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Politics : Formerly About Advanced Micro Devices -- Ignore unavailable to you. Want to Upgrade?

To: Scumbria who wrote (135123)	3/29/2001 7:29:47 PM
From: Windsock	Read Replies (1) \| Respond to of 1570917

Scumbria It is absolutely unfair to use scientific journals with peer reviewed articles as evidence. The right wing-nuts hate science -- particularly when it conflicts with their beliefs.

To: Scumbria who wrote (135123)	3/29/2001 7:38:07 PM
From: TimF	Respond to of 1570917

In your own posts you have mentions or quotes from several peer reviewed journal articles (rather then "right wing propaganda outlets") that are skeptical about a massive reduction in sperm counts. Unfortunately both the citations for the supporters of your opinion and those who are skeptical are both at least 6 years old. Seraching more more I find that even most of the sites that do believe that chemicals or tight underwear or a lack of exercise are causeing lower sperm counts give a smaller figure for the difference then your 50% drop estimate. Here are a couple of links about studies of this issue that show no reduction or no significant reduction. Neither is from a "right wing propaganda outlet". msnbc.com March 17 — Average sperm counts from American men have not changed over the past 50 years, according to a new study that disputes the theory that tight underwear, pollution and sedentary jobs are threatening virility. personalmd.com No Decline In Us Sperm Counts NEW YORK, Jan 25 (Reuters Health) -- Contrary to the results of previous studies, American men's sperm counts are not on the decline, researchers report. They believe an over-reliance on studies based in New York City -- where sperm counts are higher than average -- has led experts to the misconception that the fertility of the American male is under threat. "When accounting for this geographic difference and examining all available data, there appears to be no significant change in sperm counts in the US during the last 60 years," conclude investigators at Columbia University in New York City. Their findings are published in the February issue of The Journal of Urology. Numerous studies have suggested that sperm counts in the US and throughout the world have dropped by up to 50% over the past half-century. "The implications (of such a decline) would be tremendous," according to the investigators. However, the researchers realized that 87% of US sperm-count studies performed before 1970 were performed in one geographic area -- New York City. And they also knew that average sperm counts vary widely from place to place -- most notably, New York City men tend to have sperm concentrations about a third higher than men in other US cities. Therefore, the researchers theorized that "because most of the early studies originated from New York, and because New York has higher mean sperm counts than the rest of the country, an apparent downward decline appears if the data are not separated." To test their theory, they decided to examine data from all 29 US-based sperm count studies undertaken between 1938 and 1996. They then 'factored out' the New York-based samples. The result? "When New York studies were separated from the others... analysis failed to demonstrate a significant change (in sperm counts) with time," the authors report. Based on this finding, they suggest that previous studies tracking changes in US and world sperm counts could be "severely flawed." A more interesting question, they say, is why sperm counts vary so widely from place to place. The Columbia team believes this disparity could be due to geographic differences in "climate, seasons, ethnicity, socioeconomic factors or other unknown reasons." SOURCE: The Journal of Urology 1999;161:460-462. usc.edu Sperm counts unchanged over 50 years, USC study finds Sokol added that this new study was both large and well designed, so that the results can be trusted to be an accurate reflection of sperm quality among American men. She noted that, coincidentally, the pool of men who provided semen samples primarily worked in blue-collar jobs that could have exposed them to significant environmental toxins--so if a drop was found and if pollutants were the cause, it would have been likely to be represented in the findings. Sokol and her colleagues nevertheless found that values for the average sperm count was identical to the count reported in the 1950s. stats.org And when the post-1970 studies are examined by themselves, they show an actual increase in sperm counts between 1970 and 1990. Furthermore, it turns out that a single 1951 study accounted for a thousand of the 1,780 subjects studied before 1970; the BMJ authors acknowledge that "this early paper is...responsible for a considerable part of the observed decline" in sperm counts. But a coauthor of the large 1951 study subsequently published a 1979 paper (not included among the 61 jointly analyzed studies) that found no decline in mean sperm counts between 1951 and 1977. Furthermore, researchers know that an individual male's sperm production varies dramatically from week to week; this variation renders questionable the decision to compare 61 studies that lacked standardized conditions for collecting specimens.

To: Scumbria who wrote (135123)	3/29/2001 10:34:52 PM
From: FJB	Read Replies (1) \| Respond to of 1570917

RE:"Decline in Semen Quality Among Fertile Men in Paris During the Past 20 years," "Falling sperm quality," BRITISH MEDICAL JOURNAL "Evidence for decreasing quality of semen during past 50 years," BRITISH MEDICAL JOURNAL "Changes in Testicular Cancer in Scotland," Etc., etc. You seem to have done a dump of some kind of web search. I think you should dig through the data and find that which supports your claim of "Did you know that sperm counts in the US have dropped by 50% in the last 30 years? " Clearly, you aren't the scientific type. Just present the data to support your claim, not irrelevant garbage. BTW, I'm not sure your claim is incorrect, but I would like to see the article and data that support it. You could not have pulled the claim out of thin air.