Measurement of the proximity effect for indoor air pollutant sources in two homes

• Published in: Journal of environmental monitoring 2012-01, Vol.14 (1), p.94-14
• Main Authors: Acevedo-Bolton, Viviana, Cheng, Kai-Chung, Jiang, Ruo-Ting, Ott, Wayne R, Klepeis, Neil E, Hildemann, Lynn M
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Air Pollution, Indoor - analysis; Air Pollution, Indoor - statistics & numerical data; Carbon Monoxide - analysis; Environmental Monitoring; Housing - statistics & numerical data; Humans; Models, Chemical
• ISSN: 1464-0325; 1464-0333
• DOI: 10.1039/c1em10521c

Personal exposure to air pollutants can be substantially higher in close proximity to an active source due to non-instantaneous mixing of emissions. The research presented in this paper quantifies this proximity effect for a non-buoyant source in 2 naturally ventilated homes in Northern California (CA), assessing its spatial and temporal variation and the influence of factors such as ventilation rate on its magnitude. To quantify how proximity to residential sources of indoor air pollutants affects human exposure, we performed 16 separate monitoring experiments in the living rooms of two detached single-family homes. CO (as a tracer gas) was released from a point source in the center of the room at a controlled emission rate for 512 h per experiment, while an array of 3037 real-time monitors simultaneously measured CO concentrations with 15 s time resolution at radial distances ranging from 0.255 m under a range of ventilation conditions. Concentrations measured in close proximity (within 1 m) to the source were highly variable, with 5 min averages that typically varied by >100-fold. This variability was due to short-duration (