A CURRENT EXAMINATION OF DIETARY INTAKES OF FIBER, CALCIUM, IRON, AND ZINC AND THEIR RELATIONSHIP TO BLOOD LEAD LEVELS IN U.S. CHILDREN AGED 1-5 YEARS

A CURRENT EXAMINATION OF DIETARY INTAKES OF FIBER, CALCIUM, IRON, AND ZINC AND THEIR RELATIONSHIP TO BLOOD LEAD LEVELS IN U.S. CHILDREN AGED 1-5 YEARS Stephanie Ann Melchert, M.S. University of Nebraska, 2010 Adviser: Kaye Stanek Krogstrand The effect of lead on the health and well-being of those exposed has been well documented and many efforts have been made to reduce exposure of lead to the United States population. Despite these efforts, many studies have documented cognitive impairments and behavioral problems in children with even low levels of lead in their blood. Previous studies have suggested that a proper diet may have a role in the prevention of elevated blood lead levels in children. The objective of this study was to determine if there was an inverse correlation of blood lead levels (BLL) in children to their dietary intakes of fiber, calcium, iron, and zinc considering low levels of lead exposure. This study examined 1019 children in the National Health and Nutrition Examination Survey (NHANES) conducted from 2005-2006. Data were analyzed using Spearman’s rank correlations to correlate continuous variables to BLL in children and independent samples t-tests were used to compare mean blood lead levels of categorical variables. Results indicate that BLL in children is significantly correlated with and weight, recumbent length/standing height, dietary fiber intake and continine, a marker of cigarette smoke exposure. BLL was not significantly correlated with calcium, iron, zinc, or vitamin C. A significant difference was found in the mean BLL of children who took supplements, lived in smoking homes, as well as those who lived in homes built before 1978. Overall, this study shows that children living in homes built before 1978 remain at greater risk for lead exposure, and adequate dietary fiber intake may provide benefits to children who are exposed to lead.

BURROW-BUILDING STRATEGIES AND HABITAT USE OF VOLES IN PACIFIC NORTHWEST ORCHARDS

Seidel and Booth (1960) wrote that the "life histories of the genus Microtus are not numerous in the literature." In support of his observation he cited 6 publications, all dated between 1891 and 1953. Since then the literature has exploded with a proliferation of publications. An international literature review recently revealed over 3,500 citations for the genus. When Pitymys and Clethrionomys are included another 350 and 1,880, respectively, were found. Over the last 10 years approximately 3 new publications on voles appeared every 4 days; a significant output for what some would consider such an insignificant species. Most of the publications were the result of graduate research projects on population dynamics and species ecology. As such, many do not explore more than the rudimentary ecological relationships between the animal and their environments. Unfortunate, as well, is that all but one confined their observations to only a small part of their total environment. For many of these animals, their life underground may be more important for their survival than that above ground. Trapping studies conducted by Godfrey and Askham (1988) with permanently placed pitfall live traps in orchards revealed a significant inverse population fluctuation during the year. During the winter, when populations are expected to decrease, as many as 6 to 8 mature Microtus montanus were collected at any 1 time in the traps after several centimeters of snow accumulation. During the summer, when populations are expected to increase, virtually no animals were collected in the traps. According to current population dynamics theory, greater numbers of animals, including increasingly larger numbers of immature members of the community, should appear in any sample between the onset of the breeding period, generally in the spring, taper off during the latter part of the production season, usually late summer, and then decline as the limiting factors begin to take effect. For us, we trapped more animals in the fall and early winter than we did during the spring and summer. A review of the above literature did little to answer our question. Where are the animals going during the summer and why?