Environmental Estrogen Endocrine Disruptors



Men's Health

Women's Health

Wildlife Health and Populations



Government Response

Environmental Estrogens in Minnesota


Endocrine Disrupters in Minnesota

Mystery Frogs in Minnesota.

Feminized Fish in Minnesota?

Pesticides causing Birth Defects in Minnesota?

Mystery of Sperm in Minnesota

Mystery Frogs in Minnesota

In 1995, a group of Minnesota middle-schoolers discovered a large colony of malformed frogs at a local state park.

Scientists around the world have found similar malformations and are attempting to find out why these mutations are occurring.

The most popular theories are environmental estrogens, increasing levels of UV light, other pollutants, and microscopic parasites.

Why are frogs so affected?

  • Frogs have very permeable skin and are very sensitive to changes in water and the environment.

  • Jeff Canfield, who studies amphibian diseases and a rash of new, unexplained frog malformations in Minnesota at the state's Pollution Control Agency. "Frogs don't have a lot of protection against pollutants," says Canfield. "As a consequence, they make excellent environmental indicators."

Useful Links and References

1. Friedman, Kenneth. Possible Cause Found for Frog Deformities: Sunlight. Published on: January 9, 1998 www.suite101.com/articles/ article.cfm/4434 . Accessed 10/22/2003

2. Minnesota Pollution Control Agency. With the malformed frogs, researchers are investigating endocrine disruptors as one possible reason in Minnesota. This is a very useful and comprehensive site: http://www.pca.state.mn.us/hot/frogs.html. Study of Frogs was stopped by the MN legislature in 2001 due to funding cuts. This article describes how their research has discounted natural causes. Top theories according to this article are UV Light, Endocrine Disrupters, or chemicals or something in the water. http://www.pca.state.mn.us/hot/frog-latest.html

3. North American Reporting Center for Amphibian Malformations:
Amphibian Malformation Guide http://www.npsc.nbs.gov/narcam/pictures/looklike.htm
Minnesota Frog Statistics: http://www.npsc.nbs.gov/narcam/reports/states/27.htm. This link maps where deformed frogs have been found in Minnesota. Accessed 10/22/2003

4. Our Stolen Future :About Deformed frogs and endocrine disrupters
http://www.ourstolenfuture.com/NewScience/wildlife/frogs/frogdeformities.htm. Explores top theories of frog deformities and explores the issue of frogs and endocrine disruptors. This site has much information about endocrine disruptors.Accessed 10/22/2003

5. USGS website: There is a great discussion about deformed frogs on this site. www.npwrc.usgs.gov/narcam/info/news/20010102.htm.. This site also makes a mention of deformed dragonflies that were found in MN, although there's really no direct reason to think that's a result of endocrine disruptors.

• U.S. Department of the Interior USGS Fact Sheet 043-01. U.S. Geological Survey May 2001
Endocrine disruptors also are being studied to determine if they are responsible for some of the frog malformations in Minnesota. www.water.usgs.gov/pubs/ FS/fs-043-01/

• Radiographic Evaluation of Malformed Frogs in Minnesota, Maine, and Vermont.
http://www.nwhc.usgs.gov/research/amph_dc/frogxray.html. Accessed 10/22/2003

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Feminized Fish in Minnesota?

• Feminized fish are on the rise in many parts of the world. They were first found in the UK downstream from sewage production plants.

• In Duluth Minnesota researchers have found that male fathead minnows placed in treated sewage water here have developed female characteristics -- a sign of hormone-disrupting chemicals.

• Male walleyes tracked in the Mississippi River have been found to be sterile, apparently from estrogen-like compounds from a sewage plant that disrupted their hormone systems.

• Researchers are working hard to assess the effects of endocrine disrupters on sperm viability and testicular development in fish in Minnesota.

• There is much debate about the causes of feminized fish, one of the most prevalent theories is low levels of estrogen hormones such as "Ethinylestradiol , the active ingredient in the birth control pill or natural female hormones.

• Other theories include estrogen-mimicking degradation products of alkylphenol ethoxylate surfactants (compounds used in such things as pesticides, detergents, and cosmetics) and the plasticizers.

Useful Links and References

1. Mindfully. org
Article from the Associated Press in Duluth concerning male fathead minnows placed in treated sewage water developing female characteristics -- a sign of hormone-disrupting chemicals. http://www.mindfully.org/Water/Minnesota-Disrupted-Fish.htm
Accessed 10/22/2003

2. Sorenson, Schoenfuss, Aldman, Swackhamer. Assessing the Effects of Endocrine Disrupters from a St. Paul Sewage Treatment Plant on Sperm Viability and Testicular Development in Fish: Adding a New Dimension to an Existing Project. WRC Research 2001. http://wrc.coafes.umn.edu/pubs/tech142/sorenson.pdf. Accessed 10/22/2003

3. University of Minnesota: Control via Pheromones, studying fish and hormones . Information about studies that is being done at the University of Minnesota on Fish: Control via Pheromones, studying fish and hormones.
Accessed 10/22/2003

4. Water Observatory Web site.
Mersham, Tom. MISSISSIPPI RIVER WALLEYE FEMINIZED. Minneapolis Star Tribine. April 18, 1998. http://www.waterobservatory.org/News/news.cfm?News_ID=72
Accessed 10/22/2003

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Pesticides Causing Birth Defects in Minnesota?

• A study was done in 2003 that compared rates of birth defects in counties where wheat was grown abundantly and where it was not.

• Some researchers concluded that herbicides used on wheat may be causing birth defects

• Although causation has not been proved, Babies born in wheat growing areas of the US west are more likely to have several types of birth defects than babies born in the same region but where wheat is less common.

• The link between the birth defects seen and the herbicides used on wheat are biologically plausible.

• The chances of birth defects rose for babies conceived in the spring, when herbicide spraying was most intense. Boys born in April-May in high wheat growing counties were almost 5x more likely to have a birth defect than boys born in low wheat counties at other times of the year.

• Infant death due to congenital abnormalities was higher in boys born in wheat growing counties compared to boys in low wheat counties. Most of the infant boys' deaths were caused by heart and musculoskeletal birth defects. No comparable elevation in risk of infant death was seen for girls.
This information was retrieved from http://www.ourstolenfuture.org/NewScience/oncompounds/chlorophenoxy

Useful Links and References

1. Garry VF, Holland SE, Erickson LL, Burroughs BL. Male reproductive hormones and thyroid function in pesticide applicators in the Red River Valley of Minnesota. J Toxicol Environ Health A. 2003 Jun 13;66(11):965-86. A study of the health of pesticide applicators in the red river valley .Accessed 10/24/2003

2. Kids for Saving the Earth Site. Great information on Pesticides and Human Health. Refers to Minnesota. http://www.kidsforsavingearth.org/mnchec/articles/pesticides.htm
Accessed 10/22/2003

3. Our Stolen Future. This page talks about pesticide use in Minnesota and Birth Defects. It has a link to an article published in July 2003
Schreinemachers, DM. 2003. Birth Malformations and Other Adverse Perinatal Outcomes in Four U.S. Wheat - Producing States. Environmental Health Perspectives 111:1259-1264. http://www.ourstolenfuture.org/NewScience/human/humepi.htm

4. Bigsplat. Environmental Alert: Pesticides
Talks about Endocrine Disrupters and Mentions birth defects in Minnesota that may be related to pesticide use. http://bigsplat.net/organization/sole/pest.html. Accessed 10/24/2003

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Mystery of Sperm in Minnesota

• There is great debate about whether or not sperm counts have gone done across the world. A famous study in 1992 from Denmark came to the conclusion that sperm counts have gone down about 1% per year for the past 50 years. This study was quite controversial.
• Pollutants such as pesticides, plastics, nuclear waste, and detergents have been hypothesized to be the causes.
• There is evidence of reduced fertility in chemical and nuclear plant workers, and the fertility problems of many members of the animal kingdom that have been linked to environmental chemicals.
• There also seems to be a correlation between the amount of pollution in an area and sperm counts among males that live there.

A recent study showed that Minnesota sperm counts are high.

• Geographical differences have been seen across the US.

• A recent study compared sperm counts in Minneapolis, Minnesota, Columbia, Missouri, New York, NK and LA, California. They found Missouri to be quite a bit lower.

• One of the nations largest and oldest sperm banks is in Roseville, Minnesota and did not find changes in sperm counts over time.

The Rake in the October 2003 issue hypothesized some of the reasons for these high counts.

The Rake Theories on Minnesota Sperm Count

- Sperm are one of the few living cells that thrive in winter. Some of the highest sperm counts on the planet are in frigid Finland.
- Researchers know that sperm counts tend to fall in warmer summer temperatures—which might explain why California, the land of endless summer, has such a lethargic sperm population.
-Columbia, MO is more rural than the other cities study. Perhaps Minneapolis men are less exposed to pesticides than men in more rural areas.
- The study only looked at Minneapolis men, these things may not apply to rural men.

Useful Links and References

1. Geary, Debora. T. Why Are Sperm Counts So High in Minnesota? The Rake. October 2003 by Debora Geary http://www.rakemag.com/angle/detail.asp?catID=40&itemID=7597
Accessed 10/24/2003

2. Meersman, Tom. Spermatically speaking, Minneapolis men beat their country cousins. Star Tribune Published Nov. 12, 2002 http://forums.macrumors.com/archive/topic/14188-1.html
Accessed 10/24/2003

3. Our Stolen Future. Large Geographic Differences in Sperm Count.
http://www.ourstolenfuture.org/NewScience/reproduction/sperm/2003/2003-0201swanetal.htm.. Accessed 10/24/2003

4. Practical Hippie Website. Resource for information and sources for more information on sperm counts. Articles about what to consider when looking at sperm counts and the environment. Useful if general information about sperm counts in needed. http://www.practicalhippie.com/sperm.htm. Accessed 10/24/2003

5. Swan, SH, C Brazil, EZ Brobnis, F Liu, RL Kruse, M Hatch, JB Redmon, C Wang, JW Overstreet, and the Study for Future Families Research Group. 2003. Geographic differences in semen quality of fertile US males. Environmental Health Perspectives 111. doi:10.1289/ehp.5927. Accessed 10/24/2003

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