. 2018 Mar 31;91(5):581–589. doi: 10.1007/s00420-018-1303-x

Table 4.

Mean ratings (entire sample) and response frequencies (%) regarding symptoms attributed to environmental factors for three groups exposed to different levels of air pollution, and results from group comparisons

	Mean	Exposure level
Do the following factors usually cause you some kind of symptoms (e.g. feeling ill, headache, respiratory symptoms)^a		Low	Medium	High	Chi²	p value
Traffic exhaust^b	1.94	31 (29.0)	41(38.3)	35 (32.7)	1.84	0.39
Street dust^b	2.01	38 (32.2)	37 (31.4)	43 (36.4)	0.43	0.81
Industrial air pollution^b	1.62	16 (28.6)	18 (32.1)	22 (39.3)	0.97	0.62

^aRespondents who rated 4–5 on a 5-point scale, ranging from no symptoms (1) to very many symptoms (5)

^bRepresenting symptoms in the path analysis