Effect of short-term exposure to particulate air pollution on heart rate variability in normal-weight and obese adults

Table 1 Descriptive statistics of PM_2.5, BC and meteorological factors during the study

Pollutants	N^a	Mean ± SD	Minimum	25th	Medium	75th	Maximum	IQR
ambient PM_2.5, μg/m³	1220	55.77 ± 52.72	3.00	16.00	40.00	76.00	276.00	60.00
ambient BC, μg/m³	1220	2.78 ± 2.34	0.16	0.93	2.10	4.07	10.33	3.14
personal PM_2.5, μg/m³	23,167	28.05 ± 31.98	0.10	8.19	16.04	33.57	272.03	25.38
personal BC, μg/m³	23,182	1.80 ± 2.00	0.01	0.45	1.09	2.49	44.05	2.04
Noise (LAeqT), dB	23,185	55.69 ± 5.07	37.54	53.07	55.81	58.23	78.94	5.16
Temperature, °C	23,253	25.98 ± 3.71	9.24	23.84	26.24	28.66	37.16	4.82
Relative humidity, %	23,253	25.28 ± 8.90	6.47	18.69	23.03	30.27	75.60	11.58

Abbreviations: PM_2.5 fine particulate matter, BC black carbon, SD standard deviation, IQR interquartile range
^aObservation after removing for missing values and outliers

ISSN: 1476-069X