Effects of working posture and exposure to traffic pollutants on sperm quality.

An increasing difficulty of couples in achieving pregnancy related to male infertility has been reported. Several factors have been implicated as possible causes of this decrease, including the exposure to the endocrine disruptors and the environmental toxicants, the changes in lifestyle and the exposure to heat. The aim of this study was to evaluate the role of working posture when associated to nitrogen oxides exposure. Three hundred and seven male workers, employed in a motorway company, were enrolled into the study, underwent a complete physical examination and laboratory evaluations, endocrine screening and sperm analysis. Taking into account the exposure to fuel combustion gases and the working posture, sitting or free, the study population was divided in 4 groups. In the subjects occupationally exposed to NO2, a significant lower sperm total motility was observed than in not exposed workers. In the workers with obliged sitting working posture, lower sperm motility was also observed than in the workers with free working posture. Differences in sperm quality were strong when chemical and postural risk factors were associated. The findings of this study confirmed detrimental effects of nitrogen dioxide as a marker of traffic pollutants, showing alterations of sperm quality even if the environmental concentration of gas is very low according to the limits established by the Italian legislation. They suggest, also, the possible interaction between chemical exposure and obliged sitting position.