Chronic exposure to organophosphate pesticides as an important challenge in promoting reproductive health: A comparative study

Organophosphate Pesticide Exposure: Effect on Farmers' Sperm Quality in the Mekong Delta, Vietnam

OBJECTIVES

Using pesticides in the An Giang province is widespread. However, studies on the health effect of organophosphate pesticide have not been updated within the past 12 years. This study aimed to assess exposure to organophosphate pesticides and their effects on sperm quality among farmers in the An Giang Province, Mekong Delta, Vietnam.

METHODS

During the winter - spring crop season of December 2021 to February 2022, a cross-sectional study was conducted on farmers aged 18 to 60 years-old based on seven communes' health checkup programs. The pesticide spray group included farmers who had sprayed pesticides in the previous week and had a history of working in agriculture for more than 2 years. The control group was defined as those who lived in the same community, had not worked in agriculture, and had never sprayed pesticides. Demographic characteristics and blood, urine, and semen samples were collected and analyzed.

RESULTS

Data for 184 eligible participants were analyzed, including 116 farmers in the pesticide spray group and 68 non-farmers in the control group. Pesticide spray contributed to a decrease in the sperm quality index of 6.253 units (95% CI, 4.472-8.749). Increasing each pseudocholinesterase (PChE) unit (kIU/L) was associated with an increase of 1.181 units in the sperm quality index (95% CI, 0.757-0.947).

CONCLUSIONS

Preventive methods for organophosphate pesticide exposure, such as administrative controls, engineering controls, substitution, and personal protective equipment should be applied to control health risks. In the An Giang setting, personal protective equipment is feasible, but most types of equipment are not used. The immediate priority is to determine the cause of personal protective equipment not being used and to find solutions to encourage people to use them.

Therapeutic Potential of Pentoxifylline in Paraquat-Induced Pulmonary Toxicity: Role of the Phosphodiesterase Enzymes

Pentoxifylline (PTX), a non-selective phosphodiesterase inhibitor, has demonstrated protective effects against lung injury in animal models. Given the significance of pulmonary toxicity resulting from paraquat (PQ) exposure, the present investigation was designed to explore the impact of PTX on PQ-induced pulmonary oxidative impairment in male mice.Following preliminary studies, thirty-six mice were divided into six groups. Group 1 received normal saline, group 2 received a single dose of PQ (20 mg/kg; i.p.), and group 3 received PTX (100 mg/kg/day; i.p.). Additionally, treatment groups 4-6 were received various doses of PTX (25, 50, and 100 mg/kg/day; respectively) one hour after a single dose of PQ. After 72 hours, the animals were sacrificed, and lung tissue was collected.PQ administration caused a significant decrease in hematocrit and an increase in blood potassium levels. Moreover, a notable increase was found in the lipid peroxidation (LPO), nitric oxide (NO), and myeloperoxidase (MPO) levels, along with a notable decrease in total thiol (TTM) and total antioxidant capacity (TAC) contents, catalase (CAT) and superoxide dismutase (SOD) enzymes activity in lung tissue. PTX demonstrated the ability to improve hematocrit levels; enhance SOD activity and TTM content; and decrease MPO activity, LPO and NO levels in PQ-induced pulmonary toxicity. Furthermore, these findings were well-correlated with the observed lung histopathological changes.In conclusion, our results suggest that the high dose of PTX may ameliorate lung injury by improving the oxidant/antioxidant balance in animals exposed to PQ.

Adult Organophosphate and Carbamate Insecticide Exposure and Sperm Concentration: A Systematic Review and Meta-Analysis of the Epidemiological Evidence

BACKGROUND

Evidence of the negative impacts of contemporary use insecticides on sperm concentration has increased over the last few decades; however, meta-analyses on this topic are rare.

OBJECTIVES

This investigation assessed the qualitative and quantitative strength of epidemiological evidence regarding adult exposure to two classes of contemporary use insecticides-organophosphates (OPs) and N -methyl carbamates (NMCs)-and sperm concentration using robust and reproducible systematic review and meta-analysis methods.

METHODS

Three scientific databases (PubMed, Scopus, and Web of Science), two U.S. government databases (NIOSHTIC-2 and Science.gov), and five nongovernmental organization websites were searched for relevant primary epidemiological studies published in any language through 11 August 2022. Risk of bias and strength of evidence were evaluated according to Navigation Guide systematic review methodology. Bias-adjusted standardized mean difference effect sizes were calculated and pooled using a three-level, multivariate random-effect meta-analysis model with cluster-robust variance estimation.

RESULTS

Across 20 studies, 21 study populations, 42 effect sizes, and 1,774 adult men, the pooled bias-adjusted standardized mean difference in sperm concentration between adult men more- and less-exposed to OP and NMC insecticides was - 0.30 (95% CI: - 0.49 , - 0.10 ; P Satt < 0.01 ). Sensitivity and subgroup analyses explored statistical heterogeneity and validated the model robustness. Although the pooled effect estimate was modified by risk of bias, insecticide class, exposure setting, and recruitment setting, it remained negative in direction across all meta-analyses. The body of evidence was rated to be of moderate quality, with sufficient evidence of an association between higher adult OP and NMC insecticide exposure and lower sperm concentration.

DISCUSSION

This comprehensive investigation found sufficient evidence of an association between higher OP and NMC insecticide exposure and lower sperm concentration in adults. Although additional cohort studies can be beneficial to fill data gaps, the strength of evidence warrants reducing exposure to OP and NMC insecticides now to prevent continued male reproductive harm. https://doi.org/10.1289/EHP12678.

Contaminants of Emerging Concern (CECs) and Male Reproductive Health: Challenging the Future with a Double-Edged Sword

Approximately 9% of couples are infertile, with half of these cases relating to male factors. While many cases of male infertility are associated with genetic and lifestyle factors, approximately 30% of cases are still idiopathic. Contaminants of emerging concern (CECs) denote substances identified in the environment for the first time or detected at low concentrations during water quality analysis. Since CEC production and use have increased in recent decades, CECs are now ubiquitous in surface and groundwater. CECs are increasingly observed in human tissues, and parallel reports indicate that semen quality is continuously declining, supporting the notion that CECs may play a role in infertility. This narrative review focuses on several CECs (including pesticides and pharmaceuticals) detected in the nearshore marine environment of False Bay, Cape Town, South Africa, and deliberates their potential effects on male fertility and the offspring of exposed parents, as well as the use of spermatozoa in toxicological studies. Collective findings report that chronic in vivo exposure to pesticides, including atrazine, simazine, and chlorpyrifos, is likely to be detrimental to the reproduction of many organisms, as well as to sperm performance in vitro. Similarly, exposure to pharmaceuticals such as diclofenac and naproxen impairs sperm motility both in vivo and in vitro. These contaminants are also likely to play a key role in health and disease in offspring sired by parents exposed to CECs. On the other side of the double-edged sword, we propose that due to its sensitivity to environmental conditions, spermatozoa could be used as a bioindicator in eco- and repro-toxicology studies.

Environmental, Human and Ecotoxicological Impacts of Different Rice Cultivation Systems in Northern Thailand

Sustainable practices in rice cultivation require effective farming management concerning environmental and human health impacts. In this study, three rice cultivation systems, namely low-land, upland, and terraced rice in the Mae Chaem District, Chiang Mai Province, were assessed and the carbon footprint (CF), water footprint (WF), and human and ecotoxicological impacts were compared from pesticide application. The results showed that the highest CF intensity was observed in terraced rice with 1.15 kg CO₂eq kg^-1 rice yield, followed by lowland rice (1.02 kg CO₂eq kg^-1 rice yield) and upland rice (0.17 kg CO₂eq kg^-1 rice yield) fields. Moreover, lowland rice cultivation generated the highest total WF with 1701.6 m³ ton^-1, followed by terraced rice (1422.1 m³ ton^-1) and upland rice (1283.2 m³ ton^-1). The lowland rice fields had the most impact on human health and freshwater ecotoxicity, followed by the terraced and upland rice cultivation systems. The results also showed that most of the pesticides remaining in soils were chlorpyrifos (98.88%), butachlor (96.94%), and fipronil (95.33%), respectively. The substances with the greatest distributions in freshwater were acephate (56.74%), glyphosate (50.90%), and metaldehyde (45.65%), respectively. This study indicated that, with more agricultural inputs, higher CF, WF, human health impacts, and freshwater ecotoxicity were generated. Although the use of pesticides in the study areas did not exceed the recommendations on the packaging, glyphosate and chlorpyrifos are restricted in Thailand, so it is necessary to monitor their use due to their long-term health effects.

Temporal decline of sperm concentration: role of endocrine disruptors

INTRODUCTION

Male infertility is a widespread disease with an etiology that is not always clear. A number of studies have reported a decrease in sperm production in the last forty years. Although the reasons are still undefined, the change in environmental conditions and the higher exposure to endocrine-disrupting chemicals (EDCs), namely bisphenol A, phthalates, polychlorinated biphenyls, polybrominated diphenyl esters, dichlorodiphenyl-dichloroethylene, pesticides, and herbicides, organophosphates, and heavy metals, starting from prenatal life may represent a possible factor justifying the temporal decline in sperm count.

AIM

The aim of this study is to provide a comprehensive description of the effects of the exposure to EDCs on testicular development, spermatogenesis, the prevalence of malformations of the male genital tract (cryptorchidism, testicular dysgenesis, and hypospadias), testicular tumor, and the mechanisms of testicular EDC-mediated damage.

NARRATIVE REVIEW

Animal studies confirm the deleterious impact of EDCs on the male reproductive apparatus. EDCs can compromise male fertility by binding to hormone receptors, dysregulating the expression of receptors, disrupting steroidogenesis and hormonal metabolism, and altering the epigenetic mechanisms. In humans, exposure to EDCs has been associated with poor semen quality, increased sperm DNA fragmentation, increased gonadotropin levels, a slightly increased risk of structural abnormalities of the genital apparatus, such as cryptorchidism and hypospadias, and development of testicular tumor. Finally, maternal exposure to EDCs seems to predispose to the risk of developing testicular tumors.

CONCLUSION

EDCs negatively impact the testicular function, as suggested by evidence in both experimental animals and humans. A prenatal and postnatal increase to EDC exposure compared to the past may likely represent one of the factors leading to the temporal decline in sperm counts.

Dose-dependent efficacy of antioxidant nanoparticles on red blood cells storage

BACKGROUND

Transfusion of healthy red blood cells (RBCs) after storage is important. One of the storage lesions on blood bags is oxidative stress. One way to prevent increased oxidative stress is to use antioxidant nanoparticles (NPs). Superoxide dismutase (SOD) and catalase (CAT) play an important role in antioxidant defense on RBC. poly lactic-co-glycolic acid (PLGA) is a nontoxic biodegradable polymer that is approved by the Food and Drug Administration for drug delivery. This study aimed to assess dose-dependent efficacy of SOD-CAT-polyethylene glycol -PLGA on RBCs storage.

MATERIALS AND METHODS

Using a descriptive study, during 1 month, twenty donors from Bojnourd Blood Donation Center were selected. NPs with different concentrations were injected into the satellite bags after directing blood to them. On target days, experiments were performed on the samples taken. Electrospray was employed to prepare SOD-CAT-PLGA NPs. Twenty packed RBCs were isolated from the whole blood bags by the mechanical method, and certain amount of product was transferred to the satellite bags. On days 1, 7, 14, 21, 28, and 35, bags were sampled. Malondialdehyde (MDA), prooxidant-antioxidant balance (PAB), and Annexin V were performed on the samples taken. The repeated measures analysis with the help of SPSS software version 20 was performed on samples.

RESULTS

MDA increased in both groups. The maximum increase in test group was seen in concentration 12 mg (MDA Day 14, test [1.93 ± 0.3], [P MDA < 0.001]). Maximum increase in PAB was seen in concentration 12 mg (from 444 ± 1.7 to 563 ± 2.5) (P PAB = 0.000). Furthermore, PS expression increased in the concentration of 12 mg greater than other concentration in consecutive (from 5.00 ± 0.8 to 22.26 ± 1.7, [P < 0.001]).

CONCLUSION

Evaluation of dose dependency showed that different concentrations of antioxidant NPs affect RBC. This effect can be changed oxidative stress and apoptosis. Using both changes to evaluate functional and toxicity can be helpful.

Assessment of Organophosphate Pesticides Exposure in Men with Idiopathic Abnormal Semen Analysis: A Cross-Sectional Pilot Study

Background:

Because of the widespread use of organophosphate (OP) pesticides in agriculture, they are major environmental contaminants in developing countries. OP pesticides decrease sperm concentration and affect its quality, viability, and motility. Studies have demonstrated the association between abnormal semen analysis and OP pesticides exposure among the high-risk population. As there is limited data on the percentage of OP pesticides exposure, the study aimed to determine the OP pesticides exposure in Southern Indian men with idiopathic abnormal semen analysis and find the possible source of their OP pesticides exposure.

Materials and Methods:

In this cross-sectional pilot study, fifty men with idiopathic abnormal semen analysis as cases and fifty men with normal semen analysis as controls were recruited. Detailed history was taken and general and systemic examinations were carried out. OP pesticides exposure was determined by assessment of pseudocholinesterase and acetylcholinesterase levels and urinary OP pesticides metabolites dialkyl phosphate (DAP) consisting of dimethyl phosphate (DMP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP).

Results:

Cases had statistically significantly lower levels of pseudocholinesterase (5792.07 ± 1969.89 vs. 10267.01 ± 3258.58 IU/L) (P=0.006) and acetylcholinesterase [102.90 (45.88-262.74) vs. 570.31 (200.24-975.30) IU/L] (P=0.001) as compared to controls. Cases had a statistically significantly higher percentage of urinary DAP positivity as compared to controls (80 vs. 38%, P<0.0001). Hence, cases had a significantly higher percentage of OP pesticides exposure as compared to controls (20 vs. 4%, P=0.015). OP-exposed cases had significantly higher urinary DETP and DEDTP levels as compared to OP non-exposed cases. Also, urinary DETP and DEDTP levels were significantly negatively associated with sperm concentration, motility, and normal morphology among OP-exposed cases.

Conclusion:

Southern Indian men with idiopathic abnormal semen analysis had a significantly higher percentage of OP pesticides exposure as compared to men with a normal semen analysis.

Impact of environmental toxin exposure on male fertility potential

Idiopathic infertility is the most common individual diagnosis in male infertility, representing nearly 44% of cases. Research studies dating over the last half-century consistently demonstrate a decline in male fertility that is incompletely explained by obesity, known genetic causes, or diet and lifestyle changes alone. Human exposures have changed dramatically over the same time course as this fertility decline. Synthetic chemicals surround us. Some are benevolent; however, many are known to cause disruption of the hypothalamic-pituitary-gonadal axis and impair spermatogenesis. More than 80,000 chemicals are registered with the United States National Toxicology Program and nearly 2,000 new chemicals are introduced each year. Many of these are known toxins, such as phthalates, polycyclic aromatic hydrocarbons, aromatic amines, and organophosphate esters, and have been banned or significantly restricted by other countries as they carry known carcinogenic effects and are reproductively toxic. In the United States, many of these chemicals are still permissible in exposure levels known to cause reproductive harm. This contrasts to other chemical regulatory legislature, such as the European Union’s REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulations which are more comprehensive and restrictive. Quantification of these diverse exposures on an individual level has proven challenging, although forthcoming technologies may soon make this data available to consumers. Establishing causality and the proportion of idiopathic infertility attributable to environmental toxin exposures remains elusive, however, continued investigation, avoidance of exposure, and mitigation of risk is essential to our reproductive health. The aim of this review is to examine the literature linking changes in male fertility to some of the most common environmental exposures. Specifically, pesticides and herbicides such as dichlorodiphenyltrichloroethane (DDT), dibromochloropropane (DBCP), organophosphates and atrazine, endocrine disrupting compounds including plastic compounds phthalates and bisphenol A (BPA), heavy metals, natural gas/oil, non-ionizing radiation, air and noise pollution, lifestyle factors including diet, obesity, caffeine use, smoking, alcohol and drug use, as well as commonly prescribed medications will be discussed.

Endocrine Disrupting Chemicals and Reproductive Health in Boys and Men

Male reproductive health has declined as indicated by increasing rates of cryptorchidism, i.e., undescended testis, poor semen quality, low serum testosterone level, and testicular cancer. Exposure to endocrine disrupting chemicals (EDCs) has been proposed to have a role in this finding. In utero exposure to antiandrogenic EDCs, particularly at a sensitive period of fetal testicular development, the so-called 'masculinization programming window (MPW)', can disturb testicular development and function. Low androgen effect during the MPW can cause both short- and long-term reproductive disorders. A concurrent exposure to EDCs may also affect testicular function or damage testicular cells. Evidence from animal studies supports the role of endocrine disrupting chemicals in development of male reproductive disorders. However, evidence from epidemiological studies is relatively mixed. In this article, we review the current literature that evaluated relationship between prenatal EDC exposures and anogenital distance, cryptorchidism, and congenital penile abnormality called hypospadias. We review also studies on the association between early life and postnatal EDC exposure and semen quality, hypothalamic-pituitary-gonadal axis hormone levels and testicular cancer.