Impact of Air Pollution on Semen Quality: The Specific Situation of Terni (Central Italy)

Ceccotti, Stefano Brancorsini. Preparation of 3D-Porous Graphene Aerogel for High-Performance Anode of Lithium-Ion Batteries. Biomed J Sci & Tech Res 38(5)-2021. BJSTR. MS.ID.006207. with GraphPad Prism 6.0 and results were reported as mean ± standard deviation (SD). We report an association between ambient air pollution and sperm quality. In patient residents in areas with high environment exposure, sperm quality especially sperm concentration and count decrease significantly. Sperm motility, morphology and vitality did not demonstrated statistical differences. Identifying risk factors to improve the management of human wellness and health throughout standardized analysis, which correlates the toxic bioaccumulation of the seminal fluid with semen parameters, might be the main objective to be considered in public prevention policies.


Introduction
Infertility is a prevalent condition affecting an estimated 72, 4 million people globally that is well recognized by The World Health Organization (WHO). Although prevalence data are lacking, 9% of couples struggle with fertility issues and male factor contributes to 50% of the issues. Many genetic and lifestyle factors have been implicated in male infertility; however, about 30% of cases are still thought to be idiopathic [1]. The mechanism by which medical conditions affect fertility includes effects on hormonal levels, testicular malignancy [3]. Nowadays, environmental and lifestyle factors could be possible contributors to infertility conditions, such as use of smoke sigarettes, increasing of both parents age conception, abuse of alcohol and drugs, physical inactivity, obesity, social stress, exposure to environmental contaminants (polycyclic aromatic hydrocarbons-PAHs, or heavy metals, for examples) and air pollution [4,5]. In particular, epidemiological and experimental studies explained the link between air pollution and alterations of sperm parameters as the main risk factors for male infertility.
Human activities such as transport, industrial and agricultural emission are considered the main causes of air pollution (solid particles, liquid droplets or gases), and people that living near these area, are more exposed to henanced emission source of carbon monoxide (CO), nitrous dioxide (NO 2 ), sulfur dioxide (SO 2 ), ozone and lead [6]. Ambient air pollution is associated with systemic increases in oxidative stress, to which sperm are particularly sensitive. In this contest, reactive oxidative species (ROS) have been related with a broad array of spermatogenensis effects, including the decrease of progressive motile sperm count, viability, abnormal sperm morphology, and fertilization rate and spermatogenic cell numbers [7]. In Italy, 12,482 areas with a high risk of environmental pollution, mainly due to industrial emission, were been identified.
Some central provinces, such as Città di Castello, Foligno and Perugia exceeded the limit set for particulate matter with diameter less than 10 microns (PM 10 ) and O 3 emissions, in 2019. In particular, Terni is one of the most polluted urban and industrial area in Central Italy [8]. In fact, is situated in an intermountain depression, delimited by the Apennine mountain range. This area is characterized by the presence of typical urban PM 10 emission sources such as vehicular traffic, domestic heating and industrial emission sources from a power plant for waste treatment. Peculiar geomorphological and meteorological conditions of Terni basin, limit the dispersion and augment the accumulation of the atmospheric pollutants.
The "Thyssen Krupp AST", a large steel factory founded at the end of 19 th century and two more recent chemical industrial areas, are located close to the city center [9]. As a result of the intensive industrial activities and the geographical location, atmospheric pollution is the major local issue with high PM concentrations occurring throughout the year. According to European Commission Law, the daily maximum PM 10 concentration allowed in cities is 50 μg-3 [9]. The threshold has not to exceede more than 35 times per year. In Terni, the atmospheric PM 10 concentration exceede that daily limit on more than 70 days in 2012, as recorded by Regional Agency for Environmental Protection (ARPA), Umbria. The aim of the present study is to provide an association between ambient air pollution and sperm quality, analyzing seminal biofluid parameters of man living in the urban area of Terni-Papigno, with a high risk of pollution, comparated with those who live in rural areas with low risk of pollution.  (Table 1). Sperm motility was assessed in 200 random spermatozoa and characterized as progressive and non-progressive motility.

Study Participants
The total motility was calculated as the sum of progressive and non-progressive motility. Both progressive and total motility were expressed as percentages. Sperm morphology was evaluated in 200 spermatozoa and the value was expressed as percentages. Finally, the vitality was assessed using eosin staining according to the WHO recommendations [10].

Statistical Analysis
Data were analyzed with GraphPad Prism 6.0. Results were reported as mean ± standard deviation (SD) Analysis of variance and Kruskal-Wallis tests were performed. The significance threshold was set at 0.05.

Patients were classified according to Demographic and
Environmental characteristics (Table 1    in sperm concentration [13]. The effect of air pollutants and ozone on sperm quality, was strongly elucidated by Sokol, et al. [14]; they reported that pollutants have no effect on sperm quality, however, ozone could make changes in sperms, including sperm DNA fragmentation via oxidative stress, resulting in decreased fertility [14]. The toxicity of O 3 was largely demonstrated to be the major oxidant of photochemical smog and its exposure produces reactive ROS at respiratory level [15,16]. Extra pulmonary toxicity suggests that O 3 or O 3 reaction-products can cross blood-gas barrier and be absorbed into the circulating bloodstream, creating an environment caring to an inflammatory reaction [17,18]. It is unclear how O 3 can negatively affect sperm quality, but O 3 -induced oxidative stress could be a possible mechanism, through which testicular and sperm function could be altered [19,20]. Under physiologic conditions, spermatozoa exist in a balanced environment of ROS and antioxidants, where ROS determine the biochemical steps required for normal fertilization (capacitation and the acrosome reaction).
However, excessive amounts of ROS produced by leukocytes and immature spermatozoa can damage mature spermatozoa and the integrity of sperm DNA [21,22]. Concerning seminal volume (mL), our results did not reach significant difference between groups considered ( Figure 3). Several studies suggested that alterations of semen parameters, including volume, progressive motility, total motility or morphology, may not relate to air pollution [23].
Several works observed a reduction of both sperm motility and morphology, associated with air heavy metals (lead, mercury and cadmium) [24,25], that determine alterations in sperm DNA.
Rubes and colleagues showed that short-term exposure to pollutants caused serious damages in men and women's reproductive system. Moreover, this study demonstrated that the incidence of sperm DNA alterations due to air pollution is higher in middle-aged men [26]. Also, exposition time of contaminants seem to be determinant, in fact a study of Hammoud showed that 3 months exposure to air pollution decreases motility levels, while removing contamination can restore normal parameters levels [27].
In an extensive cross-sectional study, Xu and co-workers, founded a strong correlation between motility, concentration, and morphology of semen biofluid of men exposed to air pollutants with the use of cigarette and alcohol [28]. On the other hand, Selevan, et al. [29] did not observed any relevant alerations in sperm count, motility and morphology of young men exposed to air pollutants, except for sperm DNA and chromatin [29]. Moreover, several authors specify that the morphological change of spermatozoa after exposure to pollutants is not an indicative diagnostic parameter. Association between air pollution and alteration of specific semen parameters is not clear and different relevant factors, such as geographic areas and lifestyle, should be considered for male infertility diagnosis.

Conclusion
The current study provides evidence of an association between ambient air pollution and sperm quality. Patient residents in areas with high environment exposure had a significantly decrease in sperm quality especially for sperm concentration and count but had no impact on the other sperm parameters of spermogram (motility, morphology, vitality). The individual role of specific pollutants is difficult to identify, since patient in this study are typically exposed