Accumulation and Diffusion of PM from Outdoor to Indoor by Clothing under Haze Conditions: A Case Study of Zhengzhou, China

Table 3

Number of air changes by dynamic balance method.

Pollution levels	Fabric type	Exposure time	Number of air changes
Moderate pollution	Polyester	1 h	0.157	0.947
		2 h	0.303	0.989
		3 h	0.461	0.939
	Polyester and cotton	1 h	0.239	0.972
		2 h	0.381	0.972
		3 h	0.247	0.983
	Cotton	1 h	0.411	0.996
		2 h	0.204	0.972
		3 h	0.465	0.991
Heavy pollution	Polyester	1 h	0.282	0.994
		2 h	0.179	0.907
		3 h	0.271	0.987
	Polyester and cotton	1 h	0.237	0.894
		2 h	0.242	0.994
		3 h	0.253	0.908
	Cotton	1 h	0.623	0.980
		2 h	0.179	0.987
		3 h	0.644	0.994