Hand- and Object-Mouthing of Rural Bangladeshi Children 3–18 Months Old

Abstract

Children are exposed to environmental contaminants by placing contaminated hands or objects in their mouths. We quantified hand- and object-mouthing frequencies of Bangladeshi children and determined if they differ from those of U.S. children to evaluate the appropriateness of applying U.S. exposure models in other socio-cultural contexts. We conducted a five-hour structured observation of the mouthing behaviors of 148 rural Bangladeshi children aged 3–18 months. We modeled mouthing frequencies using 2-parameter Weibull distributions to compare the modeled medians with those of U.S. children. In Bangladesh the median frequency of hand-mouthing was 37.3 contacts/h for children 3–6 months old, 34.4 contacts/h for children 6–12 months old, and 29.7 contacts/h for children 12–18 months old. The median frequency of object-mouthing was 23.1 contacts/h for children 3–6 months old, 29.6 contacts/h for children 6–12 months old, and 15.2 contacts/h for children 12–18 months old. At all ages both hand- and object-mouthing frequencies were higher than those of U.S. children. Mouthing frequencies were not associated with child location (indoor/outdoor). Using hand- and object-mouthing exposure models from U.S. and other high-income countries might not accurately estimate children’s exposure to environmental contaminants via mouthing in low- and middle-income countries.

Where Children Play: Young Child Exposure to Environmental Hazards during Play in Public Areas in a Transitioning Internally Displaced Persons Community in Haiti

“…However, Kwong et al (2016) reported a hand-to-mouth rate of 34/h for children 6 to 12 months in household yards [21], which is higher than our estimates and those of previous studies [27,31]. Discrepancies may be explained by Kwong et al recording hand-to-mouth contacts while infants were eating.…”

“…However, when children do engage in touching soil our contact rate is comparable to rates reported by Ko et al (2006) [53] and Reed et al (1999) [54]. Our estimated geophagia rate of 0.9/h for children who engage in the behavior falls between Kwong et al (2016) estimates for soil ingestion ranging from 0.1–0.3/h for children 3 to 18 months [21] and Ngure et al (2013) estimates ranging from 1.7–2/h for children 3 to 18 months [25]. …”

A Review of the Field on Children’s Exposure to Environmental Contaminants: A Risk Assessment Approach

“…The collection of such dermal activities can be labor intensive where videotaping and video-translation methodologies have been used to collect these micro-activities for children [147,148]. Thirdly, activity patterns can be influenced by a number of other factors such as the products in the environment and the affluence of the surroundings [15,149]. Therefore, country and environment differences offer us caution in using the activity patterns determined from one study to the other.…”

Children’s Exposure to Environmental Contaminants: An Editorial Reflection of Articles in the IJERPH Special Issue Entitled, “Children’s Exposure to Environmental Contaminants”

“…For example, in developing countries, infants are carried on their mothers’ backs while cooking over wood stoves, directly exposing them to harmful VOCs [50]. Kwong et al present an informative paper on the hand- and object-to-mouth activity patterns of 148 children in Bangladesh, where a child’s environmental surroundings and familial cultural practices may influence exposure activities and therefore biological and chemical health risks [51]. The authors find significant higher hand- and object-mouthing frequencies for children in Bangladesh in comparison to children in the U.S., concluding that exposure models from U.S. and other high-income countries might not accurately estimate children’s exposure to environmental contaminants in other countries [51].…”

“…Kwong et al present an informative paper on the hand- and object-to-mouth activity patterns of 148 children in Bangladesh, where a child’s environmental surroundings and familial cultural practices may influence exposure activities and therefore biological and chemical health risks [51]. The authors find significant higher hand- and object-mouthing frequencies for children in Bangladesh in comparison to children in the U.S., concluding that exposure models from U.S. and other high-income countries might not accurately estimate children’s exposure to environmental contaminants in other countries [51]. A better understanding of how children behave in the indoor and outdoor environment improves the understanding and the estimate of health risks [15].…”