Research LettersSemen quality after prenatal exposure to polychlorinated biphenyls and dibenzofurans
Summary
Large-scale poisoning occurred in central Taiwan in 1979 from ingestion of cooking oil contaminated by polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans. To determine whether in-utero exposure to these chemicals alters reproductive function, all prenatally exposed boys and appropriate controls were contacted for medical examination in 1998. Sperm of exposed children have increased abnormal morphology, reduced motility, and reduced capacity to penetrate hamster oocytes. Whether this will cause reduced fecundity, and how these effects can be extrapolated to the general population exposed to background levels of PCBs and dioxin-like chemicals, warrants further investigation.
References (5)
- AS Faqi et al.
Reproductive toxicity and tissue concentrations of low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin in male offspring rats exposed throughout pregnancy and lactation
Toxicol Appl Pharmacol
(1998) - ST Hsu et al.
Discovery and epidemiology of PCB poisoning in Taiwan: a four-year followup
Environ Health Perspect
(1985)
Cited by (191)
Environmental toxicants and male fertility
2023, Best Practice and Research: Clinical Obstetrics and GynaecologySemen quality has declined especially among Western men. Experimental and epidemiological studies have shown potential links between exposure to environmental toxicants and poor male fertility. Some environmental exposures in utero can disrupt fetal testicular function and result in cryptorchidism, low semen quality, low serum testosterone levels, and low fertility. Environmental exposure in childhood and adulthood can also adversely affect germ cells, Sertoli cells, Leydig cells, or the hypothalamic-pituitary-testicular axis, resulting in impaired male fertility. In this review, we report the latest results from human studies that investigated the role of endocrine disrupting chemicals, heavy metals, tobacco smoking, alcohol drinking, and use of marijuana in low semen quality and impaired male fertility. Current evidence suggests the relationship between these environmental factors and low male fertility; however, some factors showed conflicting results which need further investigation.
Toxicity of polychlorinated biphenyls in aquatic environments – A review
2022, Aquatic ToxicologyThe assessment of polychlorinated biphenyls (PCBs) and their congeners resulting from the pollution of all environmental media is inherently related to its persistence and ubiquitous nature. In principle, determination of this class of contaminants are limited to the determination of their concentrations in the various environmental matrices. For solving many problems in this context, knowledge of the emission sources of PCBs, transport pathways, and sites of contamination and biomagnification is of great benefit to scientists and researchers, as well as many regulatory organizations. By far the largest amounts of PCBs, regardless of their discharged points, end up in the soil, sediment and finally in different aquatic environments. By reviewing relevant published materials, the source of origin of PCBs in the environment particularly from different pollution point sources, it is possible to obtain useful information on the nature of different materials that are sources of PCBs, or their concentrations and their toxicity or health effects and how they can be removed from contaminated media. This review focuses on the sources of PCBs in aquatic environments and critically reviews the toxicity of PCBs in aquatic animals and plants. The review also assesses the toxicity equivalency factors (TEFs) of PCBs providing valuable knowledge to other scientists and researchers that enables regulatory laws to be formulated based on selective determination of concentrations regarding their maximum permissible limits (MPLs) allowed. This review also supplies a pool of valuable information useful for designing decontamination technologies for PCBs in media like soil, sediment, and wastewaters.
Geographic variation in semen parameters from data used for the World Health Organization semen analysis reference ranges
2022, Fertility and SterilityTo study geographic variations in sperm parameters using data from the trials that defined the reference ranges of the World Health Organization 2021 manual.
Retrospective evaluation of the data used to define the World Health Organization reference ranges.
Not applicable.
Data from 11 studies, including 3,484 participants across 5 continents.
The data were divided according to geographic locations.
Differences in sperm parameters.
The semen volume was significantly lower in samples from Asia and Africa than in other regions. The sperm concentration was the lowest in Africa and highest in Australia. The total motile sperm count (TMSC) and total motile progressive sperm count (TMPS) were significantly lower in Africa than in other regions. The TMSC and TMPS in Asia and the United States were significantly lower than in Europe and Australia. The 5th percentile of the sperm concentration was lowest in the United States (12.5 × 106/mL). The 5th percentile for the normal sperm morphology was lowest in the United States (3%) and highest in Asia (5%). The 5th percentile for the TMSC and TMPS were lowest in Africa (TMSC, 15.08 million; TMPS, 12.06 million) and the United States (TMSC, 18.05 million; TMPS, 16.86 million) and highest in Australia (TMSC, 29.61 million; TMPS, 25.80 million).
Significant geographic differences in sperm parameters exist, and regional fertility societies should consider adding their own reference ranges on the basis of local experience and treatment outcomes.
Variación geográfica en los parámetros seminales a partir de datos utilizados para los rangos de referencia del análisis de semen de la Organización Mundial de la Salud.
Estudiar variaciones geográficas en parámetros seminales utilizando los datos de los ensayos que definieron los rangos de referencia del manual 2021 de la Organización Mundial de la Salud.
Evaluación retrospectiva de los datos utilizados para definir los rangos de referencia de la Organización Mundial de la Salud.
No aplica.
Datos de 11 estudios, incluyendo 3,484 participantes de los 5 continentes.
Los datos fueron divididos acorde a localizaciones geográficas.
Diferencias en parámetros seminales.
El volumen seminal fue significativamente más bajo en muestras de Asia y África que en otras regiones. La concentración espermática más baja fue en África y la más alta en Australia. El recuento total de espermatozoides móviles (TMSC) y el recuento total de espermatozoides móviles progresivos (TMPS) fueron significativamente más bajas en África que en otras regiones. El TMSC y TMPS en Asia y Estados Unidos fueron significativamente más bajos que en Europa y Australia. El percentilo 5 de concentración espermática fue el más bajo en Estados Unidos (12.5 x 106/ml). El percentilo 5 para morfología espermática normal fue el más bajo en Estados Unidos (3%) y el más alto en Asia (5%). El percentilo 5 para TMSC y TMPS fue el más bajo en África (TMSC, 15.08millones; TMPS, 12.06 millones) y Estados Unidos (TMSC, 18.05 millones; TMPS, 16.86 millones) y el más alto en Australia (TMSC, 29.61 millones; TMPS, 25.80 millones).
Existen diferencias geográficas significativas en los parámetros seminales, y las sociedades de fertilidad regionales deberían considerar agregar sus propios rangos de referencias basados en la experiencia local y resultados de tratamientos.
Associations of paternal serum dioxin-like polychlorinated biphenyl concentrations with IVF success: A pilot study
2022, Environmental ResearchDioxin-like polychlorinated biphenyls (DL-PCBs) are environmental pollutants that have been associated with impaired semen quality. However, research on the potential impact of paternal exposure to DL-PCBs and the risk of adverse pregnancy outcomes are limited. We examine the relationship between serum DL-PCB concentrations and IVF outcomes among 42 males seeking fertility treatment. Concentrations of 12 serum DL-PCBs were analyzed by high-resolution gas chromatography coupled to high-resolution mass spectrometry. Modified Poisson regressions, adjusted for confounders, were used to assess bivariate associations and to estimate risk ratios (RRs) between DL-PCBs and binary IVF outcomes. The median concentration (25th-75th percentiles) of the sum of the 12 DL-PCBs (∑DL-PCBs) obtained for the patients was 5.42 (3.78–7.78) ng/g lipid. No statistically significant association between DL-PCB levels and embryo quality was found. However, men with high serum PCB-77 concentrations present more probability of high-quality embryos (RR: 0.292; 95% CI: 0.090–0.942), whereas the opposite trend is observed for men with lower serum levels of PCB-156 (RR: 7.960; 95% CI: 1.020–62.100), who present increased odds of high-quality embryos. Serum concentrations of PCB-126 and PCB-114 were associated with decreased implantation rates (p < 0.05). Moreover, PCB-77 and ∑non-ortho PCBs were significantly associated with a lower likelihood of clinical pregnancy (p < 0.05). A lower likelihood of live birth was associated with higher levels of PCB-77, PCB-105, PCB-118, and recording significant differences for ∑non-ortho PCBs, ∑mono-ortho PCBs, and ∑DL-PCBs (p < 0.05).
These findings suggest that paternal DL-PCB exposure before conception may be related to pregnancy endpoints. However, DL-PCB measurement were limited to male partners. Therefore, we propose that future studies with larger population sizes should include both maternal and paternal factors.
Polychlorinated biphenyls, polybrominated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans
2022, Reproductive and Developmental ToxicologyPolychlorinated biphenyls (PCBs), polybrominated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans belong to a group of compounds that are structurally related and are environmentally and biologically persistent. These chemicals have a tendency to bioaccumulate and biomagnify in the food chain. Residues of these chemicals have been detected in remote areas of the world and in a variety of animal species, including humans. Exposure to these chemicals has been linked to a broad spectrum of effects. Fetal and early developmental exposures are particularly sensitive and can have more profound and irreversible outcomes when compared to adult exposure. Latent effects of early exposures include, but are not limited to, depressed circulating thyroid hormone levels and abnormal thyroid cytology; developmental effects of the heart, palate, and kidney; delayed cognitive development; altered sensory and motor abilities; and reproductive impairment and compromised neuronal function. Although AhR activation has been attributed to several dioxin-like coplanar compounds, some PCBs that are noncoplanar in nature seem to exert their toxic effects through different mechanisms including calcium signaling, oxidative stress, thyroid hormone perturbations, and neurotransmitter imbalance. While certain congeners and isomers can pose a very serious threat to the health of animals and humans, environmental exposure situations are generally such that risks of health effects are generally low. The most significant problem by these compounds involved in accidental poisoning via food supply or consumption of contaminated food from contaminated areas. Additionally, there are areas of the environment that are heavily contaminated by these chemicals because of past industrial activities. Animals and humans residing in or near contaminated locations certainly are at risk of serious health effects. Efforts must continue to reduce exposure to protect wildlife and humans. The best way to accomplish is to modernize technological processes to prevent the release of these chemicals into the environment.
Decreased serum testosterone levels associated with 17β-hydroxysteroid dehydrogenase activity in 7-year-old children from a dioxin-exposed area of Vietnam
2021, Science of the Total EnvironmentSince 2008, we have conducted epidemiological cohort studies on the relationship between dioxin exposure and disruption with children in the area sprayed with defoliants during the Vietnam War. In a long-term survey of children through the age of five, we observed androgen disruption due to decreased dehydroepiandrosterone (DHEA) and testosterone levels. In this study of 7-year-old, we separately elucidated androgen disruption for boys and girls, and discussed with respect to hormone disruption with sex differences on the steroid hormone biosynthesis process.
This follow-up was conducted with 96 mother-child pairs in Vietnam (hotspot area: 45, non-sprayed area: 51). We took a questionnaire, the physical measurement and assayed 7 steroid hormones in their serum by LC-MS/MS. We examined the relationship between the hormone levels in the serum and dioxin levels in the maternal breast milk. The results showed that the serum DHEA level in the 7-year-old children in the hotspot recovered to levels in the non-sprayed area. The testosterone level of 66.5 pg/mL for boys in the non-sprayed area was 1.5 times the girls level of 44.6 pg/mL, a male-dominant effect. The testosterone level in boys and girls from the hotspot were significantly lower than in the non-sprayed area with no sex difference. The 17β-hydroxysteroid dehydrogenase (17β-HSD) activity was significantly higher in boys than in the girls from the non-sprayed area, but was significantly lower in the hotspot boys than in the non-sprayed area boys. Both the testosterone level and 17β-HSD activity in the boys were inversely correlated with the TEQ total PCDD/Fs in the maternal breast milk.
These results indicated that dioxin delayed the expression of the testosterone level and 17β-HSD activity with growth in the 7-year-old boys. The serum DHEA in the 7-year-old children recovered to the levels of the children in the non-sprayed area.