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FREQUENCY OF MOUTHING BEHAVIOR IN YOUNG CHILDREN
Citation:
Tulve, N S., J C. Suggs, S. Davis, D. K. Mirick, T R. McCurdy, AND J Moya. FREQUENCY OF MOUTHING BEHAVIOR IN YOUNG CHILDREN. Presented at ISEA 2000 Exposure Analysis in the 21st Century: Integrating Science, Policy and Quality of Life, Monterey Peninsula, CA, October 24-27, 2000.
Impact/Purpose:
1. To identify those pesticides, pathways, and activities that represent the highest potential exposures to children;
2. To determine the factors that influence pesticide exposures to children;
3. To develop methods for measuring multimedia exposures to children, including methods that account for important activities that take place in home, school, and day care settings;
4. To generate data on multimedia pesticide concentrations, pesticide biomarkers, and exposure factors that can be used as inputs to aggregate exposure models for children.
Description:
Young children, as compared to adults, are more likely to be exposed after a pesticide application due to potential hand- and object-to-mouth contacts in contaminated areas. However, relatively few studies have specifically evaluated mouthing behavior in children <60 months of age. Previously unpublished data collected by the Fred Hutchinson Cancer Research Center (FHCRC) were analyzed to assess the mouthing behavior of 86 children (43 male/43 female). Total mouthing behavior included the daily frequency of both mouth and tongue contacts with hands, other body parts, surfaces, natural objects, and toys. Eating events were excluded. Children ranged in age from 10 to 60 months. Replicate observations on different days were available for 98% of the children.
The total data set was disaggregated by gender into 5 age groups (10-20, 20-30, 30-40, 40-50, 50-60 months). Statistical analyses of the data were then undertaken to determine if significant differences existed among the age/gender subgroups in the sample. Since the data showed correlation between multiple observations for each subject, unbalanced data, and variation between subjects, a mixed effects linear model was used to test the associations between age, gender, and mouthing frequencies. Subjects were treated as random and independent, and intra-subject variability was accounted for with an autocorrelation function.
Model results indicated that there was no association between mouthing frequency and gender. However, a clear relationship was observed between mouthing frequency and age. Using a tree analysis, two distinct groups could be identified: children <24 and children >24 months of age. Children <24 months exhibited the highest frequency of mouthing behavior with 76+5 freq hr-1 (mean+ std err) (n=30 subj, 106 obs). Children >24 months exhibited the lowest frequency of mouthing behavior with 38+3 freq hr-1 (n=56 subj, 192 obs). These results suggest that children are less likely to place objects into their mouths as they age. These changes in mouthing behavior as a child ages may help in modeling total aggregate exposure to pesticides after an application event. Further statistical analyses are being performed to categorize the types of mouthing events by age, gender, and locations.
This work has been funded wholly by the United States Environmental Protection Agency under EPA Cooperative Agreement CR 816334-01 to the Fred Hutchinson Cancer Research Center. It has been subjected to Agency review and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.