SAN DIEGO -- New research shows a link between lower sperm and the air we breathe.

What does it mean for men who are trying to conceive?

Pollutants in our air can do more than hurt our lungs, it could also affect a man's fertility -- that's the finding of a three year study done by researchers from Keck School of Medicine at University of Southern California.

Researchers analyzed sperm samples donated by 50 men living in Los Angeles.

The samples were compared to air pollution measurements from the zip code where each man lived.

The bottom line was the more smog in the air, the lower the sperm count.

"This study found there was a decrease in the average count of all 50 donors by 4 percent," said Scripps fertility specialist Dr. Lori Arnold.

The study showed when ozone levels were higher, sperm counts dropped.

Fertility specialists said men shouldn't be overly worried.

"It did not cause infertility, which is very important for patients trying to conceive," said Arnold.

There are some who suspect pollutants in the air could play a role with some people who are having trouble conceiving, 10News reported.

"That may be a factor -- the environment and the toxins in the environment," said fertility patient Jim Bunch.

Bunch's fertility issues were overcome with the help of invitro fertilization.

"There looks like there is good implantation here," said Bunch.

The cause of Bunch's infertility is still a mystery, but he hopes studies like this will give researchers a better understanding that could result in new treatments for couples trying to conceive.

"When you are passionate about something and you want it doesn't matter -- that's all that's important," said Bunch.

This new study supports another one done by scientists from the U.S. Environmental Protection Agency in the Czech Republic.

That study found men exposed to high levels of air pollution were more likely to have poor quality sperm compared to those who lived in an area with less air pollution.