Prenatal exposure to organochlorine pesticides and infant birth weight in China

Organochlorine pesticide residues and urinary arsenic and fluoride levels in mothers and their newborns who are residents of rural areas in Durango State, Mexico

Maternal and prenatal exposure to organochlorine pesticides (OCP), arsenic (As), and fluoride (F-) is a critical public health concern. The present study assessed serum OCP residues and urinary As and F- levels in mother and newborn pairs who are residents of rural areas of Durango State, Mexico, from August 2018 to February 2019. Levels of OCP, As, and F- were measured in serum and urine samples by Gas chromatography - Tandem mass spectrometry (GC - MS/MS), Hydride generation - Atomic fluorescent spectrometry (HG-AFS, and ion-selective electron analysis (ISE), respectively, in 60 binomial mothers - newborns. Dieldrin, endrin aldehyde, and endosulfan-II were significantly higher in newborns than in mothers (p ˂0.05). Meanwhile, no significant differences were observed for As and F- concentrations between mother - newborn pairs. Differences were observed in ∑Dienes and ∑DDTs comparing newborns with normal and low birth weights and a positive relationship in ƩDienes, ƩChlordanes, and ƩDDTs between mother and newborn pairs (p ˂ 0.05). These findings highlight the importance of extensive research regarding the influence of pollution.

Endocrine Disruptors in Child Obesity and Related Disorders: Early Critical Windows of Exposure

PURPOSE OF REVIEW

Endocrine disruptors (EDs) can mimic or interfere with hormones in the body, leading to non-communicable diseases, such as obesity, diabetes, and metabolic syndrome. Susceptibility to EDs increases during prenatal and postnatal life, a critical time window. This review aims to summarize the latest evidence on the relation of early life exposure to some EDs with obesity and the other metabolic disorders.  RECENT FINDINGS: There is increasing evidence that early life exposure to EDs may impair adipogenesis by increasing the number and size of adipocytes, thereby increasing susceptibility to obesity in childhood. It is stated that exposure to EDs during the prenatal and postnatal period may raise the risk of type 2 diabetes in adulthood by disrupting glucose, lipid, and insulin homeostasis in the offspring. They can also accelerate the development of type 1 diabetes through various mechanisms, like immunomodulation, gut microbiota, and vitamin D pathways. There is a growing understanding that ED exposure during critical stages of life could play an important role in the development of obesity and metabolic disorders. We suggest setting national goals, global standards, and policies to reduce environmental exposure to pregnant and lactating women, and babies, considered sensitive populations.

Triple negative breast cancer cells exposed to aryl hydrocarbon receptor ligands hexachlorobenzene and chlorpyrifos activate endothelial cells

Breast cancer is currently one of the most prevalent cancers worldwide. The mechanisms by which pesticides can increase breast cancer risk are multiple and complex. We have previously observed that two aryl hydrocarbon receptor (AhR) agonists ‒pesticides hexachlorobenzene (HCB) and chlorpyrifos (CPF)‒ act on tumor progression, stimulating cell migration and invasion in vitro and tumor growth in animal models. Elevated levels of hypoxia inducible factor-1α (HIF-1α) are found in malignant breast tumors, and HIF-1α is known to induce proangiogenic factors such as vascular endothelial growth factor (VEGF), nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2), which are fundamental in breast cancer progression. In this work, we studied HCB (0.005, 0.05, 0.5 and 5 μM) and CPF (0.05, 0.5, 5 and 50 μM) action on the expression of these proangiogenic factors in triple negative breast cancer cells MDA-MB-231, as well as the effect of their conditioned medium (CM) on endothelial cells. Exposure to pesticides increased HIF-1α and VEGF protein expression in an AhR-dependent manner. In addition, HCB and CPF boosted NOS-2 and COX-2 content and VEGF secretion in MDA-MB-231 cells. The treatment of endothelial cells with CM from tumor cells exposed to pesticides increased cell proliferation, migration, and tubule formation, enhancing both tubule length and branching points. Of note, these effects were VEGF-dependent, as they were blocked in the presence of a VEGF receptor-2 (VEGFR-2) inhibitor. In sum, our results highlight the harmful impact of HCB and CPF in modulating the interaction between breast cancer and endothelial cells and promoting angiogenesis.

Hexachlorobenzene as a differential modulator of the conventional and metronomic chemotherapy response in triple negative breast cancer cells

Aim

Triple negative breast cancer (TNBC) is usually treated with high doses of paclitaxel, whose effectiveness may be modulated by the action of environmental contaminants such as hexachlorobenzene. High doses of paclitaxel cause adverse effects such as low cellular selectivity and the generation of resistance to treatment due to an increase in the expression of multidrug resistance proteins (MRPs). These effects can be reduced using a metronomic administration scheme with low doses. This study aimed to investigate whether hexachlorobenzene modulates the response of cells to conventional chemotherapy with paclitaxel or metronomic chemotherapy with paclitaxel plus carbachol, as well as to study the participation of the MRP ATP-binding cassette transporter G2 (ABCG2) in human TNBC MDA-MB231 cells.

Methods

Cells were treated with hexachlorobenzene alone or in combination with conventional or metronomic chemotherapies. The effects of treatments on cell viability were determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and the nuclear factor kappa B pathway participation was evaluated using a selective inhibitor. ABCG2 expression and its modulation were determined by western blot.

Results

Results confirmed that paclitaxel reduces MDA-MB231 cell viability in a concentration-dependent manner. Results also showed that both conventional and metronomic chemotherapies reduced cell viability with similar efficacy. Although hexachlorobenzene did not modify cell viability per se, it did reverse the effect induced by the conventional chemotherapy, without affecting the efficacy of the metronomic chemotherapy. Additionally, a differential modulation of ABCG2 expression was determined, mediated by the nuclear factor kappa B pathway, which was directly related to the modulation of cell sensitivity to another cycle of paclitaxel treatment.

Conclusions

The findings indicate that, in human TNBC MDA-MB231 cells, in the presence of hexachlorobenzene, the metronomic combination of paclitaxel plus carbachol is more effective in affecting the tumor biology than the conventional therapeutic administration scheme of paclitaxel.

Per- and polyfluoroalkyl substances, polychlorinated biphenyls, organochlorine pesticides, and polybrominated diphenyl ethers and dysregulation of MicroRNA expression in humans and animals-A systematic review

BACKGROUND

Persistent organic pollutants (POPs) are chemicals characterized by their environmental persistence. Evidence suggests that exposure to POPs, which is ubiquitous, is associated with microRNA (miRNA) dysregulation. miRNA are key regulators in many physiological processes. It is thus of public health concern to understand the relationships between POPs and miRNA as related to health outcomes.

OBJECTIVES

This systematic review evaluated the relationship between widely recognized, intentionally manufactured, POPs, including per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (dichlorodiphenyltrichloroethane [DDT], dichlorodiphenyldichloroethylene [DDE], hexachlorobenzene [HCB]), with miRNA expression in both human and animal studies.

METHODS

We used PubMed and Embase to systematically search the literature up to September 29th, 2023. Search results for human and animal studies were included if they incorporated at least one POP of interest in relation to at least one miRNA. Data were synthesized to determine the direction and significance of associations between POPs and miRNA. We utilized ingenuity pathway analysis to review disease pathways for miRNA that were associated with POPs.

RESULTS

Our search identified 38 eligible studies: 9 in humans and 29 in model organisms. PFAS were associated with decreased expression of miR-19, miR-193b, and miR-92b, as well as increased expression of miR-128, miR-199a-3p, and miR-26b across species. PCBs were associated with increased expression of miR-15a, miR-1537, miR-21, miR-22-3p, miR-223, miR-30b, and miR-34a, as well as decreased expression of miR-130a and let-7b in both humans and animals. Pathway analysis for POP-associated miRNA identified pathways related to carcinogenesis.

DISCUSSION

This is the first systematic review of the association of POPs with miRNA in humans and model organisms. Large-scale prospective human studies are warranted to examine the role of miRNA as mediators between POPs and health outcomes.

Safe long-term therapy of Cushing's syndrome over 37 years with mitotane

While suggested, surgery is not always possible as a first-line treatment of Cushing's Disease (CD). In such cases, patients require medical therapy in order to prevent complications resulting from hypercortisolism. Although there has been a wide expansion in pharmacological options in recent years, mitotane was the agent of choice for treating hypercortisolism decades ago. Due to the introduction of other therapies, long-term experience with mitotane remains limited. Here, we report the case of a woman with CD who was treated with mitotane for 37 years. During the treatment period, biochemical and clinical disease control was achieved and the patient had two uncomplicated pregnancies. Drug-related side effects remained moderate and could be controlled by several dose adjustments. Our case highlights the ability of mitotane to allow an effective control of hypercortisolism and to represent a safe treatment option in special situations where CD requires an alternative therapeutic approach. Furthermore, we provide a literature review of the long-term use of mitotane and reported cases of pregnancy in the context of mitotane therapy.

Apparent Khat chewers exposure to DDT in Ethiopia and its potential toxic effects: A scoping review

Dichlorodiphenyltrichloroethane (DDT) is an insecticide, a member of dirty dozen persistent organic pollutants, used widely in the world until it was banned in the 1970s.The banning of DDT was strengthened by the Stockholm Convention in 2001. DDT is allowed only for malaria control in Ethiopia. However, farmers are misusing DDT and applying it to Khat (Catha edulis) farming. So, this review analyzes available data in the literature on the current trend, application, occurrence, fate and effects of DDT and its metabolites, dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE), in the chewable parts of Khat. Generally, the concentration level of DDT, DDD, and DDE, designated as DDTs, is detected in different farmlands of Ethiopia. Some of the DDTs concentrations detected are very high (141.2-973 μg/kg (Gelemso), 194.4-999 μg/kg (Aseno) and 6253-8413.3 μg/kg (Gurage), and these concentrations may indicate increasing recent unmonitored application of DDT on Khat leaves. Some of the detected concentrations of DDT in the literature were above the maximum residue limit (MRL) set by FAO/WHO (100 μg/kg) and the European Commission 10 μg/kg in vegetables and 50 μg/kg in cereals. DDT exposure of Khat chewers linked to the concentration of DDT on Khat leaves and the amount of Khat consumed. DDT might pose health risks to chewers due to chronic toxicity, bioaccumulation, persistent and endocrine disruption properties.

Environmental pollutants and their effects on human health

Numerous environmental contaminants significantly contribute to human disease, affecting climate change and public and individual health, resulting in increased mortality and morbidity. Because of the scarcity of information regarding pollution exposure from less developed nations with inadequate waste management, higher levels of poverty, and limited adoption of new technology, the relationship between pollutants and health effects needs to be investigated more. A similar situation is present in many developed countries, where solutions are only discovered after the harm has already been done and the necessity for safeguards has subsided. The connection between environmental toxins and health needs to be better understood due to difficulties in quantifying exposure levels and a lack of systematic monitoring. Different pollutants are to blame for both chronic and acute disorders. Additionally, research becomes challenging when disease problems are seen after prolonged exposure. This review aims to discuss the present understanding of the association between environmental toxins and human health in bridging this knowledge gap. The genesis of cancer and the impact of various environmental pollutants on the human body's cardiovascular, respiratory, reproductive, prenatal, and neural health are discussed in this overview.

Breast cancer progression and kynurenine pathway enzymes are induced by hexachlorobenzene exposure in a Her2-positive model

Breast cancer is one of the leading cancers among women worldwide. Given the evidence that pesticides play an important role in breast cancer, interest has grown in pesticide impact on disease progression. Hexachlorobenzene (HCB), an aryl hydrocarbon receptor (AhR) ligand, promotes triple-negative breast cancer cell migration and invasion. Estrogen receptor β (ERβ) inhibits cancer motility, while G protein-coupled ER (GPER) modulates the neoplastic transformation. Tryptophan is metabolized through the kynurenine pathway by indoleamine-2,3-dioxygenase (IDO) and tryptophan-2,3-dioxygenase (TDO), with kynurenine signaling activation often predicting worse prognosis in cancer. In this context, we examined the HCB (0.005; 0.05; 0.5 and 5 μM) effect on LM3 cells, a human epidermal growth factor receptor 2 (HER2)-positive breast cancer model. Results show that HCB increases IDO and TDO mRNA levels and promotes cell viability, proliferation and migration through the AhR pathway. Moreover, HCB boosts mammosphere formation, vascular endothelial growth factor and cyclooxygenase-2 expression and reduces IL-10 levels. For some parameters, U-shaped or inverted U-shaped dose-response curves are shown. HCB alters ER levels, reducing ERβ while increasing GPER. These results demonstrate that exposure to environmentally relevant concentrations of HCB up-regulates the kynurenine pathway and dysregulates ERβ and GPER levels, collaborating in HER2-positive breast cancer progression.

Characterization of childhood exposure to environmental contaminants using stool in a semi-urban middle-class cohort from eastern Canada

Children are exposed to various environmental organic and inorganic contaminants with effects on health outcomes still largely unknown. Many matrices (e.g., blood, urine, nail, hair) have been used to characterize exposure to organic and inorganic contaminants. The sampling of feces presents several advantages; it is non-invasive and provides a direct evaluation of the gut microbiome exposure to contaminants. The gut microbiome is a key factor in neurological development through the brain-gut axis. Its composition and disturbances can affect the neurodevelopment of children. Characterization of children exposure to contaminants is often performed on vulnerable populations (e.g., from developing countries, low-income neighborhoods, and large urban centers). Data on the exposure of children from middle-class, semi-urban, and mid-size populations to contaminants is scarce despite representing a significant fraction of the population in North America. In this study, 73 organics compounds from different chemical classes and 22 elements were analyzed in 6 years old (n = 84) and 10 years old (n = 119) children's feces from a middle-class, semi-urban, mid-size population cohort from Eastern Canada. Results show that 67 out of 73 targeted organics compounds and all elements were at least detected in one child's feces. Only caffeine (97% & 80%) and acetaminophen (28% & 48%) were detected in more than 25% of the children's feces, whereas all elements besides titanium were detected in more than 50% of the children.

Exposure to p,p´-DDE during early pregnancy, anthropometry, and gestational age at birth, in a flower-growing region of Mexico

Prenatal exposure to dichlorodiphenyldichloroethylene (p,p´-DDE) may interfere with fetal development; however, studies evaluating anthropometry and gestational age at birth show inconsistent results. Typically, p,p´-DDE exposure has been measured during the third trimester and missed the key early pregnancy period. We evaluated the association between p,p´-DDE exposure before week 18 of pregnancy and anthropometry at birth, as well as gestational length, in 170 mother-child pairs from a cohort study in a flower-growing mexican region. Maternal serum p,p´-DDE concentrations were determined by gas chromatography. The associations between p,p´-DDE and z-scores of birth weight, birth length, and gestational age were evaluated by linear multiple regression models. Logistic regression models were used for low birth weight and small size for gestational age. Effect modification by child's sex was explored. The average gestational age at the blood sample extraction was 10.6 weeks. p,p'-DDE was detected in 64.7% of mothers, at a geometric mean of 0.24 ng/mL. Prenatal p,p´-DDE exposure was not associated with the birth outcomes in the whole sample. However, a high p,p´-DDE exposure was marginally associated with greater small for gestational age risk in male newborns (OR_{≥0.076ng/mL vs <0.076 ng/mL} = 3.09, 95% CI: 0.61; 15.58), but not in female (p for interaction = 0.08).Even though, we found no reductions in anthropometric measurements or gestational length associated with early prenatal p,p´-DDE exposure, the potential effect modification by infant's sex in terms of small for the gestational age risk deserves future studies.

Pesticide exposure and child growth in low- and middle-income countries: A systematic review

BACKGROUND

In low- and middle-income countries (LMICs), pesticides are widely used in agricultural and residential settings. Little is known about how pesticides affect child growth.

OBJECTIVES

To systematically review and synthesise the evidence on the associations between pesticide exposure and adverse birth outcomes and/or impaired postnatal growth in children up to 5 years of age in LMICs.

METHODS

We searched 10 databases from inception through November 2021. We included cohort and cross-sectional studies investigating associations between self-reported or measured prenatal or postnatal pesticide exposure and child growth (postnatal child linear/ponderal growth, and/or birth outcomes). Two researchers screened studies, extracted data, and assessed certainty using GRADE. The protocol was preregistered with PROSPERO (CRD42021292919).

RESULTS

Of 939 records retrieved, 31 studies met inclusion criteria (11 cohort, 20 cross-sectional). All studies assessed prenatal exposure. Twenty-four studies reported on birth weight. Four found positive associations with organochlorines (0.01-0.25 standardised mean difference (SMD)) and two found negative associations (-0.009 SMD to -55 g). Negative associations with organophosphates (-170 g, n = 1) and pyrethroids (-97 to -233 g, n = 2) were also documented. Two (out of 15) studies reporting on birth length found positive associations with organochlorines (0.21-0.25 SMD) and one found negative associations (-0.25 to -0.32 SMD). Organophosphate exposure was negatively associated with birth length (-0.37 cm, n = 1). Organophosphate exposure was also associated with higher risk/prevalence of low birth weight (2 out of nine studies) and preterm birth (2 out of six studies). Certainty of the evidence was "very low" for all outcomes.

CONCLUSION

The limited literature from LMICs shows inconclusive associations between prenatal pesticide exposure, child growth, and birth outcomes. Studies with accurate quantitative data on exposure to commonly used pesticides in LMICs using consistent methodologies in comparable populations are needed to better understand how pesticides influence child growth.

Possible Processes and Mechanisms of Hexachlorobenzene Decomposition by the Selected Comamonas testosteroni Bacterial Strains

Background: The bacterial destructing activity toward pesticides has been the focus of research in the last few decades. Hexachlorobenzene is included in the organochlorine pesticides group that are prohibited for use. However, large hexachlorobenzene amounts are still concentrated in the soil, stressing the relevance of research on hexachlorobenzene-destroying bacteria. Methods: The ability to destroy hexachlorobenzene by Comamonas testosteroni UCM B-400, B-401, B-213 strains was investigated and established. Bacteria were cultivated (7 days at 28 °C) in mineral Luria-Bertrani (LB) medium with three hexachlorobenzene doses: 10, 20, 50 mg/L. The hexachlorobenzene concentrations were recorded by a gas chromatography method. Results: The results showed that C. testosteroni UCM B-400, B-401 have high destructive activity toward hexachlorobenzene. The highest (50 mg/L) initial concentration decreased to 41.5 and 43.8%, respectively, for C. testosteroni UCM B-400, B-401. The unadapted C. testosteroni UCM B-213 was tolerant to hexachlorobenzene (cell titers after cultivating with 10.0, 20.0, 50.0 mg/mL were higher compared to initial titer), but had a low-destructing activity level (two times less than B-400 and B-401). Conclusions: Bacterial strains C. testosteroni UCM B-400, B-401 can be seen as a potential soil bioremediation from hexachlorobenzene pollution.

Endocrine disruptor hexachlorobenzene induces cell migration and invasion, and enhances aromatase expression levels in human endometrial stromal cells

Endometriosis is the presence and growth of endometrial tissue outside of the uterus. Previous studies have suggested that endocrine disrupting chemicals such as organochlorine pesticides could be a risk factor for endometriosis. Hexachlorobenzene (HCB) is a weak ligand of the aryl hydrocarbon receptor (AhR) and promotes metalloproteinase and cyclooxygenase-2 (COX-2) expression, as well as, c-Src activation in human endometrial stromal cells (T-HESC) and in rat endometriosis model. Our aim was to evaluate the effect of HCB exposure on oestrogen receptor (ER) ɑ and β, progesterone receptor (PR) and aromatase expression, as well as, on cell migration and invasion in T-HESC and primary cultures of endometrial stromal cells from eutopic endometria of control subjects (ESC). Results show that HCB increases ERɑ and aromatase protein levels and reduces PR content in both T-HESC and ESC. However, the pesticide only increases ERβ expression in ESC, without changes in T-HESC. Moreover, cell migration and invasion are promoted by pesticide exposure involving the AhR, c-Src, COX-2 and ER pathways in T-HESC. HCB also triggers ERɑ activation via phosphorylation in Y537 through AhR/c-Src pathway. Our results provide experimental evidence that HCB induces alterations associated with endometriosis, suggesting that these mechanisms could contribute to pesticide exposure-induced endometriosis development.

In utero exposure to electronic-cigarette aerosols decreases lung fibrillar collagen content, increases Newtonian resistance and induces sex-specific molecular signatures in neonatal mice

Approximately 7% of pregnant women in the United States use electronic-cigarette (e-cig) devices during pregnancy. There is, however, no scientific evidence to support e-cig use as being 'safe' during pregnancy. Little is known about the effects of fetal exposures to e-cig aerosols on lung alveologenesis. In the present study, we tested the hypothesis that in utero exposure to e-cig aerosol impairs lung alveologenesis and pulmonary function in neonates. Pregnant BALB/c mice were exposed 2 h a day for 20 consecutive days during gestation to either filtered air or cinnamon-flavored e-cig aerosol (36 mg/mL of nicotine). Lung tissue was collected in offspring during lung alveologenesis on postnatal day (PND) 5 and PND11. Lung function was measured at PND11. Exposure to e-cig aerosol in utero led to a significant decrease in body weights at birth which was sustained through PND5. At PND5, in utero e-cig exposures dysregulated genes related to Wnt signaling and epigenetic modifications in both females (~ 120 genes) and males (40 genes). These alterations were accompanied by reduced lung fibrillar collagen content at PND5-a time point when collagen content is close to its peak to support alveoli formation. In utero exposure to e-cig aerosol also increased the Newtonian resistance of offspring at PND11, suggesting a narrowing of the conducting airways. At PND11, in females, transcriptomic dysregulation associated with epigenetic alterations was sustained (17 genes), while WNT signaling dysregulation was largely resolved (10 genes). In males, at PND11, the expression of only 4 genes associated with epigenetics was dysregulated, while 16 Wnt related-genes were altered. These data demonstrate that in utero exposures to cinnamon-flavored e-cig aerosols alter lung structure and function and induce sex-specific molecular signatures during lung alveologenesis in neonatal mice. This may reflect epigenetic programming affecting lung disease development later in life.

Differential Bioaccumulation Patterns of α, β-Hexachlorobenzene and Dicofol in Adipose Tissue from the GraMo Cohort (Southern Spain)

To identify bioaccumulation patterns of α-, β- hexachlorocyclohexane (HCH) and dicofol in relation to sociodemographic, dietary, and lifestyle factors, adipose tissue samples of 387 subjects from GraMo cohort in Southern Spain were analyzed. Potential predictors of these organochlorine pesticides (OCP) levels were collected by face-to-face interviews and assessed by multivariable linear and logistic regression. OCPs were detected in 84.2% (β-HCH), 21.7% (α-HCH), and 19.6% (dicofol) of the population. β-HCH levels were positively related to age, body mass index (BMI), mother's occupation in agriculture during pregnancy, living in Poniente and Alpujarras, white fish, milk and water consumption, and negatively related to being male, living near to an agricultural area, working ≥10 years in agriculture, and beer consumption. Detectable α-HCH levels were positively related to age, BMI, milk consumption, mother's occupation in agriculture during pregnancy, and negatively with residence in Poniente and Alpujarras, Granada city, and Granada Metropolitan Area. Residence near to an agricultural area, smoking habit, white fish and water consumption, and living in Poniente and Alpujarras, Granada city and Granada Metropolitan Area were negatively associated with detectable dicofol levels. Our study revealed different bioaccumulation patterns of α, β-HCH and dicofol, probably due to their dissimilar period of use, and emphasize the need for assessing the exposure to frequently overlooked pollutants.

Trace-level analysis of polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons in human plasma or serum by dispersive liquid-liquid microextraction and gas chromatography-tandem mass spectrometry

A method to determine 8 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs) and 16 polycyclic aromatic hydrocarbons (PAHs) was described using dispersive liquid-liquid microextraction (DLLME) of a small amount of plasma or serum sample and gas chromatography-tandem mass spectrometry (GC-MS/MS). The appropriate selection of the extraction solvent and dispersing solvent contributes to a high extraction yield and a clean extract. To verify the developed method, the interference, linearity of the calibration curve, detection limit, precision and accuracy were evaluated. The calibration curves were linear by 2-3 orders of magnitude with correlation coefficients above 0.997 in all cases. The LODs of PCBs, OCPs and PAHs were measured in the ranges of 0.0006-0.0029, 0.001-0.029 and 0.0002-0.012 ng/ml. The intraday precision achieved by this method was 2.19-10.3% (PCBs), 1.65-14.3% (OCPs) and 0.91-12.8% (PAHs), and the intraday accuracy 1.56-7.37% (PCBs), 2.34-19.6% (OCPs) and 1.49-15.7% (PAHs). The advantage of this method is that the analysis of PCBs, OCPs, and PAHs can be performed in a single chromatographic run, and the low detection limit enables monitoring of target substances in low exposure general public samples, and the analysis procedure is relatively simple and fast.

Assessment of genotoxicity and oxidative stress in pregnant women contaminated to organochlorine pesticides and its correlation with pregnancy outcome

The present study was aimed to assess the correlation between transplacental transfer of xenobiotics and resulting biochemical alterations (including genotoxicity and oxidative stress) in non-occupational pregnant women of North India along with the effect on pregnancy outcomes. Maternal and cord blood samples were collected from 221 healthy mother-infant couples and divided according to their gestational age and birth weight. Genotoxic effects in mother and cord blood were examined using comet assay. The quantitative determination of Organo-chlorine pesticides in blood serum of study population was carried out using gas chromatography-mass spectrometry (GC-MS). Notably higher Organo-chlorine pesticides levels were observed in maternal blood of preterm than term subjects for almost all of the compounds detected, with the maximum concentration found for aldrin (3.26 mg/l) in maternal blood and dieldrin (2.69 mg/l) in cord blood. The results showed a significant increment in olive tail moment, tail full length, catalase, super-oxide dismutase, and malondialdehyde levels whereas lower glutathione reductase and peroxidase were found in preterm babies when compared with term group and it varied in the order: maternal blood > cord blood. A clear trend was observed for preterm babies with their lower birth weight and cesarean mode of delivery. Therefore, reduction in birth weight in newborns may be the consequence of increased oxidative damage and genotoxicity brought about by pesticides and these markers could be employed for early detection of pesticides related ailments and toxicities. To the best of our knowledge, this was a pioneering study and it may help to increase our knowledge with regard to xenobiotic exposure in biological system and the need for stringent guidelines for agricultural use of pesticides.

Determination of organic pollutants in meconium and its relationship with fetal growth. Case control study in Northwestern Spain

OBJECTIVES

Antenatal exposure to organic pollutants is a leading public health problem. Meconium is a unique matrix to perform prenatal studies because it enables us to retrospectively evaluate fetal exposure accumulated during the second and third trimester. The aim of the present study was to evaluate associations between organic pollutant levels in meconium and birth weight in NW Spain.

METHODS

In this study, we quantify the concentrations of 50 organic pollutants together with the total values of the most important chemical groups in meconium using gas chromatography coupled to tandem mass spectrometry.

RESULTS

Organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers were detected with the highest levels in meconium from small for gestational age newborns. It was estimated that several congeners were statistically significant (p<0.05). However, organophosphorus pesticides attained higher concentrations in newborns with an appropriate weight.

CONCLUSIONS

The occurrence of transplacental transfer can be confirmed. Prenatal exposure to organic pollutants was associated with a decrease in birth weight and, therefore, organic pollutants could have an impact on fetal growth. Nevertheless, these results need validation in larger sample sized studies.

Praegnatio Perturbatio-Impact of Endocrine-Disrupting Chemicals

The burden of adverse pregnancy outcomes such as preterm birth and low birth weight is considerable across the world. Several risk factors for adverse pregnancy outcomes have been identified. One risk factor for adverse pregnancy outcomes receiving considerable attention in recent years is gestational exposure to endocrine-disrupting chemicals (EDCs). Humans are exposed to a multitude of environmental chemicals with known endocrine-disrupting properties, and evidence suggests exposure to these EDCs have the potential to disrupt the maternal-fetal environment culminating in adverse pregnancy and birth outcomes. This review addresses the impact of maternal and fetal exposure to environmental EDCs of natural and man-made chemicals in disrupting the maternal-fetal milieu in human leading to adverse pregnancy and birth outcomes-a risk factor for adult-onset noncommunicable diseases, the role lifestyle and environmental factors play in mitigating or amplifying the effects of EDCs, the underlying mechanisms and mediators involved, and the research directions on which to focus future investigations to help alleviate the adverse effects of EDC exposure.

Impact of gestational exposure to endocrine disrupting chemicals on pregnancy and birth outcomes

With the advent of industrialization, humans are exposed to a wide range of environmental chemicals, many with endocrine disrupting potential. As successful maintenance of pregnancy and fetal development are under tight hormonal control, the gestational exposure to environmental endocrine disrupting chemicals (EDC) have the potential to adversely affect the maternal milieu and support to the fetus, fetal developmental trajectory and birth outcomes. This chapter summarizes the impact of exposure to EDCs both individually and as mixtures during pregnancy, the immediate and long-term consequences of such exposures on the mother and fetus, the direct and indirect mechanisms through which they elicit their effects, factors that modify their action, and the research directions to focus future investigations.

Prenatal exposure to organochlorine pesticides and infant growth: A longitudinal study

BACKGROUND

The association between exposure to organochlorine pesticides (OCPs) and infant growth has been reported contradictorily in previous studies. Few studies have investigated the effects of prenatal exposure to OCPs on infant growth assessed longitudinally at multiple time points.

OBJECTIVES

The purpose of the study was to examine the associations between prenatal exposure to OCPs and infant growth at birth, 6, 12 and 24 months of age, and further to explore the potential sex-specific effects.

METHODS

The study population included 1039 mother-infant pairs who participated in a birth cohort study in Wuhan, China. The weight, length and body mass index (BMI) z-score of infants were measured and calculated at birth, 6, 12 and 24 months of age. The overweight status was defined as BMI z-score ≥ 85th percentile according to the standard of World Health Organization. The concentrations of OCPs were measured in cord serum, including hexachlorocyclohexanes (HCHs, consisted of α-HCH, β-HCH, and γ-HCH), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolites: p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE). Generalized linear models were applied to estimate the associations of cord OCPs with infant growth parameters. A group-based semiparametric mixture model was used to estimate growth patterns of infants. Linear-mixed growth curve models were used to examine relationships between predicted growth trajectories and prenatal exposure to OCPs. Weighted quantile sum regression (WQSR) analyses were used to estimate the mixture effects of OCPs on infant growth.

RESULTS

Higher cord serum β-HCH concentrations were associated with higher BMI z-score at 12 [β = 0.07, 95%CI: 0.01, 0.13] and 24 months of age [β = 0.08, 95% CI: 0.02, 0.14]. Similar patterns were observed for relationships of γ-HCH [β = 0.04, 95%CI: 0.01, 0.07] and p,p'-DDT [β = 0.03, 95% CI: 0.00, 0.06] with BMI z-score at 6 and 12 months of age, respectively. However, higher cord serum p,p'-DDE concentrations were associated with a reduction of BMI z-score at 6 months of age [β = -0.07, 95% CI: -0.12, -0.01]. Cord serum β-HCH was also positively associated with the risk of overweight at 12 months of age [RR = 1.16, 95% CI (1.02, 1.33), for the medium vs the lowest tertile]. Among girls, the effects of β-HCH on BMI z-score and overweight status were stronger than boys at 12 and 24 months of age. No statistically significant relationships of other OCPs with infant growth were observed.

CONCLUSIONS

Prenatal exposure to β-HCH was associated with increased BMI z-score and higher risk of overweight status in infants especially at 12 and 24 months of age, which seemed to be stronger in girls.

Dietary risk assessment of organochlorine pesticide residues in maize-based complementary breakfast food products in Nigeria

The study assessed the levels of organochlorine pesticides (OCPs) in eight brands (A-H) of regularly consumed maize-based complementary/breakfast foods in Nigeria. We also evaluated the dietary exposure of infants and young children to the detected OCPs. The OCP residues were quantified using GC-ECD. A total of 10 OCPs residues (β-HCH, δ- HCH, heptachlor, endosulfan sulfate, aldrin, endrin, dieldrin, p,p’-DDE, p,p’-DDT and methoxychlor) were detected. Total OCPs burden was highest in brands F, D, and G with mean concentrations of 45.98 mg kg⁻¹, 28.54 mg kg⁻¹ and 21.87 mg kg⁻¹, respectively and the lowest burdens in brands H (1.72 mg kg⁻¹) and A (6.61 mg kg⁻¹). Hazard index (HI) for all the age categories were >1 and all the 6 carcinogens (β-HCH, heptachlor, aldrin, dieldrin, p,p’-DDE, and p,p’-DDT) identified had cancer risk index range of 5.43 × 10⁻⁴ to 2.05 × 10⁻⁶ which were above acceptable risk. These results indicated the possibility of both systemic and cancer risks to infants and children consumers of the foods. Food brands manufacturers need to carry out regular pesticide residues analysis of raw materials especially maize prior to the production in order to ensure food safety and quality.

Agrochemicals and obesity

Obesity has become a very large concern worldwide, reaching pandemic proportions over the past several decades. Lifestyle factors, such as excess caloric intake and decreased physical activity, together with genetic predispositions, are well-known factors related to obesity. There is accumulating evidence suggesting that exposure to some environmental chemicals during critical windows of development may contribute to the rapid increase in the incidence of obesity. Agrochemicals are a class of chemicals extensively used in agriculture, which have been widely detected in human. There is now considerable evidence linking human exposure to agrochemicals with obesity. This review summarizes human epidemiological evidence and experimental animal studies supporting the association between agrochemical exposure and obesity and outlines possible mechanistic underpinnings for this link.

In utero exposure to organochlorine pesticide residues and their potential impact on birth outcomes and fetal gender

Being the largest agriculture country in the Arab world, Egypt was one of the major consumer of organochlorine pesticides (OCPs) in this area, continued to have a heavy burden of OCPs in the environment. There is growing concern that OCPs could pass from the maternal circulation through the placenta to the fetal circulation and pose several health risks to their fetuses. The current study was intended to identify OCPs residue exposure in healthy pregnant women and to justify the potential impacts of these residues on their fetuses. In this study, the prevalence of 18 OCPs was estimated in 81 maternal and cord blood samples, using Agilent 7890, gas chromatograph equipped with micro-electron capture detector (GC-μECD). Our data signposted that the heptachlor epoxide has the highest detection rate among all residues in both maternal (32%) and cord blood serum (27.16%). DDTs were still quantifiable, but with the lowest quantifiable percentage. More than 85% of mothers' serum with detectable residues transfer OCPs residue to their fetuses in a statistically significant manner (x = 42.9, p value < 0.001). The present findings showed no significant growth retardation, or preterm delivery induced by in utero exposure to the most abundant residues. There is growing evidence that exposure to OCPs residue has profound impact on sex ratio. Methoxychlor, in this study be deemed as testosterone triggers which yields high boys ratio (x = 4.37, p < 0.05). In conclusion, Egypt continued to have a heavy burden of OCPs residues, and fetuses and infants are especially the most vulnerable groups to their adverse health effects. Exposure to OCPs may disrupt the maternal hormones, which regulate the offspring gender, but these results need to be validated in larger sample sizes.

Angiogenesis signaling in breast cancer models is induced by hexachlorobenzene and chlorpyrifos, pesticide ligands of the aryl hydrocarbon receptor

Breast cancer incidence is increasing globally and pesticides exposure may impact risk of developing this disease. Hexachlorobenzene (HCB) and chlorpyrifos (CPF) act as endocrine disruptors, inducing proliferation in breast cancer cells. Vascular endothelial growth factor-A (VEGF-A), cyclooxygenase-2 (COX-2) and nitric oxide (NO) are associated with angiogenesis. Our aim was to evaluate HCB and CPF action, both weak aryl hydrocarbon receptor (AhR) ligands, on angiogenesis in breast cancer models. We used: (1) in vivo xenograft model with MCF-7 cells, (2) in vitro breast cancer model with MCF-7, and (3) in vitro neovasculogenesis model with endothelial cells exposed to conditioned medium from MCF-7. Results show that HCB (3 mg/kg) and CPF (0.1 mg/kg) stimulated vascular density in the in vivo model. HCB and CPF low doses enhanced VEGF-A and COX-2 expression, accompanied by increased levels of nitric oxide synthases (NOS), and NO release in MCF-7. HCB and CPF high doses intensified VEGF-A and COX-2 levels but rendered different effects on NOS, however, both pesticides reduced NO production. Moreover, our data indicate that HCB and CPF-induced VEGF-A expression is mediated by estrogen receptor and NO, while the increase in COX-2 is through AhR and NO pathways in MCF-7. In conclusion, we demonstrate that HCB and CPF environmental concentrations stimulate angiogenic switch in vivo. Besides, pesticides induce VEGF-A and COX-2 expression, as well as NO production in MCF-7, promoting tubulogenesis in endothelial cells. These findings show that pesticide exposure could stimulate angiogenesis, a process that has been demonstrated to contribute to breast cancer progression.

AhR ligands reactivate LINE-1 retrotransposon in triple-negative breast cancer cells MDA-MB-231 and non-tumorigenic mammary epithelial cells NMuMG

Breast cancer is the most common cancer type in females worldwide. Environmental exposure to pesticides affecting hormonal homeostasis does not necessarily induce DNA mutations but may influence gene expression by disturbances in epigenetic regulation. Expression of long interspersed nuclear element-1 (LINE-1) has been associated with tumorigenesis in several cancers. In nearly all somatic cells, LINE-1 is silenced by DNA methylation in the 5́'UTR and reactivated during disease initiation and/or progression. Strong ligands of aryl hydrocarbon receptor (AhR) activate LINE-1 through the transforming growth factor-β1 (TGF-β1)/Smad pathway. Hexachlorobenzene (HCB) and chlorpyrifos (CPF), both weak AhR ligands, promote cell proliferation and migration in breast cancer cells, as well as tumor growth in rat models. In this context, our aim was to examine the effect of these pesticides on LINE-1 expression and ORF1p localization in the triple-negative breast cancer cell line MDA-MB-231 and the non-tumorigenic epithelial breast cell line NMuMG, and to evaluate the role of TGF-β1 and AhR pathways. Results show that 0.5 μM CPF and 0.005 μM HCB increased LINE-1 mRNA expression through Smad and AhR signaling in MDA-MB-231. In addition, the methylation of the first sites in 5́'UTR of LINE-1 was reduced by pesticide exposure, although the farther sites remained unaffected. Pesticides modulated ORF1p localization in MDA-MB-231: 0.005 μM HCB and 50 μM CPF increased nuclear translocation, while both induced cytoplasmic retention at 0.5 and 5 μM. Moreover, both stimulated double-strand breaks, enhancing H2AX phosphorylation, coincidentally with ORF1p nuclear localization. In NMuMG similar results were observed, since they heighten LINE-1 mRNA levels. CPF effect was through AhR and TGF-β1 signaling, whereas HCB action depends only of AhR. In addition, both pesticides increase ORF1p expression and nuclear localization. Our results provide experimental evidence that HCB and CPF exposure modify LINE-1 methylation levels and induce LINE-1 reactivation, suggesting that epigenetic mechanisms could contribute to pesticide-induced breast cancer progression.

Organochlorine pesticides residue in placenta and their influence on anthropometric measures of infants

The objective of this study is to evaluate the influence of placental concentrations of some organochlorine pesticides on newborn's anthropometric measurements (height, weight, head circumference & ponderal index). For this study, we have collected 90 placental tissue samples for the measurement of Dichlorodiphenyltrichloroethane (DDT) & Hexachlocyclohexane (HCH) by Gas Chromatography equipped with Electron Capture Detector (GC-ECD). Regression analysis were performed between outcome variables such as birth weight, birth height, head circumference, ponderal index and independent variable i.e., organochlorine pesticide concentrations. In case of birth weight, there was a substantial decrease of 5.81, 1.94, 4.71, and 2.64 g for 1 ppb (μg/L) increase in placental α-HCH, β-HCH, γ-HCH, and total HCH concentrations respectively. Significant decrease of 2.02 and 0.43 kg/m³ in ponderal index was found with 1 μg/L increase of total-HCH and total DDT concentrations in placenta. The results of this study support an association between environmental exposure to organochlorine pesticides and anthropometric development of the fetus leading to a significant reduction in its birth weight and ponderal index, slight and non-significant reduction in birth height and head circumference. Efforts should be made to reduce exposure of women of reproductive age in relation to long-term impact on health.

Metabolomics study and meta-analysis on the association between maternal pesticide exposome and birth outcomes

BACKGROUND

Pregnant women are exposed to a number of pesticides which are widely used in China. Their potential risks on reproduction and infants are still unknown.

OBJECTIVE

We aimed to investigate whether infant's birth weight and length of gestation were associated with levels of various pesticides in maternal blood based on Nanjing Medical University (NMU) affiliated hospitals data and meta-analysis, and also to explore the possible intermediate metabolomics pathways.

METHODS

Eligible subjects (n = 102) were included in this study from the affiliated hospitals of NMU. Gas chromatography tandem mass spectrometry (GC/MS) and Q-Exactive mass spectrometer (QE) were used to detect 37 pesticides (9 organophosphorus pesticides, 7 organochlorine pesticides, 5 carbamate pesticides, and 16 others) and 161 metabolites (53 in animo acid metabolism 47 in lipid metabolism, 18 in carbohydrate metabolism, 14 in nucleotide metabolism and 29 in other metabolisms) in maternal blood, respectively. Multi-linear regression and Bayesian kernel machine regression (BKMR) were performed to identify the association of single/mixed pesticide exposure in maternal blood with birth weight and length of gestation. Moreover, we conducted a meta-analysis including additional 2497 subjects to evaluate whether exposure to key pesticide, β-hexachlorocyclohexane (β-HCH) was associated with decreased birth weight globally. Mediation analysis was used to explore the metabolic alteration mediating the association between key pesticide exposure and birth outcomes.

RESULTS

We found that decreased birth weight was significantly associated with increasing levels of mecarbam and β-HCH. We did not find any association between length of gestation and these pesticides. Among pesticides with detection rate more than 50%, BKMR analysis found an overall negative association of mixed pesticides exposure with birth weight, and verified that β-HCH was the key pesticide for such effect. Meta-analysis revealed a significantly negative association between exposure to β-HCH and birth weight. Metabolomics identified three metabolites and five metabolites as significant mediators for the effect of mecarbam and β-HCH, respectively, among which glyceraldehyde and its related glycerolipid metabolism and thyroxine and its related thyroid hormone metabolism were found to be the mostly enriched mediating metabolic pathway.

CONCLUSIONS

Based on the comprehensive pesticide exposome and metabolome wide associational study combined with meta-analysis, we found that prenatal exposure to β-HCH and mecarbam decreased birth weight via disrupting thyroid hormone metabolism and glyceraldehyde metabolism, providing new insights into the toxic effects of exposure to pesticides on birth outcomes.

Prenatal β-Hexachlorocyclohexane (β-HCH) Exposure and 7-Year Child IQ in the CHAMACOS Birth Cohort

Fetal and infant exposures to β-hexachlorocyclohexane (β-HCH) occur through placental and breastmilk transfers. No studies have examined the relationship between β-HCH and child intelligence quotient (IQ). This study examined associations between in utero β-HCH exposure and cognitive development in 7-year-old children. Data from women and children (n = 256) participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort study were evaluated. We assessed exposure to β-HCH by measuring maternal serum concentration during pregnancy. We administered the Wechsler Intelligence Scale for Children (WISC), Fourth Edition, to children at age 7. Analyses were adjusted for maternal age, country of birth, work status, parity, and other pesticide exposures, language used for child cognitive assessment, and duration of breastfeeding. Higher serum β-HCH concentrations were associated with higher cognitive scores across all unadjusted models for the full-scale and sub-scale cognitive tests. In the adjusted models, a 10-fold increase in serum β-HCH concentration was associated with a 4.5-point increase in Working Memory IQ score (95% CI, 0.6 to 8.3; p = 0.02). We observed no significant interaction by length of breastfeeding or sex on associations. Our findings suggest that prenatal exposure to β-HCH is not adversely related to IQ at age 7 in a cohort of Mexican American children with fairly high exposure in utero as measured by maternal serum levels. Future research must replicate these findings in other study cohorts of women and children.

Persistent Organic Pollutants in Food: Contamination Sources, Health Effects and Detection Methods

Persistent organic pollutants (POPs) present in foods have been a major concern for food safety due to their persistence and toxic effects. To ensure food safety and protect human health from POPs, it is critical to achieve a better understanding of POP pathways into food and develop strategies to reduce human exposure. POPs could present in food in the raw stages, transferred from the environment or artificially introduced during food preparation steps. Exposure to these pollutants may cause various health problems such as endocrine disruption, cardiovascular diseases, cancers, diabetes, birth defects, and dysfunctional immune and reproductive systems. This review describes potential sources of POP food contamination, analytical approaches to measure POP levels in food and efforts to control food contamination with POPs.

Multiple pesticides in mothers' hair samples and children's measurements at birth: Results from the French national birth cohort (ELFE)

BACKGROUND

A growing body of studies now suggests that the general population is continuously and ubiquitously exposed to numerous pesticides. However, studies investigating the possible role of environmental exposure to pesticides on fetal growth have focused on a limited set of substances, despite the hundreds of modern pesticides currently available.

AIM

To explore the relation between maternal hair concentrations of 64 pesticides and metabolites and their newborns' measurements at birth, with data from the ELFE French nationwide birth cohort.

METHODS

We measured 64 compounds (10-100% detection) in bundles of hair 9 cm long collected at birth from 311 women who gave birth in France in 2011. We assessed their associations with birth weight, length, and head circumference, adjusted for potential confounders, and used elastic net regularization to simultaneously select the strongest predictors of measurements at birth. Selected variables were multiply imputed for missing values, and unpenalized estimators were assessed by standard linear regression.

RESULTS

We observed statistically significant associations between maternal hair concentrations of seven pesticides or pesticide metabolites and birth measurements (weight: fipronil sulfone; length: TCPy, bitertanol, DEP, and isoproturon; head circumference: tebuconazole and prochloraz). Analyses restricted to boys identified 12 additional compounds: 8 independently associated with birth weight (3Me4NP, DCPMU, DMST, fipronil, mecoprop, propoxur, fenhexamid, and thiabendazole), 2 with birth length (dieldrin and β-endosulfan), and 6 with head circumference (β-endosulfan, β-HCH, fenuron, DCPMU, propoxur, and thiabendazole).

CONCLUSION

Our results suggest that prenatal exposure to 19 pesticides or metabolites from various chemical families may influence measurements at birth. As with any exploratory research findings, results should be interpreted cautiously, until they are replicated or verified by further epidemiological or mechanistic studies.

Environmental contaminants and child's growth

Experimental data have suggested that some contaminants in the environment may increase the risk of obesity. Infants can be exposed to chemicals either prenatally, by trans-placental passage of chemicals, or postnatally by their own diet and by other external pathways (air inhalation, dust, hand-to-mouth exposure) after birth. To provide a review of epidemiological evidence on the association between prenatal exposure to chemicals and prenatal and postnatal growth, we present the literature from systematic review articles and international meta-analyses, when available, or recent research articles when summarizing articles were not available. The most studied contaminants in this field were persistent organic pollutants (e.g. organochlorinated pesticides, polychlorinated biphenyls), non-persistent pollutants (e.g. phthalates, bisphenol A), toxic heavy metals (i.e. cadmium, lead and mercury), arsenic, mycotoxins and acrylamide. Mounting evidence suggests that child's growth may be associated with prenatal or postnatal exposures to environmental contaminants. Improving exposure assessment and studying the contaminants as mixtures should allow to gain knowledge about the environmental determinants of growth and obesity.

Adverse effects of hexaclorobenzene exposure in children and adolescents

BACKGROUND

Hexachlorobenzene (HCB: C₆Cl₆) is a persistent, bioaccumulative chemical formerly used worldwide in pesticide mixtures but also produced as a by-product in the chemical and metallurgical industry. Despite current international restrictions in the use and production of HCB, the majority of the general population still show detectable levels of HCB, which raises concerns on the potential health implications of the exposure.

OBJECTIVE

To compile and synthesize the available scientific evidence regarding the adverse effects of exposure to HCB in children and adolescents.

METHODS

A review of the literature focused on the adverse effects of HCB exposure in children. Eligible studies were systematically screened from searches in Medline, Scopus and Ebsco-host databases. A total of 62 studies were finally included.

RESULTS AND DISCUSSION

In our search we found evidences of potential health effects linked to HCB exposure at different levels (e.g. neurotoxic, nephrotoxic, immunotoxic, hepatotoxic and toxicogenomic), although the conclusions are still contradictory. Further prospective research is needed, considering the special vulnerability of children and adolescent population as well as the ubiquity of the exposure.

Supporting dataset and methods for Transplacental Transfer of Organochlorine Pesticides: Concentration Ratio and Chiral Properties

The dataset and methods provided in this article supports "Transplacental Transfer of Organochlorine Pesticides: Concentration Ratio and Chiral Properties" [1]. The supplementary data were as follows: 1) the information on pretreatment and instrumental methods.2) the data for concentration in the maternal serum, cord serum and placenta samples and data interpretation. 3) the correlation between the influence factors and the log-transformed concentrations of the chemicals samples. 4) the dataset for transplacental transfer ratio of the OCPs and correlations with influencing factors.

Selected persistent organic pollutants associated with the risk of primary ovarian insufficiency in women

Although some persistent organic pollutants (POPs) may not be currently in production, many of these chemicals still exist ubiquitously in the environment and continue to represent significant environmental health concern. One of the important concerns of POPs exposure may lead to the adverse reproductive consequences including primary ovarian insufficiency (POI), but the limited evidence has been reported so far. Our case-control study was performed to explore the association between serum levels of selected POPs and risk for POI in a Chinese female population, including 157 cases and 217 healthy controls. Serum concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and serum levels of reproductive hormones [follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Mullerian hormone (AMH) and estradiol] were measured. The medians of dioxin-like PCBs (DL-PCBs) and p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) were significantly higher in case sera than in controls. Higher concentrations of DL-PCBs and p,p'-DDT were significantly associated with elevated risk of POI. A dose-response relationship was observed between the sum of DL-PCBs (Σ₆ DL-PCBs) and the risk of POI (p for trend = 0.003), with odds ratios for the second and third tertiles, compared with the first, of 1.31- (95% CIs: 0.67-2.57) and 3.15-fold (95% CIs: 1.63-6.10), respectively. Similar results were observed for the sum of p,p'-DDT and its metabolites (Σ₂ p,p'-DDTs). In control women, FSH levels were negatively associated with PCBs exposure, while LH had a positive association with OCPs. In patients with POI, exposure to PCBs was correlated with higher levels of LH, whereas exposure to OCPs was associated with lower levels of AMH. To the best of our knowledge, this study for the first provided evidence that exposure to PCBs and DDT could be the potential risk factors for POI in women.

Impact of endocrine disruptor hexachlorobenzene on the mammary gland and breast cancer: The story thus far

Breast cancer incidence is increasing globally and exposure to endocrine disruptors has gained importance as a potential risk factor. Hexachlorobenzene (HCB) was once used as a fungicide and, despite being banned, considerable amounts are still released into the environment. HCB acts as an endocrine disruptor in thyroid, uterus and mammary gland and was classified as possibly carcinogenic to human. This review provides a thorough analysis of results obtained in the last 15 years of research and evaluates data from assays in mammary gland and breast cancer in diverse animal models. We discuss the effects of environmentally relevant HCB concentrations on the normal mammary gland and different stages of carcinogenesis, and attempt to elucidate its mechanisms of action at molecular level. HCB weakly binds to the aryl hydrocarbon receptor (AhR), activating both membrane (c-Src) and nuclear pathways. Through c-Src stimulation, AhR signaling interacts with other membrane receptors including estrogen receptor-α, insulin-like growth factor-1 receptor, epidermal growth factor receptor and transforming growth factor beta 1 receptors. In this way, several pathways involved in mammary morphogenesis and breast cancer development are modified, inducing tumor progression. HCB thus stimulates epithelial cell proliferation, preneoplastic lesions and alterations in mammary gland development as well as neoplastic cell migration and invasion, metastasis and angiogenesis in breast cancer. In conclusion, our findings support the hypothesis that the presence and bioaccumulation of HCB in high-fat tissues and during highly sensitive time windows such as pregnancy, childhood and adolescence make exposure a risk factor for breast tumor development.

Association between prenatal exposure to multiple persistent organic pollutants (POPs) and growth indicators in newborns

Despite the fact that many of persistent organic pollutants (POPs) have been banned for decades, they still constitute a group of harmful substances to human health. Prenatal exposure can have adverse effects on one's health as well as on their newborns. The present cross-sectional study, which includes 87% of the births registered in La Palma Island (Canary Islands, Spain) during 2016 (n = 447), aims to evaluate the potential adverse health effects exerted by a wide range of POPs on newborns. We quantified blood cord levels of twenty organochlorine pesticides, eighteen polychlorinated biphenyls (PCBs), eight bromodiphenyl ethers (BDEs), and sixteen polycyclic aromatic hydrocarbons (PAHs) using the method of gas chromatography-mass spectrometry. By groups, p,p'-DDE, PCB-28, BDE-47, and phenanthrene were the most frequently detected compounds (median values = 0.148, 0.107, 0.065, and 0.380 ng/mL, respectively). p,p'-DDE was found to be significantly associated with an increase in neonatal birth weight, with a special emphasis on girls. An inverse association between PCB-28 and PCB-52 with birth weight was observed, and these associations were determined by the gender. A similar trend was obtained for BDE-47 but not for any of the PAHs. When assessing the effect of mixtures, boys exhibiting ≥ 3 OCPs were at lower risk of having higher birth weight (OR = 0.25; 95% CI = 0.07 - 0.89; P = 0.032). The effect of these pollutants on birth weight does not go in the same direction, a fact that is conditioned by several factors, including the chemical nature of the substance or the gender of the newborn. Additional research is needed to understand the role of POPs on fetal development.

Drivers of maternal accumulation of organohalogen pollutants in Arctic areas (Chukotka, Russia) and 4,4'-DDT effects on the newborns

BACKGROUND

One of the most worrying consequence of the production and use of persistent organohalogen pollutants (POPs) is the high accumulation in Arctic populations because of long-range transport. Study of the effects in these populations may illustrate human impacts that are difficult to assess in other locations with lower exposure to these compounds and more diverse pollutant influences.

OBJECTIVE

We aimed to identify the main maternal characteristics influencing on the accumulation of these compounds and the effects on the newborns in a highly exposed Arctic population (Chukotka, Russia).

METHODS

Organochlorine and organobromine compounds were analysed in maternal venous serum (n = 250). The study included data on residence, educational level, age, parity and body mass index (BMI) from self-reported questionnaires and measured anthropometric characteristics of newborns.

RESULTS

Concentrations of β-hexachlorocyclohexanes, hexachlorobenzene, 4,4'-DDT and polychlorobiphenyls were high when compared with those generally found in adult populations later than year 2000. The polybromodiphenyl ethers were negligible. These POP concentrations were higher than in Alaska and Arctic Norway and similar to those in Canada. The Chukotka mothers living in inland areas showed significant lower concentrations than those living in the coast (p < 0.001) except for 4,4'-DDT. The population from the Chukotsky District, a specific coastal area, showed the highest concentrations. Residence was therefore a main concentration determinant (p < 0.001) followed by maternal age, and in some cases parity and BMI (p < 0.05). 4,4'-DDT showed an association with the anthropometric characteristics of the newborns (p < 0.05). Mothers with higher 4,4'-DDT concentrations had longer gestational ages and gave birth to infants with higher weight and length.

CONCLUSIONS

The maternal accumulation patterns of POPs were mainly related with residence. Most of these compounds were found in higher concentration in women living at coastal areas except 4,4'-DDE and 4,4'-DDT which were of inland origin. This last pesticide was the pollutant showing positive associations with gestational age and newborn's weight and length. To the best of our knowledge, this is the first study reporting statistically significant associations between maternal 4,4'-DDT exposure and anthropometric characteristics of the newborns.

A case study on the application of an expert-driven read-across approach in support of quantitative risk assessment of p,p'-dichlorodiphenyldichloroethane

Deriving human health risk estimates for environmental chemicals has traditionally relied on in vivo toxicity databases to characterize potential adverse health effects and associated dose-response relationships. In the absence of in vivo toxicity information, new approach methods (NAMs) such as read-across have the potential to fill the required data gaps. This case study applied an expert-driven read-across approach to identify and evaluate analogues to fill non-cancer oral toxicity data gaps for p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), an organochlorine contaminant known to occur at contaminated sites in the U.S. The source analogue p,p'-dichlorodiphenyltrichloroethane (DDT) and its no-observed-adverse-effect level of 0.05 mg/kg-day were proposed for the derivation of screening-level health reference values for the target chemical, p,p'-DDD. Among the primary similarity contexts (structure, toxicokinetics, and toxicodynamics), toxicokinetic considerations were instrumental in separating p,p'-DDT as the best source analogue from other potential candidates (p,p'-DDE and methoxychlor). In vitro high-throughput screening (HTS) assays from ToxCast were used to evaluate similarity in bioactivity profiles and make inferences toward plausible mechanisms of toxicity to build confidence in the read-across approach. This work demonstrated the value of NAMs such as read-across and in vitro HTS in human health risk assessment of environmental contaminants with the potential to inform regulatory decision-making.

Associations of Maternal Exposure to Dichlorodiphenyltrichloroethane and Pyrethroids With Birth Outcomes Among Participants in the Venda Health Examination of Mothers, Babies and Their Environment Residing in an Area Sprayed for Malaria Control

Although effective in controlling malaria, indoor residual spraying results in elevated exposure to insecticides such as dichlorodiphenyltrichloroethane (DDT) and pyrethroids. These chemicals cross the placenta, but no studies have examined their associations with birth outcomes in populations residing in indoor residual spraying areas. We investigated this question in the Venda Health Examination of Mothers, Babies and Their Environment (VHEMBE), a birth cohort study of 751 South African children born between 2012 and 2013. We measured maternal peripartum serum DDT and urine pyrethroid metabolite concentrations and collected data on birth weight, length, head circumference, and duration of gestation. We analyzed the data using marginal structural models with inverse-probability-of-treatment weights, generalized propensity scores, and standard conditional linear regression. Using all 3 analytical methods, p,p'-DDT, o,p'-DDT, and to a lesser extent p,p'-dichlorodiphenyldichloroethylene were related to elevated birth weight, birth length, and head circumference among girls. Changes in gestational duration did not mediate this relationship, suggesting that these exposures accelerate fetal growth, which is consistent with the known estrogenic properties of o,p'-DDT and p,p'-DDT. No associations with pyrethroid metabolites were found. Results suggest that prenatal exposure to DDT is related to elevated birth size. Further studies are needed to elucidate the implications of these findings.

Foetal exposure to mitotane/Op'DDD: Post-natal study of four children

OBJECTIVE

Mitotane/Op'DDD is used in the treatment of adrenocortical carcinoma and for other causes of hypercortisolism. Mitotane inhibits cortisol secretion and displays adrenolytic and antitumor actions. This compound is a metabolite of the pesticide and endocrine disruptor DDT (dichlorodiphenyltrichloroethane) and is classified among teratogenic compounds worldwide. However, little is known about its effects on human development.

DESIGN

The outcome of four children exposed to mitotane during their intrauterine life was examined.

PATIENTS

Patients having conceived while taking mitotane, or with detectable mitotane plasma levels, were retrospectively recruited via the French COMETE and FIRENDO networks.

MEASUREMENTS

Mitotane in maternal plasma, adrenocortical hormones in children.

RESULTS

Three women treated with mitotane gave birth to four children. During early pregnancy, all patients had detectable mitotane plasma levels (0.9, 2.4 and 6.7 mg/L, respectively). During pregnancy, no foetal malformations were detected. The four exposed newborns presented at birth with apparently normal adrenal function and genitalia. One twin female had a low birthweight. Evaluation at birth and after 3 months, 2 years and 7 years of follow-up showed no significant neurological abnormality. Evaluation of adrenocortical functions showed no cortisol deficiency.

CONCLUSIONS

Unexpectedly, exposure of these four children to mitotane during foetal life seemed to have no clear teratogenic effect. However, considering the sub-therapeutic mitotane concentrations used here, the small number of cases, and because long-term follow-up is unknown, we strongly advise not to take mitotane during pregnancy and still recommend avoiding pregnancy, at least as long as mitotane plasma levels remain detectable.

Exposure to environmental concentrations of hexachlorobenzene induces alterations associated with endometriosis progression in a rat model

Hexachlorobenzene (HCB) is a dioxin-like compound widely distributed and is a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is a disease characterized by growth of endometrial tissue in ectopic sites. Our aim was to investigate the impact of HCB on the endocrine, invasion and inflammatory parameters in a rat endometriosis model surgically induced. Female rats were exposed to HCB (1, 10 and 100 mg/kg b.w.) during 30 days. Results showed that HCB increases endometriotic like-lesions (L) volume in a dose-dependent manner. In L, HCB10 increases microvessel density (immunohistochemistry) and the vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and AhR levels (Western Blot), while HCB1 enhances aromatase expression (Western Blot). In addition, in eutopic endometrium (EU), HCB10/HCB100 augments microvessel density, VEGF and MMP-9 expression, while HCB1/HCB10 increases tumor necrosis factor-α (TNF-α) content in peritoneal fluid (ELISA). Interestingly, both L and EU from HCB-treated rats exhibited higher estrogen receptor α (ERα) (immunohistochemistry) and metalloproteases (MMP)-2 and -9 levels (Western Blot), as well as lower progesterone receptor (PR) expression (immunohistochemistry) than in control rats. Environmentally relevant concentrations of HCB could contribute to abnormal changes associated with endometriosis progression and development.

Background biomonitoring of residue levels of 137 pesticides in the blood plasma of the general population in Beijing

Due to the widespread use of pesticides, human exposure to pesticides is possible and can potentially cause adverse impacts on public health. We measured 137 pesticides including organophosphorus, organochlorine, pyrethroid and carbamate pesticides together with various herbicides in 100 human blood samples collected from the general population in Beijing. The samples were analysed by triple quadrupole tandem gas chromatography-mass spectrometry. In total, 24 organochlorine pesticides, 5 pyrethroid pesticides and 6 organophosphorus pesticides were detected. The detection rates of HCB, α-HCH, β-HCH, γ-HCH, p,p'-DDE and quintozene were 99, 96, 74, 72, 96 and 95%, respectively. No statistically significant gender difference in the blood concentrations of the pesticides was found. Consistent with the trend of the increasing β-HCH, p,p'-DDE and quintozene concentrations with age, a strong positive correlation between the age and concentrations of β-BHC, p,p'-DDE and quintozene was observed.

Current status of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) exposure among mothers and their babies of Korea-CHECK cohort study

Despite the global ban, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been a persistent and significant environmental health issue worldwide. Prenatal exposure to these persistent organic pollutants (POPs) has been identified as a major route of exposure among developing fetuses and newborn infants. Among Children's Health and Environmental Health of Korea (CHECK) cohort population, pregnant females (n=148) and their matching newborn infants (n=117) recruited from four cities of Korea in 2011 were investigated. The blood serum and cord blood serum were sampled at delivery, and measured for 19 OCPs and 19 PCBs. In addition, a questionnaire regarding demographic characteristics, and dietary habits were conducted. The most frequently detected POPs in both maternal blood and cord blood were p,p'-dichlorodiphenyl dichloroethylene (DDE) (99% detection in maternal, and 98% in cord blood serum) and PCB153 (95% in maternal, 74% in cord blood serum). The levels of dichlorodiphenyl trichloroethanes (DDTs) in both maternal (average 82.5ng/g lw) and cord blood serum (average 77.5ng/g lw) were comparable to or greater than those reported in Japan about a decade ago. Approximately two thirds of the pregnant women and newborn infants showed the p,p'-DDE concentrations exceeding the biological equivalent (BE) corresponding to 10^-6 excess cancer risk. In addition, less chlorinated PCBs were detected higher in both maternal and cord serum. Less chlorinated PCBs also showed greater transplacental ratio. Dairy consumption among the subjects was positively associated, and tea consumption was negatively associated with serum levels of several POPs. Our results show that the exposure to legacy POPs, especially DDTs, among pregnant women and newborn infants is still prevailing, thus warrants measures for exposure mitigation among these vulnerable populations.

Prenatal organochlorine pesticide exposure and the disruption of steroids and reproductive hormones in cord blood: The Hokkaido study

Certain organochlorine pesticides (OCPs) are designated as persistent organic pollutants and are regulated in many countries. The effects of OCPs on pediatric endocrinology are a concern; however, only limited data exist from human studies on maternal OCP exposure and its effects on infants' hormone levels. This study was conducted as part of the Hokkaido Study Sapporo Cohort, a prospective birth cohort study in Japan. Participants included 514 women who enrolled at 23-35weeks of gestation between 2002 and 2005; maternal blood samples were collected in late pregnancy, and 29 OCPs were measured. Reproductive and steroid hormone levels in cord blood were also determined. Characteristics of mothers and their infants were obtained from self-administered questionnaires and medical records. Ultimately, 232 samples with both OCP and hormone data were analyzed. Fifteen of 29 investigated OCPs were detected in over 80% of the samples, with p,p'-dichlorodiphenyldichloroethylene showing the highest concentration (median value: 619pg/g-wet). The association between OCPs and sex hormone levels varied by sex. Linear regression models after sex stratification showed that chlordanes, cis-hexachlorobenzene, heptachlor epoxide, Mirex, and toxaphenes in maternal blood were inversely associated with testosterone, cortisol, cortisone, sex hormone-binding globin, prolactin, and androstenedione-dehydroepiandrosterone (DHEA) and testosterone-androstenediones ratios among boys. Furthermore, these OCPs were positively correlated with DHEA, follicle stimulating hormone (FSH), and adrenal androgen-glucocorticoid and FSH-inhibin B ratios among boys. In categorical quartile models, testosterone and DHEA were inversely and positively associated with OCPs, respectively. Estradiol-testosterone and adrenal androgen-glucocorticoid ratios tended to increase with increasing OCP concentrations in the higher quartile, while the testosterone-androstenedione ratio tended to decrease. Sex hormone-binding globulin and prolactin showed an inverse association with OCPs. Among girls, the linear regression model showed that only p,p'-dichlorodiphenyltrichloroethane was inversely associated with the level of DHEA and the adrenal androgen-glucocorticoid ratio, but was positively associated with cortisone levels. However, no associations were observed using the quartile categorical model. These results suggest that prenatal exposure to OCPs disrupt reproductive hormones of fetuses in utero among boys, even at relatively low levels.

Variations in serum concentrations of selected organochlorines among delivering women in Argentina. The EMASAR study

The EMASAR study is the first study to describe the body burden of OCs in Argentinian women after delivery. In total, 698 maternal serum samples from Salta (n = 498) and Ushuaia (n = 200) were collected in 2011-2012 and analyzed for a total of 7 polychlorinated biphenyls (PCBs) and 12 pesticide-related compounds. Only 11 of the compounds had detection rates above 60% in one or both places. Compared with Ushuaian women, those from Salta exhibited higher lipid-adjusted concentrations of p,p'-DDE, p,p'-DDT, β-HCH, and PCB 118 (p ≤ 0.003), with no differences in concentrations of PCB 153 and 138. After controlling for age, parity and heritage (born in the province or migrated there from other regions of Argentina), concentrations of p,p'-DDE, p,p'-DDT, β-HCH and all PCBs were significantly higher in Salta natives compared with Ushuaia natives or migrants (p ≤ 0.010). No variations between native and migrated Ushuaian women were observed other than for PCB 153 (6.1 versus 8.6 μg kg^-1 lipid, p = 0.022). Age was generally associated positively with the body burden of nearly all OCs and parity negatively so, with p,p'-DDD, o,p'-DDT, and o,p'-DDD residues and α-HCH in Ushuaia being the exceptions. The regional differences in OC concentrations are explained by contrasting domestic sources, historical and current uses, industrial emissions, dietary patterns and lifestyle factors, as well as long-range-transport. The relatively high PCB 118/PCB 180 ratio observed for both Argentinian communities likely reflects the use of technical mixtures with congener-specific composition. In a comprehensive comparison with other countries, the Argentinian OC concentrations were mostly in the lower range. It is concluded that a latitude effect equivalent to that operative in the Arctic region seems unlikely.

Neonatal exposure to environmental pollutants and placental mitochondrial DNA content: A multi-pollutant approach

BACKGROUND

Placental mitochondrial DNA (mtDNA) content can be indicative of oxidative damage to the placenta during fetal development and is responsive to external stressors. In utero exposure to environmental pollutants that may influence placental mtDNA needs further exploration.

OBJECTIVES

We evaluated if placental mtDNA content is altered by environmental pollution in newborns and identified pollutants independently associated to alterations in placental mtDNA content.

METHODS

mtDNA content was measured in placental tissue of 233 newborns. Four perfluoroalkyl compounds and nine organochlorine compounds were quantified in cord blood plasma samples and six toxic metals in whole cord blood. We first applied a LASSO (least absolute shrinkage and selection operator) penalized regression model to identify independent associations between environmental pollutants and placental mtDNA content, without penalization of several covariates. Then adjusted estimates were obtained using an ordinary least squares (OLS) regression model evaluating the pollutants' association with placental mtDNA content, adjusted for several covariates.

RESULTS

Based on LASSO penalized regression, oxychlordane, p,p'-dichlorodiphenyldichloroethylene, β-hexachlorocyclohexane, perfluorononanoic acid, arsenic, cadmium and thallium were identified to be independently associated with placental mtDNA content. The OLS model showed a higher placental mtDNA content of 2.71% (95% CI: 0.3 to 5.2%; p=0.03) and 1.41% (0.1 to 2.8%, p=0.04) for a 25% concentration increase of respectively cord blood β-hexachlorocyclohexane and arsenic. For a 25% concentration increase of cord blood thallium, a 4.88% lower placental mtDNA content (95% CI: -9.1 to -0.5%, p=0.03) was observed.

CONCLUSION

In a multi-pollutant approach, low fetal exposure levels of environmental organic and inorganic pollutants might compromise placental mitochondrial function as exemplified in this study by alterations in mtDNA content.

Agricultural pesticide use and adverse birth outcomes in the San Joaquin Valley of California

Virtually all agricultural communities worldwide are exposed to agricultural pesticides. Yet, the health consequences of such exposure are poorly understood, and the scientific literature remains ambiguous. Using individual birth and demographic characteristics for over 500 000 birth observations between 1997–2011 in the agriculturally dominated San Joaquin Valley, California, we statistically investigate if residential agricultural pesticide exposure during gestation, by trimester, and by toxicity influences birth weight, gestational length, or birth abnormalities. Overall, our analysis indicates that agricultural pesticide exposure increases adverse birth outcomes by 5–9%, but only among the population exposed to very high quantities of pesticides (e.g., top 5th percentile, i.e., ~4200 kg applied over gestation). Thus, policies and interventions targeting the extreme right tail of the pesticide distribution near human habitation could largely eliminate the adverse birth outcomes associated with agricultural pesticide exposure documented in this study.

The health consequences of exposure to pesticides are uncertain and subject to much debate. Here, the effect of exposure during pregnancy is investigated in an agriculturally dominated residential area, showing that an increase in adverse birth outcomes is observed with very high levels of pesticide exposure.