Environmental factors and semen quality.
OBJECTIVE
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.


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.
Jurewicz
Joanna
J
Department of Environmental Epidemiology, Nofer Institute of Occupational Medicine, Łódź, Poland. joannaj@imp.lodz.pl
Hanke
Wojciech
W
Radwan
Michał
M
Bonde
Jens Peter
JP
D040421:Cell Phone; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000633:toxicity*; D006801:Humans; D007248:Infertility, Male / Q000139:chemically induced*; D008297:Male; D010575:Pesticides / Q000633:toxicity; D010795:Phthalic Acids / Q000633:toxicity; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D012307:Risk Factors; D012661:Semen / Q000187:drug effects*; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects; D022882:Trihalomethanes / Q000633:toxicity
D004785:Environmental Pollutants; D010575:Pesticides; D010795:Phthalic Acids; D022882:Trihalomethanes; C032279:phthalic acid; D011078:Polychlorinated Biphenyls