A 10-year time-series analysis of respiratory and cardiovascular morbidity in Nicosia, Cyprus: the effect of short-term changes in air pollution and dust storms

Table 1 Summary statistics for daily number of admissions, levels of air pollutants and meteorological factors in the 10-year period 1 Jan 1995–30 Dec 2004 (n = 3652 days).

A. Daily number of hospital admissions for all, cardiovascular and respiratory causes
		Total number (% Nicosia residents)¹	Mean	SD	Min	25%	Median	75%	Max
All causes		178 091	48.8	20.1	4	31	50	63	111
Cardiovascular²		10 896 (75%)	3.0 (2.2)	2.4 (1.9)	0 (0)	1 (1)	3 (2)	4 (3)	22 (11)
Respiratory²		14 827 (86%)	4.1 (3.5)	3.7 (3.1)	0 (0)	1 (1)	3 (2)	6 (5)	20 (18)
B. Levels of air pollutants, shown separately for cold and warm months ³
		Number of Days (% of total days)⁴	Mean	SD	Min	5%	Median	95%	Max
Nicosia Central
PM₁₀ 24-hour average (μg/m³)	Cold	1553 (85.7%)	57.6	52.5	5.0	20.0	50.8	103.0	1370.6
	Warm	1664 (90.4%)	53.4	30.7	18.4	32.0	50.5	77.6	933.5
O₃ 8-hour MA max (ppb)	Cold	1514 (83.6%)	28.7	12.6	3.7	9.9	27.5	50.2	63.6
	Warm	1692 (92.0%)	44.4	10.3	7.8	24.4	46.1	58.8	71.1
Ayia Marina ⁵
PM₁₀ 24-hour average (μg/m³)	Cold	918 (84.5%)	25.9	28.0	6.3	9.3	19.0	62.3	553.2
	Warm	903 (81.8%)	35.7	40.5	8.1	16.0	30.9	58.9	952.4
O₃ 8-hour MA max (ppb)	Cold	1155 (80.1%)	45.7	6.8	30.2	35.1	44.6	58.4	71.0
	Warm	1247 (84.7%)	54.9	8.2	28.9	40.6	55.2	68.1	78.7
C. Meteorological factors
Temperature	Cold	1812 (100%)	12.9	3.6	1.9	7.4	12.5	19.1	27.2
	Warm	1840 (100%)	25.8	3.9	11.8	19.0	26.3	31.4	35.5
Rel. Humidity		3591 (98.3%)	65.0	14.0	16.6	38.5	66.2	85.8	96.5
Dew Point		3591 (98.3%)	11.3	5.5	-7.6	2.4	10.8	20.4	24.2

Notes: ¹ In the case of cause-specific admissions, information on residence was available allowing the analyses to be restricted to those resident in the Nicosia district; the same was not possible for all-cause admissions as only aggregated data were available. In parentheses, the proportion of Nicosia residents among total number of admissions. ² Summary statistics when restricting numbers to Nicosia residents are shown in parentheses. ³ Cold months include Jan, Feb, Mar Apr, Nov and Dec, based on monthly average temperatures, while warm months include all the rest. ⁴ About 10% of the 3652 days in the 10-year study period were excluded as no data were available as well as an additional 2% of days for which only less than 12 hourly measurements were recorded. ⁵ PM₁₀ and O₃ data from the station of Ayia Marina were available only from 1999 and 1997 onwards reducing the study period to 6 and 8 years respectively.

ISSN: 1476-069X