Occupational Exposure Associated with Reproductive Dysfunction

Maternal occupational exposure to asthmogenic during pregnancy and the future risk of asthma in children: A meta-analysis

The association between maternal occupational exposure during pregnancy and the subsequent development of asthma in their children has always been a matter of debate, and the results of cohort studies on this issue have been controversial. The current study is the first systematic review and meta-analysis aimed at evaluating the risk of developing subsequent asthma in children based on maternal occupational exposure during the gestation period. To retrieve eligible studies, an advanced literature search was performed up to August 10, 2023 from the following databases: PubMed, Scopus, and Google Scholars. The title and abstract of related articles were screened; hence, the full texts were reviewed. Data extraction was conducted; hence, the included articles were analyzed to assess the mention association. From a total of 10 cohort studies with a total record of 5372, it was found that there is no significant relationship between occupational exposure to asthmogenic during pregnancy and later asthma in children. The pooled odds ratio of asthmatic children in patients with maternal occupational exposure to asthmogenic during pregnancy was 1.03 (95% confidence interval, 0.97-1.09) I2= 13% p=0.62. It was concluded that there is no significant association between maternal occupational exposure and future asthma in children. However, future large-scale studies are required to support these results.

Prediction of pregnancy disorders in female workers in the industrial sector

Context

As female workers face a higher risk of exposure to workplace hazards than women in general, it is imperative that measures be put in place in the workplace to ensure safe and healthy pregnancies.

Objectives

This study aimed to analyze the effects of occupational hazards in the workplace environment on the potential for pregnancy disorders experienced by female workers.

Methods

This was an analytical, observational study with a case-control design. The participants were female workers who worked in industrial environments in both formal and nonformal industries. The inclusion criteria used in this study were female workers who had been or were pregnant at the time of the study, had worked in the industrial sector for at least one year, and did not smoke or consume alcohol. The samples were collected from 144 female workers. Midwives assisted in collecting data and conducting examinations of female workers. This study was conducted in Surabaya and Sidoarjo between June and December 2020. Data were analyzed descriptively, and a multivariable logistic regression test was performed. The study was conducted in accordance with the health protocols and prevention of COVID-19.

Results

The results showed that occupational hazards in the workplace environment that affect pregnancy disorders include workload (p = 0.004, OR = 28.676 (2.979-276.076); hot working environment (p = 0.014, OR = 3.077 (1.254-7.552); strong odors (p = 0.017, OR = 7.640 (1.436-40.656); shift work (p = 0.023, OR = 8.063 (1.337-48.623); irregular shift work (p = 0.018, OR = 7.371 (1.409-38.557); and night shift work (p = 0.015, OR = 11.780 (1.605-86.450).

Conclusions

Companies are expected to pay special attention to female workers regarding various workplace controls to prevent potential pregnancy-related disorders.

Elevated Levels of Gonadotrophic Hormones and Antioxidant Biomarker in Male Rats Following Administration of Hydromethanol Leaf Extract of Justicia secunda in Response to 2,4-Dinitrophenylhydrazine Induction

Background

2,4-Dinitrophenylhydrazine induces testicular toxicity and can result in reproductive dysfunction in male rats.

Aim

This study investigated the effects of hydromethanolic leaf extract of Justicia secunda on phenylhydrazine (PHZ)-induced reproductive dysfunction in male Wistar rats.

Settings and Design

Twenty rats (90-170 g) were grouped into five (A-E) (n = 4) with the approval of the research ethics committee.

Materials and Methods

Group A (control) received 0.5 mL of normal saline, Groups B to E received PHZ, PHZ + Astymin (0.5 mL), PHZ + J. secunda (0.2 mg/kg) and PHZ + J. secunda (0.5 mg/kg), respectively. All animals in Groups B to E received 2 mg/kg PHZ intraperitoneally for 2 days, and thereafter, administration of Astymin and J. secunda commenced in Groups C, D and E for 14 days using gavage.

Statistical Analysis Used

The data were analysed using a one-way analysis of variance and the Bonferroni post hoc test.

Results

Follicle-stimulating hormone (FSH) decreased significantly in PHZ, PHZ + Astymin and PHZ + J. secunda (0.2 mg/kg) and increased significantly in PHZ + J. secunda (0.5 mg/kg) than control. Luteinising hormone (LH) and testosterone significantly (P < 0.001) reduced in treated groups than control. Total cholesterol, triglyceride, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol and very-low-density lipoprotein-cholesterol were significantly reduced in the treated groups than the control. Tumour necrosis factor alpha (TNF-α) significantly (P < 0.001) increased in treated groups than in control. Testicular glutathione (GSH), glutathione peroxidase, catalase and malondialdehyde significantly increased in extract-treated groups compared to control. Superoxide dismutase significantly decreased in PHZ-treated group than in the control.

Conclusion

PHZ administration caused testicular toxicity and altered biochemical markers, astymin treatment reduced male reproductive hormones, while J. secunda (0.5 mg/kg) increased FSH and LH, decreased TNFα levels and altered the concentration of testicular antioxidant markers. These alterations may be linked to the toxic effect of PHZ and could negatively affect spermatogenesis.

Exposure risk to rural Residents: Insights into particulate and gas phase pesticides in the Indoor-Outdoor nexus

Rural residents are exposed to both particulate and gaseous pesticides in the indoor-outdoor nexus in their daily routine. However, previous personal exposure assessment mostly focuses on single aspects of the exposure, such as indoor or gaseous exposure, leading to severe cognition bias to evaluate the exposure risks. In this study, residential dust and silicone wristbands (including stationary and personal wearing ones) were used to screen pesticides in different phases and unfold the hidden characteristics of personal exposure via indoor-outdoor nexus in intensive agricultural area. Mento-Carlo Simulation was performed to assess the probabilistic exposure risk by transforming adsorbed pesticides from wristbands into air concentration, which explores a new approach to integrate particulate (dust) and gaseous (silicone wristbands) pesticide exposures in indoor and outdoor environment. The results showed that particulate pesticides were more concentrated in indoor, whereas significantly higher concentrations were detected in stationary outdoor wristbands (p < 0.05). Carbendazim and chlorpyrifos were the most frequently detected pesticides in dust and stationary wristbands. Higher pesticide concentration was found in personal wristbands worn by farmers, with the maximum value of 2048 ng g-1 for difenoconazole. Based on the probabilistic risk assessment, around 7.1 % of farmers and 2.6 % of bystanders in local populations were potentially suffering from chronic health issues. One third of pesticide exposures originated mainly from occupational sources while the rest derived from remoting dissipation. Unexpectedly, 43 % of bystanders suffered the same levels of exposure as farmers under the co-existence of occupational and non-occupational exposures. Differed compositions of pesticides were found between environmental samples and personal pesticide exposure patterns, highlighting the need for holistic personal exposure measurements.

Occupational Exposure to Physical and Chemical Risk Factors: A Systematic Review of Reproductive Pathophysiological Effects in Women and Men

The human reproductive system can be affected by occupational exposure to many physical and chemical risk factors. This study was carried out to review the studies conducted on the issue of the pathophysiological effects of occupational physical and chemical risk factors on the reproductive system of females and males. In this systematic review, the databases such as "Google Scholar," "Pub-Med," "Scopus," and "Web of Science" were used. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA 2020), the studies included in our study were published between 2000 and 2021. In order to extract the required data, all sections of the articles were reviewed. Out of 57 articles we reviewed, 34 articles were related to field studies and 23 articles to clinical studies. Among them, 43 studies dealt with the pathophysiological effects of chemical agents, six studies dealt with the pathophysiological effects of physical factors, and 8 studies dealt with the pathophysiological effects of physicochemical factors on the human reproductive system. Physical (noise, heat, and radiofrequency radiation) and chemical (such as carbamate and organophosphate pesticides, benzene, toluene, xylene, formaldehyde, NO₂, CS₂, manganese, lead, nickel, and n-hexane) risk factors had pathophysiological effects on the human reproductive system. The presence of these risk factors in the workplace caused damage to the human reproductive system. The rate of these negative pathophysiological effects can be reduced by performing appropriate managerial, technical, and engineering measures in work environments.

Toxic and carcinogenic effects of hexavalent chromium in mammalian cells in vivo and in vitro: a recent update

Chromium VI (Cr (VI)) can cross cell membranes readily and causes the formation of Cr-DNA adducts, genomic damages, elevation of reactive oxygen species (ROS) and alteration of survival signaling pathways, as evidenced by the modulation in p53 signaling pathway. Mammals, including humans are exposed to Cr, including Cr (VI), frequently through inhalation, drinking water, and food. Several studies demonstrated that Cr (VI) induces cellular death through apoptosis and autophagy, genotoxicity, functional alteration of mitochondria, endocrine and reproductive impairments. In the present review, studies on deleterious effects of Cr (VI) exposure to mammalian cells (in vivo and in vitro) have been documented. Special attention is paid to the underlying molecular mechanism of Cr (VI) toxicity.

Interactive effect of carbendazim and imidacloprid on buffalo bone marrow derived mesenchymal stem cells: oxidative stress, cytotoxicity and genotoxicity

The effect of a combination of two pesticides, carbendazim (CBZ) and imidacloprid (IMI), was investigated on mesenchymal stem cells derived from the bone marrow of buffalo (bMSCs). The bMSCs were exposed to the CBZ (2.25 µM, 4.49 µM, and 8.98 µM) and IMI (0.81 mM, 1.61 mM, and 3.22 mM) alone as well as in combinations. The bMSCs were found to be positive for the stem cell markers, AP, CD73, and OCT4. The bMSCs showed a significant reduction (p ≤ 0.05) in cell viability, and status of anti-oxidants while a significant increase (p ≤ 0.05) in the level of LDH, ALP, and CK-MB in CBZ and IMI-treated groups. A significant increase (p ≤ 0.05) was noticed in LPO, O^2─ radical, total ROS, loss of ΔΨm, apoptotic index, and DNA damage in CBZ and IMI-treated groups. A low-dose combination group showed an elevated effect compared to the groups treated with the single pesticide. The interaction index was calculated for CBZ-IMI combined treatment groups on various parameters that showed the majority of antagonist effects. Present findings confirmed that CBZ and IMI-induced cytotoxicity in bMSCs was mediated via ROS production, altered ΔΨm and LPO along with depressed antioxidant status which was responsible for cell apoptosis and cell damage. This study suggested that CBZ and IMI had a dose-dependent toxic effect when the pesticides were used alone, while, co-exposure to both the pesticides simultaneously had an antagonist or non-additive effect on buffalo bMSCs at lower dose combinations and they induced a potentiating effect at high-dose combination.

Seminal trace elements and their relationship with sperm parameters

Male reproductive problems may derive from many reasons including the environmental toxicants which may either intaken by occupational exposure, nutrition or bad air quality. The increased exposure to these substances due to rapid industrial development and technology has raised the questions: Is there a relationship between sperm parameters and these substances, and if so, in what extent? Results of studies on the subject reported conflicting results, many of which were not investigated in the seminal plasma. The aim of the current study was to evaluate the relationship between 23 metals and trace elements in human seminal plasma and semen parameters many of which were not investigated before. Levels of 23 metals in human seminal plasma were assessed by inductively coupled plasma mass spectrometry (ICP-MS). We examined the differences between subjects with normal ejaculate (normozoospermia) and pathologic ejaculate (with at least one abnormal semen parameter) according to the WHO criteria. The only significant difference was detected for Se while the other element's difference was not statistically significant. Se was statistically significantly increased in normal semen group suggesting the positive effect of this element on semen parameters.

Occupational Factors Affecting Women Workers’ Sexual and Reproductive Health Outcomes in Oil, Gas, and Mining Industry: A Scoping Review

Objectives: Globally, female workers workforce in Oil, Gas, and Mining (OGM) industry have increased significantly. The complexities of the OGM operations and the extensive exposure to workplace hazards potentially affect the health status of workers, including sexual and reproductive health (SRH) outcomes of female workers. Yet, the current state of knowledge on SRH issues in OGM contexts seems to be limited and fragmented. This scoping review aims to identify the occupational factors that influence women’s SRH outcomes in OGM industry.

Methods: This scoping review followed the Joanna Briggs Institute’s guidelines (PRISMA) and was conducted in five databases, including the citation chaining via Google Scholar and manual search through relevant organisations and Government websites. Sixteen articles met the inclusion criteria and were analysed.

Results: Despite the scarcity of evidence, chemical and physical are found to be the predominant factors greatly influencing women workers’ SRH outcomes in OGM. Most studies showed menstrual and cycle disorders, and risky pregnancy as key SRH issues. However, menstruation disorder was considerably linked with psychological and organisational factors.

Conclusion: This review suggests further empirical research on the relationship between OGM occupational hazards and women workers’ SRH. This will contribute to improvements in workplace safety legislations, measures, policies, and management systems taking into account women’s needs.

The Preliminary Chronic Effects of Electromagnetic Radiation from Mobile Phones on Heart Rate Variability, Cardiac Function, Blood Profiles, and Semen Quality in Healthy Dogs

The present study aims to determine the effects of long-term exposure to electromagnetic radiation from mobile phones (MPs) on heart rate variability (HRV), cardiac function, blood profiles, body surface temperature, and semen quality in healthy dogs. Eight male dogs were exposed to MPs (1962–1966 MHz; specific absorption rate 0.96 W/kg) for 2 h/day, 5 days/week, for 10 weeks. Holter monitoring for HRV analysis was performed at baseline (BL) and every 2 weeks, until the end of the study. Electrocardiograms (ECG), blood pressure (BP), echocardiography, cardiac troponin I (cTnI), hematology and biochemistry profiles, body surface temperature, and semen quality were evaluated at BL, week 5, and week 10 during exposure. The results showed that most of the HRV parameters did not significantly differ among timepoints, except for the mean of an interval between continuous normal R waves in week 6 that was higher than that at BL (p = 0.022). The RR and QT intervals from ECG in week 5 were prolonged, compared to the BL values (p = 0.001 and p = 0.003, respectively), but those parameters were within the normal limits. The echocardiography, BP, cTnI concentrations, body surface temperature, and semen quality results were not different from BL values. In conclusion, this study found no evidence suggesting an adverse effect of cell phone exposure on HRV, cardiac function, blood profiles, body surface temperature, or semen quality in healthy dogs, when exposed for 10 weeks.

Assessment of reproductive toxicity of carbofuran and copper sulfate in male Nile tilapia (Oreochromis niloticus)

This study's hypothesis is that carbofuran and copper sulfate have a synergistic harmful impact on the fertility of male Nile tilapia. Hence, this study was designed to assess the toxic reproductive outcome of carbofuran, copper sulfate, and their mixture in male Nile tilapia. Sixty male Nile tilapia fishes were separated into four groups (15 fish/group). The control group; carbofuran group, was given dechlorinated tap water containing 0.02 mg/L (1/10 dose of LC50) carbofuran; copper group was given dechlorinated tap water containing 4.0 mg/L (1/10 dose of LC50) copper sulfate; carbofuran + copper sulfate group received dechlorinated tap water containing 0.02 mg/L carbofuran plus 4.0 mg/L copper sulfate. After 6 weeks, results revealed a significant rise in testicular malondialdehyde levels and a significant decrease in testicular reduced glutathione contents among all experimental groups compared to the control group. Testicular testosterone levels were significantly declined in copper and combined groups compared to the control. The seminal evaluation using computer-assisted sperm analysis showed a significant decline in the progressive motility percentage, motile ratio percentage, sperm concentration, curvilinear velocity, straight-line velocity, average path velocity, and wobble in all intoxicated groups, particularly, the combined group. The histopathology of testes in all intoxicated groups revealed a detachment of the basal membrane of some seminiferous tubules, and others were free from spermatogonia and spermatozoa with interstitial eosinophilic granular cell infiltration. Testicular lesions were more severe in the combined group. Finally, it was concluded that carbofuran and copper sulfate exerted a negative effect on the reproductive function of male Nile tilapia, and they have a synergistic harmful impact on the fertility of male Nile tilapia.

Effects of Organochlorine Pesticide Residues in Maternal Body on Infants

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

Do inequalities exist in housing and working conditions among local and migrant industrial workers in Vietnam? Results from a multi-site survey

BACKGROUND

While internal migrants in Vietnam have been a key driving force in the country's rapid economic development, they also face many vulnerabilities. Our study seeks to explore possible inequalities in housing and working conditions between local and internal migrant industrial workers in Vietnam.

METHODS

Cross-sectional surveys were conducted with 1200 industrial workers in four regions of Vietnam. Dependent variables included housing conditions (satisfaction with convenience of accommodation, sanitation and water of accommodation, and accommodation in general) and working conditions (satisfaction with income, monthly income, number of hazardous working conditions, and work-related stress measured through the modified Effort-Reward Imbalance Questionnaire). The primary independent variable is migrant status. Covariates included region, gender, education, marital status, accommodation status, living arrangements, industry, age, monthly income, experience, and working hours.

RESULTS

Of the sample, 24.7% (n=296) were migrants. Overall, no differences were found regarding housing conditions by migrant status. In adjusted regression models, migrants reported higher numbers of hazardous working conditions (β=0.07, 95%CI=0.01-0.13, p=.01) and higher monthly income (β=0.05, 95%CI=0.01-0.09, p=.02).

DISCUSSION

Recent state-level changes in the Vietnamese household registration system may explain the lack of differences in housing conditions by migrant status. Future research should utilize longitudinal designs to examine impacts over time of state policy on migrants' housing conditions as well as well-being. Regarding working conditions, findings highlight the need for stronger social protection policy and better information channels on occupational health and safety for migrants. Further research, including qualitative studies, is needed to explore why migrants face more hazardous working conditions.

Impact of Heavy Metals on Human Male Fertility-An Overview

Heavy metals are endocrine disruptors which interfere with processes mediated by endogenous hormones of the organism, negatively affecting endocrine functions. Some studies have correlated heavy metal exposure with male infertility. However, the number of studies conducted on humans are limited. Therefore, the aim of this study is to summarize the current knowledge on how heavy metals influence human male fertility. Hence, three distinct databases were consulted—PubMed, Scopus and Web of Science—using single keywords and combinations of them. The total number of identified articles was 636. Nevertheless, by using the inclusion and exclusion criteria, 144 articles were finally included in this work. Results display that the development of adequate instruments for heavy metal assessment may play an important function in human male fertility diagnosis and treatment. Furthermore, clinical trials could be useful to confirm the role of heavy metals in human male fertility diagnosis. Overall, further research is required to fully understand the molecular and cellular basis of the influence of environmental and occupational exposure to heavy metals on human male infertility and reproductive outcomes.

Toxic elements in follicular fluid adversely influence the likelihood of pregnancy and live birth in women undergoing IVF

STUDY QUESTION

Are follicular fluid (FF), arsenic (As), mercury (Hg), cadmium (Cd) and lead (Pb) concentrations associated with IVF outcomes among women undergoing IVF?

SUMMARY ANSWER

There was a non-linear association between higher FF Hg concentration and a lower likelihood of biochemical pregnancy and live birth. Higher FF Pb concentration was also associated with a lower probability of live birth.

WHAT IS KNOWN ALREADY

Previous research suggests that toxic elements may affect fertility among couples conceiving with and without assistance. However, the results have been inconsistent, possibly related in part to exposure misclassification. Very few studies have used ovarian FF to measure toxic elements, as it requires an invasive collection procedure, yet it may offer a more accurate estimate of a biologically effective dose than blood or urine.

STUDY DESIGN SIZE DURATION

This is a prospective study of 56 women undergoing IVF, from October 2015 to June 2017. FF was collected for analysis on the day of oocyte retrieval.

PARTICIPANTS/MATERIALS SETTING METHODS

As, Cd, Hg and Pb were determined in 197 FF specimens, using inductively coupled plasma tandem mass spectrometry. FF glutathione peroxidase, glutathione reductase, total glutathione-S-transferase, superoxide dismutase, arylesterase and paraoxonase (PON1p) activities were measured using kinetic enzyme assays.

MAIN RESULTS AND THE ROLE OF CHANCE

Non-linear associations were detected, in which the probabilities of biochemical pregnancy (P = 0.05) and live birth (P = 0.05) were lower in association with FF Hg greater than ∼0.51 µg/l Hg, adjusted for age, race, cigarette smoking and recent seafood consumption. Higher FF Pb was also associated with a lower likelihood of live birth (relative risk (RR) = 0.68, 95% CI: 0.46, 1.00; P = 0.05). We also found a suggestive, although imprecise, antagonizing mediating effect of PON1p activity on the association between FF Pb and live birth (-28.3%; 95% CI: -358%, 270%).

LIMITATIONS REASONS FOR CAUTION

The results should be interpreted judiciously given the limited sample size and difficulty accounting for correlated data in generalized additive models and mediation analyses. Additionally, women undergoing IVF are highly selected with respect to age and socioeconomic status, and so the generalizability of the results may be limited.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, the results suggest that FF Hg was associated with a lower likelihood of biochemical pregnancy and live birth, with a potential threshold effect, and that higher FF Pb was associated with a lower probability of live birth. These results may help to guide clinical recommendations for limiting the exposure of patients to Hg and Pb and ultimately improve IVF success rates.

STUDY FUNDING/COMPETING INTERESTS

This work was funded in part by the National Institute of Environmental Health Sciences (NIEHS), grant number 1R56ES023886-01, to the University at Albany (M.S.B.), and in part by the National Institute of Environmental Health Sciences (NIEHS), grant number 1U2CES026542-01, to the Wadsworth Center (P.J.P.). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of work place pesticide concentration and health complaints among women workers in tea plantation, Southern India

BACKGROUND

Women contribute fifty percent of the total work force in tea plantation sector. The continuous use of chemical pesticides in plantation may increase the risk of exposure and can cause detrimental health effects.

OBJECTIVES

To assess the health status of women worker exposed to pesticides in tea plantation and to evaluate the pesticide levels in work environment.

METHODS

A cross sectional study was performed (n = 204) to assess the health complaints among exposed women workers (n = 116) and non-exposed women (n = 88) using a predesigned questionnaire. Work environmental air samples collected using PUF sampler and personal samplers were analyzed for various pesticides.

RESULTS

Musculoskeletal disorder, skin color changes, allergies and asthma were the most commonly reported health complaints. Notably, only 16% of the women used personal protective equipment (PPE) while 68% reported to have experienced tea plantation work up to 6 month of their pregnancy period. Chlorpyrifos methyl (8.3%), carbendazim (6.7%), thiamethoxam (4.2%), ethion (4.2%) and thiophanate methyl (2.1%) were detected in work place air samples.

SIGNIFICANCE

This study is the first to characterize pesticide levels in work place of women workers in India. Women are continuously exposed to pesticides through their work and environmental exposure. Preventive measures are essential to mitigate the adverse health effects of pesticides among women workers.

Prenatal exposure to hexavalent chromium disrupts testicular steroidogenic pathway in peripubertal F1 rats

We have reported sub-fertility in F1 progeny rats with gestational exposure to hexavalent chromium [Cr(VI)], which had disrupted Sertoli cell (SC) structure and function, and decreased testosterone (T). However, the underlying mechanism for reduced T remains to be understood. We tested the hypothesis "transient prenatal exposure to Cr(VI) affects testicular steroidogenesis by altering hormone receptors and steroidogenic enzyme proteins in Leydig cells (LCs)." Pregnant Wistar rats were given drinking water containing 50, 100, and 200 mg/L potassium dichromate during gestational days 9-14, encompassing fetal differentiation window of the testis from the bipotential gonad. F1 male rats were euthanized on postnatal day 60 (peripubertal rats with adult-type LCs alone). Results showed that prenatal exposure to Cr(VI): (i) increased accumulation of Cr(III) in the testis of F1 rats; (ii) increased serum levels of luteinizing and follicle stimulating hormones (LH and FSH), and 17β estradiol, and decreased prolactin and T; (iii) decreased steroidogenic acute regulatory protein, cytochrome P450 11A1, cytochrome P450 17A1, 3β- and 17β-hydroxysteroid dehydrogenases, cytochrome P450 aromatase and 5α reductase proteins, (iv) decreased specific activities of 3β and 17β hydroxysteroid dehydrogenases; (v) decreased receptors of LH, androgen and estrogen in LCs; (vi) decreased 5α reductase and receptor proteins of FSH, androgen, and estrogen in SCs. The current study concludes that prenatal exposure to Cr(VI) disrupts testicular steroidogenesis in F1 progeny by repressing hormone receptors and key proteins of the steroidogenic pathway in LCs and SCs.

Exploiting the Freshwater Shrimp Neocaridina denticulata as Aquatic Invertebrate Model to Evaluate Nontargeted Pesticide Induced Toxicity by Investigating Physiologic and Biochemical Parameters

As a nicotinoid neurotoxic insecticide, imidacloprid (IMI) works by disrupting nerve transmission via nicotinic acetylcholine receptor (nAChR). Although IMI is specifically targeting insects, nontarget animals such as the freshwater shrimp, Neocaridina denticulata, could also be affected, thus causing adverse effects on the aquatic environment. To investigate IMI toxicity on nontarget organisms like N. denticulata, their physiology (locomotor activity, heartbeat, and gill ventilation) and biochemical factors (oxidative stress, energy metabolism) after IMI exposure were examined. IMI exposure at various concentrations (0.03125, 0.0625, 0.125, 0.25, 0.5, and 1 ppm) to shrimp after 24, 48, 72 h led to dramatic reduction of locomotor activity even at low concentrations. Meanwhile, IMI exposure after 92 h caused reduced heartbeat and gill ventilation at high concentrations. Biochemical assays were performed to investigate oxidative stress and energy metabolism. Interestingly, locomotion immobilization and cardiac activity were rescued after acetylcholine administration. Through molecular docking, IMI demonstrated high binding affinity to nAChR. Thus, locomotor activity and heartbeat in shrimp after IMI exposure may be caused by nAChR blockade and not alterations caused by oxidative stress and energy metabolism. To summarize, N. denticulata serves as an excellent and sensitive aquatic invertebrate model to conduct pesticide toxicity assays that encompass physiologic and biochemical examinations.

DNA fragmentation of sperm in automobile painters

Reproductive health is a major concern for workers constantly exposed to chemicals at work, especially in developing countries. The problems mainly stemmed from chronic exposure to the chemicals contained in paint thinner, which is mainly toluene, used during automobile painting. Unfortunately, in Indonesia, there is no study on the reproductive health of male workers in automobile workshops, especially in relation to spermatogenesis. This study aimed to explore the possibility of reproductive problems, namely spermatozoa DNA fragmentation, among male workers in an automobile workshop in Malang. We recruited workers who have worked as automobile painters for years at an automobile workshop in Malang and have been chronically exposed to thinner. Semen samples were collected from 15 automobile workshop workers who were married and had children. Twelve office workers were used as the control group. The two groups of semen samples were tested with the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay combined with propidium iodide and analyzed by flow cytometry. The results showed a significant difference between DNA fragmentation of the control group and workshop workers at 14.9% and 47.66%, respectively. Risk factor analysis showed a significant increase in risk factors (p = 0.001). Taken together, chronic exposure to paint thinner in those engaged in painting at the automobile workshop increased the risk of DNA fragmentation in spermatozoa. Our study highlighted the importance of health education for the risked workers on minimization of exposure, which could be recommended to the health policy makers.

Long-term exposure to chromium contaminated waters and the associated human health risk in a highly contaminated industrialised region

Disposal of industrial waste is of great concern because it releases toxic metals resulting into the degradation of environments and consequently causes health effects on humans. The present study was carried out with the objectives of identifying the possible source and migration of contaminants in the surface water and groundwater and the associated health risks in the industrial region of Ranipet, Tamil Nadu, India. A total of 22 water samples were collected and analysed for the concentration of major ions and trace elements. Chemical speciation of chromium and lead in surface and groundwater was calculated using the geochemical code, PHREEQC. The concentration of total dissolved solids, chromium and lead was high in the surface water than groundwater in this region. The chromium in most of the sampled water is dominated with Cr(OH)²⁺ and Cr(OH)₃ species and the dominant species of lead was PbCO₃. The major source of contamination is the waste dumped in this region and also the improper disposal of effluents from the small-scale industries in this region. Use of groundwater with the present level of chromium and lead in this region will cause several health effects through oral and dermal pathways. Hence, stringent monitoring of quality of water sources of this region, enforcement of regulation of the disposal of wastes from the industries, recover and treat the dumped solid waste are very much necessary to prevent the spread of contamination.

Seafood consumption is associated with higher follicular fluid arsenic (As) and mercury (Hg) concentrations in women undergoing in vitro fertilization (IVF)

Human exposure to non-essential toxic metals such as cadmium (Cd), mercury (Hg), and lead (Pb), and metalloids such as arsenic (As) commonly occurs through diet. Toxic trace element exposures have been reported in association with fertility and fecundity in epidemiologic studies even at low to moderate levels. While most previous studies employed blood and urine biomarkers of exposure, few have assessed toxic trace elements in ovarian follicular fluid (FF), which surrounds the developing oocyte and hence may better reflect concentrations potentially affecting reproductive outcomes. Our objective was to identify dietary predictors of FF toxic trace elements in n = 56 women (mean age: 38.3 years) undergoing in vitro fertilization (IVF) at the University of California at San Francisco. We determined As, Hg, Cd, and Pb in 197 FF specimens, collected on the day of oocyte retrieval, using inductively coupled plasma tandem mass spectrometry. A comprehensive food frequency questionnaire was used to assess the weekly and annual dietary "patterns" of participants. Consumption of specific seafood items and turkey were correlated with individual FF toxic trace elements. We also found that each unit higher seafood consumption in the past week dominated by mollusks, shrimp, and bass was associated with 60% higher FF As (95% confidence interval (CI): 25%, 105%) and FF Hg (95%CI: 7%, 136%) concentrations. Higher annual seafood consumption dominated by urchin, crab, and trout was associated with 16% higher FF As (95%CI: -2%, 38%) and 31% higher FF Hg (95%CI: 7%, 60%) concentrations per unit intake. No associations were noted between diet and Cd and Pb levels in FF. Overall, our results suggest that higher seafood consumption contributes to elevated levels of As and Hg in FF. These findings are consistent with previous IVF studies that assessed toxic trace element exposures in blood and urine. To our knowledge, this is the first study to report that diet might be a source of As, Hg, Cd, and Pb in FF.

Congenital anomalies in the offspring of occupationally exposed mothers: a systematic review and meta-analysis of studies using expert assessment for occupational exposures

STUDY QUESTION

Is there an association between maternal occupational exposure to solvents, pesticides and metals as assessed by expert-based assessment and congenital anomalies in the offspring?

SUMMARY ANSWER

There is an association between maternal occupational exposure to solvents and congenital anomalies in the offspring, including neural tube defects, congenital heart defects and orofacial clefts.

WHAT IS KNOWN ALREADY

One important environmental risk factor for development of congenital anomalies is maternal occupational exposure to chemicals in the workplace prior to and during pregnancy. A number of studies have assessed the association with often conflicting results, possibly due to different occupational exposure assessing methods.

STUDY DESIGN, SIZE, DURATION

For this systematic review with meta-analysis, the search terms included maternal occupation, exposure, congenital anomalies and offspring. Electronic databases MEDLINE and EMBASE were searched for English studies up to October 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two reviewers independently screened all citations identified by the search. Case-control studies and cohort studies were included if (I) they reported on the association between maternal occupational exposure to solvents, pesticides or metals and congenital anomalies, and (II) assessment of occupational exposure was performed by experts. Data on study characteristics, confounders and odds ratios (ORs) were extracted from the included studies for four subgroups of congenital anomalies. Methodological quality was assessed using the Newcastle-Ottawa Scale. In the meta-analysis, random effects models were used to pool estimates.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 2806 titles and abstracts and 176 full text papers were screened. Finally, 28 studies met the selection criteria, and 27 studies could be included in the meta-analysis. Our meta-analysis showed that maternal occupational exposure to solvents was associated with neural tube defects (OR: 1.51, 95%CI: 1.09–2.09) and congenital heart defects (OR: 1.31, 95%CI:1.06–1.63) in the offspring. Also maternal occupational exposure to glycol ethers, a subgroup of solvents, was associated with neural tube defects (OR: 1.93, 95%CI: 1.17–3.18) and orofacial clefts (OR: 1.95, 95%CI: 1.38–2.75) in the offspring. Only one study investigated the association between maternal occupational exposure to solvents and hypospadias and found an association (OR: 3.63, 95%CI: 1.94–7.17). Results of the included studies were consistent. In our meta-analysis, we found no associations between occupational exposure to pesticides or metals and congenital anomalies in the offspring.

LIMITATIONS, REASONS FOR CAUTION

A limited number of studies was included, which made it impossible to calculate pooled estimates for all congenital anomalies, analyse individual chemicals or calculate exposure–response relations. Bias could have been introduced because not all included studies corrected for potentially confounding factors.

WIDER IMPLICATIONS OF THE FINDINGS

Employers and female employees should be aware of the possible teratogenic effects of solvent exposure at the workplace. Therefore, is it important that clinicians and occupational health specialist provide women with preconception advice on occupational solvent exposure, to reduce the congenital anomaly risk.

STUDY FUNDING/COMPETING INTEREST(S)

NSp was paid by the Graduate School of Medical Sciences (MD/PhD program), UMCG, Groningen, the Netherlands. EUROCAT Northern Netherlands is funded by the Dutch Ministry of Health, Welfare and Sports. There are no competing interests.

REGISTRATION NUMBER

CRD42017053943.

Oestrogenic Endocrine Disruptors in the Placenta and the Fetus

Endocrine disrupting chemicals (EDCs) are exogenous substances that interfere with the stability and regulation of the endocrine system of the body or its offspring. These substances are generally stable in chemical properties, not easy to be biodegraded, and can be enriched in organisms. In the past half century, EDCs have gradually entered the food chain, and these substances have been frequently found in maternal blood. Perinatal maternal hormone levels are unstable and vulnerable to EDCs. Some EDCs can affect embryonic development through the blood-fetal barrier and cause damage to the neuroendocrine system, liver function, and genital development. Some also effect cross-generational inheritance through epigenetic mechanisms. This article mainly elaborates the mechanism and detection methods of estrogenic endocrine disruptors, such as bisphenol A (BPA), organochlorine pesticides (OCPs), diethylstilbestrol (DES) and phthalates (PAEs), and their effects on placenta and fetal health in order to raise concerns about the proper use of products containing EDCs during pregnancy and provide a reference for human health.

Pregnancy, childbirth, and puerperium outcomes in female firefighters in Korea

Background

Female firefighters are exposed to hazardous environmental (chemical and physical) and working (shift work, psychological, and ergonomic factors) conditions that have reported or are suspected of adverse effects on reproductive health. However, no previous studies have reported on pregnancy, childbirth, and puerperium outcomes (PCPOs) in female firefighters.

Methods

The present study compared hospital admissions for PCPOs, based on 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) codes, among Korean female firefighters with those of the general Korean population. Standardized admission ratios (SARs) and their 95% confidence intervals (CIs) were calculated.

Results

The study population included 1,766 female firefighters. Total follow-up duration was 9,659 person-years. Compared to the general female population, the female firefighters' SARs were higher in all admissions for PCPOs (SAR, 1.92; 95% CI: 1.79–2.05); pregnancy and abortive outcomes (SAR, 1.56; 95% CI: 1.12–2.12); other maternal disorders predominantly related to pregnancy (SAR, 2.65; 95% CI: 1.99–3.46); maternal care related to the fetus, amniotic cavity, and possible delivery problems (SAR, 2.13; 95% CI: 1.74–2.57); labor and delivery complications (SAR, 1.55; 95% CI: 1.15–2.06); delivery (SAR, 1.94; 95% CI: 1.80–2.08); and complications predominantly related to puerperium (SAR, 4.68; 95% CI: 2.02–9.23).

Conclusion

The results of this study showed high SARs in all and specific subcategories of PCPOs in female firefighters.

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.

Potentiating effect of imidacloprid on arsenic-induced testicular toxicity in Wistar rats

BACKGROUND

It is an established fact that humans and animals are exposed to more than one chemical concurrently from various sources such as food, air and water. In the past, much emphasis was laid on evaluating the toxic effects of a single chemical. Nowadays an increased attention is being paid to the interaction of xenobiotics with one another. Therefore, a study was aimed to evaluate the potentiating effect of imidacloprid (IMI) on arsenic-induced testicular toxicity in rats.

METHODS

Adult male Wistar rats randomly divided into eight groups with six in each were subjected to daily oral administrations for 28 days. Group I served as control, group II received IMI at the dose rate of 16.9 mg/kg body weight, group III, IV and V received arsenic at the dose rate of 50, 100 and 150 ppb in drinking water whereas group VI, VII and VIII received both arsenic and IMI.

RESULTS

Repeated oral administrations of IMI or arsenic (150 ppb) alone resulted in a significant (P < 0.05) elevation in the levels of malondialdehyde (MDA) and advanced oxidation protein product (AOPP) along with significant (P < 0.05) decline in total thiols and antioxidant enzymatic activities indicating reduced antioxidant defense in testicular tissue of exposed rats. These findings were further corroborated with histological alterations in testes like fluid accumulation in interstitial spaces in IMI administered rats. Similarly, rats provided access exclusively to arsenic-containing drinking water induced degenerative changes in seminiferous tubules in a concentration-dependent manner. Concurrent administration of IMI and arsenic produced more severe antioxidant and histopathological alterations of testes as compared to exposure to either toxicant.

CONCLUSIONS

Reduced antioxidant activities, increased MDA and AOPP levels with severe histopathological alterations in testes of rats on concurrent exposure indicated that IMI potentiated the arsenic-induced testicular toxicity in Wistar rats.

Antioxidants retard the ageing of mouse oocytes

The aim of the present study was to verify the effects of heavy metal coupling agents (sodium citrate and EDTA) and antioxidants (acetyl carnitine and lipoic acid) on the number of oocytes, as well as the ageing of mitochondria, chromosomes and spindles in mice. C57BL/6 female mice were randomly classified into four groups (n=12 per group): i) Heavy metal coupling agent; ii) antioxidant; iii) mixed group; and iv) the normal control group. For the treatments, heavy metal coupling agents and antioxidants were added to the drinking water provided to the mice. Following 3, 6, 9 and 12 months of treatment, the number of oocytes and mitochondrial membrane potential were determined, and chromosome and spindle structures were observed. With increasing age, the experimental mice in the four groups showed significantly decreased numbers of oocytes, reduced mitochondrial activity, and increased rates of spindle and chromosome abnormalities, which indicated age-induced ageing of mouse oocytes; thus, a mouse ageing oocyte model had been successfully established. For mice of the same age, more oocytes, higher mitochondrial activity, and lower spindle and chromosome malformation rates were detected in the antioxidant and mixed groups when compared with the normal control groups. Furthermore, no significant difference in the number of oocytes, mitochondrial activity or chromosome malformation rates was observed between the heavy metal coupling agent group and normal control group, which was possibly due to less metal being absorbed during the breeding process. Therefore, the results demonstrated that the antioxidants acetyl carnitine and lipoic acid may serve a role in delaying oocyte ageing.

Trends in Radiation Practices for Female Ocular Oncologists in North America: A Collaborative Study of the International Society of Ocular Oncology

Background

The aim of this study was to determine the known radiation exposure, attitudes, and consequent risk modifications among female ocular oncologists in North America who routinely administer radioactive plaque brachytherapy treatment and are members of the International Society of Ocular Oncology.

Methods

Nineteen female ocular oncologists completed an anonymous 17-question radiation exposure survey.

Results

Eleven of the participants chose to routinely wear lead protection during surgery; 8 did not. Fifteen of 19 participants reported using an unloaded "nonactive" template to prepare for plaque implantation. During pregnancy, 11 of 13 participants continued to perform plaque brachytherapy. Eight of these 11 undertook measures to decrease radiation exposure self-reported as lead wear and other. The average reported anxiety regarding fertility was 2.1 (SD, 2.2) on a scale from 1 to 10.

Conclusion

This study corroborates prior literature that surgeons' exposure to radiation during plaque brachytherapy is minimal. Nonetheless, there remains some anxiety regarding exposure risk to women, due to potential effects on fertility and fetal health. We found variability in exposure monitoring, required training, and precautions during pregnancy amongst this group of surgeons. Improved education and clearer pregnancy guidelines may equip female ocular oncologists with optimal knowledge regarding risk of radiation exposure.

Decline in semen parameters from 2000 to 2016 among Bangladeshi men attending a tertiary care hospital

Introduction:

The objective of this study was to analyze longitudinal changes in sperm parameters of Bangladeshi men. We hypothesized that semen parameters declined for this population.

Methods:

We retrospectively analyzed semen data from men aged 18-64 years who sought care for general sperm quality or updates on fertility status at an infertility clinic in Dhaka, Bangladesh, from January 2000 to June 2016 (n = 13,953). Samples with incomplete data were excluded (n = 143). The WHO normal criteria and semen analysis procedures were used to evaluate parameters of the remaining 13,810 specimens. Samples with missing values on sperm concentration (n = 6187) were excluded from concentration analyses. Age and duration of abstinence at testing were recorded and adjusted for. Data were imported into SAS^® 9.4 statistical software. Temporal significance was investigated using one-way ANOVA for motility parameters and Chi-square test for raw concentration. Logistic regression analyzed the effects of confounders on azoospermia and raw concentration, while median regression modeling adjusted confounders for concentration, total motility, and rapid linear (RL) motility.

Results:

Age distribution was significantly correlated with annual parameter changes (concentration, total motility, and RL motility [P < 0.0001]). Adjusted total motility and RL motility declined by 20% from their maximum values to end of the study (P < 0.0001). Raw concentration lacked clear trends and was unaffected by adjustment. Azoospermia increased by 18% between the 2000–2010 and 2011–2016 participants (odds ratio = 0.16 [0.14–0.16]).

Conclusion:

In agreement with the hypothesis, Bangladeshi males attending this clinic have experienced decline in semen parameters (total motility and RL motility) and increased frequency of azoospermia.

Occupational Pesticide Exposure, Impaired DNA Repair, and Diseases

Pesticides are a mixture of chemical substances used to kill pests. Apart from their toxicity to pests, thy affect nontarget organisms. They also generate free radicals producing reactive oxygen species (ROS) which can disturb cellular pathways by inhibiting various enzymes or receptors. Pesticides also induce oxidative DNA damage, DNA adducts, and single or double strand DNA breaks. Various mechanisms of DNA repair deal with such damages and help to maintain cell integrity. Alteration in DNA repair genes modulates the individual's susceptibility towards DNA repair and various diseases. Biological monitoring provides a useful tool for the estimation of genetic risk in populations exposed to pesticides. Large numbers of evidences show that occupational exposure to pesticides in agricultural workers has been associated with an increased incidence of various diseases such as cancer, Parkinson's disease, Alzheimer's disease, reproductive disorders, and birth defects. In this review, we have discussed occupational pesticide exposure, various mechanisms of DNA damage caused by pesticides, DNA repair mechanisms, biomonitoring tools, and various diseases caused by pesticide exposure.

Pesticides exposure through environment and risk of pre-term birth: a study from Agra city

Pre-term birth is an increasingly prevalent complex condition with multiple risk factors including environmental pollutants. Evidences linking organochlorine pesticides with adverse pregnancy outcomes are inconsistent for link between organochlorine pesticides and adverse pregnancy outcomes. We performed a case-control study of 50 cases of full-term births and 40 cases of pre-term births in this study. Placental organochlorine pesticides like metabolites of dichlorodiphenyltrichloroethane that is, (p,p-DDE, p,p-DDT and o,p-DDD) and isomers of hexachlorocyclohexane (α, β, γ and δ HCH) were analyzed by gas chromatography. Although the mean levels of pesticide were found higher in the placenta of the women with pre-term delivery cases placentas, but only α-HCH, total-HCH, p,p-DDE and total-DDT were found statistically significant. It was observed that pesticide exposed women were approximately 1.7 times more likely to deliver pre-term baby as compare to pregnant women that were not exposed to any pesticides. We also observed that increasing maternal age reduced the risk of having pre-term birth (OR = 0.99). Among all pesticides, α-HCH was found to be strongest isomer to induce premature baby birth (p < 0.001). This study found that pregnant women's age and chronic disease, baby's weight at the time of birth and α-HCH were important risk factors for pre-term births.

Routine assessment of occupational exposure and its relation to semen quality in infertile men: a cross-sectional study

BACKGROUND/AIM

Concerns about the detrimental effects of occupational and environmental exposure on male reproductive function have been raised by reports of declining sperm quality over the last decades. The aim of this study was to investigate the association between altered semen parameters and exposure to occupational risk factors as assessed by questionnaire.

MATERIALS AND METHODS

We conducted a cross-sectional questionnaire-based study among a population of 2122 men who underwent andrological investigation for couple infertility. All participants were interviewed and their semen samples were analyzed. Information about medical history and occupational exposure was used to classify participants into exposed and unexposed groups.

RESULTS

Exposure to pesticides was associated with a significantly higher risk of asthenozoospermia (adjusted odds ratio [OR] = 1.6; 95% CI, 1.0-2.4) and necrozoospermia (OR = 2.6; 95% CI, 1.4-4.7). Exposure to cement was found to be correlated with a higher risk of oligozoospermia (OR = 1.1; 95% CI, 0.9-1.4). There was no association between semen impairment and exposure to solvents, excess heat, or mechanical vibrations.

CONCLUSION

We found an association between self-reported occupational exposure and altered semen parameters. These results support the usefulness of questionnaires for routine assessment and management of occupational exposures in infertile men.

New insights on 'old' toxicants in occupational toxicology (Review)

In order to deliver the best possible working environment, it is essential to identify professional conditions that could be harmful for worker's health and prevent (or limit) the occurrence of such conditions. The appropriate use of personal protective equipment and the development of appropriate regulations allowed to reduce the prevalence of 'classic' occupational diseases, such as occupational hearing loss or asbestosis, just to name a few. Nowadays, environmental pollution seems to be one of the most relevant concerns for human and animal health, and toxicology is becoming one of the most prominent fields of interest in occupational settings. An increasing number of studies demonstrate that the presence of toxicants in the workplace could be responsible for the development of chronic diseases, even at doses that were considered 'safe'. The present review summarizes some of the most recent advancements in occupational toxicology, focusing on topics that have long been debated in the past and that have recently returned to the fore.

Occupational exposure to pesticides as a possible risk factor for the development of chronic diseases in humans (Review)

It is well known that pesticides are widely used compounds. In fact, their use in agriculture, forestry, fishery and the food industry has granted a huge improvement in terms of productive efficiency. However, a great number of epidemiological surveys have demonstrated that these toxic compounds can interact and exert negative effects not only with their targets (pests, herbs and fungi), but also with the rest of the environment, including humans. This is particularly relevant in the case of workers involved in the production, transportation, preparation and application of these toxicants. Accordingly, a growing body of evidence has demonstrated the correlation between occupational exposure to pesticides and the development of a wide spectrum of pathologies, ranging from eczema to neurological diseases and cancer. Pesticide exposure is often quite difficult to establish, as many currently used modules do not take into account all of the many variables that can occur in a diverse environment, such as the agricultural sector, and the assessment of the real risk for every single worker is problematic. Indeed, the use of personal protection equipment is necessary while handling these toxic compounds, but education of workers can be even more important: personal contamination with pesticides may occur even in apparently harmless situations. This review summarises the most recent findings describing the association between pesticide occupational exposure and the development of chronic diseases.

Molecular perspectives and recent advances in microbial remediation of persistent organic pollutants

Nutrition and pollution stress stimulate genetic adaptation in microorganisms and assist in evolution of diverse metabolic pathways for their survival on several complex organic compounds. Persistent organic pollutants (POPs) are highly lipophilic in nature and cause adverse effects to the environment and human health by biomagnification through the food chain. Diverse microorganisms, harboring numerous plasmids and catabolic genes, acclimatize to these environmentally unfavorable conditions by gene duplication, mutational drift, hypermutation, and recombination. Genetic aspects of some major POP catabolic genes such as biphenyl dioxygenase (bph), DDT 2,3-dioxygenase, and angular dioxygenase assist in degradation of biphenyl, organochlorine pesticides, and dioxins/furans, respectively. Microbial metagenome constitutes the largest genetic reservoir with miscellaneous enzymatic activities implicated in degradation. To tap the metabolic potential of microorganisms, recent techniques like sequence and function-based screening and substrate-induced gene expression are proficient in tracing out novel catabolic genes from the entire metagenome for utilization in enhanced biodegradation. The major endeavor of today's scientific world is to characterize the exact genetic mechanisms of microbes for bioremediation of these toxic compounds by excavating into the uncultured plethora. This review entails the effect of POPs on the environment and involvement of microbial catabolic genes for their removal with the advanced techniques of bioremediation.

Sperm motility and morphology changes in rats exposed to cadmium and diazinon

BACKGROUND

Humans are ubiquitously exposed to multiple environmental contaminants. Consequences of combined action on the reproductive system remain unknown. This study aimed to assess single and joint effects of cadmium and diazinon exposure on sperm quality parameters.

METHODS

Male adult Wistar rats were randomized into 4 groups of ten animals each. Group A was used as a control, animals from group B were exposed to cadmium (30 mg/L), rats from group C were administered with diazinon (40 mg/L), and rats from group D were exposed simultaneously to cadmium (30 mg/L) and diazinon (40 mg/L) via drinking water for 90 days. Sperm morphology and motility were evaluated using a bright field microscope and a computer-assisted semen analysis.

RESULTS

The percentage of motile spermatozoa and morphologically normal sperm was markedly reduced in rats from the group B. Rats from the C group showed an increase in velocity parameters, amplitude of lateral head displacement, decrease in beat-cross frequency, and an increase in abnormal sperm morphology. Simultaneous coexposure to cadmium and diazinon increased distance and velocity parameters, and amplitude of lateral head displacement. Reductions were observed in straightness, linearity, wobble, and beat-cross frequency. The decreased normal sperm morphology rates were related to defects of the sperm tail.

CONCLUSIONS

Exposure to cadmium and diazinon at relatively low doses impairs sperm quality and can reduce male fertility. Cadmium and diazinon caused significant changes on sperm morphology with varying effects on motility patterns. These parameters were significantly higher in the group D as compared to the group C. The findings have important implications for reproductive risk assessment of combined exposures to multiple chemicals.

Organochlorine pesticides in follicular fluid of women undergoing assisted reproductive technologies from central China

Female infertility rates have increased by approximately 4% since the 1980s. There is evidence of adverse effects on female fertility in relation to exposure of chemical pollution in recent years. Follicular fluid samples were collected from 127 woman patients (aged 20-35) who underwent assisted reproductive technologies (ART) and had no records indicating occupational exposure to OCPs. Seventeen OCPs were analyzed in this study. The results showed that methoxychlor was dominant, accounted for 13.4% of total OCPs with a mean concentration of 167.9 ± 33.9 ng/g lipid weight (lw), followed by heptachlor-epoxide, hexachlorocyclohexanes, endrin and DDT. The concentrations of OCPs in the follicular fluid samples in the present study were moderate in comparison with those reported from developed or industrialized countries. All these pollutants can accumulate in different tissues of human body through diet, drinking water and respiration. No correlation between patient age and OCP concentrations was observed in this study.

Persistent organochlorine pesticides and oxidant/antioxidant status in the placental tissue of the women with full-term and pre-term deliveries

In India pre-term birth is the leading cause of death of infants and this number is continuously increasing.

Effects of subchronic exposure to cadmium and diazinon on testis and epididymis in rats

The present study aimed to elucidate the structural changes in testis and epididymis of adult rats following subchronic peroral administration of cadmium at 30 mg/L, diazinon at 40 mg/L, cadmium at 30 mg/L, and diazinon at 40 mg/L, respectively. At the end of 90-day experiment, the samples of the testes and epididymis were assayed by qualitative and quantitative histological methods. The testis and epididymis weights increased following exposure to cadmium and simultaneous exposure to cadmium and diazinon. Testicular damage following cadmium and diazinon coexposure was significantly less expressive than in groups with individual administration of these compounds. Cadmium caused a significant thickening of seminiferous epithelium, cellular degeneration, and necrosis. Desquamation of immature germ cells resulted in a significant increase of intraepithelial spaces and reduced tubule volume in all experimental groups. Vascular dilation and congestion were detected in the interstitial tissue. The changes in epididymal histology in the group exposed to cadmium and group exposed simultaneously included a reduction of epithelium, necrotic epithelial cells, vasoconstriction, and interstitial edema together with mononuclear cell infiltration. Results did not indicate a synergistic or any additional effect from the simultaneous administration of both toxicants. Further research is needed to determine the significance and the mechanism of the adverse effects.

Metals and female reproductive toxicity

Research into occupational exposure of metals and consequences of reproductive systems has made imperative scientific offerings in the preceding few decades. Early research works focused on possible effects on the reproductive functions rather than the complete reproductive health of the woman. Later, it was realized that metals, as reproductive toxins, may also induce hormonal changes affecting other facets of reproductive health such as the menstrual cycle, ovulation, and fertility. Concern is now shifting from considerations for the pregnant woman to the entire spectrum of occupational health threats and thus reproductive health among women.

Lead-induced impairments in the neural processes related to working memory function

Background

It is well known that lead exposure induces neurotoxic effects, which can result in a variety of neurocognitive dysfunction. Especially, occupational lead exposures in adults are associated with decreases in cognitive performance including working memory. Despite recent advances in human neuroimaging techniques, the neural correlates of lead-exposed cognitive impairment remain unclear. Therefore, this study was aimed to compare the neural activations in relation to working memory function between the lead-exposed subjects and healthy controls.

Methodology/Principal Findings

Thirty-one lead-exposed subjects and 34 healthy subjects performed an n-back memory task during MRI scan. We performed fMRI using the 1-back and 2-back memory tasks differing in cognitive demand. Functional MRI data were analyzed using within- and between-group analysis. We found that the lead-exposed subjects showed poorer working memory performance during high memory loading task than the healthy subjects. In addition, between-group analyses revealed that the lead-exposed subjects showed reduced activation in the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, pre supplementary motor areas, and inferior parietal cortex.

Conclusions/Significance

Our findings suggest that functional abnormalities in the frontoparietal working memory network might contribute to impairments in maintenance and manipulation of working memory in the lead-exposed subjects.

Gene-environment interaction among GSTT1, PON2 polymorphisms and organic solvents on gestational age in a Chinese women cohort

PURPOSE

To investigate interactions on gestational age among two environmental risk factors and four maternal genetic polymorphisms: organic solvents, passive smoking, CYP1A1 rs4646903 (MspI), EPHX1 rs2234922 (His139Arg), GSTT1 and PON2 rs12026 (Ala148Gly).

METHODS

A pregnant women cohort was conducted at Beijing Yanshan Petrochemical Corporation, and 1,097 mothers with live singleton births were included in analysis. Generalized Multifactor Dimensionality Reduction (GMDR) method was used to explore interactions among these factors with adjustment for important potential confounders. Multiple linear regression models were used to estimate the association of interaction with gestational age.

RESULTS

A three-factor model of organic solvents, GSTT1 and PON2 rs12026 had the highest testing balanced accuracy (57.05 %) and best cross-validation consistency (10/10). Compared with organic solvents unexposed mothers with GSTT1 non-null genotype and PON2 rs12026 CC genotype, organic solvents exposed mothers with GSTT1 null genotype and PON2 rs12026 CG + GG genotype had the largest reduction in gestational age (-0.36 weeks, 95%CI: -0.70 to -0.02). The significant reductions in different groups were from 0.24 weeks to 0.36 weeks.

CONCLUSIONS

Maternal genetic susceptibility GSTT1 and PON2 rs12026 could significantly modify the association of organic solvents with gestational age.

Reproductive toxicity and histopathological changes induced by lambda-cyhalothrin in male mice

Lambda-cyhalothrin (LCT) is a widely used broad-spectrum pyrethroid insecticide. Oral LCT administration to adult male mice at 3 doses (0.2, 0.4, and 0.8 mg/kg/day) for 6 weeks caused a significant reduction in the weight of the seminal vesicles. The epididymal sperm count was lower in mice that received at the highest dose than in control mice. However, the proportions of live and motile spermatozoa were reduced at both the medium and the high doses compared with control mice. All doses induced an increase in the number of morphologically abnormal spermatozoa. Histopathological observations of the testes, liver, kidneys, and spleen showed dose-related degenerative damage in LCT-treated mice. The results indicate that LCT has reproductive toxicity, hepatotoxicity, nephrotoxicity, and splenotoxicity in male mice at the tested doses. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 750-762, 2014.