Table 1.

Characteristics of outpatient for allergic conjunctivitis in Urumqi (01/01/2013 to 12/31/2020).

Variables	Number of measurements	Mean (SD)	Min	P25	Median	P75	Max
Air pollutant concentration
PM2.5 (μg/m3)	2,921	64.5 (61.9)	6	23	39	84	397
PM10 (μg/m3)	2,921	120.2 (90.8)	10	62	98	153	1,766
SO2 (μg/m3)	2,921	16 (15.2)	2	8	10	17	177
NO2 (μg/m3)	2,921	48.5 (21)	7	33	44	60	141
CO (mg/m3)	2,921	1.2 (1)	0.01	0.6	0.9	1.5	6
O3 (μg/m3)	2,921	68.2 (37.7)	2	35	67	99	182
Meteorological factors
Mean temperature (°C)	2,921	8.4 (13.7)	−26	−4.5	10.7	20.6	35.1
Relative humidity (%)	2,921	55.5 (21.3)	6	37	54	74	100
Atmospheric pressure (hpa)	2,921	912.7 (7.8)	842	908	913	918	934
Wind speed (m/s)	2,921	2 (1.1)	0	1.4	1.9	2.4	14.8
Number of conjunctivitis outpatient visits (n)
Total	3,325	1.1 (2.1)	0	0	0	1	19

SD, standard deviation; Min, minimum; P25, 25th percentile; P75, 75th percentile; Max, maximum.