Additional file 1 - PLOS

Additional file 1: Pre-and post-imputation descriptives of all study variables

Variable

Pre-imputation Mean (SD) N (%)

Post imputation (N=884) Mean (SD) %

Gender

NA (%) 0.0 %

Male Female Hg in urine (µg/l) 42.75 (216.29) Hg in blood (µg/l) 12.56 (28.67) Hg in hair (µg/g) 7.39 (35.18) Hg urine/crea (µg/g) 22.68 (82.45) Exposure group Control low exposed medium exposed high exposed Metallic taste No Yes Excessive salivation No Yes Sleep disturbances No Yes Loss of hair No Yes Tremor at work No Yes Feel nervous No Yes Palpitations No Yes Headache No Yes Nausea No Yes Feel numbness, prickling, aching No Yes Tired easily No Yes Need to rest more No Yes Feel sleepy or drowsy No Yes No longer able to start anything No Yes Always lack energy No

512 (57.9 %) 372 (42.1 %)

57.9 % 42.1 % 42.83 (215,90) 12.70 (28.75) 7.66 (34.1) 22.64 (82.25)

0.3 % 0.6 % 8.5 % 0.6 % 0.0 %

100 (11.3 %) 255 (28.8 %) 149 (16.9 %) 380 (43.0 %)

11.3 % 28.8 % 16.9 % 43.0 %

788 (89.1 %) 96 (10.9 %)

89.1 % 10.9 %

751 (85.0 %) 133 (15.0 %)

85.0 % 15.0 %

690 (78.1 %) 194 (21.9 %)

78.1 % 21.9 %

744 (85.6 %) 125 (14.4 %)

85.7 % 14.3 %

759 (86.0 %) 124 (14.0 %)

86.0 % 14.0 %

793 (89.9 %) 89 (10.1 %)

89.8 % 10.2 %

738 (83.6 %) 145 (16.4 %)

83.5 % 16.5 %

635 (72.0 %) 247 (28.0 %)

72.0 % 28.0 %

757 (85.7 %) 126 (14.3 %)

85.7 % 14.3 %

681 (77 %) 203 (23 %)

77 % 23 %

670 (75.8 %) 214 (24.2 %)

75.8 % 24.2 %

730 (82.8 %) 152 (17.2 %)

82.7 % 17.3 %

745 (84.4 %) 138 ( 15.6 %)

84.3 % 15.7 %

845 (96.0 %) 35 (4.0 %)

96.0 % 4.0 %

730 (82.7 %)

82.6 %

0.0 %

0.0 %

0.0 %

1.7 %

0.1 %

0.2 %

0.1 %

0.2 %

0.1 %

0.0 %

0.0 %

0.2 %

0.1 %

0.5 %

0.1 %

Yes 153 (17.3 %) Less strength in muscles No 734 (83.1 %) Yes 149 (16.9 %) Feel weak No 721 (81.7 %) Yes 161 (18.3 %) Get weak as go on No 747 (84.5 %) Yes 137 (15.5 %) Concentrating problems No 760 (86.1 %) Yes 123 (13.9 %) Problems to think clear No 810 (91.6 %) Yes 74 (8.4 %) Problems to find correct words No 849 (96.1 %) Yes 34 (3.9 %) Problems with eyestrain No 731 (82.8 %) Yes 152 (17.2 %) Memory problems No 665 (75.6 %) Yes 215 (24.4 %) Teeth with amalgam fillings No 883 (99.9 %) Yes 1 (0.1 %) Grey to bluish discoloration of the oral cavity No 719 (81.3 %) Yes 165 (18.7 %) Ataxia of gait (walking) No 640 (72.4 %) Yes 244 (27.6 %) Finger to nose tremor No 827 (93.6 %) Yes 57 (6.4 %) Dysdiadochokinesis No 627 (70.9 %) Yes 257 (29.1 %) Heel to shin ataxia No 669 (75.9 %) Yes 213 (24.1 %) Heel to shin intentional No 872 (98.9 %) Yes 10 (1.1 %) Mentolabial reflex No 684 (77.6 %) Yes 198 (22.4 %) Bradykinesia No 779 (88.4 %) Yes 102 (11.6 %) Hypomimia No 785 (89.1 %) Yes 96 (10.9 %) Proteinuria No 784 (88.9 %) Yes 98 (11.1 %) Matchbox test 20.81 (5.51)

17.4 % 0.1 % 83.1 % 16.9 % 0.2 % 81.7 % 18.3 % 0.0 % 84.5 % 15.5 % 0.1 % 86.0 % 14.0 % 0.0 % 91.6 % 8.4 % 0.1 % 96.2 % 3.8 % 0.1 % 82.8 % 17.2 % 0.5 % 75.5 % 24.5 % 0.0 % 99.9 % 0.1 % 0.0 % 81.3 % 18.7 % 0.0 % 72.4 % 27.6 % 0.0 % 93.6 % 6.4 % 0.0 % 70.9 % 29.1 % 0.2 % 75.9 % 24.1 % 0.2 % 98.8 % 1.2 % 0.2 % 77.5 % 22.5 % 0.3 % 88.4 % 11.6 % 0.3 % 89.1 % 10.9 % 0.2 % 88.9 % 11.1 % 20.82 (5.5)

0.3 %

Pencil tapping test 52.1 (11.99) Age (years) 27.66 (12.29) Height (cm) 157.38 (12.9) Weight (kg) 53.7 (14.8) Years in area (years) 10.59 (10.54) Storing Hg at home Never At work At home Working cloth at home No Yes Years,working with Hg 3.12 (4.58) Is a smoker No Yes Drinks alcohol No Yes Handling with insecticides No Yes Medical history of malaria No Yes Fish consumption None or low Medium or high Consumes local chicken Never >= once a month >= once a week >= once a day Consumes local meat Never ≥ once a month ≥ once a week ≥ once a day Consumes local vegetables or fruits Never ≥ once a month ≥ once a week ≥ once a day Quadrizeps reflex (knee) No Yes Achilles reflex (ankle jerk) No Yes Visual field (radian) 2.87 (0.24) Health problems No Yes

52.09 (11.98) 27.66 (12.29) 157.35 (12.8) 53.68 (14.73) 10.66 (10.37)

0.7 % 0.0 % 2.5 % 2.5 % 5.2 % 1.1 %

311 (35.6 %) 169 (19.3 %) 394 (45.1 %)

35.7 % 19.3 % 45.0 %

270 (30.6 %) 612 (69.4 %)

30.6 % 69.4 %

0.2 %

3.12 (4.58)

0.0 % 0.9 %

657 (75 %) 219 (25 %)

74.8 % 25.2 %

716 (81.1 %) 167 (18.9 %)

81.0 % 19.0 %

485 (55 %) 397 (45 %)

55 % 45 %

360 (40.7 %) 524 (59.3 %)

40.7 % 59.3 %

119 (13.6 %) 758 (86.4 %)

13.5 % 86.5 %

87 (9.9 %) 332 (37.6 %) 370 (41.9 %) 94 (10.6 %)

9.8 % 37.7 % 41.8 % 10.6 %

108 (12.3 %) 351 (39.9 %) 330 (37.5 %) 90 (10.2 %)

12.3 % 39.9 % 37.5 % 10.2 %

53 (6.0 %) 25 (2.8 %) 155 (17.5 %) 651 (73.6)

6.0 % 2.8 % 17.5 % 73.6 %

720 (81.5 %) 163 (18.5 %)

81.5 % 18.5 %

584 (66.4 %) 295 (33.6 %)

66.4 % 33.6 %

0.1 %

0.2 %

0.0 %

0.8 %

0.1 %

0.6 %

0.0 %

0.1 %

0.6 %

2.87 (0.24) 846 (95.9 %) 36 (4.1 %)

1.9 % 0.2 % 95.9 % 4.1 %