An outbreak of cardiovascular syndromes requiring urgent medical treatment and its association with environmental factors: an ecological study

Table 2 Descriptive statistics. Descriptive statistics (percentiles) of weather and pollution variables during the study period 25 Jan 2002 and 31 May 2005.

		Comparison period (April & May 2002–2004)				Outbreak period (April & May 2005)				Total period
	Daily	N	25th	50th	75th	N	25th	50th	75th	N	25th	50th	75th
PM10 CBMS^a (ug/m³)^b	Min	183	3.2	5.7	9.3	55	4.3	8.6	13.3	1183	3.0	6.5	10.8
PM10 Earlwood^c (ug/m³)	Min	183	4.0	7.2	11.7	61	6.8	9.5	12.5	1191	4.0	7.7	12.2
PM2.5 Earlwood (ug/m³)	Mean	183	7.5	10.0	13.3	61	8.6	10.6	13.2	1216	7.6	10.0	13.4
NEPH^d Earlwood	Mean	176	0.2	0.2	0.4	61	0.2	0.2	0.3	1209	0.1	0.2	0.3
CO CBMS (ppm)^e	Mean	181	0.1	0.3	0.5	59	0.1	0.2	0.4	1187	0.1	0.1	0.3
NO2 CBMS (ug/m³)	Mean	183	24.9	32.1	40.5	57	25.2	33.6	42.2	1183	17.5	26.7	37.8
NO2 Earlwood (pphm)^f	Mean	182	1.2	1.5	1.8	61	1.1	1.5	1.8	1189	0.8	1.3	1.7
NO CBMS (ug/m³)	Mean	183	10.3	24.5	46.9	57	12.9	27.0	57.8	1183	3.4	11.3	29.8
Ozone Earlwood (pphm)	Max	177	2.2	2.6	3.0	61	2.5	2.7	3.1	1199	2.3	2.8	3.3
Relative Humidity Airport^g (%)	Max	183	82.0	90.0	95.0	61	85.5	89.0	91.0	1223	78.5	87.5	93.0
Air Temperature	Min	183	12.5	14.3	16.4	61	12.9	15.0	17.2	1194	11.2	15.3	18.6
Airport (°C)	Max	183	19.1	21.0	23.0	61	20.0	22.3	24.4	1223	19.0	22.1	25.3
Solar Radiation CBMS (w/m²)	Mean	183	108.6	143.6	166.8	61	110.6	148.8	166.6	1223	127.5	174.8	258.6
Precipitation Airport (mm)	Max	183	0.0	0.1	5.2	61	0.0	0.0	0.4	1223	0.0	0.0	2.0
Station Pressure Airport (hPa)	Mean	183	1015.4	1020.0	1023.6	61	1018.6	1021.9	1024.3	1223	1012.2	1016.9	1021.3
Wind Speed Airport (km/h)	Mean	183	13.3	15.9	21.8	61	12.9	16.7	19.7	1223	15.0	18.8	23.7

^a A community based monitoring station of the Road and Traffic Authority.
^b ug/m³ = micrograms per cubic meter, i.e. mass of pollutant per volume of air.
^c A monitoring station of the Environmental Protection Agency at Earlwood.
^d Coefficient of light scattering by fine particles per 10 km.
^e ppm = parts per million by volume, i.e. parts of million parts of air.
^f pphm = parts per hundred million by volume, i.e. parts of pollutant per hundred million parts of air.
^g A weather monitoring station at the Sydney Kingsford-Smith Airport.

ISSN: 1476-069X