Table 2.

Pearson correlation (r) between the counts of three types of illnesses and predictive variables (Data in December, January and February were excluded); p represents p-value and n represents the sample size. Bolded results represent significant correlations at the level of 0.001

Variables		Gastrointestinal Illness	Respiratory illness	Dermal illness
School days (yes/no)	r	0.166	0.537	−0.461
	p	< 0.001	< 0.001	< 0.001
	n	1100	1100	1100
Holiday (yes/no)	r	− 0.028	0.052	0.087
	p	0.348	0.087	0.004
	n	1100	1100	1100
O3	r	−0.056	−0.218	0.357
	p	0.066	< 0.001	< 0.001
	n	1100	1100	1100
SO2	r	0.030	0.095	−0.135
	p	0.320	0.002	< 0.001
	n	1100	1100	1100
NO2	r	0.112	0.045	−0.158
	p	< 0.001	0.129	< 0.001
	n	1100	1100	1100
CO	r	0.052	0.219	−0.135
	p	0.084	< 0.001	< 0.001
	n	1100	1100	1100
PM2.5	r	−0.176	−0.182	0.264
	p	< 0.001	< 0.001	< 0.001
	n	1100	1100	1100
Daily precipitation	r	0.001	−0.053	−0.081
	p	0.971	0.080	0.007
	n	1100	1100	1100
Daily mean temperature	r	−0.214	−0.450	0.561
	p	< 0.001	< 0.001	< 0.001
	n	1100	1100	1100
Cyanobacteria concentration (maximum from 5 pixels)	r	0.150	0.152	−0.200
	p	0.013	0.012	0.001
	n	273	273	273