Impossible. Only chemicals can do that. 🙂
“Men’s sperm quality may be significantly affected by their levels of physical activity, according to a new study led by researchers at Harvard School of Public Health (HSPH). They found that healthy young men who were sedentary, as measured by hours of TV viewing, had lower sperm counts than those who were the most physically active. “We know very little about how lifestyle may impact semen quality and male fertility in general so identifying two potentially modifiable factors that appear to have such a big impact on sperm counts is truly exciting,” said lead author Audrey Gaskins, a doctoral student at HSPH. The study will be published online February 4, 2013 in the British Journal of Sports Medicine.” [EurekAlert]
Some of the network ads played on “family friendly shows” could affect sperm couny if anything on TV would.
Another student paper from Harvard — Harvard is training them well in junkscience. The questionnaires from the Rochester Young Men’s Study database have been used to report all sorts of supposed links, seemingly intent on finding problems with modern lifestyles, all based on weak questionnaire data and ridiculously poorly controlled risk ratios. They’ve reported equally meaningless correlations between sperm counts or motility and “Western” diets — dairy, transfats, red meat — and also anus-scrotum distance, which they attributed to environmental phylates. This Rochester study is associated with the European Union’s DEER (Developmental Effects of the Environment on Reproductive Health) grant, which is looking at environmental chemical contaminant exposures (“endocrine disrupters”, phylates, dioxins…) and sperm quality and metabolic disorders later in life.