Figure 1Selection process for study subjects. *Highly exposed area: the area that had seashores covered with thick crude oil in Sowon-myeon, Wonbuk-myeon, Iwon-myeon, Geunheung-myeon in the beginning of the Hebei Spirit Oil Spill accident.
Table 1General characteristics and health behaviors of the subjects according to sex
Variable |
Male |
Female |
Total |
Age (y) |
26–49 |
24 (9.2) |
47 (10.7) |
71 (10.1) |
50–59 |
61 (23.5) |
119 (27.0) |
180 (25.7) |
60–69 |
104 (40.0) |
181 (41.0) |
285 (40.7) |
70–81 |
71 (27.3) |
94 (21.3) |
165 (23.5) |
Educational attainmenta
|
Kindergarten or lower |
30 (11.5) |
227 (51.5) |
257 (36.7) |
Elementary school |
128 (49.2) |
152 (34.5) |
280 (39.9) |
Middle school or higher |
102 (39.2) |
62 (14.1) |
164 (23.4) |
Marital statusa
|
Married |
242 (93.1) |
329 (74.6) |
571 (81.5) |
Others |
18 (6.9) |
112 (25.4) |
130 (18.5) |
Type of health insurance |
National health insurance |
154 (59.2) |
258 (58.5) |
412 (58.8) |
Medicaid |
106 (40.8) |
183 (41.5) |
289 (41.2) |
Monthly household income (KRW)a
|
< 500,000 |
144 (55.4) |
293 (66.4) |
437 (62.3) |
500,000–999,999 |
35 (13.5) |
67 (15.2) |
102 (14.6) |
1,000,000–1,999,999 |
49 (18.8) |
51 (11.6) |
100 (14.3) |
≥ 2,000,000 |
32 (12.3) |
30 (6.8) |
62 (8.8) |
Religiona
|
Yes |
120 (46.2) |
257 (58.3) |
377 (53.8) |
No |
140 (53.8) |
184 (41.7) |
324 (46.2) |
Occupationa
|
Farming and fishing |
154 (59.2) |
182 (41.3) |
336 (47.9) |
Others |
106 (40.8) |
259 (58.7) |
365 (52.1) |
Body mass index (kg/m2) |
Underweight to normal (< 23.0) |
77 (30.8) |
119 (27.8) |
196 (28.9) |
Overweight (23.0–25.0) |
61 (24.4) |
101 (23.6) |
162 (23.9) |
Obese (> 25.0) |
112 (44.8) |
208 (48.6) |
320 (47.2) |
Chronic diseaseb
|
Yes |
112 (43.1) |
190 (43.1) |
302 (43.1) |
No |
148 (56.9) |
251 (56.9) |
399 (56.9) |
Smokinga
|
Non-smoker |
140 (54.3) |
428 (97.3) |
568 (81.4) |
Ex-smoker |
61 (23.6) |
4 (0.9) |
65 (9.3) |
Smoker |
57 (22.1) |
8 (1.8) |
65 (9.3) |
Drinkinga
|
Yes |
139 (53.9) |
54 (12.3) |
193 (27.7) |
No |
119 (46.1) |
386 (87.7) |
505 (72.3) |
Weekly exercise frequency |
None |
181 (70.2) |
313 (71.1) |
494 (70.8) |
1 or 2 times |
13 (5.0) |
37 (8.4) |
50 (7.2) |
3 or 4 times |
24 (9.3) |
36 (8.2) |
60 (8.6) |
5 or 6 times |
40 (15.5) |
54 (12.3) |
94 (13.5) |
Total |
260 (100.0) |
441 (100.0) |
701 (100.0) |
Table 2Exposure characteristics of the subjects by sex
Variable |
Male |
Female |
Total |
Number of clean-up days in acute stagea
|
1–14 |
10 (3.7) |
32 (6.9) |
42 (5.7) |
15–19 |
14 (5.5) |
37 (8.6) |
51 (7.5) |
20–24 |
232 (90.6) |
359 (83.9) |
591 (86.4) |
Total number of clean-up daysa
|
3–60 |
26 (10.0) |
76 (17.3) |
102 (14.6) |
61–90 |
30 (11.6) |
83 (18.9) |
113 (16.2) |
91–120 |
41 (15.8) |
70 (15.9) |
111 (15.9) |
121–150 |
84 (32.4) |
125 (28.5) |
209 (29.9) |
151–325 |
78 (30.1) |
85 (19.4) |
163 (23.4) |
Distance from the accident point (km) |
≤ 14.0 |
48 (18.7) |
81 (18.5) |
129 (18.6) |
14.1–15.0 |
68 (26.5) |
92 (21.1) |
160 (23.1) |
15.1–16.0 |
62 (24.1) |
106 (24.3) |
168 (24.2) |
16.1–17.0 |
21 (8.2) |
54 (12.4) |
75 (10.8) |
> 17.0 |
58 (22.6) |
104 (23.8) |
162 (23.3) |
Distance from contaminated seashore (km) |
≤ 0.20 |
56 (22.3) |
91 (21.5) |
147 (21.8) |
0.21–0.40 |
38 (15.1) |
65 (15.3) |
103 (15.3) |
0.41–0.60 |
56 (22.3) |
92 (21.7) |
148 (21.9) |
0.61–0.80 |
40 (15.9) |
60 (14.2) |
100 (14.8) |
> 0.80 |
61 (24.3) |
116 (27.4) |
177 (26.2) |
Respiratory symptoms |
Yes |
122 (47.1) |
203 (46.1) |
325 (46.5) |
No |
137 (52.9) |
237 (53.9) |
374 (53.5) |
Dermatologic symptoms |
Yes |
53 (20.5) |
108 (24.5) |
161 (23.0) |
No |
206 (79.5) |
332 (75.5) |
538 (77.0) |
PTSD risk |
Yes |
87 (33.9) |
173 (40.0) |
260 (37.7) |
No |
170 (66.1) |
260 (60.0) |
430 (62.3) |
Total |
273 (100.0) |
463 (100.0) |
736 (100.0) |
Table 3Hematologic parameters of the subjects in 2009 and 2012
Hematologic tests |
Subject (n) |
2009 |
2012 |
p-valuea
|
CBC |
WBC count (/μL) |
698 |
6,176.5 ± 1672.9 |
6,356.0 ± 2034.1 |
0.011 |
Hb (mg/dL) |
698 |
14.0 ± 1.3 |
14.0 ± 1.3 |
0.798 |
Hct (%) |
698 |
39.3 ± 3.5 |
39.5 ± 3.5 |
0.027 |
PLT count (/μL) |
692 |
25.1 ± 5.3 |
25.2 ± 6.1 |
0.532 |
Biochemistry |
AST (IU/L) |
699 |
26.7 ± 13.5 |
29.0 ± 12.3 |
0.000 |
ALT (IU/L) |
699 |
25.8 ± 16.9 |
28.2 ± 18.9 |
0.002 |
γ-GT (IU/L) |
699 |
44.7 ± 61.4 |
41.7 ± 55.4 |
0.143 |
Glucose (mg/dL) |
699 |
103.6 ± 22.8 |
106.6 ± 25.0 |
0.000 |
HbA1c (%) |
698 |
5.9 ± 0.7 |
6.1 ± 0.8 |
0.000 |
BUN (mg/dL) |
699 |
16.1 ± 4.7 |
15.3 ± 4.1 |
0.001 |
Cr (mg/dL) |
699 |
0.9 ± 0.2 |
0.8 ± 0.2 |
0.000 |
T-chol (mg/dL) |
699 |
207.9 ± 39.8 |
206.2 ± 38.3 |
0.250 |
HDL (mg/dL) |
699 |
51.9 ± 12.2 |
50.1 ± 12.3 |
0.000 |
TG (mg/dL) |
699 |
145.9 ± 99.9 |
135.4 ± 93.1 |
0.004 |
Table 4Multiple regression analysis of the changes in Hct, AST, ALT, glucose, HbA1c, BUN, HDL, TG, and Cr levels
Variable |
Regression coefficients |
Hct |
AST |
ALT |
Glucose |
HbA1c |
BUN |
HDL |
TG |
Cr |
Women (ref. men) |
|
|
|
|
|
1.089*
|
|
|
0.215*
|
Age (y) (ref. 26–49 y) |
50–59 |
|
|
|
|
|
−0.941 |
|
|
|
60–69 |
|
|
|
|
|
−1.444 |
|
|
|
70–81 |
|
|
|
|
|
−2.514*
|
|
|
|
Education (ref. kindergarten or lower) |
Elementary school |
|
|
|
|
|
|
|
|
0.000 |
Middle school or higher |
|
|
|
|
|
|
|
|
−0.012 |
Marital status (ref. married) |
|
−2.498 |
|
|
|
|
|
|
|
Medicaid (ref. health insurance) |
|
|
3.686*
|
2.621 |
|
|
|
|
|
Monthly household income (KRW) (ref. < 500,000 KRW) |
500,000–999,999 |
|
5.372*
|
4.879*
|
|
|
|
|
|
0.016 |
1,000,000–1,999,999 |
|
3.653*
|
4.447*
|
|
|
|
|
|
−0.017 |
≥ 2,000,000 |
|
0.029 |
−0.480 |
|
|
|
|
|
−0.058 |
Not having a religion (ref. yes) |
|
|
|
|
|
|
|
19.108*
|
−0.028 |
Occupation (ref. farming and fishing) |
|
|
|
|
|
|
|
−15.888*
|
|
Body mass index (kg/m2) (ref. < 23.0 kg/m2) |
23.0–25.0 |
|
|
|
|
−0.004 |
−1.330 |
|
|
−0.038 |
> 25.0 |
|
|
|
|
−0.120*
|
−1.726*
|
|
|
−0.063*
|
Presence of a chronic disease (ref. no) |
|
|
|
|
|
|
|
|
−0.051*
|
Smoking (ref. nonsmoker) |
Ex-smoker |
|
|
|
|
|
|
0.478 |
−36.379*
|
−0.036 |
Smoker |
|
|
|
|
|
|
−3.093*
|
14.253 |
−0.044 |
Drinking (ref. none) |
|
|
|
|
|
|
|
17.321*
|
0.026 |
Number of days of clean-up work during the acute stage (ref. 1–14) |
15–19 |
|
|
|
|
|
|
−10.584*
|
|
|
20–24 |
|
|
|
|
|
|
−12.226*
|
|
|
Number of days of total clean-up work (ref. 3–60) |
61–90 |
|
|
|
|
|
1.435 |
|
|
|
91–120 |
|
|
|
|
|
−0.897 |
|
|
|
121–150 |
|
|
|
|
|
0.035 |
|
|
|
151–325 |
|
|
|
|
|
0.739 |
|
|
|
Distance (km) from the accident site (ref. > 17.0) |
≤ 14.0 |
|
|
|
−6.384*
|
|
|
−3.225*
|
|
|
14.1–15.0 |
|
|
|
0.120 |
|
|
0.373*
|
|
|
15.1–16.0 |
|
|
|
2.012 |
|
|
−2.207*
|
|
|
16.1–17.0 |
|
|
|
0.706 |
|
|
−3.550*
|
|
|
Distance (km) from contaminated seashore (ref. > 0.80) |
≤ 0.20 |
−0.631 |
|
|
−6.412*
|
|
−1.629*
|
|
|
|
0.21–0.40 |
0.121 |
|
|
0.498 |
|
−1.819 |
|
|
|
0.41–0.60 |
−0.532*
|
|
|
2.040 |
|
−0.671 |
|
|
|
0.61–0.80 |
−0.799*
|
|
|
−1.248 |
|
0.201 |
|
|
|
Presence of respiratory symptoms |
|
|
|
|
0.095*
|
0.704 |
|
|
|
Risk of PTSD |
|
|
|
|
|
0.740 |
|
|
|
R2
|
0.018 |
0.025 |
0.020 |
0.053 |
0.021 |
0.071 |
0.006 |
0.044 |
0.215 |
F statistics |
3.028*
|
4.426*
|
3.549 |
4.077*
|
4.804*
|
2.984*
|
3.078*
|
6.372*
|
13.853*
|