Environmental and occupational exposure of metals and female reproductive health

The rationale, design of the Assisted reproductive technology cohort nested in a pre-pregnancy family cohort (APP-Cohort)

INTRODUCTION

Infertility has become a major global issue due to the trend of delaying marriage and advanced maternal age. Family/Birth cohort studies are essential for exploring ways to enhance health outcomes at both the individual and societal levels. However, there is a shortage of cohorts that include families who have utilized assisted reproductive technology (ART), particularly initiated at the early stages before pregnancy. The Assisted Reproductive Technology Cohort (APP-Cohort) is a prospective study aiming to investigate the epidemiology and risk factors of adverse gestational outcomes and other health issues in couples who have conceived through ART or naturally.

METHODS

The cohort study's baseline survey commenced in January 2022 at several locations in Beijing, and enrollment is currently in progress. Both spouses filled out a questionnaire covering demographic, socio-economic, and various modifiable risk factors to gather information on their lifestyle. Physical examinations and biochemical tests were carried out, alongside regular yearly health check-ups throughout pregnancy and childhood. The survey data will be connected to electronic medical records to compile health information on the couples, newborns, and children.

DISCUSSION

The APP-Cohort study collected data from both wives and husbands before conception, allowing for early assessment of environmental risk factors for maternal and offspring health. With a focus on various types of risk factors such as genetic, environmental, and shared familial traits, the ongoing follow-up of this study will enable researchers to evaluate and distinguish the impacts of these factors on pregnancy outcomes, perinatal health, and children's health for individuals conceived naturally versus those conceived through ART. By utilizing practical experience and advanced mathematical analysis of the extensive data, the APP-Cohort study will provide valuable insights to promote the administration and success rate of ART in China.

Development of a direct dilution method for the simultaneous determination of 40 metal and non-metallic elements in urine and blood samples within 6 min using ICP-MS: Application of comprehensive biomonitoring of elementomic phenotypes of individuals in paired biological samples

The deficiency and overnutrition of both metal and non-metallic elements in human body can pose harmful effects to human health. Therefore, it is necessary to determination of elements in human body for assessing health risk of elementome. In this study, a simple and accurate biomonitoring approach was developed for quantifying 40 elements in biological samples within 6 min using a direct dilution method combined with inductively coupled plasma mass spectrometry (ICP-MS). It had good linearity (R2 ≥ 0.999) and high sensitivity (limit of detection (LOD) as low as 2 ng/L) with spiked recovery rates ranged between 82.53 % and 110.03 % for serum samples and between 81.92 % and 108.66 % for urine samples. The intra-day and inter-day precision are less than 15 %. In addition, uncertainty indicators and green analytical chemistry (GAC) approaches are used to evaluate the sources of uncertainty and greenness of developed analytical procedures. This method was finally used to detect the paired biofluids samples collected from 202 Chinese children. The distribution of element in this population through detection rate and level of body burden was analyzed. Furthermore, the function of paired serum and urine samples for detection of 40 elements is first explored by analyzing pairing samples. These results demonstrated that the proposed method for analysis of paired biological samples provides an alternative quantitative elementomics method to enable the comprehensive assessment of health risk associated with 40 elemental phenotypes of individuals.

The Menstrual Cycle as a Vital Sign: a comprehensive review

Some medical professional organizations have advocated for including the menstrual cycle as a vital sign in adolescence, but not in adulthood. However, documenting menstrual cycle patterns is not routine clinical or research practice. Vital signs are used to predict health outcomes, indicate needed treatment, and monitor a clinical course. They can help identify pathologies, affirm wellness, and are responsive to exposures. Here we review the scientific evidence showing how the menstrual cycle meets these criteria and should therefore be treated as a vital sign. Using key words and controlled vocabulary terms, we carried out multiple literature searches, prioritizing the inclusion of systematic reviews, meta-analyses, and clinical practice guidelines. This review describes how the menstrual cycle is a health indicator, can cyclically impact health conditions, and its associations with long-term post-menopausal health outcomes. We review exposures influencing the menstrual cycle, evidence underlying its use to optimize wellness, and available tools for documenting cycles. Supplementary materials include patient handouts on menstrual cycle tracking, and an index of related clinical practice guidelines and reviews by subject. The menstrual cycle is a vital sign from menarche through menopause, an underutilized but powerful tool for understanding gynecological and general health.

Cadmium exposure and health outcomes:An umbrella review of meta-analyses

OBJECTIVE

This umbrella review synthesizes evidence from meta-analyses to assess the health outcomes associated with cadmium (Cd) exposure.

METHODS

Literature search was conducted in four Databases: PubMed, Embase, APA PsycNe, and the Cochrane Databases. Evaluating evidence strength via Assess Systematic Reviews 2 (AMSTAR 2), umbrella review methodology and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE).

RESULTS

Our review encompassed 79 non-overlapping studies, investigating 48 unique health outcomes through 113 independent effect sizes. Using the AMSTAR 2 tool, we found that 2 (3 %) meta-analyses were rated as high quality, 6 (8 %) as moderate quality, 38 as low quality, and 33 as very low quality. Applying the GRADE criteria, we observed that 1 (1 %) effect size was rated A (male fertility), 8 (7 %) were rated B (breast cancer, prostate cancer, hypertension, stroke, urolithiasis), 30 were rated C, and 74 were rated D. According to the umbrella review methodology, 5 (4 %) outcomes provided highly suggestive evidence, 13 (12 %) provided suggestive evidence, 51 provided weak evidence (class IV), and 44 had insufficient evidence for statistically significant results (class V). Meta-analyses on circulatory diseases, pregnancy outcomes, perinatal outcomes, skeletal and connective tissue diseases, neurological disorders, urinary system diseases, and male fertility had >80 % statistically significant results, while endocrine system diseases and mental and behavioral disorders had <33 %.

CONCLUSION

Cd exposure is significantly linked to various health outcomes, with implications for clinical practice and public health recommendations.

A Prospective Ultrasound Study of Whole Blood Metals and Incidence of Uterine Leiomyomata

BACKGROUND

Uterine leiomyomata (UL), hormone-dependent neoplasms, are a major source of gynecologic morbidity. Metals are hypothesized to influence UL risk through endocrine disruption, and their effects may vary by vitamin D status.

OBJECTIVE

We estimated associations of a metal mixture with incident UL, overall and by vitamin D status.

METHODS

We analyzed data from the Study of Environment, Lifestyle and Fibroids, a Detroit-area prospective cohort study of 1,693 black women 23-35 years of age. We measured concentrations of 17 metals/metalloids in whole blood and 25-hydroxyvitamin D [25(OH)D] in serum collected at baseline (2010-2012). Participants underwent ultrasonography at baseline and after 20 months to detect UL. We used Bayesian kernel machine regression to estimate adjusted associations (β ) of the metal mixture with probit of incident UL. We also ran Cox regression models with interaction terms to estimate incidence rate ratios (IRR) by vitamin D status.

RESULTS

Among 1,132 UL-free participants at baseline, 832 (73%) had vitamin D deficiency [25(OH)D < 20  ng / mL ] and 117 (10%) developed UL within 20 months. Increasing all metals from their 50th to 75th percentiles was weakly positively associated with UL overall [β = 0.06 ; 95% credible interval (CrI): - 0.03 , 0.16] and among vitamin D-deficient participants (β = 0.13 ; 95% CrI: 0.01, 0.24), driven by cadmium (overall and vitamin D-deficient) and mercury (vitamin D-deficient only). Increasing cadmium from its 25th to 75th percentile was positively associated with UL overall (β = 0.03 ; 95% CrI: - 0.05 , 0.11) and among vitamin D-deficient participants (β = 0.13 , 95% CrI: 0.02, 0.24). In Cox models, cadmium [IRR = 1.55 ; 95% confidence interval (CI): 1.07, 2.24, per 1-unit increase in standardized concentration] and mercury (IRR = 1.38 ; 95% CI: 0.99, 1.92) were positively associated with UL among vitamin D-deficient participants.

DISCUSSION

The metal mixture was positively associated with incident UL, but the association was weak and imprecise. We observed a stronger association among vitamin D-deficient participants that was driven by cadmium and mercury. https://doi.org/10.1289/EHP15218.

Association of Personal Care and Consumer Product Chemicals with Long-Term Amenorrhea: Insights into Serum Globulin and STAT3

Chemicals in personal care and consumer products are suspected to disrupt endocrine function and affect reproductive health. However, the link between mixed exposure and long-term amenorrhea is not well understood. This study analyzed data from 684 women (2013-2018 National Health and Nutrition Examination Survey) to assess exposure to eight polyfluorinated alkyl substances (PFASs), 15 phthalates (PAEs), six phenols, and four parabens. Various statistical models for robustness tests and mediation analysis were used to explore associations with long-term amenorrhea and the role of serum globulin. Biological mechanisms were identified through an integrated strategy involving target analysis of key chemicals and long-term amenorrhea intersections, pathway analysis, and target validation. Results showed that women with long-term amenorrhea had higher exposure levels of Perfluorodecanoic acid, Perfluorohexane sulfonic acid (PFHxS), Perfluorononanoic acid, n-perfluorooctanoic acid (n_PFOA), n-perfluorooctane sulfonic acid, and Perfluoromethylheptane sulfonic acid isomers. Logistic regression with different adjustments consistently found significant associations between elevated PFAS concentrations and increased long-term amenorrhea risk, confirmed by Partial Least Squares Discriminant Analysis. Mediation analysis revealed that serum globulin partially mediated the relationship between PFAS exposure and long-term amenorrhea. Network and target analysis suggested that PFHxS and n_PFOA may interact with Signal Transducer and Activator of Transcription 3 (STAT3). This study highlights significant associations between PFAS exposure, particularly PFHxS and n_PFOA, and long-term amenorrhea, with serum globulin and STAT3 serving as mediators in the underlying mechanisms.

Single- and combined-heavy metals/metalloids exposures are associated with infertility in US women aged 20-44: NHANES 2013-2020 analysis

Infertility is a major medical and social issue, with environmental factors, including metal exposure, playing a crucial role. This study analyzes how individual metals and their mixtures, which include a selection of heavy metals and metalloids totaling sixteen metals, contribute to infertility risk, using data from the National Health and Nutrition Examination Surveys. The study included 1326 women aged 20-44 years, comprising 1145 classified as fertile and 181 as infertile, with data on reproductive questionnaires and covariates. Infertility was defined through self-reported data. To assess the associations between exposure to these elements and infertility risk, we employed logistic regression, principal component analysis (PCA), restricted cubic splines (RCS), quantile regression with group-specific combination (qgcomp), and bayesian kernel machine regression (BKMR). After adjusting for potential confounders, logistic regression revealed positive associations of blood manganese (BMn) and urinary tin (USn) with infertility, whereas serum selenium (SSe) was negatively associated. RCS analysis demonstrated nonlinear relationships between urinary barium (UBa), urinary molybdenum (UMo), and urinary antimony (USb) and infertility. Potential interactions were identified between the following metal pairs: UMo and urinary cadmium, USb and UBa, and USb and UMo. PCA identified a positive association between PC3 and infertility (OR = 1.17, 95 % CI: 1.00, 1.36). The qgcomp model also indicated a positive association between metal mixtures and female infertility (OR = 1.25, 95 % CI: 1.03, 1.52). In conclusion, this study highlights significant associations between exposure to specific metals and infertility risk among women of reproductive age.

Carbon Monoxide Poisoning: Diagnosis, Prognostic Factors, Treatment Strategies, and Future Perspectives

Carbon monoxide (CO) poisoning is a significant public health issue, with diagnosis often complicated by non-specific symptoms and limited access to specialised tools. Early detection is vital for preventing long-term complications. The review examines diagnostic challenges, prognostic factors, management strategies, and future advancements in CO poisoning. It highlights the limitations of current diagnostic techniques such as blood carboxyhaemoglobin levels and pulse CO-oximetry, while exploring emerging methods for rapid detection. Prognosis is influenced by exposure severity and delayed treatment, which increases the risk of neurological damage. Hyperbaric oxygen therapy (HBOT) remains the primary treatment but is not always accessible. Advances in portable CO-oximeters and biomarkers offer potential for improved early diagnosis and monitoring. Addressing resource limitations and refining treatment protocols are crucial for better patient outcomes. Future research should focus on personalised management strategies and the integration of modern technologies to enhance care.

A new quinoline-based fluorescent-colorimetric chemosensor for sensitive and selective "on-off" detection of Pb2+ ions

For the first time, a novel mono Schiff base of a quinoline-based reversible fluorescent-colorimetric receptor (L) has been designed for the detection of Pb2+ ions in a semi-aqueous medium. The receptor L exhibited a very good selective fluorescent-colorimetric quick on-off response when exposed to Pb2+. The colorimetric assay showed a sensitivity of 1.2 × 10-6 M, while the fluorescent assay exhibited a sensitivity of 9.9 × 10-7 M for Pb2+. A 1 : 1 stoichiometric complexation between L and Pb2+ was determined using ESI-MS spectra and Job's plot measurements. Pb2+ was successfully measured using receptor L in both real samples and in an aqueous solution of the protein bovine serum albumin, as well as in the construction of an INHIBIT-type molecular logic gate.

Inorganic Metal Nanoparticles in Reproductive Biology: Applications, Toxicities and Future Prospects

The development of inorganic metal and metal oxide nanoparticles (MNPs) has attracted significant attention in diverse biomedical and biotechnological fields including bio-detection, drug delivery, imaging, and theranostics. An emerging field in this context is the use of MNPs for applications in reproductive biology. In this article, we offer a rational review of the development of MNPs employed in the field of reproductive biology by focusing on their interactions with highly delicate and specialized germ cells like spermatozoa, oocytes, and developing embryos. By their unique physicochemical properties, MNPs are versatile and strong candidates for targeted imaging and delivery of various therapeutic molecules to the specific sites of the gametes and reproductive cells. Functionalized MNPs can serve as transfection vectors for the generation of transgenic animals by spermatozoon-supported gene transfer. In addition, MNPs have shown great promise in application fields such as semen collection, nano-purification, cryopreservation, and sex sorting of sperm in the livestock industry. Recently, the potential toxicity of MNPs on maturing oocytes has been investigated, as well as the use of MNPs to preserve fertility by improving cryopreservation and reducing oxidative stress in oocytes. The article further elaborates on the uptake, translocation mechanism, and biocompatibility issues of the MNPs to reproduction-relevant sites on cellular and molecular levels. Based on these promising achievements, the current challenges and prospects for the development of these functionalized MNPs for clinical research in conjunction with the reproductive system will be discussed.

Remediating contaminated environmental systems: the role of plants in cadmium removal

Cadmium (Cd) is one of the most harmful heavy metals in the environment, negatively impacting plant growth and development. However, phytoremediation which is an environmentally friendly and cost-effective technique can be used to treat Cd contaminated environments. It effectively removes Cd from polluted soil and water through processes, such as phytoextraction, phytostabilization, phytostimulation, phytofiltration, and phytotransformation. Numerous research has shown evidences that biological, physical, chemical, agronomic, and genetic methods are being utilized to improve phytoremediation. A special group of plants known as hyperaccumulator plants further enhance Cd removal, turning polluted areas into productive land. These plants accumulate Cd in root cell vacuoles and aerial parts. Despite the morphological and genetic variations, different plant species remediate Cd at different rates using either one or multiple mechanisms. To improve the effectiveness of phytoremediation, it is essential to thoroughly understand the mechanisms that control the accumulation and persistence of Cd in plants, including absorption, translocation, and elimination processes. However, what missing in understanding is in depth of idea on how the limitations of phytoremediation can be overcome. The limitations of phytoremediation can be addressed through various strategies, including natural and chemical amendments, genetic engineering, and natural microbial stimulation, broadly categorized into soil amelioration and plant capacity enhancement approaches. This review presents a concise overview of the latest research on various plants utilized in Cd phytoremediation and the different methods employed to enhance this process. Moreover, this review also underscores the creditability of phytoremediation technique to remediate Cd pollution as it offers a promising approach for eliminating Cd from contaminated sites and restoring their productivity. Additionally, we recommend directing future research toward enhancing the biochemical capabilities of plants for remediation purposes, elucidating the molecular mechanisms underlying the damage caused by Cd in plants, and understanding the fundamental principles regulating the enrichment of Cd in plants.

Parental occupational exposure to anticancer drugs and radiation: Risk of fetal loss and physical abnormalities in The Japan Environment and Children's Study

BACKGROUND

Many studies have indicated an association between maternal occupational exposure to hazardous agents, such as anticancer drugs and ionizing radiation, and an increased risk of adverse pregnancy outcomes, including stillbirths or miscarriages and physical abnormalities in offspring. However, the effects of recent advancements in protective measures to reduce these risks have not been clarified. Aim To investigate the current impact of parental occupational exposure to anticancer drugs and ionizing radiation on stillbirths or miscarriages as well as physical abnormalities under the circumstances of the developed safety protocols.

METHODS

This cohort study utilized The Japan Environment and Children's Study dataset, which included 96,606 fetuses born between January 2011 and March 2014. This study focused on the association between occupational exposure to these agents during pregnancy and the incidence of stillbirths or miscarriages and physical abnormalities in offspring, employing Poisson regression models for adjusted relative risk.

RESULTS

From the study population, 471 cases of stillbirths or miscarriages and 4493 infants with physical abnormalities were identified. Fisher's exact tests indicated no significant differences in fetal loss or physical abnormalities between the exposure groups. A multivariable analysis also found no significant association between maternal exposure to anticancer drugs and ionizing radiation and these adverse outcomes.

CONCLUSION

Under improved safety measures, maternal occupational exposure to anticancer drugs and ionizing radiation does not significantly affect the occurrence of stillbirths or miscarriages and physical abnormalities in offspring. These findings highlight the critical role of current safety practices and indicate lower reproductive risks with proper precautions.

Relationship between pregnant women's combined exposure to heavy metals and their offspring's congenital heart defects in Lanzhou, China

Background

Previous research has demonstrated that exposure to individual heavy metals elevates the incidence rate of congenital heart defects (CHDs). However, there is a paucity of data concerning the relationship between combined exposure to multiple heavy metals and the occurrence of CHDs. This study seeks to investigate the association between combined heavy metal exposure in pregnant women and the incidence of CHDs in their offspring in Lanzhou, China.

Methods

We conducted a comprehensive review of the birth cohort study undertaken at our hospital from 2010 to 2012, with the objective of investigating the association between combined heavy metal exposure in pregnant women and the incidence of CHDs in their offspring. This analysis was performed utilizing a multifactorial conditional logistic regression model.

Result

A nested case-control study was conducted involving 97 case groups and 194 control groups. The median concentrations of nickel (Ni), barium (Ba), lead (Pb), and titanium (Ti) in the blood of pregnant women were measured at 25.58 μg/L, 84.38 μg/L, 69.67 μg/L, and 304.65 μg/L, respectively. The research identified a significant correlation between the concentrations of Ni, Pb, and Ti in the blood of pregnant women and the risk of CHDs (P < 0.05). The optimal cut-off for heavy metals in pregnant women's blood was determined using the ROC curve. Levels below this threshold indicated low exposure, while levels at or above it indicated high exposure. In comparison to low exposure levels, high exposure to nickel (≥189.29 μg/L) in pregnant women was associated with a 2.098-fold increase in the risk of CHDs in their offspring (OR = 3.098, 95% CI: 1.322-7.260). Similarly, high lead exposure (≥86.70 μg/L) resulted in a 1.192-fold increase in the risk of CHDs in offspring (OR = 2.192, 95% CI: 1.021-4.707). Furthermore, high exposure to titanium (≥404.22 μg/L) was linked to a 3.065-fold increase in the risk of CHDs in offspring (OR = 4.065, 95% CI: 1.887-8.758). When compared to low exposure levels, the combined exposure to four heavy metals in the blood of pregnant women is linked to a 4.946-fold increased risk of CHDs in their offspring (OR= 5.946, 95% CI: 2.872-12.309). A significant correlation was observed between Ti exposure levels and the combined exposure levels of four heavy metals in pregnant women, with respect to the risk of isolated CHDs and multiple CHDs (P < 0.05). Additionally, high Ni exposure levels in pregnant women are associated with an increased risk of multiple CHDs (OR 4.321, 95% CI: 1.646-11.348).

Conclusion

The cumulative exposure levels of Ni, Ba, Pb, and Ti in the blood of pregnant women are correlated with an elevated risk of CHDs in their offspring.

Association between heavy metal exposure and bacterial vaginosis: A cross-sectional study

Bacterial vaginosis (BV) is a prevalent cause of vaginal symptoms in women of reproductive age. With the widespread of heavy metal pollutants and their harmful function on women's immune and hormonal systems, it is necessary to explore the association between heavy metal exposure and BV. This study investigates the potential relationship between serum heavy metals and bacterial vaginosis in a cohort of American women. The present study employed a cross-sectional analysis of 2,493 women participating in the 2001-2004 National Health and Nutrition Examination Survey (NHANES). Multivariable logistic regression models were utilized in the study to assess the correlation between these variables. A stratified analysis was performed to investigate the relationship among different population groups further, and smooth curve fittings were conducted to intuitively evaluate the correlation. According to the current cross-sectional study results, a significant correlation was identified between the high levels of lead and cadmium in the serum and the likelihood of developing bacterial vaginosis. We found that serum lead (OR = 1.35, 95% CI: 1.06-1.72, p = 0.016) and serum cadmium (OR = 1.41, 95% CI: 1.01-1.98, p = 0.047) increased the risk of bacterial vaginosis by 35% and 41%, respectively, in the highest level group in comparison to the lowest level group in the fully adjusted model. Furthermore, the research discovered no statistically significant association between the levels of total mercury in the serum and a heightened susceptibility to bacterial vaginosis (OR = 0.96, 95% CI: 0.75-1.23, p = 0.763). Results of our study indicated an inverse association between serum heavy metals and bacterial vaginosis risk, including lead and cadmium. Reducing exposure to heavy metals could be vital to preventing and managing bacterial vaginosis.

Protective Effects of Curcumin and Nanomicelle Curcumin on Chlorpyrifos-induced Oxidative Damage and Inflammation in the Uterus, Ovary and Brain of Rats

BACKGROUND AND AIMS

Chlorpyrifos (CPF), which is classified as an Organophosphorus Pesticide (OP), has been identified as a toxic agent for the reproductive system due to its capacity to induce oxidative stress and inflammation. Curcumin (CUR) has been reported as a natural antioxidant and anti-inflammatory agent that could combat toxicity in various tissues. This study aims to examine the protective effects of CUR and its nanoformulation against reproductive impairment induced by CPF.

METHODS

Forty-eight female Wistar albino rats were randomly allocated to six groups (n=8): control (0.5 mL of corn oil, the solvent for CPF), CPF (10 mg/kg), CPF + CUR 100 mg/kg/day, CPF + CUR 300 mg/kg/day, CPF + nano-micelle curcumin (NMC) 2.5 mg/kg/day, and CPF + NMC 5 mg/kg/day. The experimental treatment was performed for 30 days. Then, brain, ovary and uterus tissues were collected for measuring oxidative stress and inflammatory indices.

RESULTS

MDA, NO, IL-6, and TNF-α concentrations significantly increased in the brain, ovary and uterus of the CPF group versus the control group (p < 0.001). The levels of GSH and SOD in the uterus, ovaries, and brain exhibited a significant decrease in the CPF group compared to the control group (p < 0.05). However, CUR (300 mg/kg) and NMC (5 mg/kg) significantly decreased MDA, NO, TNF-α, and Il-6 and increased SOD and GSH levels in the uterus, ovaries and brain of the CPF-exposed animals versus the CPF-exposed non-treated animals (p < 0.001).

CONCLUSION

Our findings indicated that CUR and NMC could be effective in alleviating CPFinduced reproductive toxicity.

Impact of oxidative stress induced by heavy metals on ovarian function

As a crucial organ of the female reproductive system, the ovary has both reproductive and endocrine functions. Oxidative stress refers to an increase in intracellular reactive oxygen species (ROS), which play a role in the normal physiological activity of the ovary. However, excessive ROS can cause damage to the ovary. With the advancement of human industrial activities, heavy metal pollution has become increasingly severe. Heavy metals cause oxidative stress through both direct and indirect mechanisms, leading to changes in signal transduction pathways that damage the ovaries. This review aims to outline the adverse effects of oxidative stress on the ovaries triggered by heavy metals such as copper, arsenic, cadmium, mercury, and lead. The detrimental effects of heavy metals on ovaries include follicular atresia and decreased estrogen production in experimental animals, and they also cause premature ovarian insufficiency in women. Additionally, this review discusses the role of antioxidants, provides some treatment methods, summarizes the limitations of current research, and offers perspectives for future research directions.

Associations between prenatal exposure to metal mixtures and infant reproductive hormones during mini-puberty

BACKGROUND

The reproductive hormone homeostasis is crucial for child development. Exposure to metals during pregnancy may have adverse effects on offspring health. However, the association between prenatal exposure to metals and infant reproductive hormone levels remains unknown.

METHODS

This study involved 812 mother-infant pairs from Wuhan, China, assessing prenatal exposure to 13 metals in maternal plasma during early pregnancy and measuring five reproductive hormones in urine samples of one-month-old infants. Generalized linear models were employed to investigate the associations between individual metal exposures and urinary hormone levels in infants. Additionally, weighted quantile sum (WQS) regression and quantile g-computation were employed to evaluate the impact of metal mixtures.

RESULTS

Most of the detected metals in maternal plasma were associated with lower levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in infants. Each interquartile range (IQR) increase in manganese (Mn), barium (Ba), thallium (Tl), vanadium (V), cobalt (Co), nickel (Ni), and lead (Pb) was significantly associated with an approximately 9.87 % to 38.24 % decrease in FSH or LH. WQS and quantile g-computation models confirmed a significant association between prenatal metal mixtures and reduced FSH and LH in male infants, and WQS indicated a significant association between metal mixtures and decreased FSH in female infants.

CONCLUSIONS

Maternal exposure to mixed metals during early pregnancy was associated with lower levels of FSH and LH in infants, suggesting that prenatal exposure to metals may disrupt the balance of infant reproductive hormones. Further research is warranted to confirm these associations and explore the underlying mechanisms.

E-waste in the environment: Unveiling the sources, carcinogenic links, and sustainable management strategies

E-waste refers to the electrical and electronic equipment discarded without the intent of reuse or at the end of its functional lifespan. In 2022, approximately 62 billion kg of e-waste, equivalent to 7.8 kg per capita, was generated globally. With an alarming annual growth of approximately 2 million metric tonnes, e-waste production may exceed 82 billion kg by 2030. Improper disposal of e-waste can be detrimental to human health and the entire biosphere. E-waste encompasses a wide range of materials, including heavy metals, Polychlorinated Biphenyls (PCBs), Per- and Polyfluoroalkyl Substances (PFAS), Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Dibenzo-dioxins and -furans (PCDD/Fs), Polybrominated Diphenyl Ethers (PBDEs), and radioactive elements. E-waste, when disposed inappropriately can directly contaminate the aquatic and terrestrial environment, leading to human exposure through ingestion, inhalation, dermal absorption, and trans-placental transfer. These detrimental contaminants can directly enter the human body from the environment and may fuel carcinogenesis by modulating cell cycle proteins, redox homeostasis, and mutations. Heavy metals such as cadmium, mercury, arsenic, lead, chromium, and nickel, along with organic pollutants like PAHs, PCBs, PBDEs, PFAS, and radioactive elements, play a crucial role in inducing malignancy. Effective collection, sorting, proper recycling, and appropriate disposal techniques are essential to reduce environmental contamination with e-waste-derived chemicals. Hence, this comprehensive review aims to unravel the global environmental burden of e-waste and its links to carcinogenesis in humans. Furthermore, it provides an inclusive discussion on potential treatment approaches to minimize environmental e-waste contamination.

Protective Role of Vitamin B6 Against Teratogenic Effects Induced by Lead in Chick Embryo

BACKGROUND

Heavy metals like lead (Pb) have been used by humans for a very long time, but throughout the industrial revolution, their use expanded, increasing exposure to the metal. Lead, however, has no biological purpose in the human body and is hazardous when it gets into soft tissues and organs. Lead is still used in a variety of industries, including battery manufacturing and car maintenance, despite efforts to limit its usage.

OBJECTIVE

This study investigates the teratogenic and morphometric effects of lead on chick embryos and the potential ameliorative effects of vitamin B6.

METHODS

Two hundred fertilized eggs from the golden black chicken were divided into four groups: control, lead acetate, vitamin B6, and lead + vitamin B6.

RESULTS

On the 14th day, embryos were analyzed. Significant reductions in body weight and size were observed in the lead-exposed group (33.93 ± 1.27 g) compared to the control (41.12 ± 0.97 g). Pronounced deformities included rudimentary beaks, protruding eyes, tridactyl limbs, hydrocephaly, and neck deformities. Appendicular deformities like phocomelia, amelia, and abnormal phalanges growth were also noted. Vitamin B6 demonstrated therapeutic benefits, significantly improving mean embryo weight in the Lead + Vitamin B6 group (42.37 ± 0.99 g). The lead-exposed group showed a reduction in maxilla length (3.61 ± 1.30 mm) compared to the Lead + Vitamin B6 group (7.57 ± 0.79 mm). This group also showed reduced severity of muscular dystrophy and bone thinning, with signs of recovery in beak and bone sizes.

CONCLUSIONS

The study highlights vitamin B6's beneficial impact in mitigating lead's toxic effects on chick embryonic development.

Methylmercury chloride inhibits meiotic maturation of mouse oocytes in vitro by disrupting the cytoskeleton

Methylmercury chloride (MMC) is a persistent heavy metal contaminant that can bioaccumulate in humans via the food chain, exerting detrimental effects on health. Nevertheless, the specific influence of MMC on oocyte meiotic maturation has yet to be elucidated. This research demonstrated that MMC exposure during the in vitro cultivation of mouse oocytes did not influence germinal vesicle breakdown but markedly decreased oocyte maturation rates. Subsequent analysis indicated that MMC exposure resulted in aberrant spindle morphology and disorganized chromosome alignment, alongside continuous activation of the spindle assembly checkpoint (SAC). However, MMC exposure didn't alter the localization pattern of microtubule-organizing center-associated proteins. MMC exposure considerably diminished the acetylation level of α-tubulin, signifying reduced microtubule stability. Additionally, MMC exposure disrupted the dynamic alterations of F-actin. MMC exposure didn't affect mitochondrial localization, mitochondrial membrane potential, adenosine triphosphate content or the concentrations of reactive oxygen species. Nonetheless, MMC exposure triggered DNA damage and modified histone modification levels. Consequently, the defects in oocyte maturation induced by MMC exposure can be attributed to impaired cytoskeleton dynamics and DNA damage. This study offers the first comprehensive elucidation of the negative impacts of MMC on oocyte maturation, highlighting the potential reproductive health risks associated with MMC exposure.

Cadmium Exposure in Male Rats Results in Ovarian Granulosa Cell Apoptosis in Female Offspring and Paternal Genetic Effects

The aim of this study was to investigate whether the damage to male offspring induced by cadmium (Cd) exposure during embryonic period leads to the apoptosis of ovarian granulosa cells (OGCs) in the next generation of female offspring, and whether this apoptosis in the offspring was due to paternal genetic effects. Pregnant Sprague-Dawley (SD) rats were exposed to CdCl2 (0, 0.5, 2.0, or 8.0 mg/kg) by gavage daily for 20 days to produce the filial 1 (F1) generation. F1 males were mated with newly purchased females to produce the F2 generation, and the F3 generation was generated in the same way. No apoptotic bodies were observed in the OGCs of either the F2 or F3 generation as shown by electron microscopy, and a reduced OGC apoptosis rate (detected by flow cytometry) was observed in F2 OGCs from the Cd-exposed group. Moreover, the mRNA (qRT-PCR) levels of Bax and Bcl-2 and the protein (western blotting) level of pro-caspase-8 increased in the F2 generation (p < 0.05). The expression of apoptosis-related miRNAs (qRT-PCR) and methylation of apoptosis-related genes (determined via bisulfite-sequencing PCR) in OGCs were further determined. Compared with those of the controls, the expression patterns of microRNAs (miRNAs) in the F2 offspring were different in the Cd-exposed group. The miR-92a-2-5p expression levels were decreased in both the F2 and F3 generations (p < 0.05), while the average methylation level of apoptosis-related genes did not change significantly (except for individual loci). In summary, this study showed that the paternal genetic intergenerational effect of male Cd exposure during embryonic period induced apoptosis of OGCs in the offspring was weakened, and the transgenerational effect disappeared; nevertheless, intergenerational and transgenerational changes in apoptosis-related genes, epigenetic modifications, DNA methylation, and miRNAs were observed, and may be important for understanding the homeostatic mechanisms of the body to alleviate the intergenerational transmission of Cd-induced damage.

Association of coexposure to perfluoroalkyl and polyfluoroalkyl compounds and heavy metals with pregnancy loss and reproductive lifespan: The mediating role of cholesterol

Previous studies have demonstrated the toxic effects of per- and polyfluoroalkyl substances (PFASs) and heavy metals on the reproductive system. However, the interactions and combined effects of these substances remain unexplored. This study utilizes data from the National Health and Nutrition Examination Survey to investigate the associations between coexposure to four types of PFASs, lead (Pb), mercury (Hg) and self-reported pregnancy loss and reproductive lifespan in females. Genes associated with these substances and abortion were identified via the Comparative Toxicogenomics Database. The results revealed that Ln-PFOA (IRR=1.88, 95 % CI=1.42-2.50, Ln--: log transformed), Ln-PFOS (IRR=1.58, 95 % CI=1.12-2.22), Ln-PFHxS (IRR=1.99, 95 % CI=1.57-2.52), and Ln-Hg (IRR=1.92, 95 % CI=1.41-2.43) were positively associated with the risk of pregnancy loss. Ln-PFOA (β=1.27, 95 % CI=0.28-2.27), Ln-PFOS (β=1.01, 95 % CI=0.39-1.63), Ln-PFHxS (β=0.71, 95 % CI=0.12-1.63), Ln-PFNA (β=1.15, 95 % CI=0.23-2.08), Ln-Pb (β=3.87, 95 % CI=2.58-5.15), and Ln-Hg (β=1.01, 95 % CI=0.39-1.64) exposures were positively associated with reproductive lifespan. The mixed and overall effects of coexposure to PFASs and heavy metals were positively correlated with the risk of pregnancy loss and reproductive lifespan. Cholesterol partially mediated the association with the risk of pregnancy loss, whereas delay in menopause fully mediated the association with reproductive lifespan. Significant additive interactions were observed between PFOA and Pb and between PFOS, PFHxS, PFNA and Hg at high levels of coexposure. Thirty-nine overlapping genes associated with abortion were identified for these substances, and further analyses revealed that these genes significantly interact and may contribute to abortion through oxidative stress.

Reproductive Toxicity and Multi/Transgenerational Effects of Emerging Pollutants on C. elegans

Emerging pollutants (EPs) are receiving increasing attention due to the threats they pose to the environment and human health. As EPs continue to emerge, risk assessment requires many model animals. Caenorhabditis elegans (C. elegans) has been an outstanding toxicological model organism due to its growth and development characteristics. Particularly, in studying the transgenerational influences of EPs, C. elegans has advantages in saving time and cost due to its short generation cycle. As infertility has become a major problem in human reproductive health, reproductive toxicities of EPs on contemporary nematodes and across generations of C. elegans were introduced in this review. Moreover, the underlying mechanisms involved in germ cell apoptosis, spermatogenesis, and epigenetic alteration were discussed. Future research opportunities and challenges are also discussed to expand our understanding of the reproductive influences of EPs.

Human Exposure through the Diet to Arsenic and Other Toxic Elements: A Literature Review of Scientific Studies Conducted in Catalonia, Spain, in the Current Century

Human exposure to arsenic and other toxic elements such as cadmium, lead and mercury may lead to a wide range of adverse health effects. In relation to this, it is well established that the diet is the main route of exposure to both essential and toxic trace elements. In recent years, the levels of toxic elements in foodstuffs have been measured in numerous studies conducted all over the world. Scientific databases show that, in the current century, China and Spain have been the countries where the most surveys on this topic have been carried out. Regarding Spain, Catalonia is the region where most studies aimed at determining the concentrations of trace elements in food have been performed. The objective of this paper was to review the studies carried out in Catalonia on the concentrations of As and toxic metals (including Cd, Hg and Pb) in food, as well as their estimated dietary intakes (EDIs). The results of total diet studies (TDSs) and duplicate diet (DD) studies have been included. For most toxic elements, a continued reduction in the EDI has been observed. This reduction is associated with a decrease in their concentrations in food, and with certain changes in dietary habits. Fish and seafood is the food group showing the highest content of toxic elements. However, none of the adult groups exceeded-in general-the safety thresholds for As, Cd, Hg and Pb established by the European Food Safety Agency (EFSA).

Reproductive toxicology: keeping up with our changing world

Reproductive toxicology testing is essential to safeguard public health of current and future generations. Traditional toxicological testing of male reproduction has focused on evaluating substances for acute toxicity to the reproductive system, with fertility assessment as a main endpoint and infertility a main adverse outcome. Newer studies in the last few decades have significantly widened our understanding of what represents an adverse event in reproductive toxicology, and thus changed our perspective of what constitutes a reproductive toxicant, such as endocrine disrupting chemicals that affect fertility and offspring health in an intergenerational manner. Besides infertility or congenital abnormalities, adverse outcomes can present as increased likelihood for various health problems in offspring, including metabolic syndrome, neurodevelopmental problems like autism and increased cancer predisposition, among others. To enable toxicologic studies to accurately represent the population, toxicologic testing designs need to model changing population characteristics and exposure circumstances. Current trends of increasing importance in human reproduction include increased paternal age, with an associated decline of nicotinamide adenine dinucleotide (NAD), and a higher prevalence of obesity, both of which are factors that toxicological testing study design should account for. In this perspective article, we highlighted some limitations of standard testing protocols, the need for expanding the assessed reproductive endpoint by including genetic and epigenetic sperm parameters, and the potential of recent developments, including mixture testing, novel animal models, in vitro systems like organoids, multigenerational testing protocols, as well as in silico modelling, machine learning and artificial intelligence.

Confined within a sugarcane monoculture: A participatory assessment of water pollution and potential health risks in the community of El Tiple, Colombia

Communities neighboring monoculture plantations are vulnerable to different forms of pollution associated with agro-industrial operations. Herein, we examine the case of El Tiple, a rural Afro descendant community embedded within one of the largest sugarcane plantations in the Americas. We implemented a participatory approach to assess water pollution, exposure via water ingestion, and non-carcinogenic health risks associated with the use of local water sources available to the community. We conducted household surveys to unveil demographic characteristics and family dynamics linked to water consumption. Additionally, we measured water quality parameters and assessed the concentration glyphosate, its major metabolite (aminomethylphosphonic acid) and metals and metalloids. Drinking water El Tiple households is sourced from three primary sources: the local aqueduct system, water delivery trucks, and private deep wells. Tests on water samples from both the local aqueduct and delivery trucks showed no traces of pesticides, metals, or metalloids surpassing regulatory limits set by Colombian or EPA standards. However, we found concentration of contaminants of primary concern, including mercury (up to 0.0052 ppm) and lead (up to 0.0375 ppm) that exceed the permissible regulatory thresholds in water from groundwater wells. Residents of the peripheric subdivisions of El Tiple are four times more reliant on well water extraction than residents of the central area of the town due to lack of access to public drinking water and sanitation infrastructure. Finally, adult women and school-age children have a higher health risk associated with exposure to local pollutants than adult men due to their constant presence in the town. We conclude that expanding the coverage of clean water and sanitation infrastructure to include all households of the community would be the most recommended measure to minimize exposure and risk via ingestion of water pollutants.

Metal(loid)-gut microbiota interactions and microbiota-related protective strategies: A review

Human exposure to metal(loid)s has dramatically increased over the past five decades, which has triggered public concern worldwide. Recently, gut microbiota has been considered a target for metal(loid)s, and some literature has reviewed the interactions between gut microbiota and heavy metal(loid)s (HMs) with high toxicity. However, whether there is an interaction between gut microbiota and metal(loid)s with essential roles or some normal functions are far from clear to date. Importantly, in addition to traditional probiotics that have been clarified to alleviate the adverse effect of HMs on the body, some novel probiotics, prebiotics, synbiotics, and postbiotics may also exhibit comparable or even better abilities of metal(loid) remediation. In this review, we mainly outline and discuss recent research findings on the metal(loid)-gut microbiota interactions and microbiota-related protective strategies.

Quantitative analysis and health risk assessment of selected heavy metals in pet food samples using ultrasound assisted hydrogen peroxide extraction followed by ICP-OES analysis

There is a lack of information regarding the presence of heavy metals in feed ingredients for animals. Therefore, this study examines 10 feed samples collected from commercial pet food in South African market. The optimal working parameters for ultrasound assisted hydrogen peroxide extraction (UA-HPE) confirmed by multivariate optimization were sonication temperature at 80 °C for 60 min, sample mass of 0.1 g, and H2O2 concentration of 5 mol/L. The UA-HPE results demonstrated high accuracy of (>95%), reproducibility (≤1.9%), low method of detection limits (0.3498 and 0.49 μg/g), and strong linearity as confirmed by regression analysis. The environmental friendliness of the UA-HPE method was assessed using AGREEPrep metric tool that resulted with a score of 0.74. The concentration levels of Cd, Pb and As, ranged between 0.86 and 11.34, 4.50-11.45, and 2.61-12.5 μg/g, respectively greater than the standardized limits, whilst Cr, and Sn were below the limits of detection in all pet food. The health index calculations (HI > 1) revealed that the cat, dog, and horse feed pose health risk for animal consumption. Consequently, this study demonstrated a green, efficient, and cost-effective method for the analysis of animal feed with high accuracy.

The effects of climate change and environmental pollution on human reproduction: A scientific review commissioned by the European Board and College of Obstetrics and Gynaecology (EBCOG)

The European Board and College of Obstetrics and Gynaecology (EBCOG) and the European Network of Trainees in Obstetrics and Gynaecology (ENTOG) express their concerns on the effect of climate change and environmental pollution. This paper reviews the impact on reproductive health and the contribution to climate change by the field of obstetrics and gynaecology. It concludes that its contributors and the effects of climate change cause definite adverse consequences to fertility and adverse obstetric outcomes. Mankind, and obstetrics and gynaecology personnel as well, must be aware and responsible of its contribution to climate change and consider the impact of their actions and interventions.

Association between urinary mixture metal levels and olfactory function in coal miners

Background

Exposure to occupational metallic mixtures has a potential impact on olfactory function. However, research evidence is limited on the potential impact of exposure to metallic mixtures and olfactory dysfunction. Furthermore, the coal dust generated contains multiple various metals during coal mining, and no study yet has focus on the olfactory dysfunction of coal miners.

Objectives

In this study, we evaluate the association between urinary metallic mixtures and olfactory function in coal miners, while also exploring the potential applicability of plasma olfactory marker protein (OMP) as a biomarker for assessing olfaction.

Methods

From July to October 2023, coal workers from seven different coal mining enterprises were recruited for the survey when they come for the employee health checkup. Ultimately, 376 participants were met the inclusion criteria and, respectively, determined with the concentrations of urine (16 metals) and plasma (OMP). Meanwhile, applying UPSIT to access their olfactory function. Binary logistic regression and restricted cubic spline (RCS) model were used to estimate the association of individual metals with olfactory function. Bayesian kernel machine regression (BKMR) and Quantile g-computation (QG-C) regression were employed to assess the overall association between metal mixtures and olfactory function and identify the major contributing elements.

Results

In a single-metal model, two metals in urine were found to be significantly associated with olfactory function. RCS analysis further revealed that the association between Iron (Fe) and olfactory function was linear, while Lead (Pb) exhibited a non-linear. The BKMR model demonstrated a significant positive association between metal mixture concentration and olfactory function. Combined QG-C regression analysis suggested that metals Cr, Fe, Se, Sb, and Pb could impact the performance of the olfactory test (UPSIT), with Pb being identified as the most influential contributor. The correlation between plasma OMP protein levels and urinary metal concentrations was weak.

Conclusion

Multiple metals are associated with olfactory function in the coal miners. A significant positive association was observed between metal mixture concentrations and olfactory function, with Pb being the most important contributor. In this study, plasma OMP has not been demonstrated to serve as a biomarker for olfactory function.

Associations of urinary heavy metals with age at menarche, age at menopause, and reproductive lifespan: A cross-sectional study in U.S. women

Female reproductive timing and lifespan, with a close relation to long-term health outcomes, have been altered in U.S. women over the past decades. However, epidemiologic evidence of the potential causes was lacking. On the basis of 1981 naturally postmenopausal women from the National Health and Nutrition Examination Survey 1999-2020, this study aimed to investigate the associations of urinary heavy metals with age at menarche, age at menopause, and reproductive lifespan. Multivariate generalized linear regression and addictive models were used for single metal exposure analysis, and weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were employed for mixed exposures. In the fully adjusted model, higher urinary antimony concentration was associated with earlier age at menarche of 0.137 years, while higher concentrations of cadmium, cesium, lead, antimony, and thallium were associated with delayed age at menopause of 0.396-0.687 years. Additionally, urinary barium, cesium, lead, antimony, and thallium levels were associated with longer reproductive lifespan ranging between 0.277 and 0.713 years. Both WQS and BKMR models showed significantly positive associations of metal mixtures with age at menopause (β: 0.667, 95 % CI: 0.120-1.213) and reproductive lifespan (β: 0.686, 95 % CI: 0.092-1.280), with cadmium and lead identified as principal contributors. In conclusion, heavy metal exposures were associated with reproductive timing and lifespan of U.S. women, highlighting the need for further prevention and intervention strategies.

Environmental arsenic exposure and reproductive system toxicity in male and female and mitigatory strategies: a review

Environmental Arsenic (As) exposure is one of the main health challenges in different area of the world. As is a significant factor responsible to the reproductive system toxicity in both male and female. In this study, the most important effects mechanisms and biomarkers related to environmental exposure to As and the reproductive system toxicity, and infertility risk are reviewed in male and female. The results showed that the most important As-induced reproductive system toxicity in the male were alteration in the quantity and quality of semen, testicular toxicity, oxidative stress, testosterone reduction, and sperm apoptosis. For female were oxidative stress, spontaneous miscarriage, reproductive cycle disruption, decrease in the estradiol, progesterone, and testosterone levels and impair fecundity. The main mechanisms of reproductive system toxicity caused by As exposure in male were, genotoxic effects, reduction of glutathione, disruption of sex hormones, sperm flagellum formation impairment, inhibition of spermatogenesis, disruption of cell signaling pathways, and metabolites disruption. For female were abnormal signaling in gene expression, hormonal homeostasis, As-accumulation in placental tissue and creation of reactive oxygen, disruption in the neurotransmitters balance, and sex hormones disruption. The suitable biomarkers for As-induced reproductive toxicity in male were changes in testosterone, one-carbon and lipid metabolism, noncoding RNAs, and steroid hormone homeostasis, and for female was human chorionic gonadotropin (hCG) changes. Finaly, taking selenium, zinc, silymarin, vitamins (C and E) and phytonutrients can be effective in reducing the As-induced reproductive system toxicity and infertility risk.

Transcriptomic evaluation of metals detected in placenta

This research aims to assess the concentration of metals in human and canine placentas from the same geographic area and to investigate how these metal levels influence gene expression within the placenta. Placentas of 25 dogs and 60 women who had recently given birth residing in Ankara, Turkey were collected and subjected to metal analysis using ICP-OES. Placentas with detectable metal levels underwent further examination including Next Generation Sequencing, transcriptional analysis, single nucleotide polymorphism investigation, and extensive scrutiny across various groups. For women, placentas with concurrent detection of aluminum (Al), lead (Pb), and cadmium (Cd) underwent transcriptomic analysis based on metal analysis results. However, the metal load in dog placentas was insufficient for comparison. Paired-end sequencing with 100-base pair read lengths was conducted using the DNBseq platform. Sequencing quality control was evaluated using FastQC, fastq screen, and MultiQC. RNA-sequencing data is publicly available via PRJNA936158. Comparative analyses were performed between samples with detected metals and "golden" samples devoid of these metals, revealing significant gene lists and read counts. Normalization of read counts was based on estimated size factors. Principal Component Analysis (PCA) was applied to all genes using rlog-transformed count data. Results indicate that metal exposure significantly influences placental gene expression, impacting various biological processes and pathways, notably those related to protein synthesis, immune responses, and cellular structure. Upregulation of immune-related pathways and alterations in protein synthesis machinery suggest potential defense mechanisms against metal toxicity. Nonetheless, these changes may adversely affect placental function and fetal health, emphasizing the importance of monitoring and mitigating environmental exposure to metals during pregnancy.

Occupational exposure limits for reproductive toxicants - A comparative analysis

We investigated the level of protection of reproductive and developmental toxicity offered through occupational exposure limits (OELs) and Derived No-Effect Levels for workers' inhalation exposure (wDNELs). We compared coverage of substances that have a harmonised classification as reproductive toxicant 1 A or 1B (Repr.1 A/B), numerical values and scientific basis of 12 lists of OELs and wDNELs from REACH Registrants' and the Committee for Risk Assessment. Across the 14 sources of OELs and wDNELs, 53 % of the Repr1A/B-substances had at least one exposure limit (counting groups of metals as one entry). Registrants' wDNELs covered the largest share, 40 %. The numerical values could be highly variable for the same substance across the lists. How often reproductive toxicity is identified as the critical effect varies between the examined lists, both due to different assessments of the same substance and different substance coverage. Reviewing the margin of safety to reproductive toxicity cited in the documents, we found that 15 % of safety margins were lower to reproductive toxicity than the critical effect. To conclude, neither the REACH nor work environment legislation supply wDNELs or OELs for a substantial share of known reproductive toxicants. EU OELs cover among the fewest substances in the range, and in many cases national OELs or wDNELs are set at more conservative levels.

Flavonoid metabolism plays an important role in response to lead stress in maize at seedling stage

BACKGROUND

Pb stress, a toxic abiotic stress, critically affects maize production and food security. Although some progress has been made in understanding the damage caused by Pb stress and plant response strategies, the regulatory mechanisms and resistance genes involved in the response to lead stress in crops are largely unknown.

RESULTS

In this study, to uncover the response mechanism of maize to Pb stress phenotype, physiological and biochemical indexes, the transcriptome, and the metabolome under different concentrations of Pb stress were combined for comprehensive analysis. As a result, the development of seedlings and antioxidant system were significantly inhibited under Pb stress, especially under relatively high Pb concentrations. Transcriptome analysis revealed 3559 co-differentially expressed genes(co-DEG) under the four Pb concentration treatments (500 mg/L, 1000 mg/L, 2000 mg/L, and 3000 mg/L Pb(NO3)2), which were enriched mainly in the GO terms related to DNA-binding transcription factor activity, response to stress, response to reactive oxygen species, cell death, the plasma membrane and root epidermal cell differentiation. Metabolome analysis revealed 72 and 107 differentially expressed metabolites (DEMs) under T500 and T2000, respectively, and 36 co-DEMs. KEGG analysis of the DEMs and DEGs revealed a common metabolic pathway, namely, flavonoid biosynthesis. An association study between the flavonoid biosynthesis-related DEMs and DEGs revealed 20 genes associated with flavonoid-related metabolites, including 3 for genistin and 17 for calycosin.

CONCLUSION

In summary, the study reveals that flavonoid metabolism plays an important role in response to Pb stress in maize, which not only provides genetic resources for the genetic improvement of maize Pb tolerance in the future but also enriches the theoretical basis of the maize Pb stress response.

Intestinal toxicity of Pb: Structural and functional damages, effects on distal organs and preventive strategies

Lead (Pb) is one of the most common heavy metal pollutants that possesses multi-organ toxicity. For decades, great efforts have been devoted to investigate the damage of Pb to kidney, liver, bone, blood cells and the central nervous system (CNS). For the common, dietary exposure is the main avenue of Pb, but our knowledge of Pb toxicity in gastrointestinal tract (GIT) remains quite insufficient. Importantly, emerging evidence has documented that gastrointestinal disorders affect other distal organs like brain and liver though gut-brain axis or gut-liver axis, respectively. This review focuses on the recent understanding of intestinal toxicity of Pb exposure, including structural and functional damages. We also review the influence and mechanism of intestinal toxicity on other distal organs, mainly concentrated on brain and liver. At last, we summarize the bioactive substances that reported to alleviate Pb toxicity, providing potential dietary intervention strategies to prevent or attenuate Pb toxicity.

Environmental BaP/BPDE suppressed trophoblast cell invasion/migration and induced miscarriage by down-regulating lnc-HZ01/MEST/VIM axis

Environmental benzo(a)pyrene (BaP) and itsmetabolite benzo(a)pyrene-7, 8-dihydrodiol-9, 10-epoxide (BPDE), classic endocrine disrupting chemical and persistent organic pollutant, could cause miscarriage. However, the detailed mechanisms are still largely unclear and should be further explored. In this study, we discovered that exposure of trophoblast cells with BPDE could suppressed cell invasion/migration by inhibiting MEST/VIM (Vimentin) pathway. Moreover, BPDE exposure also increased lnc-HZ01 expression level, which further inhibited MEST/VIM pathway and then suppressed invasion/migration. Knockdown of lnc-HZ01 or overexpression of MEST could efficiently rescue invasion/migration of BPDE-exposed Swan 71 cells. Furthermore, lnc-HZ01 was highly expressed and MEST/VIM were lowly expressed in recurrent miscarriage (RM) villous tissues compared with healthy control (HC) group. Finally, we also found that BaP exposure inhibited murine Mest/Vim pathway in placental tissues and induced miscarriage in BaP-exposed mice. Therefore, the regulatory mechanisms were similar in BPDE-exposed human trophoblast cells, RM villous tissues, and placental tissues of BaP-exposed mice with miscarriage, building a bridge to connect BaP/BPDE exposure, invasion/migration, and miscarriage. This study provided novel insights in the toxicological effects and molecular mechanisms of BaP/BPDE-induced miscarriage, which is helpful for better elucidating the toxicological risks of BaP/BPDE on female reproduction.

Green, Low-carbon Silk-based Materials in Water Treatment: Current State and Future Trends

The improper and inadequate treatment of industrial, agricultural, and household wastewater exerts substantial pressure on the existing ecosystem and poses a serious threat to the health of both humans and animals. To address these issues, different types of materials have been employed to eradicate detrimental pollutants from wastewater and facilitate the reuse of water resources. Nevertheless, owing to the challenges associated with the degradation of these traditional materials post-use and their incompatibility with the environment, natural biopolymers have garnered considerable interest. Silk protein, as a biomacromolecule, exhibits advantageous characteristics including environmental friendliness, low carbon emissions, biodegradability, sustainability, and biocompatibility. Considering recent research findings, this comprehensive review outlines the structure and properties of silk proteins and offers a detailed overview of the manufacturing techniques employed in the production of silk-based materials (SBMs) spanning different forms. Furthermore, it conducts an in-depth analysis of the state-of-the-art SBMs for water treatment purposes, encompassing adsorption, catalysis, water disinfection, desalination, and biosensing. The review highlights the potential of SBMs in addressing the challenges of wastewater treatment and provides valuable insights into prospective avenues for further research.

Occupational carcinogens in Italy: an overview on exposure to cadmium and its compounds

Given the recognized carcinogenicity of cadmium, several regulatory interventions have been carried out over the years to protect exposed workers. The aim of the study is to investigate the prevalence and extent of exposure to cadmium among Italian workers. Data was collected from a nation-wide occupational exposure registry (SIREP, 1996-2022). Gender-specific statistical analysis was carried out for some exposure-related variables (cadmium compound, activity sector, occupational group, firm size). Potentially exposed workers were estimated for some industrial sectors. Concurrent exposures were investigated using cluster analysis. Overall 4,264 measurements were analyzed. Four industrial sectors were found to be most involved by cadmium exposure: base metal manufacturing, fabricated metal products, machinery and equipment, and other transport equipment (55% of measurements). Jewellery/precious-metal workers, and glass/ceramic plant operators were found to be most at exposure risk. A total of 26,470 workers potentially exposed was estimated (69% men). Concurrent exposures to other occupational carcinogens were detected quite frequently (52% of workers). Several situations of exposure and co-exposure to cadmium deserve attention and awareness in order to minimize the risks associated with workers' health. Recognition of potentially hazardous exposure conditions is an important step in prevention strategies to better protect workers against cancer-causing agents.

Associations between co‑exposure to heavy metals and vertebral compression fracture, as well as femoral neck bone mineral density: A cross-sectional study from NHANES data

OBJECTIVE

Accumulating evidence showed that exposure to heavy metals was harmful to human health. Little is known regarding the mixing effects of multiple metal exposures on vertebral compression fracture (VCF) and femoral neck bone mineral density (BMD). This study aimed to explore the individual and joint effects of four heavy metals [manganese (Mn), lead (Pb), cadmium (Cd) and mercury (Hg)] on VCF risk and femoral neck BMD.

METHODS

This cross-sectional study included 1,007 eligible individuals with vertebral fractures from National Health and Nutrition Examination Survey 2013-2014. The outcome was the risk of VCF and femoral neck BMD. Weighted multivariate logistic regression was used to explore the individual effect of four heavy metals on the VCF risk, separately. Weighted multivariate linear regression was used to explore the individual effect of four heavy metals on the femoral neck BMD, separately. Adopted bayesian kernel machine regression (BKMR) model and quantile-based g computation (qgcomp) to examine the joint effects of four heavy metals on the VCF risk and femoral neck BMD.

RESULTS

Among the population, 57 individuals developed VCF. After adjusting covariates, we found no statistical differences regarding the individual effects of four heavy metals on the risk of VCF. BKMR model and qgcomp indicated that there were no statistical differences regarding the joint effects between four heavy metals on the VCF risk. In addition, we found that Cd was associated with femoral neck BMD, and an increase in the mixture of heavy metal exposures was associated with a decreased risk of femoral neck BMD.

CONCLUSION

No significant correlation was observed between co-exposure to Mn, Pb, Cd and Hg and VCF risk. But co-exposure to Mn, Pb, Cd and Hg may be associated with femoral neck BMD.

Exposure to heavy metallic and trace essential elements and risk of diminished ovarian reserve in reproductive age women: A case-control study

The associations between metallic elements and ovarian reserve function have remained uncertain yet. In this case-control study, we involved 149 women with diminished ovarian reserve (DOR) and 151 women with normal ovarian reserve, and assessed the levels of six heavy metallic (Cr, Cd, As, Hg, Pb, and Mn) and seven trace essential (Se, Fe, Zn, Co, Mo, Cu, I) elements in their follicular fluid with inductively coupled plasma mass spectrometry. Associations were examined with logistic regressions and Bayesian kernel machine regression (BKMR). As a result, we found that the medium and the highest tertiles of Pb were significantly associated with an increased likelihood of DOR compared to the lowest tertile, while the medium or/an the highest tertiles of Cu, I, and Fe showed significantly lower likelihoods of DOR compared to the lowest tertiles. Cu and Pb showed significantly non-linear associations with ovarian reserve markers such as follicle-stimulating, anti-mullerian hormone levels, and antral follicle count. With the rising overall concentrations of heavy metals, the likelihood of DOR increased although not significant. There was a trend of a "U-shaped" association across the whole concentration range of trace essential elements and the likelihood of DOR. Our study revealed that avoiding heavy metallic elements and properly supplementing trace essential elements are conducive to ovarian function.

Association between Prenatal Dietary Toxicants and Infant Neurodevelopment: The Role of Fish

More research is needed to understand how the maternal consumption of fish and fish-borne toxicants impacts infant neurodevelopment. The present analysis was conducted over 460 mother-infant pairs within the ECLIPSES study. Dietary intake of metals and persistent organic pollutants from fish (including white fish, blue fish, and seafood) was estimated in pregnant women. The infants underwent cognitive, language, and motor function assessments using the Bayley Scales of Infant Development-III at the 40-day postpartum. Associations between dietary toxicants and outcomes were assessed using multivariable linear regression models. Estimated prenatal exposure to fish-borne toxicants, such as arsenic, inorganic arsenic, methylmercury, dioxin-like polychlorinated biphenyls (DL-PCBs), and non-DL-PCBs, was associated with poorer language functions in infants, whereas no significant associations were found with motor or cognitive functions. Maternal fish consumption exceeding the Spanish recommendation of no more than 71 g per day was linked to these adverse effects on language abilities without affecting motor or cognitive development. This highlights the importance of vigilant monitoring of environmental toxicants and the provision of dietary guidance for pregnant women, with potential implications for public health and child development.

Research advances on production and application of algal biochar in environmental remediation

Algae, comprising microalgae and macroalgae, have emerged as a promising feedstock for the production of functional biochar. Recently, the application of algal biochar in environmental remediation gains increasing attention. This review summarizes research advancements in the synthesis and application of algal biochar, a versatile and sustainable material for environmental remediation ranging from wastewater treatment to soil improvement. Algal biochar can be prepared by pyrolysis, microwave-assisted pyrolysis, and hydrothermal carbonization. Physical and chemical modifications have proven to be effective for improving biochar properties. Algal biochar is promising for removing diverse pollutants including heavy metals, organic pollutants, and microplastics. The role in soil improvement signifies a sustainable approach to enhancing soil structure, nutrient retention, and microbial activity. Research gaps are identified based on current understanding, necessitating further exploration into variations in biochar characteristics, the performance improvement, large-scale applications, and the long-term evaluation for environmental application. This review provides a better understanding of algal biochar as a sustainable and effective tool in environmental remediation.

Anemia in Pregnancy With CKD

Chronic kidney disease (CKD), anemia, and iron deficiency are global health issues affecting individuals in both high-income and low-income countries. In pregnancy, both CKD and iron deficiency anemia increase the risk of adverse maternal and neonatal outcomes, including increased maternal morbidity and mortality, stillbirth, perinatal death, preterm birth, and low birthweight. However, it is unknown to which extent iron deficiency anemia contributes to adverse outcomes in CKD pregnancy. Furthermore, little is known regarding the prevalence, pathophysiology, and treatment of iron deficiency and anemia in pregnant women with CKD. Therefore, there are many unanswered questions regarding optimal management with oral or i.v. iron and recombinant human erythropoietin (rhEPO) in these women. In this review, we present a short overview of the (patho)physiology of anemia in healthy pregnancy and in people living with CKD. We present an evaluation of the literature on iron deficiency, anemia, and nutritional deficits in pregnant women with CKD; and we evaluate current knowledge gaps. Finally, we propose research priorities regarding anemia in pregnant women with CKD.

Ascertaining sensitive exposure biomarkers of various metal(loid)s to embryo implantation

Close relationships exist between metal(loid)s exposure and embryo implantation failure (EIF) from animal and epidemiological studies. However, there are still inconsistent results and lacking of sensitive metal(loid) exposure biomarkers associated with EIF risk. We aimed to ascertain sensitive metal(loid) biomarkers to EIF and provide potential biological explanations. Candidate metal(loid) biomarkers were measured in the female hair (FH), female serum (FS), and follicular fluid (FF) with various exposure time periods. An analytical framework was established by integrating epidemiological association results, comprehensive literature searching, and knowledge-based adverse outcome pathway (AOP) networks. The sensitive biomarkers of metal(loid)s along with potential biological pathways to EIF were identified in this framework. Among the concerned 272 candidates, 45 metal(loid)s biomarkers across six time periods and three biomatrix were initially identified by single-metal(loid) analyses. Two biomarkers with counterfactual results according to literature summary results were excluded, and a total of five biomarkers were further determined from 43 remained candidates in mixture models. Finally, four sensitive metal(loid) biomarkers were eventually assessed by overlapping AOP networks information, including Se and Co in FH, and Fe and Zn in FS. AOP networks also identified key GO pathways and proteins involved in regulation of oxygen species biosynthetic, cell proliferation, and inflammatory response. Partial dependence results revealed Fe in FS and Co in FH at their low levels might be potential sensitive exposure levels for EIF. Our study provided a typical framework to screen the crucial metal(loid) biomarkers and ascertain that Se and Co in FH, and Fe and Zn in FS played an important role in embryo implantation.

Assessment of potentially toxic and mineral elements in paddy soils and their uptake by rice (Oryza sativa L.) with associated health hazards in district Malakand, Pakistan

Rice, a primary food source in many countries of the world accumulate potentially harmful elements which pose a significant health hazard to consumers. The current study aimed to evaluate potentially toxic and mineral elements in both paddy soils and rice grains associated with allied health risks in Malakand, Pakistan. Rice plants with intact root soil were randomly collected from paddy fields and analyzed for mineral and potentially toxic elements (PTEs) through inductively coupled plasma optical emission spectrometry (ICP‒OES). Through deterministic and probabilistic risk assessment models, the daily intake of PTEs with allied health risks from consumption of rice were estimated for children and adults. The results of soil pH (< 8.5) and electrical conductivity (EC > 400 μs/cm), indicated slightly saline nature. The mean phosphorus concentration of 291.50 (mg/kg) in soil samples exceeded FAO/WHO permissible limits. The normalized variation matrix of soil pH with respect to Ni (0.05), Ca (0.05), EC (0.08), and Mg (0.09), indicated significant influence of pH on PTEs mobility. In rice grains, the mean concentrations (mg/kg) of Mg (463.81), Al (70.40), As (1.23), Cr (12.53), Cu (36.07), Fe (144.32), Mn (13.89), and Ni (1.60) exceeded FAO/WHO safety limits. The transfer factor >1 for K, Cu, P and Zn indicated bioavailability and transfer of these elements from soil to rice grains. Monte Carlo simulations of hazard index >1 for Cr, Zn, As, and Cu with certainties of 89.93% and 90.17%, indicated significant noncarcinogenic risks for children and adults from rice consumption. The total carcinogenic risk (TCR) for adults and children exceeded the USEPA acceptable limits of 1×10-6 to 1×10-4, respectively. The sensitivity analysis showed that the ingestion rate was a key risk factor. Arsenic (As) primarily influenced total cancer risk (TCR) in children, while chromium (Cr) significantly impacted adults. Deterministic cancer risk values slightly exceeded probabilistic values due to inherent uncertainties in deterministic analysis. Rice consumption poses health risks, mainly from exposure to Cr, Ni and As in the investigated area.

Association and mediation analyses among multiple metal exposure, mineralocorticoid levels, and serum ion balance in residents of northwest China

Toxic metals are vital risk factors affecting serum ion balance; however, the effect of their co-exposure on serum ions and the underlying mechanism remain unclear. We assessed the correlations of single metal and mixed metals with serum ion levels, and the mediating effects of mineralocorticoids by investigating toxic metal concentrations in the blood, as well as the levels of representative mineralocorticoids, such as deoxycorticosterone (DOC), and serum ions in 471 participants from the Dongdagou-Xinglong cohort. In the single-exposure model, sodium and chloride levels were positively correlated with arsenic, selenium, cadmium, and lead levels and negatively correlated with zinc levels, whereas potassium and iron levels and the anion gap were positively correlated with zinc levels and negatively correlated with selenium, cadmium and lead levels (all P < 0.05). Similar results were obtained in the mixed exposure models considering all metals, and the major contributions of cadmium, lead, arsenic, and selenium were highlighted. Significant dose-response relationships were detected between levels of serum DOC and toxic metals and serum ions. Mediation analysis showed that serum DOC partially mediated the relationship of metals (especially mixed metals) with serum iron and anion gap by 8.3% and 8.6%, respectively. These findings suggest that single and mixed metal exposure interferes with the homeostasis of serum mineralocorticoids, which is also related to altered serum ion levels. Furthermore, serum DOC may remarkably affect toxic metal-related serum ion disturbances, providing clues for further study of health risks associated with these toxic metals.

Association between exposure to multiple metals and stress urinary incontinence in women: a mixture approach

There is limited evidence linking exposure to heavy metals, especially mixed metals, to stress urinary incontinence (SUI). This study aimed to explore the relationship between multiple metals exposure and SUI in women. The data were derived from the National Health and Nutrition Examination Survey (NHANES), 2007-2020. In the study, a total of 13 metals were analyzed in blood and urine. In addition, 5155 adult women were included, of whom 2123 (41.2%) suffered from SUI. The logistic regression model and restricted cubic spline (RCS) were conducted to assess the association of single metal exposure with SUI risk. The Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) were used to estimate the combined effect of multiple metals exposure on SUI. First, we observed that blood Pb, Hg and urinary Pb, Cd were positively related to SUI risk, whereas urinary W was inversely related by multivariate logistic regression (all p-FDR < 0.05). Additionally, a significant non-linear relationship between blood Hg and SUI risk was observed by RCS analysis. In the co-exposure models, WQS model showed that exposure to metal mixtures in blood [OR (95%CI) = 1.18 (1.06, 1.31)] and urine [OR (95%CI) = 1.18 (1.03, 1.34)] was positively associated with SUI risk, which was consistent with the results of BKMR model. A potential interaction was identified between Hg and Cd in urine. Hg and Cd were the main contributors to the combined effects. In summary, our study indicates that exposure to heavy metal mixtures may increase SUI risk in women.

Toxoplasma gondii infection and testosterone alteration: A systematic review and meta-analyses

BACKGROUND

Toxoplasma gondii (T. gondii) is a worldwide distributed protozoan parasite which has infected a wide range of warm-blooded animals and humans. The most common form of T. gondii infection is asymptomatic (latent); nevertheless, latent toxoplasmosis can induce various alterations of sex hormones, especially testosterone, in infected humans and animals. On the other hand, testosterone is involved in behavioral traits and reproductive functions in both sexes. Hence, the purpose of this systematic review is to summarize the available evidence regarding the association between T. gondii infection and testosterone alteration.

METHODS

In the setting of a systematic review, an electronic search (any date to 10 January 2023) without language restrictions was performed using Science Direct, Web of Science, PubMed, Scopus, and Google Scholar. The PRISMA guidelines were followed. Following the initial search, a total of 12,306 titles and abstracts were screened initially; 12,281 were excluded due to the lack of eligibility criteria or duplication. Finally, 24 articles met the included criteria. A mean±standard deviation (SD) was calculated to assess the difference of testosterone between T. gondii positive and T. gondii negative humans. The possibility of publication bias was assessed using Egger's regression. P-value < 0.05 was considered statistically significant.

RESULTS

This systematic review identified 24 articles (18 studies in humans and six studies in animals). Most human studies (13 out of 19) reported an increased level of testosterone following latent toxoplasmosis in males, while three studies reported decreased levels and two studies reported an insignificant change. Eleven articles (seven datasets in males and seven datasets in females) were eligible to be included in the data synthesis. Based on the random-effects model, the pooled mean± SD of testosterone in T. gondii positive than T. gondii negative was increased by 0.73 and 0.55 units in males and females, respectively. The Egger's regression did not detect a statistically significant publication bias in males and females (p = value = 0.95 and 0.71), respectively. Three studies in male animals (rats, mice, and spotted hyenas) and two studies in female animals (mice and spotted hyenas) reported a decline in testosterone in infected compared with non-infected animals. While, one study in female rats reported no significant changes of testosterone in infected than non-infected animals. Moreover, two studies in male rats reported an increased level of testosterone in infected than non-infected animals.

CONCLUSIONS

This study provides new insights about the association between T. gondii infection and testosterone alteration and identifies relevant data gaps that can inform and encourage further studies. The consequence of increased testosterone levels following T. gondii infection could partly be associated with increased sexual behavior and sexual transmission of the parasite. On the other hand, declining testosterone levels following T. gondii infection may be associated with male reproductive impairments, which were observed in T. gondii-infected humans and animals. Furthermore, these findings suggest the great need for more epidemiological and experimental investigations in depth to understand the relationship between T. gondii infection and testosterone alteration alongside with future consequences of testosterone alteration.