**2.7 Diet**

Nutrition and diet have a great impact on sperm quality. Balanced and proper nutrition improves fertility and sperm quality [19]. High-fat dairy, coffee, alcohol, sugary drinks, and processed meats are associated with low sperm quality and low fertility. Low-fat dairy products, grains, poultry and fish, vegetables and fruits increase sperm quality [19].

### **2.8 Other lifestyle risk factor**

An important risk factor for male infertility is genital heat stress caused by increased scrotal temperature. Varicocele, exposure to radiant heat, cryptorchidism, and prolonged sitting can all lead to testicular heat stress [20]. Increased scrotal temperature leads to spermatogenicsuppression, sperm DNA damage, oxidative stress andgerm cell apoptosis [21]. Cycling is associated with an increase in testicular temperature [22]. The detrimental effects of sleep disorders on male fertility are likely, as semen volume is lower in patients who have difficulty starting to sleep, such as smokers and alcoholics [23]. Radio frequencies emitted from a mobile phone and exposed to magnetic radiation can have devastating effects on the testicles [24]. A study has shown that exposure to mobile radiation can reduce sperm motility and viability [25], While another study showed that these destructive effects occur only in vitro [26].

The role of environmental pollution is critical because of its impact on sperm quality [27]. Since 1960, the rate of male infertility in industrialized countries has risen from 7–35% [28]. Research has shown with certainty that environmental toxins have a detrimental effect on male fertility in many ways. These toxins reduce the number and function of sperm [29]. The worst toxins that interfere with fertility bisphenol A (BPA), organochlorine compounds (chlorinated pesticides, polychlorinated biphenyls, and dioxins), and organophosphate pesticides and herbicides. However, many other chemicals, metals, and air pollutants seriously damage fertility [29]. In infertile couples, mercury levels were significantly higher than in the control group [30]. There is a significant relationship between blood cadmium levels in men and infertility [31].

### **3. Bisphnol A**

The plastic monomer and plasticizer BPA is one of the chemicals produced worldwide, producing more than 66 million pound a year [32]. BPA is used in the production of epoxy resins and polycarbonate plastics used in metal cans and in many plastic products, including water pipes, sports safety equipment, dental monomers, toys, spectacle lenses and pipes [33]. Oral exposure to bisphenol A occurs more frequently. Another possible route that exposes humans to bisphenols is by inhalation and through the skin [34].

### **3.1 Metabolism and toxicokinetics**

Bisphenol is metabolized in the liver by uridine 5-disphospho-glucuronyl transferase (UGT), and is catalyzed by glucuronidation (**Figure 1**) [35].

BPA interacts with estrogen receptors due to its phenolic structure and acts as an antagonist and agonist through endocrine receptor-dependent (ER) signaling pathways [36]. Accordingly, BPA appears to play a role in the pathogenesis of endocrine disorders including infertility in both men and women [37].

As the concentration of BPA in the urine increases, the number of sperm per ejaculation decreases. It also reduces sperm motility and sperm viability [38]. The results of clinical research conducted in recent decades have shown that the destructive effects on the endocrine glands of bisphenol A on male reproductive function, possible mechanisms by which bisphenol A may regulate spermatogenesis, mainly through the hypothalamic–pituitary-gonadal axis Specify to be involved [39]. In rodent models, with the exception of some cases, in vitro exposure to BPA at different doses (largely ranging from2 μg/kg/day to 960 mg BPA/kg body

*The Effects of Bisphenols on Semen Quality DOI: http://dx.doi.org/10.5772/intechopen.99171*

**Figure 1.** *Structure of bisphenol.*

weight/day) and time intervals (from 5 to 84 days) caused a significant reduction in sperm count [40–43], sperm motility [41, 44], normal sperm morphology [42], increase in sperm DNA damage [44], and poor spermatogenesis [45, 46]. In a study adjusted using linear regression of confounders, increased urinary BPA levels were significantly associated with decreased total sperm count, decreased sperm motility, decreased sperm viability, and decreased sperm concentration [47]. BPA can affect sperm density and quality [48].
