Intersex Fish and Water Pollution
Sep 15 at 5:05pm by Aileen
Back in February of 2008 the U.S. Geological Survey [USGS] conducted research on smallmouth bass in the Potomac River basin, finding that 80-100% of the fish collected from the Shenandoah were intersex. Meaning that males of the species had testicular oocytes [TO], or immature female egg cells in the testes.
The USGS researchers also documented that the highest prevalence of TO came attached to areas with the highest human populations and most intensive farming activity. This type of birth defect is connected to environmental exposures to endocrine disrupters (hormone precursors that affect the endocrine system), which are found in most agricultural pesticides, herbicides and fertilizers, and in many human/animal drugs. The prevalence of intersex had been at that time documented in other wild fish populations, including spot-tail shiners in the St. Lawrence, white suckers in Colorado, shovelnose sturgeon in the Mississippi, white perch in the Great Lakes, and in several species in the UK, Europe, Africa and Japan.
Intersex associated with endocrine disrupters in wastewater and farm runoff is nothing new, as reproductive anomalies in amphibians has been on the rise especially in farming regions for decades. Now the USGS has published new results of research on intersex in bass in the journal Aquatic Toxicology. They found that a third of all male smallmouth bass and a fifth of all male largemouth bass tested were intersex. The fish came from many different rivers and basins, including the Apalachicola, Colorado, Columbia, Rio Grande, Savannah, Pee Dee and Yukon. The Yukon is the only river basin where researchers found no intersex fish.
The Pee Dee river basin appears to have the biggest problem, though intersex bass are prevalent throughout the agricultural southeast. Relatively high incidence of intersex was also found in the lower Rio Grande basin, the Colorado and Gila in Arizona, and the Colorado basin. Lead author and USGS biologist Jo Ellen Hink suggested that “the widespread occurrence of intersex in fish would be a critical environmental concern.”
Well, duh. Any prognostications on when (or if) EPA and the USDA might get around to being critically concerned about it? Will “Intersex” become the new macho?
Valentine Report: The Science of Kissing
Feb 16 at 6:06pm by Aileen
At the annual meeting of the American Academy for the Advancement of Science [AAAS] in Chicago on Friday the 13th, research was presented by a psychology professor at the University of Albany on the subject of kissing.
CNN reports in its coverage that the science of kissing is called “philematology.” Rutgers professor Helen Fisher says kissing is “a major escalation or de-escalation point in a powerful process of mate choice.” Kissing, says the study’s leader Gordon Gallup, Jr., transmits sensory information – smells, tastes, sound and tactile signals – that affect the couple’s perceptions of each other and whether they want to continue the relationship. In a survey of more than a thousand college students, Gallup and his colleagues found that 59% of men and 66% of women reported that after the first kiss their attraction ended.
The subconscious processing of the sensory information received in a kiss reveals some very interesting details about mate choices, too. The researchers found that women tend to be attracted to partners with a different immune system makeup than their own – information that is transmitted by the sense of smell. They also looked at increases and decreases in hormone levels before and after kissing, particularly oxytocin (the “love hormone”) and cortisol.
Kissing can quickly determine the success or failure of a potential mate choice, and that first kiss seems to be the most important in that respect. So all us fans of the Adam Sandler-Drew Barrymore romantic comedy 50 First Dates get some scientific explanation for why we feel it’s so sweet that Barrymore’s brain-damaged character who forgets Sandler every night falls in love with him all over again every day at the first kiss.
Pucker up: Scientists study kissing
What Happens To Your Anti-Bacterial Soaps
May 20 at 5:05pm by Aileen
The “germ-free” craze not only contributes to a generation of homebound children who have no developed resistance to real world ‘germs’ or irritants, we’ve also been warned over and over again for more than a decade that those bacteria we’re fighting will themselves develop resistance to the anti-biotics we use against them. Now a study by the Biodesign Institute at Arizona State University has traced the active ingredients in antibacterial soaps to their final resting place in the shallow sediments of estuaries into which treated wastewater is dumped.
The active ingredients traced are triclosan (TCS), which is structurally similar to dioxin, and triclocarban (TCC), a closely related compound. Biodesign Institute researcher Rolf Halden and coworkers traced these compounds to the shallow sediments of New York City’s Jamaica Bay and the Chesapeake Bay, the world’s largest estuary. Both of these compounds operate as endocrine (hormone) disruptors in mammals, much as agricultural chemicals operate to disrupt the sexual development of amphibians in the midwest.
Halden made use of concentrations of radioactive fallout from nuclear testing in the last half of the 20th century to determine how long ago the antimicrobial residues were deposited (and thus how long they’re lasting in the environment). And while core samples determined that a 1978 improvement in a Baltimore waste treatment plant did drop the levels of deposited TCC, the upgraded technology just put more of the substance into the sewage sludge that is disposed of by being applied as “fertilizer” on agricultural cropland.
Halden is planning to continue his research and study body burdens and health effects in pregnant women, nursing mothers and infants. Ecologically speaking, we are probably better off living with a few germs, and hand washing with regular soap has been shown to be just as effective as with antimicrobial soaps in sanitizing hands. Yet another good reason to reconsider our fear of germs – sometimes, it seems, the cure is worse than the disease.
Who’s Responsible for Irresponsible Science News?
Sep 19 at 7:07pm by Aileen
The New York Times published an article last weekend about how science news is reported, entitled Do We Really Know What Makes Us Healthy? It’s a lengthy examination of the sometimes sensationalist nature of press releases from research labs indicating that this or that supplement or dietary choice or treatment is supposed to cure what ails us, make us live healthier lives, and maybe even prevent the ravages of time and disease.
We’re all too familiar with how that so often turns out. The linkage that author Gary Taubes cites in the article is the infamous Hormone Replacement Therapy [HRT] doctors once recommended to all women of menopausal and post-menopausal age to prevent bone loss and heart disease. It was the magic cure-all against the consequences of getting old, and by 2001 at least 15 million women were filling HRT prescriptions annually.
RECENT COMMENTS