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Sperm Count Concerns Scientists

Two years ago when fertility specialist Gil Wilshire came to Columbia from his practice in New Jersey, one detail jumped out at him. His male patients in Mid-Missouri were much less fertile than those he treated on the East Coast.

Source: Environmental Health Perspectives, research done in part by the Department of Family and Community Medicine at the University of Missouri

"Nobody I saw had a normal sperm count," said Wilshire, a reproductive endocrinologist at Mid-Missouri Reproductive Medicine and Surgery Inc. "It took about two or three weeks until a normal semen analysis came through the door. I kept asking myself, 'Am I in a hellhole of toxins?'"

Danny Schust, another endocrinologist who arrived here from Harvard University in 2006, had an almost identical experience. He was accustomed to treating men with low sperm counts, but those he saw in Missouri all had low counts.

"I went to" an andrologist at the Missouri Center for Reproductive Medicine and Fertility. "And I said, 'Are you guys doing something different here because I never see normal sperm counts?' " Schust recalled. "And she was like, 'No, this is Missouri sperm.' "

Their stories are part of a chorus of local people who work in the field of male fertility asking questions about low sperm counts in Mid-Missouri. Some suspect pesticides have percolated into ground water, but no definitive link is known. They say they are frustrated by the lack of attention to the problem and the lack of funding for further research.

"We don't see very many normal samples. ... It's completely a mystery," said Erma Drobnis, the andrologist working at Columbia Regional Hospital with Schust. She said in recent years, she and other researchers have tried repeatedly to get funding from the National Institutes of Health to examine the problem, without success.

The problem is not new.

In 1999, a group of researchers including Drobnis were working on a study comparing semen quality across major metropolitan areas, suspecting that sperm counts were dropping worldwide. They selected New York, Minneapolis and Los Angeles for their study. But reviewers of the grant application recommended adding add another, more rural town. They selected Columbia.

Researchers believed that including Columbia would serve as a baseline by which to judge the other cities. More rural settings, so the theory goes, tend to have fewer toxic pollutants such as smog in the air that impact reproductive health.

So researchers were caught off-guard when the Columbia sperm samples turned out to be significantly lower than samples from three other cities. The sample of Columbia men had average sperm counts of 58.7 million sperm per milliliter, or about 57 percent of those in New York. All cities studied were considered within the normal range, but Columbia pushes at the lower end.

"We were very surprised," said Shanna Swan, the lead researcher on the study who is now at the University of Rochester in New York.

Because the men in the Missouri study were from different backgrounds, variable ages and occupations, and they had lived in the area for both short and long periods of time, scientists labeled the cause for the low sperm counts "environmental." They said drinking water was the most likely cause.

After getting the initial results, scientists subjected the sperm samples from 50 men to a battery of new tests to look for pesticides. They found "significant" links between three common pesticides and low sperm counts in the Missouri men and possible associations with two other pesticides.

This summer, Swann will get the results from a follow-up test by the Centers for Disease Control and Prevention, which tested 400 other men for the same pesticides.

"If we see something similar in a larger data set, then people will really have to pay attention to it," Swann said. "We don't know if it's the water. We suspect that, but we really can't say that until we have more information."

At the request of the Tribune, Barry Kirchhoff, city water plant superintendent, reviewed the findings. He said pesticides that show up in men's sperm samples did not come from Columbia drinking water. He said he almost never sees restricted pesticides in Columbia water.

"We're drawing water from 15 different wells scattered out over areas two miles wide and four miles long," Kirchhoff said. "So if it turns up in source water, it's not going to be here one day, gone the next."

But one of the three pesticides that showed a significant association with low sperm counts also was found in 24 of the samples - an insecticide called diazinon, which is not regulated by the Environmental Protection Agency in drinking water. In 2004, diazinon was banned from residential use, though it is still lawfully used in some agriculture. Another herbicide used for weed control - metolachlor - showed up in 34 of the Missouri semen samples. It also is on the EPA's list of candidates for designation as a contaminant.

Researchers are not exclusively pointing fingers at water. They said any number of factors such as exposure to pesticides on farms, eating fruits and vegetables or even tobacco use could be the cause.

Drobnis said she trusts Columbia water. She doesn't know the reason for the low sperm counts; she just knows it's a problem she has seen ever since she arrived here to practice medicine in 1994.

"Environmentalists have said it's usually not looking at one chemical, it's when you combine everything that you get the problems," Drobnis said. "It's the whole picture taken together" that "can end up giving you a reduction in health."