ACS News Service Weekly PressPac: October 17, 2007

• Excess female to male births in Canada linked to chronic dioxin exposure
• Tiny capers pack big disease-fighting punch
• Bacteria in the intestines can influence results of drug tests
• Recycling of e-waste in China may expose mothers, infants to high dioxin levels
• Chemistry of San Andreas Fault may offer clues to earthquake mysteries

Almost 90 Canadian communities have experienced a shift in the normal 51:49 ratio of male to female births, so that more girls than boys are being born, according to two studies in the Oct. 1 issue of ACS’ Environmental Science & Technology, a semi-monthly journal. James Argo, who headed the research, attributes this so-called “inverted sex ratio” of the residents in those communities to dioxin air pollutants from oil refineries, paper mills, metal smelters and other sources.

The studies analyzed information in the Environmental Quality Database (EQDB), an inventory of pollution sources, cancer data, and other factors developed for Canadian government research on how early exposure to environmental contaminants affects the health of Canadians. Argo points out that the EQDB enables researchers to pinpoint the location of 126,000 homes relative to any of about 65 air pollution sources-types and the occurrence of cancer among residents of those homes.

Argo focused on air pollutants from those sources and the corresponding incidence of cancer among more than 20,000 residents and 5,000 controls. He identified inverted male sex ratios, sometimes as profound as 46:54 in almost all of the communities. The ratio indicated that more females than males were born, a situation that Argo attributed to chronic exposure of parents to dioxin, based on previous studies. The study “may represent one of only a few studies explicitly designed to identify the impact of carcinogens from industrial sources on residents at home,” Agro stated.

Back to Top

Bacteria living in the intestines of laboratory rats — those test tubes on four feet that stand in for humans in a wide range of research — may influence the results of drug safety and other tests, scientists in Michigan are reporting. The findings are scheduled for the Dec. 7 issue of ACS’ Chemical Research in Toxicology, a monthly journal.

Cynthia M. Rohde and colleagues note growing recognition of the hidden role of the approximately 100 trillion bacteria that thrive in the intestines of humans. Studies have shown that this so-called “gut microflora” can influence the immune system, how the body responds to foods, the action of drugs, and other functions. Researchers started the new study after noting that a genetically identical population of rats widely used in laboratory tests had developed two distinctively different metabolic types. The types involve differences in the way those animals metabolize, or breakdown, drugs and nutrients.

After detailed studies of substances in the urine of the rats, researchers concluded that the differences result from differences in the gut microbial populations between the two types. The report recommends that scientists in the future check lab rat populations for such metabolic differences due to gut microflora in order to assure accurate results, especially in experiments to evaluate the safety of new drugs.

Back to Top

R Scientists have obtained core samples from deep inside California’s San Andreas Fault for the first time, a finding that may lead to a better understanding of the underground molecular events associated with earthquakes, according to an article scheduled for the Oct. 22 issue of Chemical & Engineering News, ACS’ weekly newsmagazine.

The 800-mile-long fault that bisects California is infamous as the source of the region’s most devastating earthquakes. Conventional sampling of the fault yields slurries of rock chips that are fragmented and difficult to study. In the article, C&EN senior editor Elizabeth K. Wilson describes how new technology borrowed from the oil-drilling industry allows scientists to reach more than 2 miles into the earth to bring up virtually intact core samples from the San Andreas Fault Observatory at Depth in Parkfield, Calif. The core samples will provide an unprecedented picture of the minerals and fluids that are produced at an earthquake source, including new information about the chemistry behind plate movements and fluid flow in fault zones, the writer notes.

“Earthquake scientists around the world have been invited to a “sample party” at Stanford University in December, where they’ll get a chance to inspect the cores and request pieces for them to study,” Wilson writes.

Back to Top

• Science Elements: An ACS Science News Podcast
  The ACS Office of Communications is podcasting PressPac contents in order to make cutting-edge scientific discoveries from ACS journals available to a broad public audience at no charge. Science Elements includes selected content from ACS’s prestigious suite of 36 peer-reviewed scientific journals and Chemical & Engineering News, ACS’s weekly news magazine. Those journals, published by the world’s largest scientific society, contain about 30,000 scientific reports from scientists around the world each year. The reports include discoveries in medicine, health, nutrition, energy, the environment and other fields that span science’s horizons from astronomy to zoology. Podcaster for Science Elements is Steve Showalter, Ph.D., a chemist at the U. S. Department of Energy’s Sandia National Laboratories in Albuquerque, New Mexico, and ACS member.
• YouTube Videos
  Detergents with an On/Off Switch
  Good Chemistry: Health & Wellness for Kids
  It’s Alive!!!

• ACS Press releases
  A treasure trove of news sources, background material and story ideas is available from the ACS' latest National Meeting. Reporters can view press releases, search an archive with abstracts of 9,500 scientific presentations and 1,000 non-technical summaries of those presentations, and access other resources at:
  http://www.acspresscenter.org/index.php
• General Chemistry Glossary
• PressPac Archives
  
  
  
  

Back to Top