Exposure to multiple metals/metalloids and human semen quality: A cross-sectional study.
BACKGROUND
Exposure to metals/metalloids, including essential and nonessential elements, has been associated to male reproductive health in animals. However, findings from human studies are inconsistent.


OBJECTIVES
To investigate the impact of exposure to multiple metals/metalloids at environmental levels on the conventional human semen-quality parameters.


MATERIALS AND METHODS
Men living in rural or industrial areas were recruited by personalized letters. No exclusion criteria were applied. Each man provided one semen sample and one blood sample. We analyzed the semen sample both to determine conventional sperm parameters (concentration, progressive motility and normal forms) and to quantify lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), vanadium (V) and selenium (Se) levels. The levels of these metals/metalloids were also quantified in venous blood and spermatozoa samples. Associations between the blood/seminal plasma metal/metalloid levels and semen quality parameters were assessed using confounder adjusted logistic regression models. Correlation and interactions between blood/seminal plasma and semen metal/metalloid levels were investigated using the Spearman's correlation.


RESULTS
We found a positive association of seminal plasma cadmium level with lower Total count (OR = 4.48, 95%CI 0.25-80); whereas lead (OR = 4.51, 95%CI 0.86-23) and cadmium (OR = 3.45, 95%CI 0.77-16) seminal plasma levels had a positive association with progressive sperm motility. Overall, these associations remained suggestive after adjustment, though statistically unstable risks. Finally, we found weak interactions between beneficial effects of Se and detrimental ones only for Cd and Pb blood level on sperm concentration, total sperm count and progressive sperm motility.


CONCLUSIONS
Our findings suggest that environmental exposure to Pb and Cd contributes to a decline in human semen quality, whereas Se can have beneficial effects. Measurements of metals/metalloids in the seminal fluid may be more predictable of semen quality than conventional blood measurements.
['Calogero|Aldo E|AE|', 'Fiore|Maria|M|', 'Giacone|Filippo|F|', 'Altomare|Maria|M|', 'Asero|Paola|P|', 'Ledda|Caterina|C|', 'Romeo|Giulietta|G|', 'Mongioì|Laura M|LM|', 'Copat|Chiara|C|', 'Giuffrida|Maria|M|', 'Vicari|Enzo|E|', 'Sciacca|Salvatore|S|', 'Ferrante|Margherita|M|']
D000328:Adult D001151:Arsenic D001826:Body Fluids D002104:Cadmium D003430:Cross-Sectional Studies D004781:Environmental Exposure D006801:Humans D008297:Male D008628:Mercury D058955:Metalloids D008670:Metals D009532:Nickel D012643:Selenium D012661:Semen D055101:Semen Analysis D013076:Sperm Count D013081:Sperm Motility D013094:Spermatozoa D014639:Vanadium
Metals/metalloids Semen quality Environmental pollution Male infertility