Table 5. Sensitivity analyses for varying degrees of freedom for time trend and weather conditions: df = 4–7 per year for time trend (A), df = 3–6 for current day temperature/relative humidity (B)^a.

	A
	4	5	6	7
Warm season	0.153 (−0.191, 0.498)	0.154 (−0.190, 0.499)	0.156 (−0.189, 0.502)	0.158 (−0.187, 0.504)
Cool season	0.242 (0.203, 0.280)	0.242 (0.203, 0.281)	0.244 (0.204, 0.283)	0.245 (0.205, 0.285)
Entire period	0.194 (0.076, 0.311)	0.195 (0.078, 0.313)	0.197 (0.078, 0.315)	0.199 (0.080, 0.318)

^aWe used 2-day moving average (lag 01) of PM₁₀ concentration, and current day temperature and humidity (lag0).