Table 2.

Characteristics of Weather Factors and Air Pollutants in Greater Boston Area, Massachusetts, March, 2016-October, 2017.

	Mean (SD)	IQR	Pearson Correlation Coefficients
			Relative humidity	Pressure	PM2.5	NO2	SO2	O3	CO
Temperature, °F	56.9 (16.0)	26.0	0.06	−0.15	−0.25	−0.27	−0.13	0.40	−0.13
Relative humidity, %	67.3 (16.7)	26.5		−0.09	−0.15	−0.03	0.01	−0.39	0.05
Barometric pressure, inHg	30.0 (0.2)	0.3			0.16	0.19	0.19	−0.06	0.12
Fine particulate matter (PM2.5), μg/m3	7.3 (3.2)	3.6				0.49	0.41	0.12	0.52
Nitrogen dioxide (NO2), ppb	24.5 (9.1)	11.7					0.58	−0.06	0.61
Sulfur dioxide (SO2)a, ppb	0.9 (0.7)	0.6						−0.16	0.65
Ozone (O3)b, ppb	33.7 (10.4)	14.0							−0.14
Carbon monoxide (CO)c, ppb	337.2 (122.2)	150.0

Abbreviations: SD, standard deviation; IQR, interquartile range.

^a1 day missing.

^b6 days missing.

^c4 days missing.