C McDuffie | PubMed Health

PubMed1993

The effects of removing cloudwater and lowering ambient O3 on red spruce grown at high elevations in the southern Appalachians.

This study was conducted to determine whether acidic cloudwater and ozone (O3) influence the growth of red spruce (Picea rubens L.) seedlings growing at a high elevation site in the southern Appalachian Mountains. A field exclusion chamber study was established at Whitetop Mountain, VA (elevation 1689 m) which included the following treatments: (1) clouds and O3 excluded (COE); (2) exposure to ambient O3 with clouds excluded (CE); (3) exposure to clouds and O3 (CC); and (4) ambient air plots (AA) that served as a control to evaluate possible chamber effects. After 2 years, seedlings exposed to ambient levels of O3 and cloudwater (AA and CC) did not differ in biomass accumulation, diameter growth, or epicuticular wax amounts from seedlings grown in chambers where pollution levels were reduced (CE and COE). Treatments receiving cloudwater (AA and CC) had statistically lower current-year needle concentrations of Ca and Mg, indicating that the cloudwater exposure dynamics occurring at this site elicited reductions in needle Ca and Mg. Ozone had negligible impact on all of the seedling parameters measured.

Journal Article↗

PubMed1989

Screening for hypercholesterolemia in college students.

Two national panels have recommended similar, specific strategies for detecting hypercholesterolemia: selective screening for children aged 2 to 19, and mass screening for individuals aged 20 and over. It is, however, unclear how best to apply these recommendations to a college student population. In order to determine which strategy is more efficient, this study compared mass with selective screening of college students for hypercholesterolemia. In the mass screening strategy, all entering students were asked to have their cholesterol levels measured and to provide other coronary risk factor information. In the selective screening strategy, all sophomores with a family history of heart disease were asked to participate in a risk factor screening program. In this study, mass screening identified more hypercholesterolemic students with less effort per case found than did selective screening. We recommend that college health practitioners consider mass screening programs to identify students who could benefit from coronary risk reduction.

Adolescent↗