Table 5. Respiratory symptoms using self–reported questionnaire in the toner–handling group and the non–toner–handling group in 2004, 2008, and 2013.

Respiratory symptoms	Groups	n	2004		2008		2013
			n	(%)	n	(%)	n	(%)
Persistent cough	Toner–handling group	13	3	(23.1)	1	(7.7)	0	(0.0)
	Non–toner–handling group	24	2	(8.3)	0	(0.0)	2	(8.3)
	p valuea		0.321		0.351		0.532
Persistent phlegm	Toner–handling group	13	3	(23.1)	2	(15.4)	1	(7.7)
	Non–toner–handling group	24	3	(12.5)	0	(0.0)	0	(0.0)
	p valuea		0.643		0.117		0.351
Persistent cough and phlegm	Toner–handling group	13	2	(15.4)	0	(0.0)	0	(0.0)
	Non–toner–handling group	24	2	(8.3)	0	(0.0)	0	(0.0)
	p valuea		0.602		—		—
Wheezing without asthmatic response	Toner–handling group	13	1	(7.7)	2	(15.4)	0	(0.0)
	Non–toner–handling group	24	1	(4.2)	0	(0.0)	1	(4.2)
	p valuea		1.000		0.117		1.000
Breathlessness	Toner–handling group	13	1	(7.7)	0	(0.0)	0	(0.0)
	Non–toner–handling group	24	0	(0.0)	0	(0.0)	0	(0.0)
	p valuea		0.351		—		—

^a Fisher’s exact test was performed for annual comparisons of prevalence rates of each respiratory symptom between the toner–handling and non–toner–handling groups.