Frequency of mouthing behavior in young children

Abstract

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 Previously unpublished data collected by the Fred Hutchinson Cancer Research Center ( FHCRC ) were analyzed to assess the mouthing behavior of 72 children ( 37 males / 35 females ). 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 1 day were available for 78% of the children. The total data set was disaggregated by gender into five 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 among age, gender, and mouthing frequencies. Subjects were treated as random and independent, and intrasubject 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 / h ( mean ± SE ) ( n = 28 subjects, 69 observations ). Children >24 months exhibited the lowest frequency of mouthing behavior with 42 ± 4 events / h ( n = 44 subjects, 117 observations ). 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.

Quantified outdoor micro-activity data for children aged 7–12-years old

“…Freeman et al (2001) observed children aged 3-12 years and also report a difference in object-to-mouth but not hand-to-mouth contact frequency in children o5 years compared with those Z5 years. In other studies, significant differences in mouthing frequency have been reported between infants and toddlers (Beamer et al, 2008), children o and Z2 years of age (Tulve et al, 2002;AuYeung et al, 2004) and among children o6 years of age . Our study is the first to specifically document that mouthing behavior does not decrease with age among 7-12-year olds.…”

“…Several studies have quantified these mouthing and hand contact behaviors in children (Zartarian et al, 1997aBrinkman et al, 1999;Reed et al, 1999;Freeman et al, 2001Freeman et al, , 2005Tulve et al, 2002;AuYeung et al, 2004;Black et al, 2005;Auyeung et al, 2006;Beamer et al, 2008); however, we know of only one other study that has reported any data on children over 6 years of age (Freeman et al, 2001). Meta-analyses of the data collected from younger children have indicated that mouthing decreases with age and other studies have reported differences by age in the frequency, with which children contact different types of objects or fomites with their hands (Freeman et al, 2001;Auyeung et al, 2006;Beamer et al, 2008).…”

Bioaccessibility of pesticides and polychlorinated biphenyls from house dust: in-vitro methods and human exposure assessment

“…2,69,75 According to the literature, children in general ingest about 50 mg/day house dust during the summer and 100 mg/day during the winter, when they spend more time indoors. 57,58 In the case of pica behavior (eating of non-nutritive substances), uptake can reach up to 2--30 g/day.…”

A meta-analysis of children's object-to-mouth frequency data for estimating non-dietary ingestion exposure

“…Observations may be conducted by a parent, after receiving special instructions, or by a trained observer (Tulve et al, 2002). Videotaping to record children's behavior is done by a trained technician.…”