Epidemiological study of PM_2.5 and risk of COPD-related hospital visits in association with particle constituents in Chuncheon, Korea

Figures & data

Table 1 Descriptive statistics of hospital visits in Chuncheon, Korea, from 2006 to 2012

N/day	Mean ± SD	Min	Percentiles					Max
			5th	25th	50th	75th	95th
Total	8.49±5.42	1.00	1.00	5.00	8.00	11.00	18.00	36.00
Male	6.42±4.28	0.00	1.00	3.00	6.00	9.00	15.00	23.00
Female	2.07±1.93	0.00	0.00	1.00	2.00	3.00	5.00	14.00
Admission	0.24±0.48	0.00	0.00	0.00	0.00	0.00	1.00	2.00
Male	0.21±0.43	0.00	0.00	0.00	0.00	0.00	1.00	2.00
Female	0.04±0.19	0.00	0.00	0.00	0.00	0.00	0.00	1.00
Outpatient visit	8.25±5.36	0.00	1.00	4.00	8.00	11.00	18.00	35.00
Male	6.21±4.23	0.00	1.00	3.00	6.00	8.00	14.00	23.00
Female	2.04±1.91	0.00	0.00	1.00	2.00	3.00	5.00	14.00

Table 2 Percentage increase in hospital visits and 95% CI as PM_2.5 increases 10 µg/m³

	Lag1		Lag2		Lag3		Lag4		Lag5
	% increase	95% CI	% increase	95% CI	% increase	95% CI	% increase	95% CI	% increase	95% CI
Total	0.11	−0.07, 0.30	0.26*	0.06, 0.46	0.26*	0.04, 0.44	0.25*	0.05, 0.44	0.10	−0.08, 0.28
Male	0.02	−0.20, 0.23	0.15	−0.07, 0.38	0.32*	0.10, 0.53	0.25*	0.02, 0.48	0.07	−0.14, 0.28
Female	0.40*	0.01, 0.78	0.58*	0.17, 0.99	0.09	−0.27, 0.44	0.25	−0.14, 0.63	0.17	−0.19, 0.53
Admission	0.17	−0.89, 1.23	0.51	−0.72, 1.72	0.99	−0.33, 2.29	0.36	−0.86, 1.57	−0.68	−1.78, 0.41
Male	0.19	−0.90, 1.29	0.77	−0.70, 2.22	0.83	−0.59, 2.24	0.93	−0.72, 2.56	0.99	−0.19, 2.19
Female	0.40	−0.01, 0.81	0.11	−0.21, 0.42	0.02	−0.45, 0.50	0.05	−0.22, 0.32	0.08	−0.23, 0.40
Outpatient visit	0.11	−0.07, 0.30	0.25	−0.05, 0.45	0.24*	0.06, 0.43	0.25*	0.05, 0.45	0.12	−1.66, 1.88
Male	0.28	−1.89, 2.41	0.13	−0.09, 0.36	0.30*	0.08, 0.52	0.24	−0.01, 0.47	0.10	−0.11, 0.32
Female	0.36	−0.03, 0.74	0.62*	0.20, 1.03	0.44	−0.38, 1.10	0.28	−0.12, 0.67	0.17	−0.20, 0.53

Notes:

* P≤0.05, which represents statistically significant changes as time progressed. Environmental effects may be delayed over a period of several days, and thus, we considered the lagged effects of the day of the event and up to 5 days (from Lag0 to Lag5).

Abbreviations: CI, confidence interval; PM_2.5, particulate matter with aerodynamic diameters ≤2.5 µm.

Table 3 Percentage increase in COPD-related hospital visits and 95% CI in all participants as each particle constituent increased 10 µg/m³

	Lag1		Lag2		Lag3		Lag4		Lag5
	% increase	95% CI	% increase	95% CI	% increase	95% CI	% increase	95% CI	% increase	95% CI
Na	−0.024	−0.086, 0.037	−0.022	−0.128, 0.085	−0.005	−0.077, 0.068	−0.029	−0.085, 0.027	0.072	−0.091, 0.234
Mg	0.044	−0.006, 0.094	0.100	−0.372, 0.572	0.366	−0.455, 1.188	−0.300	−0.610, 0.010	0.679	−1.371, 2.730
Al	0.016*	0.000, 0.031	0.065	−0.055, 0.185	0.028	−0.066, 0.121	−0.108	−0.220, 0.005	−0.066	−0.253, 0.120
Si	0.007*	0.000, 0.014	0.031	−0.020, 0.082	0.014	−0.024, 0.052	−0.053	−0.107, 0.000	−0.033	−0.119, 0.053
Cl	−0.034	−0.162, 0.094	0.009	−0.138, 0.156	−0.058	−0.231, 0.113	−0.059	−0.199, 0.080	−0.056	−0.280, 0.167
K	0.017	−0.027, 0.061	0.038	−0.040, 0.115	0.027	−0.046, 0.100	−0.080	−0.153, 0.007	−0.054	−0.202, 0.095
Ca	0.021	−0.001, 0.043	0.073	−0.126, 0.272	0.041	−0.154, 0.236	−0.164	−0.339, 0.010	−0.134	−0.461, 0.193
Ti	0.242	−0.008, 0.493	0.729	−0.443, 1.900	0.396	−0.529, 1.320	−1.546	−2.964, −0.127	−0.988	−3.370, 1.394
V	3.370	−1.184, 7.925	−1.994	−8.585, 4.594	−4.433	−11.317, 2.451	4.309	−3.170, 11.788	−1.129	−10.709, 8.451
Cr	2.113	−1.997, 4.229	2.278	−1.846, 4.711	3.212	−3.023, 5.401	0.717	−0.908, 2.342	1.546	−1.366, 4.458
Mn	0.706	−0.150, 1.563	0.571	−1.681, 2.823	−0.143	−1.959, 1.674	−0.745	−2.585, 1.095	−0.535	−3.016, 1.946
Fe	0.023	−0.001, 0.048	0.050	−0.074, 0.174	0.008	−0.084, 0.101	−0.064	−0.165, 0.036	−0.043	−0.188, 0.101
Ni	−4.014	−7.642, −0.384	−1.827	−6.302, 2.647	−1.834	−5.771, 2.102	−0.192	−4.485, 4.101	4.409	−9.373, 18.192
Cu	−0.332	−0.797, 0.131	0.292	−0.290, 0.873	0.553	−0.120, 1.227	−1.109	−1.912, 0.307	−0.527	−2.092, 1.039
Zn	0.016	−0.349, 0.383	0.114	−0.355, 0.584	−0.026	−0.389, 0.337	−0.137	−0.511, 0.237	−0.130	−0.623, 0.363
As	−2.260	−5.777, 1.256	3.153	−2.681, 8.987	1.446	−3.053, 5.946	−5.162	−10.553, 0.227	−3.303	−12.073, 5.468
Se	−2.700	−8.540, 3.139	−1.011	−7.361, 5.338	−3.695	−10.738, 3.350	0.500	−6.347, 7.348	−1.123	−10.604, 8.359
Br	−0.685	−2.850, 1.481	1.674	−1.137, 4.485	1.414	−1.160, 3.987	−4.834	−8.618, −1.049	−3.932	−11.641, 3.779
Pb	0.196	−0.660, 1.052	0.023	−1.162, 1.208	−0.447	−1.918, 1.024	−0.463	−1.598, 0.672	−0.320	−2.248, 1.608
OC	−0.172	−0.474, 0.129	0.118	−0.145, 0.382	0.042	−0.244, 0.329	0.044	−0.311, 0.398	−0.118	−0.451, 0.216
EC	0.751	−0.404, 1.906	1.336*	0.218, 2.455	0.417	−0.873, 1.706	−0.862	−2.229, 0.504	0.223	−0.959, 1.406

Notes:

* P≤0.05, which represents statistically significant changes as time progressed. Environmental effects may be delayed over a period of several days, and thus, we considered the lagged effects of the day of the event and up to 5 days (from Lag0 to Lag5).

Abbreviations: CI, confidence interval; EC, elemental carbon; OC, organic carbon.

Table 4 Percentage increase in COPD-related hospital visits and 95% CI in males and females as each particle constituent increased 10 µg/m³

	Lag1		Lag2		Lag3		Lag4		Lag5
	% increase	95% CI	% increase	95% CI	% increase	95% CI	% increase	95% CI	% increase	95% CI
Male
Na	−0.031	−0.106, 0.045	−0.023	−0.152, 0.106	0.003	−0.081, 0.087	−0.042	−0.107, 0.022	0.130	−0.094, 0.355
Mg	0.059*	0.001, 0.116	0.376	−0.291, 1.043	0.711	−0.546, 1.968	−0.373	−0.724, −0.023	1.316	−1.291, 3.923
Al	0.021*	0.002, 0.039	0.182*	0.002, 0.361	0.010	−0.097, 0.117	−0.126	−0.265, 0.014	−0.122	−0.367, 0.123
Si	0.009*	0.001, 0.018	0.078*	0.008, 0.148	0.008	−0.035, 0.052	−0.063	−0.133, 0.005	−0.060	−0.178, 0.057
Cl	−0.077	−0.225, 0.070	0.036	−0.137, 0.209	−0.142	−0.343, 0.060	−0.068	−0.231, 0.094	−0.119	−0.397, 0.158
K	0.021	−0.032, 0.075	0.110	−0.006, 0.227	0.013	−0.072, 0.098	−0.096	−0.186, −0.008	−0.099	−0.294, 0.097
Ca	0.028*	0.002, 0.053	0.229	−0.063, 0.521	−0.018	−0.243, 0.208	−0.192	−0.401, 0.016	−0.234	−0.658, 0.190
Ti	0.324*	0.031, 0.617	1.699*	0.197, 3.202	0.310	−0.741, 1.362	−1.981	−3.916, −0.045	−1.886	−5.375, 1.603
V	3.355	−2.110, 8.819	−3.661	−11.135, 3.814	−7.785	−15.965, 0.398	5.262	−3.669, 14.193	−3.829	−15.626, 7.968
Cr	1.708	−1.336, 4.049	2.035	−1.350, 4.720	2.735	−2.297, 5.174	−0.056	−2.130, 2.010	−0.493	−4.570, 3.584
Mn	0.855	−0.177, 1.886	1.371	−1.394, 4.134	−0.825	−2.890, 1.239	−0.754	−2.920, 1.412	−1.192	−4.253, 1.869
Fe	0.030*	0.001, 0.059	0.137	−0.037, 0.311	−0.020	−0.126, 0.086	−0.069	−0.189, 0.052	−0.083	−0.267, 0.100
Ni	−5.920	−10.281, −1.561	−3.030	−8.205, 2.147	−2.283	−6.722, 2.158	−0.910	−5.944, 4.123	7.795	−18.351, 22.811
Cu	−0.359	−0.919, 0.201	0.601	−0.064, 1.265	0.746	−0.030, 1.523	−1.514	−2.584, −0.445	−0.189	−2.165, 1.788
Zn	−0.079	−0.511, 0.352	0.279	−0.295, 0.853	−0.164	−0.577, 0.249	−0.139	−0.578, 0.301	−0.270	−0.884, 0.346
As	−3.351	−7.512, 0.809	8.714*	0.045, 17.383	0.530	−4.614, 5.673	−6.099	−12.773, 0.576	−6.173	−17.761, 5.418
Se	−5.232	−11.914, 1.448	−1.564	−8.819, 5.692	−7.275	−15.630, 1.077	0.490	−7.550, 8.530	−3.745	−15.376, 7.885
Br	−0.856	−3.447, 1.734	3.876*	0.340, 7.410	1.302	−1.635, 4.238	−6.840	−12.238, −1.442	−8.630	−22.321, 5.063
Pb	0.091	−0.926, 1.107	0.179	−1.208, 1.567	−1.205	−2.942, 0.533	−0.569	−1.890, 0.751	−0.858	−3.227, 1.513
OC	−0.122	−0.458, 0.216	0.120	−0.163, 0.404	−0.012	−0.336, 0.310	−0.135	−0.582, 0.312	−0.260	−0.632, 0.111
EC	0.888	−0.454, 2.230	1.489*	0.206, 2.770	0.443	−1.004, 1.890	−1.458	−3.046, 0.130	0.165	−1.078, 1.407
Female
Na	−0.009	−0.090, 0.073	−0.017	−0.179, 0.145	−0.040	−0.133, 0.053	−0.001	−0.073, 0.071	0.055	−0.158, 0.268
Mg	0.016	−0.060, 0.091	−0.189	−0.857, 0.479	0.000	−0.964, 0.964	−0.119	−0.517, 0.279	0.467	−2.299, 3.232
Al	0.006	−0.017, 0.030	−0.066	−0.244, 0.112	0.087	−0.036, 0.210	−0.085	−0.227, 0.057	−0.051	−0.298, 0.196
Si	0.003	−0.008, 0.013	−0.030	−0.112, 0.051	0.034	−0.016, 0.084	−0.042	−0.108, 0.024	−0.026	−0.138, 0.086
Cl	0.080	−0.126, 0.285	−0.052	−0.281, 0.176	0.144	−0.103, 0.390	−0.045	−0.230, 0.140	−0.034	−0.339, 0.270
K	0.014	−0.048, 0.076	−0.041	−0.153, 0.071	0.072	−0.024, 0.168	−0.054	−0.146, 0.038	−0.041	−0.238, 0.156
Ca	0.009	−0.024, 0.041	−0.103	−0.385, 0.179	0.201	−0.057, 0.459	−0.117	−0.342, 0.108	−0.102	−0.539, 0.336
Ti	0.092	−0.282, 0.465	−0.726	−2.692, 1.242	0.791	−0.421, 2.002	−1.148	−2.856, 0.559	−0.795	−3.833, 2.243
V	3.705	−3.125, 10.534	0.677	−10.871, 12.225	2.487	−7.761, 12.736	2.344	−7.348, 12.037	−0.022	−13.145, 13.100
Cr	3.209	−2.155, 6.263	3.132	−1.362, 0.602	4.270	−3.066, 7.474	2.130	−0.500, 4.760	4.074	−0.580, 8.727
Mn	0.496	−0.736, 1.727	−0.812	−4.202, 2.577	1.729	−0.744, 4.204	−0.796	−3.206, 1.614	−0.296	−3.664, 3.072
Fe	0.011	−0.024, 0.047	−0.058	−0.238, 0.120	0.090	−0.034, 0.213	−0.060	−0.190, 0.070	−0.029	−0.225, 0.167
Ni	−0.290	−5.747, 5.166	0.234	−7.304, 7.773	−1.931	−7.358, 3.495	1.026	−4.286, 6.339	4.300	−12.344, 20.944
Cu	−0.270	−0.964, 0.425	−0.303	−1.387, 0.783	0.301	−0.681, 1.283	−0.579	−1.537, 0.378	−0.668	−2.780, 1.444
Zn	0.258	−0.303, 0.819	−0.177	−0.887, 0.534	0.351	−0.144, 0.845	−0.148	−0.638, 0.341	−0.076	−0.744, 0.591
As	0.058	−5.147, 5.263	−3.097	−11.747, 5.552	4.315	−1.576, 10.207	−3.941	−10.738, 2.858	−2.334	−13.955, 9.288
Se	4.160	−5.759, 14.080	−0.632	−11.233, 9.971	4.039	−6.413, 14.491	0.276	−8.751, 9.304	−0.063	−13.049, 12.922
Br	−0.206	−3.281, 2.869	−1.723	−6.486, 3.040	2.230	−1.160, 5.620	−2.973	−7.354, 1.406	−3.042	−12.438, 6.353
Pb	0.515	−0.760, 1.791	−0.331	−2.188, 1.525	1.263	−0.864, 3.390	−0.288	−1.795, 1.219	−0.101	−2.734, 2.532
OC	−0.356	−0.965, 0.254	0.098	−0.465, 0.660	0.273	−0.203, 0.749	0.318	−0.176, 0.812	0.256	−0.257, 0.768
EC	0.340	−1.692, 2.372	1.099	−1.079, 3.277	0.552	−1.813, 2.919	0.193	−1.892, 2.279	0.366	−1.664, 2.396

Notes:

* P≤0.05, which represents statistically significant changes as time progressed. Environmental effects may be delayed over a period of several days, and thus, we considered the lagged effects of the day of the event and up to 5 days (from Lag0 to Lag5).

Abbreviations: CI, confidence interval; EC, elemental carbon; OC, organic carbon.