News From The American Chemical Society

Main Category: Biology / Biochemistry
Also Included In: Public Health;  Women's Health / Gynecology;  Pediatrics / Children's Health
Article Date: 23 Oct 2007 - 1:00 PST

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Excess female to male births in Canada linked to chronic dioxin exposure

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 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.

"Chronic Disease and Early Exposure to Air-Borne Mixtures: 1. The Environmental Quality Database" and "Chronic Disease and Early Exposure to Air-Borne Mixtures: 2. Exposure Assessment"

CONTACT:
James Argo, Ph.D.
IntrAmericas Centre for Environment and Health
Ontario, Canada

Tiny capers pack big disease-fighting punch

Capers, used in such culinary delights as chicken piccata and smoked salmon, may be small. But they are an unexpectedly big source of natural antioxidants that show promise for fighting cancer and heart disease when added to meals, particularly meats, researchers in Italy are reporting in the current issue of ACS' Journal of Agricultural and Food Chemistry, a bi-weekly publication.

The flower buds of a small bush, capers have been used for centuries in Mediterranean cuisine, where they provide a salty tang and decorative flair to a variety of meats, salads, pastas and other foods. In the new study, Maria A. Livrea and colleagues note that other foods in the so-called Mediterranean diet have gotten plenty of attention for their health benefits. Capers, however, have been largely overlooked.

Their laboratory study involved adding caper extracts to grilled ground-turkey, and analyzing byproducts formed during simulated digestion. The scientists found that caper-extract helped prevent the formation of certain byproducts of digested meat that have been linked by others to an increased risk of cancer and heart disease. That beneficial effect occurred even with the small amounts of caper typically used to flavor food. "Caper may have beneficial health effects, especially for people whose meals are rich in fats and red meats," the study concluded.

"Bioactive Components of Caper (Capparis spinosa L.) from Sicily and Antioxidant Effects in a Red Meat Simulated Gastric Digestion"

CONTACT:
Maria A. Livrea, Ph.D.
Universita di Palermo
Palermo, Italy

Bacteria in the intestines can influence results of drug tests

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.

"Metabonomic Evaluation of Schaedler Altered Microflora Rats"

CONTACT:
Cynthia M. Rohde, Ph.D.
Metabonomics Evaluation Group
Pfizer Global Research and Development
2800 Plymouth Road
Ann Arbor, Michigan 48105

Recycling of e-waste in China may expose mothers, infants to high dioxin levels

With China now the destination for 70 percent of the computers, TVs, cell phones, and other electronic waste (e-waste) recycled worldwide each year, a new study has concluded that Chinese recycling methods significantly increase dioxin levels in women and their breast-fed infants. The study is scheduled for the Nov. 15 issue of ACS' Environmental Science & Technology, a semi-monthly publication.

Ming H. Wong and colleagues did one of what they describe as "very few" studies of dioxin levels among women of child bearing age at an e-waste recycling site, and compared those levels to women in an area without e-waste recycling. They analyzed levels of dioxins -- compounds linked to cancer, developmental defects, and other health problems -- in samples of breast milk, placenta, and hair.

Samples from the e-waste site showed significantly higher levels of dioxins than those taken at the reference site. Researchers estimated that the daily intake of infants from 6 months of breast feeding at the recycling site was more than double that of the reference site. Therefore, this implies that these levels at the recycling site and the reference site were at least 25 times and 11 times higher, respectively, than the World Health Organization tolerable daily limit for adults regarding dioxins and dioxin-like PCBs. The study includes descriptions of recycling methods, which include heating scrap electronic components over coal fires in the open air.

"Body Loadings and Health Risk Assessment of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans at an Intensive Electronic Waste Recycling Site in China"

CONTACT:
Ming H. Wong, Ph.D.
Hong Kong Baptist University
Kowloon Tong
Hong Kong

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Article adapted by Medical News Today from original press release.
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The American Chemical Society -- the world's largest scientific society -- is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Source: Michael Woods
American Chemical Society