*Not many studies->difficult to do
*Decreased sperm motility is associated with air pollution in Salt Lake City
*Analysis of levels of particulate air pollution (particulate matter [PM] 2.5) over a five-year period in relation to sperm parameters obtained from semen analyses     and separately in relation to sequences of sperm parameters at the time of semen preparations for artificial insemination.
*The study included 1,699 semen analyses and 877 inseminations.
*PM 2.5 levels were highest in the winter months, when the ambient temperature was the lowest. Semen analysis data showed that values of PM 2.5 were    negatively correlated to sperm motility two months and three months following the recording of the PM 2.5 values. Artificial insemination data also showed that  sperm motility correlated negatively with PM 2.5 values recorded three months previously. CONCLUSION(S): Both semen analysis and sperm parameters data  obtained from men presenting for multiple inseminations over time showed that air pollution is associated with reduced sperm motility two to three month after  exposure.

Fertil Steril. 2009 Feb 11-Hammoud et al