Hand-to-mouth and other hand-to-face touching behavior in a quasi-naturalistic study under controlled conditions

Abstract

Data gaps exist in our understanding of hand-to-mouth touching behavior among adults, despite its relevance for accurately characterizing inadvertent ingestion exposures to chemical and pathogenic microbial agents and consequent associated health risks. The present study describes detailed observations of the frequency and nature of hand-to-mouth and other hand-to-face touching behavior among 14 male and female volunteers in a controlled, quasi-naturalistic setting. Participants performed four 15-min tasks: 1) installation of a brass object as part of a short home improvement project, 2) completion of a pen-and-paper survey, 3) engagement in a telephone conversation, and 4) use of headphones to listen to music. Video recordings of the participants performing each task were reviewed and coded for touches to the face with emphasis on specific regions of the face and palmar versus dorsal contacts. During the installation task, only one of the 14 participants was observed touching his face; this was to the nose, on two separate occasions. Summed across the three non-installation tasks, including palmar and dorsal contacts, participants touched their lips, their mouth, and anywhere on their face on average (range) 5.1 (0-19), 0.4 (0-3), and 27.7 (6-49) times, respectively. Facial contacts during these three non-installation tasks were predominantly with the palmar surface of the hand. The implications of these data are contextually specific, as the potential health impacts of face touching behavior among adults might differ based upon toxicity or virulence of hand contaminants of interest.

Hand-to-face contact behaviors during indoor activities in daily life among Korean adults: an observational pilot study using videotaping

“…The average CF of HFC in this study was higher than those reported in previous studies: 23/person/hr [ 4 ], and 15.7/person/hr [ 5 ], 9.5/person/hr [ 9 ], and 2.6/person/hr [ 10 ]; however, our results are consistent with the finding of 27.7 (6-49)/45 min of another study [ 12 ]. The most frequently encountered non-mucous membrane and mucous membrane HFC areas in this study were the head and the mouth, nose, and eyes, respectively.…”

“…This was a pilot study to describe the frequency, duration, and intensity of HFC however, our results were consistent with 27.7(6-49)/45 min of the other study [12]. The most frequently encountered non-mucous membrane and mucous membrane HFC areas identified in this study were the head, and the mouth, nose, and eyes, respectively.…”

“…Therefore, understanding the characteristics of HFC is important for estimating infectious pathogen exposure in addition to chemical exposure [ 12 ]. However, few studies have described the frequency or patterns of HFC in terms of infectious exposures, despite strong recommendations to avoid HFC [ 13 ].…”

“…However, few studies have described the frequency or patterns of HFC in terms of infectious exposures, despite strong recommendations to avoid HFC [ 13 ]. Studies on HFC have mostly focused on chemical exposures [ 12 , 14 ]. Additionally, the reported characteristics of HFCs in previous studies have varied [ 4 , 9 , 10 , 12 , 14 , 15 ].…”

Community Transmission of SARS-CoV-2 by Fomites: Risks and Risk Reduction Strategies

“…Viruses readily transfer from contaminated surfaces to the hand upon contact [19][20][21] and from hands to the mucous membranes on the face [21][22][23] . People touch their faces frequently, with studies reporting average handto-face contacts ranging from 16 to 37 times an hour [24][25][26] . Taken together, this suggests surface contamination could pose a risk for indirect SARS-CoV-2 transmission, similar to other respiratory viruses 8 .…”