Reproductive organs are essential not only for the life of an individual but also for the survival and development of the species. The response of reproductive organs to toxic substances differs from that of other target organs, and they may serve as an ideal “barometer” for the deleterious effects of environmental pollution on animal and human health. The incidence of infertility, cancers, and associated maladies has increased in the last fifty years or more, while various anthropogenic activities have released into the environment numerous toxic substances, including cadmium, lead, and mercury. Data from epidemiological studies suggested that environmental exposure to cadmium, lead, and mercury may have produced reproductive and developmental toxicity. The present review focused on experimental studies using rats, mice, avian, and rabbits to demonstrate unambiguously effects of cadmium, lead, or mercury on the structure and function of reproductive organs. In addition, relevant human studies are discussed. The experimental studies reviewed have indicated that the testis and ovary are particularly sensitive to cadmium, lead, and mercury because these organs are distinguished by an intense cellular activity, where vital processes of spermatogenesis, oogenesis, and folliculogenesis occur. In ovaries, manifestation of toxicity induced by cadmium, lead, or mercury included decreased follicular growth, occurrence of follicular atresia, degeneration of the corpus luteum, and alterations in cycle. In testes, toxic effects following exposure to cadmium, lead, or mercury included alterations of seminiferous tubules, testicular stroma, and decrease of spermatozoa count, motility and viability, and aberrant spermatozoa morphology.

The goal of this study is to summarize the current knowledge on the effects of one of the essential metals, copper (Cu) on the reproductive system. The development of past four decades addressing effects of Cu on reproductive organs is reviewed. The most relevant data obtained from in vivo and in vitro experiments performed on humans and other mammals, including effects of copper nanoparticles (CuNPs) on the reproductive functions are presented. Short term Cu administration has been found to exert deleterious effect on intracellular organelles of rat ovarian cells in vivo. In vitro administration in porcine ovarian granulosa cells releases insulin-like growth factor (IGF-I), steroid hormone progesterone (P4), and induces expression of peptides related to proliferation and apoptosis. Adverse effect of Cu on male reproductive functions has been indicated by the decrease in spermatozoa parameters such as concentration, viability and motility. Copper nanoparticles are capable of generating oxidative stress in vitro thereby leading to reproductive toxicity. Toxic effect of CuNPs has been evident more in male mice than in females. Even though further investigations are necessary to arrive at a definitive conclusion, Cu notably influences the reproductive functions by interfering with both male and female reproductive systems and also hampers embryo development in dose-dependent manner.

The aim of this study was to monitor accumulation of lead, cadmium, mercury and arsenic in leg skeletal muscle of some wild birds from selected areas of Slovakia and the correlations among the heavy metals. A total of 160 wild birds representing 3 species—Eurasian coot (Fulica atra) (n = 24), mallard (Anas platyrhynchos) (n = 68) and pheasant (Phasianus colchicus) (n = 68) were involved for analyses. Concentrations of heavy metals from samples were measured using atomic absorption spectrophotometry (AAS). Metal concentrations are expressed as mg/kg wet weight. The order of lead and arsenic concentrations in muscles of wild birds were as follows: mallard > pheasant > Eurasian coot; in the case of arsenic the differences were significant (P < 0.05). Muscle of Eurasian coot accumulated the highest concentration of cadmium and mercury followed by pheasant and the lowest in mallard, but differences were not significant (P > 0.05). Moderately negative correlations were noted in pheasant between cadmium and mercury (r = −0.39), and between mercury and arsenic (r = −0.45). Moderately negative correlation between cadmium and arsenic (r = −0.31) was found for Eurasian coot.

Various studies have shown that the reproductive organs are highly sensitive to toxic elements found in the environment. Due to technological progress, the use of nanoparticles has become more common nowadays. Nanoparticles are used for drug delivery because their dimensions allow them to circulate throughout the body and enter directly into the cell. Antimicrobial properties are increasingly used in the manufacture of medical devices, textiles, food packaging, cosmetics, and other consumer products. Nanoparticles provide several benefits, but aspects related to their effects on living organisms and the environment are not well known. This review summarizes current in vivo, and in vitro animal studies focused on the evaluation of toxicity of selected metal nanoparticles (Ag, ZnO, TiO₂) on male and female reproductive health. It can be concluded that higher concentrations of metal nanoparticles in the male reproductive system can cause a decrease in spermatozoa motility, viability and disruption of membrane integrity. Histopathological changes of the testicular epithelium, infiltration of inflammatory cells in the epididymis, and prostatic hyperplasia have been observed. Nanoparticles in the female reproductive system caused their accumulation in the ovaries and uterus. Metal nanoparticles most likely induce polycystic ovary syndrome and follicular atresia, inflammation, apoptosis, and necrosis also occurred.

This study assessed the effect of Pilates exercises on balance and fall risk in older women. Participants comprised 50 older women aged over 60 years, divided randomly into two groups: the experimental group (n = 30), which took part in Pilates sessions two times per week for three months, and the control group (n = 20). The control group did not participate in such sessions but also did not participate in any other rehabilitation programs or additional physical activity except everyday activities. Before and after the training cycle, all women underwent an assessment using Timed Up and Go (TUG), the One Leg Stance Test (OLST), a test performed on a Freestep baropodometric platform, and the tests performed on a Biosway platform. After the training, significantly decreased values of the surface of the ellipse (p = 0.0037) and mean values of velocity (p = 0.0262) for the right foot in the experimental group were observed. The Limits of Stability (LoS) test (p = 0.005) and the Modified Clinical Test of Sensory Interaction on Balance (m-CTSIB) performed on an unstable surface with eyes closed (p = 0.0409) indicated statistically significant changes in the experimental group. None of the above changes were statistically significant in relation to the control group. Pilates training affected the participants’ balance by improving LOS and reducing fall risk.

In this study the concentrations of trace elements such as lead, cadmium, iron, nickel, copper and zinc in the human semen (n = 47), occurrence of pathological spermatozoa, and correlations of these elements to pathological forms were investigated. For each sample of human spermatozoa at least 500 spermatozoa were evaluated. Metal contents were determined by the voltametric method and flame absorption spectrophotometry method. The concentrations of trace elements in human semen were: lead 1.49 ± 0.40 mg.kg^{− 1}, cadmium 0.13 ± 0.15 mg.kg^{− 1}, iron 2.59 ± 0.21 mg.kg^{− 1}, nickel 0.40 ± 0.07 mg.kg^{− 1}, copper 0.28 ± 0.06 mg.kg^{− 1}, and zinc 153.93 ± 67.08 mg.kg^{− 1}, respectively. The total percentage of pathological spermatozoa was 41.61 ± 9.80% with predominancy of broken flagellum, flagellum torso and separated flagellum. In relation to trace elements the analysis showed correlation between copper and lead (r = −0.47), nickel and iron (r = 0.36), lead and flagellum ball (r = −0.39), cadmium and large heads (r = 0.37) and between iron and other forms of pathological spermatozoa (r = −0.32). Results of this study describe possible effects of trace elements on the spermatozoa quality in normal human sperm.