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FREQUENCY OF MOUTHING BEHAVIOR IN YOUNG CHILDREN
Tulve, N S., J C. Suggs, T R. McCurdy, E A. CohenHubal, AND J Moya. FREQUENCY OF MOUTHING BEHAVIOR IN YOUNG CHILDREN. JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 12(4):259-264, (2002).
The two main objectives of this research are (1) to improve and update and (2) to analyze the CHAD database.
For objective 1, we will
* Reconfigure the CHAD program into a completely modularized Oracle database.
* Redesign User Interface for effcient utilization of the program's capability.
* Obtain dates for those surveys that did not provide them to us, so that we can obtain associated meteorological/climatic inputs for the person-days of information without them.
* Revise the upper and lower bound delimiters in the energy expenditure distributions used for activity-specific estimates.
For objective 2, we will
* Evaluate data quality.
* Evaluate trends and activities for various subgroups.
* Identify temporal patterns for longitudinal data.
* Characterize resolution required for output for exposure and dose models.
Young children may be more likely than adults to be exposed to pesticides following a residential application as a result of hand- and object-to-mouth contacts in contaminated areas. However, relatively few studies have specifically evaluated mouthing behavior in children less than 5 years of age. Previously unpublished data collected by the Fred Hutchinson Cancer Research Center (FHCRC) were analyzed to assess the mouthing behavior of 72 children (37 male/35 female). Total mouthing behavior data 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 11 to 60 months. Observations for more than one day were available for 78% 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. 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. 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 81+7 events/hr (mean+std err) (n=28 subj, 69 obs). Children >24 months exhibited the lowest frequency of mouthing behavior with 42+4 events/hr (n=44 subj, 117 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 should be accounted for when assessing aggregate exposure to pesticides in the residential environment.
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.