See other Science/Tech Articles
Title: Scientists think pesticides led to frog sex changes
Source:
LAT via HC
URL Source: http://www.chron.com/cs/CDA/ssistory.mpl/bizarre/3102897
Published: Mar 28, 2005
Author: unlisted
Post Date: 2005-03-28 06:18:33 by 2Trievers
Keywords: Scientists, pesticides, changes
Views: 146
Comments: 4
Scientists who compared frogs collected over the past 150 years have discovered a dramatic increase in hermaphrodites during the times when contamination from the pesticide DDT and other organochlorine chemicals was widespread. Frogs with both male and female reproductive organs were rare in the 19th century and early 20th century but abundant during the 1950s, when the largest volumes of the popular chemicals were used. The findings were reported earlier this month in the journal Environmental Health Perspectives. The ability of chemicals to mimic or block estrogen and testosterone, critical for normal reproduction, is considered one of the most disturbing discoveries in environmental science of the past decade. Scientists believe the phenomenon has been occurring for decades but wasn't documented in wildlife until the early 1990s, when it was observed first in Florida alligators and then many other species. Toxicologists and veterinarians at the University of Illinois at Urbana-Champaign, led by Amy Reeder, examined the reproductive organs of 814 cricket frogs collected in Illinois between 1852 and 2001 and stored at natural history museums. Cricket frogs, once abundant, declined dramatically around Chicago and other regions in the 1960s, and the scientists found that the times and places with high rates of hermaphrodites, also called intersexes, overlapped with when and where the frogs disappeared in Illinois. The scientists theorize that DDT, PCBs, and other contaminants had an anti-estrogenic effect, reducing the proportion of females and causing them to develop skewed sex organs, triggering a population crash, particularly in the Chicago region. "These guys have been around a long time, since before the dinosaurs, and they are declining all over the place," said Val Beasley, a co-author of the study and a professor of ecotoxicology at the university's College of Veterinary Medicine. "Endocrine disruptors seem to be a factor, but certainly not the only factor."
Post Comment Private Reply Ignore Thread
Top • Page Up • Full Thread • Page Down • Bottom/Latest
#1. To: 2Trievers (#0)
Note to San Franciscans: Does not work in humans.
F.A.G.S. is the new enumeration for the FEDGOV personnel (nearly-human resources) department. Regardless of Party Affiliations, queers, paedophiles and serial murderers will now be given preferential treatment in hiring. Federal Agency Gay Sanctioning [F.A.G.S.] authority will be managed by the homo- land defense agency, and administered by NAMBLA. Janet Reno, has been asked to report for duty by Hillary Clinton in an effort to "get the agency off" ... to a great start.
Tracie21230 will be crushed to hear that.
#2. To: 2Trievers (#0)
Republicans and Democrats with both male and female reproductive organs were rare in the 19th century and early 20th century but abundant during the 1950s, when the largest volumes of nazis and the popular chemicals such as cocaine and oxycontin were imported.
#3. To: Tauzero (#1)
Does not work in humans.
#4. To: Tauzero (#1)
Top • Page Up • Full Thread • Page Down • Bottom/Latest