Introduction
Participants and methods
Study design
Participants
Subjective neurological symptoms
Objective sensory disturbances
Arsenic concentration of drinking water
Statistical analyses
Results
Subjective neurological symptoms
Symptom | VLOW (< 10 ppb) | LOW (10–50 ppb) | MOD (≥ 50 ppb) | P (chi-square) | |
---|---|---|---|---|---|
All participants (≥ 5 years old, N = 1867) | |||||
Smell defects | Yes | 13 (1.4) | 11 (1.9) | 3 (0.9) | 0.446 |
No | 922 | 573 | 345 | ||
Visual defects | Yes | 298 (31.9) | 188 (32.2) | 100 (28.7) | 0.616 |
No | 637 | 396 | 248 | ||
Taste defects | Yes | 12 (1.3) | 11 (1.9) | 8 (2.3) | 0.401 |
No | 923 | 573 | 340 | ||
Hearing defects | Yes | 63 (6.7) | 46 (7.8) | 22 (6.4) | 0.639 |
No | 872 | 540 | 324 | ||
Feeling of weakness | Yes | 122 (13.0) | 110 (18.8) | 54 (15.5) | 0.020*,a |
No | 813 | 474 | 294 | ||
Chronic numbness or pain | Yes | 191 (20.4) | 151 (25.9) | 79 (22.7) | 0.095 |
No | 744 | 433 | 269 | ||
Children (5–15 years old, n = 456) | |||||
Smell defects | Yes | 0 (0) | 0 (0) | 0 (0) | |
No | 240 | 126 | 90 | ||
Visual defects | Yes | 8 (3.3) | 4 (3.2) | 1 (1.1) | 0.549 |
No | 232 | 122 | 89 | ||
Taste defects | Yes | 0 (0) | 0 (0) | 0 (0) | |
No | 240 | 126 | 90 | ||
Hearing defects | Yes | 2 (0.8) | 1 (0.8) | 2 (2.2) | 0.523 |
No | 238 | 125 | 88 | ||
Feeling of weakness | Yes | 8 (3.3) | 2 (1.6) | 3 (3.3) | 0.614 |
No | 232 | 124 | 87 | ||
Chronic numbness or pain | Yes | 9 (3.8) | 2 (1.6) | 5 (5.6) | 0.295 |
No | 231 | 124 | 85 |
Symptom | < 10 ppb | ≥ 10 ppb |
P
| < 50 ppb | ≥ 50 ppb |
P
| |
---|---|---|---|---|---|---|---|
All participants (≥ 5 years old, N = 1867) | |||||||
Smell defects | Yes | 13 (1.4) | 14 (1.5) | 0.497 | 24 (1.6) | 3 (0.9) | 0.230 |
No | 922 | 918 | 1495 | 345 | |||
Visual defects | Yes | 298 (31.9) | 288 (30.9) | 0.344 | 486 (32.0) | 100 (28.7) | 0.132 |
No | 637 | 644 | 1033 | 248 | |||
Taste defects | Yes | 12 (1.3) | 19 (2.0) | 0.137 | 23 (1.5) | 8 (2.3) | 0.207 |
No | 923 | 913 | 1496 | 340 | |||
Hearing defects | Yes | 63 (6.7) | 68 (7.3) | 0.351 | 109 (7.2) | 22 (6.4) | 0.334 |
No | 872 | 864 | 1410 | 324 | |||
Feeling of weakness | Yes | 122 (13.0) | 164 (17.6) | 0.004** | 232 (15.3) | 54 (15.5) | 0.483 |
No | 813 | 768 | 1287 | 294 | |||
Chronic numbness or pain | Yes | 191 (20.4) | 230 (24.7) | 0.016* | 342 (22.5) | 79 (22.7) | 0.495 |
No | 744 | 702 | 1177 | 269 | |||
Children (5–15 years old, n = 456) | |||||||
Smell defects | Yes | 0 (0) | 0 (0) | 0 (0) | 0 (0) | ||
No | 240 | 216 | 366 | 90 | |||
Visual defects | Yes | 8 (3.3) | 5 (2.3) | 0.358 | 12 (3.3) | 1 (1.1) | 0.237 |
No | 232 | 211 | 354 | 89 | |||
Taste defects | Yes | 0 (0) | 0 (0) | 0 (0) | 0 (0) | ||
No | 240 | 216 | 366 | 90 | |||
Hearing defects | Yes | 2 (0.8) | 3 (1.4) | 0.451 | 3 (0.8) | 2 (2.2) | 0.257 |
No | 238 | 213 | 363 | 88 | |||
Feeling of weakness | Yes | 8 (3.3) | 5 (2.3) | 0.358 | 10 (2.7) | 3 (3.3) | 0.490 |
No | 232 | 211 | 356 | 87 | |||
Chronic numbness or pain | Yes | 9 (3.8) | 7 (3.2) | 0.486 | 11 (3.0) | 5 (5.6) | 0.190 |
No | 231 | 209 | 355 | 85 |
Objective sensory disturbances
Impairment | VLOW (< 10 ppb) | LOW (10–50 ppb) | MOD (≥ 50 ppb) | P (chi-square) | |
---|---|---|---|---|---|
All participants (> 5 years old, n = 1526) | |||||
Pain sensation | Yes | 38 (5.0) | 21 (4.3) | 25 (9.0) | 0.021*,a |
No | 726 | 463 | 253 | ||
Vibration sensation | Yes | 33 (4.3) | 14 (2.9) | 18 (6.5) | 0.070 |
No | 731 | 470 | 260 | ||
Two-point discrimination | Yes | 34 (4.5) | 11 (2.3) | 20 (7.2) | 0.006*,b |
No | 730 | 473 | 258 | ||
Children (5–15 years old, n = 133) | |||||
Pain sensation | Yes | 3 (3.8) | 0 (0) | 2 (9.1) | 0.243 |
No | 77 | 31 | 20 | ||
Vibration sensation | Yes | 1 (1.3) | 0 (0) | 2 (9.1) | 0.060 |
No | 79 | 31 | 20 | ||
Two-point discrimination | Yes | 2 (2.5) | 0 (0) | 0 (0) | 0.516 |
No | 78 | 31 | 22 |
Impairment | < 10 ppb | ≥10 ppb |
P
| < 50 ppb | ≥ 50 ppb |
P
| |
---|---|---|---|---|---|---|---|
All participants (> 5 years old, n = 1526) | |||||||
Pain sensation | Yes | 38 (5.0) | 46 (6.0) | 0.212 | 59 (4.7) | 25 (9.0) | 0.005** |
No | 726 | 716 | 1189 | 253 | |||
Vibration sensation | Yes | 33 (4.3) | 32 (4.2) | 0.504 | 47 (3.8) | 18 (6.5) | 0.036* |
No | 731 | 730 | 1201 | 260 | |||
Two-point discrimination | Yes | 34 (4.5) | 31 (4.1) | 0.800 | 45 (3.6) | 20 (7.2) | 0.007** |
No | 730 | 731 | 1203 | 258 | |||
Children (5–15 years old, n = 133) | |||||||
Pain sensation | Yes | 3 (3.8) | 2 (3.8) | 0.664 | 3 (2.7) | 2 (9.1) | 0.191 |
No | 77 | 51 | 108 | 20 | |||
Vibration sensation | Yes | 1 (1.3) | 2 (3.8) | 0.349 | 1 (0.9) | 2 (9.1) | 0.071 |
No | 79 | 51 | 110 | 20 | |||
Two-point discrimination | Yes | 2 (2.5) | 0 (0) | 0.360 | 2 (1.8) | 0 (0) | 0.695 |
No | 78 | 53 | 109 | 22 |