Table 1.
Sample Characteristics by Quartile of Current BAs
| Total n = 697 | Quartile 1 BAs≤2.20 μg /L (n=17 4) | Quartile 2 2.20<BAs≤3.48 μg /L (n=17 5) | Quartile 3 3.48<BAs≤5.81 μg /L (n=17 4) | Quartile 4 BAs >5.81 μg /L (n=17 4) | ||
|---|---|---|---|---|---|---|
| Measures | Mean ± SD or % (n) | Mean ± SD or % (n) | Mean ± SD or % (n) | Mean ± SD or % (n) | Mean ± SD or % (n) | p-value |
| Child characteristics | ||||||
| Male | 46.48 (324) | 37.93 (66) | 46.29 (81) | 45.40 (79) | 56.32 (98) | 0.0075 |
| Age (years) | 14.75 ± 0.69 | 14.73 ± 0.71 | 14.70 ± 0.65 | 14.77 ± 0.66 | 14.82 ± 0.72 | 0.2905 |
| Years in school | 6.86 ± 2.18 | 7.38 ± 1.80 | 6.93 ± 2.21 | 6.91 ± 2.13 | 6.24 ± 2.39 | <0.0001 |
| Currently attending school | 83.86 (582) | 91.28 (157) | 86.21 (150) | 81.61 (142) | 76.44 (133) | 0.0015 |
| Currently employed | 11.19 (78) | 4.02 (7) | 9.14 (16) | 12.64 22) | 18.97 (33) | <0.0001 |
| Head circumference (cm) | 51.67 ± 1.72 | 51.80 ± 1.80 | 51.75 ± 1.75 | 51.42 ± 1.65 | 51.72 ± 1.65 | 0.0676 |
| BMI | 18.28 ± 2.83 | 18.30 ± 3.03 | 18.55 ± 3.08 | 18.26 ± 2.77 | 18.01 ± 2.42 | 0.6497 |
| Family characteristics | ||||||
| Paternal age at baseline | 47.24 ± 7.15 (n=664) | 47.36 ± 7.12 (n=167) | 47.43 ± 7.62 (n=168) | 46.60 ± 6.84 (n=163) | 47.54 ± 7.01 (n=166) | 0.5445 |
| Paternal education (years) | 4.27 ± 4.14 (n=684) | 5.17 ± 4.20 (n=171) | 4.45 ± 4.19 (n=173) | 4.31 ± 4.23 (n=172) | 3.15 ± 3.72 (n=168) | 0.0001 |
| Paternal education 6–16 years 1–5 years None | 33.33 (228) 28.51(195) 38.16 (261) | 38.60 (66) 33.33 (57) 28.07 (48) | 36.99 (64) 25.43 (44) 37.57 (65) | 37.21 (64) 21.51 (37) 41.28 (71) | 20.24 (34) 33.93 (57) 45.83 (77) | 0.0002 |
| Maternal age (years) | 40.41 ± 5.17 | 40.09 ± 5.05 | 40.69 ± 5.50 | 40.10 ± 5.10 | 40.75 ± 5.01 | 0.3675 |
| Maternal education (years) | 3.62 ± 3.57 | 4.41 ± 3.81 | 3.58 ± 3.55 | 3.72 ± 3.61 | 2.78 ± 3.12 | 0.0008 |
| Maternal education 6–13 years 1–5 years None | 27.40 (191) 31.42 (219) 41.18 (287) | 34.48 (60) 31.03 (54) 34.48 (60) | 27.43 (48) 31.43 (55) 41.14 (72) | 29.31 (51) 29.31 (51) 41.38 (72) | 18.39 (32) 33.91 (59) 47.7 0 (83) | 0.0453 |
| Maternal IQ (WASI) | 33.36 ± 9.01 | 35.09 ± 9.38 | 33.43 ± 8.98 | 33.24 ± 9.38 | 31.69 ± 7.96 | .0039 |
| HOME Total | 3.71 ± 1.82 | 4.33 ± 1.63 | 3.58 ± 1.83 | 3.62 ± 1.84 | 3.31 ± 1.81 | <0.0001 |
| Home construction (concrete wall) | 28.12 (196) | 29.7.93 (66) | 32.57 (57) | 25.29 (44) | 16.67 (29) | <0.0001 |
| Exposure characteristics | ||||||
| Baseline well water As: WAs (μg /L) | 73.87 ± 103.97 | 40.20 ± 82.34 | 62.83 ± 100.68 | 76.78 ± 106.96 | 115.75 ± 109.36 | <0.0001 |
| Baseline well water Mn: WMn (μg /L) | 1284.18±882.04 (n=695) | 1030.98±965.82 | 1214.74±864.14 | 1411.19±895.85(n=173) | 1482.09±719.40(n=173) | <0.00 01 |
| Baseline maternal urinary As UAs/Cr (μg/gCr) | 283.22 ± 308.41 | 182.52 ± 225.96 | 235.63 ± 236.37 | 292.09 ± 357.04 | 422.89 ± 342.20 | <0.0001 |
| Current well water As: WAs (μg /L) | 37.57± 65.95 (n=674) | 4.06 ± 9.01 (n=162) | 13.46 ± 22.49 (n=169) | 31.19 ± 36.37 (n=171) | 99.16 ± 98.67 (n=172) | <0.0001 |
| Current well water Mn: WMn (μg /L) | 1141.65±1014.34 (n=682) | 742.01±886.70 (n=168) | 822.09±752.98 (n=171) | 1292.59±1002.78 (n=171) | 1699.63±1082.29 (n=172) | <0.0001 |
| Biological measures | ||||||
| UAs/Cr (μg /gCr) | 157.79 ± 208.87 (n=694) | 53.28 ± 50.23 | 90.05 ± 92.19 (n=174) | 153.43 ± 191.38 | 336.47 ± 284.05 (n=172) | <0.0001 |
| Urine %DMA | 74.32 ± 8.78 (n=693) | 74.16 ± 11.37 | 75.30 ± 8.21 (n=174) | 74.79 ± 7.76 (n=173) | 73.00 ± 7.03 (n=172) | 0.0004 |
| Urine %MMA | 11.17 ± 3.54 (n=693) | 10.62 ± 3.51 | 10.96 ± 3.40 (n=174) | 10.90 ± 3.43 (n=173) | 12.21± 3.65 (n=172) | 0.0003 |
| Urine %InAs | 14.51 ± 8.27 (n=693) | 15.22 ± 11.90 | 13.74 ± 7.50 (n=174) | 14.31 ± 6.88 (n=173) | 14.79 ± 5.26 (n=172) | 0.0090 |
| Blood Mn: BMn (μg /L) | 11.38 ± 3.70 | 11.55 ± 3.59 | 11.44 ± 3.99 | 11.32 ± 3.56 | 11.21 ± 3.65 | 0.6489 |
| Blood As: BAs (μg /L) | 4.84 ± 4.62 | 1.55 ± 0.35 | 2.78 ± 0.37 | 4.51 ± 0.66 | 10.54 ± 6.09 | <0.0001 |
| Blood Pb: BPb (μg /L) | 98.65 ± 43.02 | 97.28 ± 46.48 | 101.09 ± 41.03 | 97.29 ± 42.78 | 98.95 ± 41.84 | 0.4638 |
| Blood Cd: BCd (μg /L) | 0.61 ± 0.31 | 0.65 ± 0.33 | 0.65 ± 0.36 | 0.59 ± 0.30 | 0.55 ± 0.25 | 0.0312 |
| Blood Se: BSe (μg /L) | 132.29 ± 18.11 | 132.19 ± 17.47 | 134.01 ± 16.45 | 131.97 ± 19.61 | 130.99 ± 18.76 | 0.2964 |
| Hematocrit | 39.57 ± 5.57 (n=658) | 39.60 ± 5.57 (n=166) | 39.63 ± 5.92 (n=169) | 39.45 ± 5.70 (n=163) | 39.59 ± 5.09 (n=160) | 0.9617 |
| Child Intelligence (raw scores) | ||||||
| Full Scale | 177.63 ± 36.82 | 187.04 ± 37.13 | 181.91 ± 37.70 | 176.28 ± 33.36 | 165.25 ± 35.64 | <0.0001 |
| Working Memory | 27.39 ± 6.09 | 28.93 ± 6.15 | 27.66 ± 5.76 | 27.54± 5.73 | 25.43 ± 6.24 | <0.0001 |
| Verbal Comprehensi on | 39.28 ± 9.53 | 41.40 ± 9.47 | 40.44 ± 9.69 | 38.53 ± 9.01 | 36.73 ± 9.32 | <0.0001 |
| Perceptual Reasoning | 54.64 ± 15.18 | 57.20 ± 15.75 | 55.93 ± 16.26 | 53.87 ±13.85 | 51.54 ± 14.26 | 0.0032 |
| Processing Speed | 56.32 ± 14.16 | 59.51 ± 14.02 | 57.88 ± 14.55 | 56.33± 13.17 | 51.55 ± 13.74 | <0.0001 |
p-values are from testing group differences in categorical variables (Chi-square test) and in quantitative variables (Kruskal-Wallis test).