Gasp! Ozone Limits Don't Protect Babies

from SCIENCE NEWS

By Raloff, Janet ENVIRONMENT

In healthy infants, even ozone concentrations well below those allowed by federal law trigger asthmalike symptoms, a new study shows.

The finding indicates that federal limits on this pervasive pollutant, a prime constituent of smog, don't protect infants "from rather severe respiratory symptoms," says epidemiologist Elizabeth W. Triche of the Yale University School of Medicine.

Triche's team recruited 691 women with 3-to-5-month-old infants from nonsmoking households around Roanoke, Va. Sixty-one moms had asthma, signaling that their babies were at high risk for developing the disease.

The researchers collected daily respiratory data, as reported by the mothers, on all the children for 8.3 days in summer- the peak ozone season-and then correlated the infant's symptoms with outdoor measurements of several air pollutants. As ozone values climbed, so did the risk of wheezing and troubled breathing in the babies, Triches team reports in the June Environmental Health Perspectives.

The other pollutants, such as fine particulates. didn't show that correlation. For each 11.8 parts per billion (ppb) increase in average daily concentrations in ozone, the likelihood of wheezing increased by 41 percent in all the infants and 91 percent in those with asthmatic moms. Each 11.8 ppb increase in ozone also increased the risk of labored breathing by almost 30 percent for all kids and more than doubled it in babies with asthmatic moms.

These findings dovetail with those that Triche's group reported 3 years ago in 6-to-12-year-old children. The big difference: Those children had asthma. In the new infant study, she notes, "children were not asthmatic." -J.R.

Global warming -- yes, it's real!

The list of doubters has gotten pretty short, and the National Research Council has weighed in: the last few decades have been the hottest in at least 400 years. -- and maybe a lot longer than that.

For more, see
http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=11676

Unfortunately, even the best scientific evidence doesn't seem to be enough to win over the professional political doubters, led by Senator James Inhofe (R-OK) and Rep. Joe Barton (R-TX).

Another reason to worry about global warming: poison ivy!

Duke University researchers report that poison ivy grows bigger and faster as carbon dioxide levels in the atmosphere rise.

The study appears in the Proceedings of the National Academy of Sciences.

Proc. Natl. Acad. Sci. USA,Environmental Sciences-Biological SciencesBiomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2
( global change forest ecology Rhus radicans ) Jacqueline E. Mohan *, Lewis H. Ziska ¶, William H. Schlesinger *, Richard B. Thomas **, Richard C. Sicher ¶, Kate George ¶, and James S. Clark *
*Department of Biology and Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC 27708; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138; Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543; ¶Agricultural Research Service, Crop Systems, and Global Change Laboratory, U.S. Department of Agriculture, Beltsville, MD 20705; and **Department of Biology, West Virginia University, Morgantown, WV 26506
Contributed by William H. Schlesinger, April 22, 2006
Contact with poison ivy (Toxicodendron radicans) is one of the most widely reported ailments at poison centers in the United States, and this plant has been introduced throughout the world, where it occurs with other allergenic members of the cashew family (Anacardiaceae). Approximately 80% of humans develop dermatitis upon exposure to the carbon-based active compound, urushiol. It is not known how poison ivy might respond to increasing concentrations of atmospheric carbon dioxide (CO2), but previous work done in controlled growth chambers shows that other vines exhibit large growth enhancement from elevated CO2. Rising CO2 is potentially responsible for the increased vine abundance that is inhibiting forest regeneration and increasing tree mortality around the world. In this 6-year study at the Duke University Free-Air CO2 Enrichment experiment, we show that elevated atmospheric CO2 in an intact forest ecosystem increases photosynthesis, water use efficiency, growth, and population biomass of poison ivy. The CO2 growth stimulation exceeds that of most other woody species. Furthermore, high-CO2 plants produce a more allergenic form of urushiol. Our results indicate that Toxicodendron taxa will become more abundant and more "toxic" in the future, potentially affecting global forest dynamics and human health.