Analysis of durations and frequencies of mouthing behaviors in children 6 months to 6 years: an advanced videotaping and translation approach

Background Children are susceptible to harmful substances found in indoor dust through frequent hand-to-mouth and object-to-mouth contacts. Despite the importance of this exposure route, few studies have quantified the frequency, duration, or patterns of mouthing behaviors in indoor residential settings, creating uncertainty in exposure and risk models. Objective This study quantified the frequency and duration of indoor mouthing contacts for children 6 months to 6 years across sociodemographic variables including age, sex, ethnicity, race and geographic region using advanced videotaping and video translation methodologies. Methods Ninety-nine children were videotaped for 3–4 h during natural indoor play across three U.S. regions (Arizona, Florida, and North Carolina). 360-degree cameras were mounted in different rooms to capture natural behavior without researcher presence. Footage was tracked and merged sequentially, then translated into Micro-Level Activity Time Series (MLATS) using the Virtual Timing Device (VTD), documenting each mouthing contact with specific surfaces and household locations to generate frequency (contacts/h) and duration (minutes/h) data. Results Mouthing duration showed significant age-related differences (Kruskal–Wallis χ 2 = 12.0, p = 0.007), with median duration declining from 18.67 min/h in children 6–