Simultaneous and multi-point measurement of ammonia emanating from human skin surface for the estimation of whole body dermal emission rate

•Simultaneous and multi-point measurement of dermal emission flux of ammonia was conducted for ten healthy young volunteers.•Ammonia emanating from human skin surface was non-invasively collected by Passive Flux Sampler and determined by Ion chromatography.•Using the measured emission fluxes at 13 positions and surface area of the volunteers, the whole body dermal emission rate of ammonia was estimated.•The dermal emission was found more significant odor source than the breath exhalation in indoor environment. Ammonia is one of the members of odor gases and a possible source of odor in indoor environment. However, little has been known on the actual emission rate of ammonia from the human skin surface. Then, this study aimed to estimate the whole-body dermal emission rate of ammonia by simultaneous and multi-point measurement of emission fluxes of ammonia employing a passive flux sampler – ion chromatography system. Firstly, the emission fluxes of ammonia were non-invasively measured for ten volunteers at 13 sampling positions set in 13 anatomical regions classified by Kurazumi et al. The measured emission fluxes were then converted to partial emission rates using the surface body areas estimated by weights and heights of volunteers and partial rates of 13 body regions. Subsequent summation of the partial emission rates provided the whole body dermal emission rate of ammonia. The results ranged from 2.9 to 12mgh−1 with an average of 5.9±3.2mgh−1 per person for the ten healthy young volunteers. The values were much greater than those from human breath, and thus the dermal emission of ammonia was found more significant odor source than the breath exhalation in indoor environment.