iran were investigated for the residual of fifty pesticides with the aid of gas chromatography coupled with electron capture detector (GC-ECD) and mass detector for confirmation; and ultra-high performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS). No pesticide residue was determined in more than 91% of examined samples. However, the dimethoate residue was detected in 3 raw milk samples in levels higher than EU recommended MRL. While in 3 human milk samples, organochlorine pesticides residue, p,p'-DDT, and p,p'-DDD was recognized below MRLs, only in 1 human sample residue of p,p'-DDE was more than CODEX recommended MRL. HI in adults and children were 0.72 and 3.55, respectively. However, the health risk assessment based on HI demonstrated that adult consumers are not at considerable risk. The HI, higher than 1 in children, confirms the risks raised due to ingestion of organochlorine (OCP) and organophosphorus (OPP) pesticides via milk consumption. In addition, no carcinogenic risk to milk consumers was calculated. Therefore, implementation of good farming practices on farms, improving the knowledge and consciousness of pesticide users, use other safe methods for pest control such as biotechnology-based, and use a rational program for application of pesticides, continuous monitoring of pesticides in crops, and strict government regulations on pesticide residues in food are recommended.

Quantifying exposure source allocation factors of pesticides in support of regulatory human health risk assessment

One of the challenges while assessing the aggregate exposure risk of pesticides is quantifying exposure doses from various exposure pathways. To address this issue, a regulatory screening approach is proposed for evaluating pesticide allocation factors (AFs) for major exposure pathways for rural and urban residents. This was achieved by integrating dynamiCrop and other screening models to estimate the potential human intake of residues from major crops at harvest, livestock products, and main environmental media (air, water, and soil). The AFs were calculated from the average daily dose factors (ADDFs) of pesticides via major exposure pathways, where a large AF of an exposure pathway indicates that a greater margin of exposure should be given to that exposure pathway. The simulated results for many current-use pesticides showed that the ingestion of crops had pesticide AFs close to 1.0, which indicated that the crop exposure pathway contributed to a significant portion of the total exposure to pesticides. In contrast, for legacy pesticides with high lipophilicity and low degradability in the environment, the simulated AFs for major environmental compartments (air, freshwater, and soil) accounted for relatively large exposures. As legacy pesticides have been banned globally, exposure pathways via the food web and environmental media cannot be neglected because of their high lipophilicity and environmental persistence. Although other factors such as geographical conditions and living habits should be considered to improve the spatial resolution of the model, the method proposed in this study can serve as a preliminary tool to conduct screening-level risk assessments for populations by considering the allocated exposure to pesticides via major exposure pathways.

Effects of Organochlorine Pesticide Residues in Maternal Body on Infants

There are many organochlorine pollutants in the environment, which can be directly or indirectly exposed to by mothers, and as estrogen endocrine disruptors can cause damage to the lactation capacity of the mammary gland. In addition, because breast milk contains a lot of nutrients, it is the most important food source for new-born babies. If mothers are exposed to organochlorine pesticides (OCPs), the lipophilic organochlorine contaminants can accumulate in breast milk fat and be passed to the infant through breast milk. Therefore, it is necessary to investigate organochlorine contaminants in human milk to estimate the health risks of these contaminants to breastfed infants. In addition, toxic substances in the mother can also be passed to the fetus through the placenta, which is also something we need to pay attention to. This article introduces several types of OCPs, such as dichlorodiphenyltrichloroethane (DDT), methoxychlor (MXC), hexachlorocyclohexane (HCH), endosulfan, chlordane, heptachlorand and hexachlorobenzene (HCB), mainly expounds their effects on women's lactation ability and infant health, and provides reference for maternal and infant health. In addition, some measures and methods for the control of organochlorine pollutants are also described here.

Occurrence, sources, and ecological risks of three classes of insecticides in sediments of the Liaohe River basin, China

The frequent and extensive use of insecticides has caused serious aquatic pollution, thus posing a great threat to ecosystems and public health. In this study, three classes of insecticides including 20 organochlorine pesticides (OCPs), 6 organophosphorus pesticides (OPs), and 8 pyrethroids were analyzed in 24 sediments from the Liaohe River basin. The results showed that all sediment samples were contaminated with insecticides, with the total concentrations ranging from 7.3 ng/g dry weight (dw) to 242.8 ng/g dw. Among them, pyrethroids (2.2-102.5 ng/g dw) contributed 55% of the total insecticide concentration, followed by OCPs (1.3-94.8 ng/g dw) and OPs (2.6-45.5 ng/g dw), representing 24% and 21% of the total concentrations, respectively. For OCPs, hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) showed the highest concentrations of 0.37-37.5 ng/g dw and 0.05-23.2 ng/g dw, respectively. Historical inputs of lindane and technical DDT were the major sources of HCHs and DDTs, respectively, as indicated by isomer or metabolite ratios. Additionally, dichlorvos (0.26-17.1 ng/g dw) was the main OP, while cypermethrin dominated the pyrethroids with the concentrations of 1.6-32.6 ng/g dw. The spatial distribution revealed that significantly higher residues of insecticides were observed in sediments from the Daliao River system than those from the Liao River. This implied that these insecticides were most likely from the discharge of highly polluted sewage and industrial wastewater from adjacent industrial and populous cities as well as urban applications (e.g., landscape maintenance and household pest control). An ecological risk assessment based on risk quotients suggested that the three classes of insecticides analyzed here pose a low risk to aquatic organisms in the study area.

Human Biomonitoring of Environmental and Occupational Exposures by GC-MS and Gas Sensor Systems: A Systematic Review

Environmental chemicals and contaminants coming from multiple external sources enter the human body, determining a potential risk for human health. Human biomonitoring (HBM), measuring the concentrations of biomarkers in human specimens, has become an emerging approach for assessing population-wide exposure to hazardous chemicals and health risk through large-scale studies in many countries. However, systematic mapping of HBM studies, including their characteristics, targeted hazardous pollutants, analytical techniques, and sample population (general population and occupationally exposed workers), has not been done so far. We conducted a systematic review of the literature related to airborne hazardous pollutants in biofluids to answer the following questions: Which main chemicals have been included in the literature, which bodily fluids have been used, and what are the main findings? Following PRISMA protocol, we summarized the publications published up to 4 February 2021 of studies based on two methods: gas-chromatography/mass spectrometry (GC/MS) and electronic noses (e-noses). We screened 2606 records and 117 publications were included in the analysis, the most based on GC/MS analysis. The selected HBM studies include measurements of biomarkers in different bodily fluids, such as blood, urine, breast milk, and human semen as well as exhaled air. The papers cover numerous airborne hazardous pollutants that we grouped in chemical classes; a lot of hazardous and noxious compounds, mainly persistent organic pollutants (POPs) and volatile organic compounds (VOCs), have been detected in biological fluids at alarming levels. The scenario that emerged from this survey demonstrates the importance of HBM in human exposure to hazardous pollutants and the need to use it as valid tool in health surveillance. This systematic review represents a starting point for researchers who focus on the world of pollutant biomonitoring in the human body and gives them important insights into how to improve the methods based on GC/MS. Moreover, it makes a first overview of the use of gas sensor array and e-noses in HBM studies.

Metal/metalloid levels in hair of Shenzhen residents and the associated influencing factors

129 Shenzhen residents' hair samples were collected and the metal/metalloid concentrations of Hg, As, Pb, Cd, Cr, Cu, Mn, Zn, Fe and Ni were detected. Meanwhile, the relationships between metal/metalloid contents in human hair and gender, age, seafood diet habit, smoking habit, as well as the housing type (dwelling environment) were analyzed. Results showed that the average content of Hg, As, Pb, Cd, Cr, Cu, Mn, Zn, Fe and Ni in human hair of Shenzhen residents was 0.76 ± 0.96, 0.10 ± 0.04, 5.25 ± 4.88, 0.25 ± 0.33, 0.60 ± 0.31, 13.84 ± 3.67, 2.82 ± 2.01, 196.90 ± 145.01, 12.20 ± 5.10 and 0.34 ± 0.32 μg/g, respectively. Compared with other regions at home and abroad, most metal/metalloids in Shenzhen residents were at a moderate level, and the highly toxic elements (i.e. Pb, Cd, As and Hg) didn't exceed the upper limit of normal values in China. Statistical analysis showed that the young male people contained significantly higher (p < 0.05) level of Pb (in age group of 20-30 years old) and Fe (in age group of 20-40 years old) in hair than the female people. Smokers had significantly (p < 0.05) higher level of Cd (0.35 μg/g) but lower level of Zn (101.24 µg/g) than non-smokers (Cd: 0.17 μg/g; Zn: 252.63 µg/g). Hg and Pb contents in hair of Shenzhen people were positively related with the frequencies of seafood consumption and the age, respectively. Moreover, residents lived in private buildings (well decorated house) accumulated significantly higher (p < 0.05) levels of Pb, Cr, Fe and Ni as compared with those lived in public rental house and village house (no decoration or simple decoration), suggesting that decoration material was also an important way for human exposure to heavy metals.