Environmental factors and semen quality

Abstract

Objectives: An increasing number of reports suggest that chemical and physical agents in the environment, introduced and spread by human activity, may affect male fertility in humans. This article aims at evaluating the impact of environmental exposures (pesticides, phthalates, PCBs, air pollution, trihalomethanes (THMs), mobile phones) on semen quality, by reviewing most recent published literature. Materials and Methods: Epidemiological studies focusing on exposure to environmental factors and semen quality for the last ten years were identified by a search of the Pubmed, Medline, Ebsco, Agricola and Toxnet literature bases. Results: The results from the presented studies suggest that there are strong and rather consistent indications that some pesticides besides DBCP (e.g. DDT/Dichlorodiphenyldichloroethylene [DDE], ethylenedibromide, organophosphates) affects sperm count. PCBs are detrimental to sperm motility. In case of air pollution, studies suggest a link between ambient air pollutants and various semen characteristics. Additional research is needed to corroborate this association and to establish the causal agents. Results of few studies on subfertile men demonstrate associations between phthalate levels commonly experienced by the public and impaired sperm quality (impact on sperm concentration, morphology, motility), but the findings have not been corroborated in studies of men from the general population. Mobile phones might adversely affect the quality of semen by decreasing mostly motility but also the sperm counts, viability and morphology. In spite of their consistent results, most of the studies are rather small. Association between exposure to THMs and poor semen quality was not observed. Conclusions: Epidemiological studies suggest awareness of environmental factors which may affect semen quality. In case both of well proven and disputable reproductive and developmental hazards, it is necessary to prevent parental exposure to the agents associated with those hazards.

Reproductive Toxicity of Metals in Men

“…Several studies established an increasing incidence of various abnormalities of the human reproductive system, including a decreased sperm count and an increased incidence of testicular and prostate cancer (2-7), but also great differences among countries and different locations within a country. This has triggered an increasing interest in the possible causes of these abnormalities and factors that contribute to this deterioration and the geographical differences, including environmental and lifestyle factors (8)(9)(10)(11)(12)(13).…”

Spermatozoa as biomarkers for the assessment of human male infertility and genotoxicity

“…Sperm biomarkers as a tool for assessing environmental hazards Epidemiological studies have reported that semen quality can be altered by a broad variety of chemical and physical environmental factors [Jurewicz et al 2009]. Despite the increasing interest in this field, the strength of the associations while evident, still remain uncertain.…”

“…Male fertility can be impaired by a wide array of environmental/occupational hazards (reviewed by [Jurewicz et al 2009]). One of the hallmarks of the modern industrial age is the continued decline in the concentration of sperm that characterizes the normal fertile human male [Carlsen et al 1992;Swan et al 2000].…”

Influence of Male Obesity on Fertility

“…Most environmental contaminants are lipophilic and accumulate in fatty tissue around the scrotum and testes or elsewhere in the body. Epidemiological studies evaluating the impact of environmental exposures to pesticides, phthalates, polychlorinated biphenyls (PCBs), air pollution, trihalomethanes and mobile phones on semen quality suggest awareness of environmental factors which may have a detrimental eff ect on the semen quality 41 . Although PCBs were banned by most countries several decades ago, the general population continues to be exposed due to their persistence and bioaccumulation and therefore concerns regarding the altered male fertility in relation to PCBs remain present 42 .…”