| Blood Pb Levels (mg/dL) | N = 4,306 | N = 3,413 |
|---|---|---|
| Blood Pb Levels (μg/dL) | 4.7 (3.9), 3.6 (2.4, 5.7), 0.2, 42.5 | 4.7 (4.4), 3.1 (2.2, 6.4), 0.2, 42.5 |
| bloodpblevelsmgdl_5cat | ||
| <4 | 2,437 (56.60%) | 2,437 (71.40%) |
| 4-6 | 893 (20.74%) | 0 (0.00%) |
| 6-10 | 647 (15.03%) | 647 (18.96%) |
| 10-20 | 275 (6.39%) | 275 (8.06%) |
| >20 | 54 (1.25%) | 54 (1.58%) |
| 1 Mean (SD), Median (Q1, Q3), Min, Max; n (%) |
Childhood Blood Level Analysis Using Full SAMPADA Data
Part 1. Descriptives of Blood Lead Levels
The following shows the descriptives of blood lead levels We removed blood levels of 4 to 6 µg/dL for risk factor analysis as this is the range where there is uncertainty in the measurement of blood lead levels.
Map of the distribution of blood lead levels by district: This shows the average blood lead levels in each district, with darker colors indicating higher levels. Districts with mean BLL >6 are labelled.
Map of the distribution of blood lead levels by PSU: This map shows the average blood lead levels in each PSU, with darker colors indicating higher levels. From each PSU, roughly 1 to 3 samples were randomly selected for blood lead level testing. PSUs with mean BLL >20 are labelled.
Major insights from the descriptive analysis of blood lead levels
Prevalence of high blood lead levels (>6 µg/dL) is 22.6% in the whole sample and 28.6% in the sample with blood lead levels of 4 to 6 µg/dL removed.
There is a wide variation in blood lead levels across districts and PSUs, with some districts and PSUs having much higher average blood lead levels than others. It is possible that risk factors are not common across India but likely highly contextual and dependent on regional factors. Possible stratified analysis by region may be required if numbers are adequate.
Overaching guidance for analysis
The diagram below captures the overarching hypothesis for high blood levels and guides the further risk factor analysis
Part 2. Bivariate analysis of blood lead levels with all SAMPADA variables
We removed blood levels of 4 to 6 µg/dL for risk factor analysis for all the below results
A. Demographic
Note: Other religion types: Buddhist, Sikh, Jain, Sindhi, Indigenous, Uraon, etc.
| Characteristic | N = 3,413 | N | Mean Difference | 95% CI | p-value | Overall N = 3,413 |
<4 N = 2,437 |
>6 N = 976 |
p-value | PR | 95% CI | p-value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSU Rural/Urban | 3,413 | 0.003 | ||||||||||
| Rural | 4.6 (4.4) | — | — | 2,344 (100%) | 1,710 (73%) | 634 (27%) | — | — | ||||
| Urban | 4.9 (4.4) | 0.28 | -0.04, 0.60 | 0.084 | 1,069 (100%) | 727 (68%) | 342 (32%) | 1.18 | 1.06, 1.32 | 0.003 | ||
| Gender | 3,413 | 0.014 | ||||||||||
| Female | 4.5 (4.2) | — | — | 1,624 (100%) | 1,192 (73%) | 432 (27%) | — | — | ||||
| Male | 4.9 (4.5) | 0.42 | 0.12, 0.71 | 0.005 | 1,789 (100%) | 1,245 (70%) | 544 (30%) | 1.14 | 1.03, 1.27 | 0.014 | ||
| age_gp | 3,413 | 0.067 | ||||||||||
| 1-2 | 5.2 (5.0) | — | — | 501 (100%) | 333 (66%) | 168 (34%) | — | — | ||||
| 2-3 | 4.5 (3.9) | -0.75 | -1.2, -0.26 | 0.003 | 807 (100%) | 581 (72%) | 226 (28%) | 0.84 | 0.71, 0.99 | 0.033 | ||
| 3-4 | 4.8 (4.6) | -0.46 | -0.93, 0.02 | 0.058 | 963 (100%) | 693 (72%) | 270 (28%) | 0.84 | 0.71, 0.98 | 0.028 | ||
| 4-5 | 4.6 (4.2) | -0.64 | -1.1, -0.18 | 0.006 | 1,142 (100%) | 830 (73%) | 312 (27%) | 0.81 | 0.70, 0.95 | 0.010 | ||
| Caste | 3,399 | <0.001 | ||||||||||
| Other Caste | 4.1 (3.6) | — | — | 677 (100%) | 521 (77%) | 156 (23%) | — | — | ||||
| SC | 4.9 (4.3) | 0.76 | 0.31, 1.2 | <0.001 | 774 (100%) | 533 (69%) | 241 (31%) | 1.35 | 1.14, 1.61 | <0.001 | ||
| ST | 3.9 (3.7) | -0.21 | -0.66, 0.25 | 0.4 | 717 (100%) | 580 (81%) | 137 (19%) | 0.83 | 0.68, 1.02 | 0.072 | ||
| OBC | 5.5 (5.1) | 1.4 | 0.96, 1.8 | <0.001 | 1,183 (100%) | 760 (64%) | 423 (36%) | 1.55 | 1.33, 1.82 | <0.001 | ||
| Not known | 4.1 (2.8) | 0.00 | -1.3, 1.3 | >0.9 | 48 (100%) | 33 (69%) | 15 (31%) | 1.36 | 0.83, 2.01 | 0.2 | ||
| Religion | 3,399 | <0.001 | ||||||||||
| Hindu | 5.1 (4.7) | — | — | 2,560 (100%) | 1,712 (67%) | 848 (33%) | — | — | ||||
| Muslim | 4.0 (3.9) | -1.2 | -1.7, -0.64 | <0.001 | 296 (100%) | 236 (80%) | 60 (20%) | 0.61 | 0.48, 0.76 | <0.001 | ||
| Christian | 3.3 (2.5) | -1.8 | -2.3, -1.3 | <0.001 | 361 (100%) | 313 (87%) | 48 (13%) | 0.40 | 0.30, 0.52 | <0.001 | ||
| Others | 2.8 (2.3) | -2.3 | -2.9, -1.6 | <0.001 | 182 (100%) | 166 (91%) | 16 (8.8%) | 0.27 | 0.16, 0.41 | <0.001 | ||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| 1 Blood Pb Levels (μg/dL): Mean (SD) | ||||||||||||
| 2 n (%) | ||||||||||||
| 3 Pearson's Chi-squared test |
Findings: Urban residence, male, younger age, scheduled caste, OBC, Hindu religion. These are non-modifiable and possibly point to distal determinants rather than actual causes.
B. Household characteristics
Note: Other house ownership types: begar, quarters, encroached, landless, relatives, etc. Other Latrine types: Community latrine, present at home and not using, dry toilet, katcha, compost, no toilet, etc. Other cooking fuel types: cow dung, solar, biogas, electricity, kerosene, coal, weed, other, multiple types, etc. Other cooking/drinking water types: hand pump, rainwater, metro, tube well, share water, public tap, protected well, pipeline, chara, etc. Other water purification types: solar disinfection, let it stand, water filter, etc.
| Characteristic | N = 3,413 | N | Mean Difference | 95% CI | p-value | Overall N = 3,413 |
<4 N = 2,437 |
>6 N = 976 |
p-value | PR | 95% CI | p-value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Type of Family | 3,399 | 0.10 | ||||||||||
| Extended | 4.3 (4.0) | — | — | 428 (100%) | 322 (75%) | 106 (25%) | — | — | ||||
| Joint | 4.7 (4.6) | 0.36 | -0.16, 0.88 | 0.2 | 756 (100%) | 547 (72%) | 209 (28%) | 1.12 | 0.92, 1.37 | 0.3 | ||
| Nuclear | 4.8 (4.4) | 0.41 | -0.04, 0.87 | 0.075 | 2,215 (100%) | 1,558 (70%) | 657 (30%) | 1.20 | 1.01, 1.44 | 0.046 | ||
| Ownership of house | 3,385 | 0.7 | ||||||||||
| Own House | 4.7 (4.5) | — | — | 2,988 (100%) | 2,138 (72%) | 850 (28%) | — | — | ||||
| Rented/Other | 4.6 (3.6) | -0.10 | -0.56, 0.36 | 0.7 | 397 (100%) | 280 (71%) | 117 (29%) | 1.04 | 0.88, 1.21 | 0.7 | ||
| Type of House | 3,397 | 0.4 | ||||||||||
| Pucca | 4.6 (4.3) | — | — | 2,048 (100%) | 1,479 (72%) | 569 (28%) | — | — | ||||
| Semi-pucca | 4.7 (4.3) | 0.15 | -0.20, 0.50 | 0.4 | 855 (100%) | 598 (70%) | 257 (30%) | 1.08 | 0.95, 1.22 | 0.2 | ||
| Kutcha | 5.0 (4.8) | 0.41 | -0.02, 0.84 | 0.062 | 494 (100%) | 350 (71%) | 144 (29%) | 1.05 | 0.90, 1.22 | 0.5 | ||
| No of rooms in house | 3,388 | <0.001 | ||||||||||
| >1 | 4.6 (4.4) | — | — | 3,062 (100%) | 2,228 (73%) | 834 (27%) | — | — | ||||
| 0-1 | 5.8 (4.5) | 1.2 | 0.66, 1.7 | <0.001 | 326 (100%) | 190 (58%) | 136 (42%) | 1.53 | 1.32, 1.75 | <0.001 | ||
| Separate Kitchen | 3,396 | 0.017 | ||||||||||
| Yes | 4.5 (4.2) | — | — | 2,436 (100%) | 1,767 (73%) | 669 (27%) | — | — | ||||
| No | 5.1 (4.7) | 0.56 | 0.23, 0.89 | <0.001 | 960 (100%) | 657 (68%) | 303 (32%) | 1.15 | 1.02, 1.29 | 0.016 | ||
| Cooking fuel | 3,413 | 0.043 | ||||||||||
| Firewood | 4.8 (4.6) | — | — | 1,076 (100%) | 774 (72%) | 302 (28%) | — | — | ||||
| LPG | 4.6 (4.3) | -0.20 | -0.52, 0.12 | 0.2 | 2,268 (100%) | 1,623 (72%) | 645 (28%) | 1.01 | 0.90, 1.14 | 0.8 | ||
| Others | 6.3 (5.5) | 1.5 | 0.48, 2.6 | 0.004 | 69 (100%) | 40 (58%) | 29 (42%) | 1.50 | 1.08, 1.96 | 0.007 | ||
| Drinking Water | 3,397 | <0.001 | ||||||||||
| Bore well | 4.8 (4.8) | — | — | 911 (100%) | 658 (72%) | 253 (28%) | — | — | ||||
| Open well | 4.1 (4.1) | -0.72 | -1.4, -0.08 | 0.028 | 219 (100%) | 177 (81%) | 42 (19%) | 0.69 | 0.51, 0.91 | 0.013 | ||
| Others | 5.3 (5.2) | 0.53 | -0.21, 1.3 | 0.2 | 161 (100%) | 107 (66%) | 54 (34%) | 1.21 | 0.94, 1.52 | 0.13 | ||
| RO/Bottled/Purchased water | 5.2 (4.1) | 0.38 | -0.13, 0.90 | 0.14 | 402 (100%) | 252 (63%) | 150 (37%) | 1.34 | 1.14, 1.58 | <0.001 | ||
| Surface/Spring water | 4.1 (3.2) | -0.66 | -1.5, 0.15 | 0.11 | 130 (100%) | 95 (73%) | 35 (27%) | 0.97 | 0.70, 1.29 | 0.8 | ||
| Tap water | 4.5 (4.2) | -0.27 | -0.63, 0.09 | 0.14 | 1,488 (100%) | 1,084 (73%) | 404 (27%) | 0.98 | 0.86, 1.12 | 0.7 | ||
| Water tanker | 5.6 (4.6) | 0.77 | -0.20, 1.7 | 0.12 | 86 (100%) | 52 (60%) | 34 (40%) | 1.42 | 1.05, 1.85 | 0.014 | ||
| Cooking water | 3,395 | 0.005 | ||||||||||
| Bore well | 4.8 (4.8) | — | — | 928 (100%) | 669 (72%) | 259 (28%) | — | — | ||||
| Open well | 4.1 (4.1) | -0.67 | -1.3, -0.02 | 0.042 | 221 (100%) | 176 (80%) | 45 (20%) | 0.73 | 0.54, 0.95 | 0.028 | ||
| Others | 5.3 (5.6) | 0.51 | -0.20, 1.2 | 0.2 | 171 (100%) | 116 (68%) | 55 (32%) | 1.15 | 0.89, 1.45 | 0.2 | ||
| RO/Bottled/Purchased water | 4.8 (3.6) | 0.05 | -0.57, 0.67 | 0.9 | 244 (100%) | 160 (66%) | 84 (34%) | 1.23 | 1.00, 1.50 | 0.041 | ||
| Surface/Spring water | 4.2 (3.3) | -0.55 | -1.3, 0.25 | 0.2 | 133 (100%) | 96 (72%) | 37 (28%) | 1.00 | 0.73, 1.31 | >0.9 | ||
| Tap water | 4.6 (4.2) | -0.18 | -0.53, 0.17 | 0.3 | 1,608 (100%) | 1,153 (72%) | 455 (28%) | 1.01 | 0.89, 1.16 | 0.8 | ||
| Water tanker | 5.6 (4.6) | 0.85 | -0.10, 1.8 | 0.079 | 90 (100%) | 54 (60%) | 36 (40%) | 1.43 | 1.07, 1.85 | 0.010 | ||
| Water purification method | 3,398 | <0.001 | ||||||||||
| Water filter/ E. Purifier | 3.8 (3.9) | — | — | 245 (100%) | 199 (81%) | 46 (19%) | — | — | ||||
| Boiling | 3.7 (3.0) | -0.09 | -0.73, 0.56 | 0.8 | 603 (100%) | 482 (80%) | 121 (20%) | 1.07 | 0.79, 1.47 | 0.7 | ||
| Strain through a cloth | 5.0 (4.3) | 1.2 | 0.41, 2.0 | 0.003 | 236 (100%) | 157 (67%) | 79 (33%) | 1.78 | 1.31, 2.47 | <0.001 | ||
| Add bleach/chlorine tablets | 6.6 (5.3) | 2.8 | 1.0, 4.6 | 0.002 | 26 (100%) | 13 (50%) | 13 (50%) | 2.66 | 1.58, 4.09 | <0.001 | ||
| None | 5.2 (4.8) | 1.4 | 0.84, 2.0 | <0.001 | 1,975 (100%) | 1,317 (67%) | 658 (33%) | 1.77 | 1.38, 2.36 | <0.001 | ||
| Others/Multiple | 3.8 (3.3) | 0.03 | -0.70, 0.76 | >0.9 | 313 (100%) | 258 (82%) | 55 (18%) | 0.94 | 0.66, 1.34 | 0.7 | ||
| Latrine type | 3,413 | <0.001 | ||||||||||
| Present and using | 4.6 (4.3) | — | — | 2,914 (100%) | 2,105 (72%) | 809 (28%) | — | — | ||||
| Others | 3.8 (3.1) | -0.81 | -1.5, -0.14 | 0.017 | 175 (100%) | 138 (79%) | 37 (21%) | 0.76 | 0.56, 1.00 | 0.068 | ||
| Open Defecation | 6.0 (5.4) | 1.4 | 0.94, 1.9 | <0.001 | 324 (100%) | 194 (60%) | 130 (40%) | 1.45 | 1.24, 1.66 | <0.001 | ||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 28 | 19 | 9 | |||||||||
| Unknown | 16 | 10 | 6 | |||||||||
| Unknown | 25 | 19 | 6 | |||||||||
| Unknown | 17 | 13 | 4 | |||||||||
| Unknown | 16 | 12 | 4 | |||||||||
| Unknown | 18 | 13 | 5 | |||||||||
| Unknown | 15 | 11 | 4 | |||||||||
| 1 Blood Pb Levels (μg/dL): Mean (SD) | ||||||||||||
| 2 n (%) | ||||||||||||
| 3 Pearson's Chi-squared test |
Findings: Nuclear family, small houses, no separate kitchen, water from RO/bottled/water tanker, inadequate or improper water purification, and open defecation were all associated with high blood lead. We get some indication that water with lead contamination may be a source via ingestion. This needs to explored further in the case-control data where water has been tested for lead contamination. However, we would not know water from which source was tested.
C. Household Assets
| Characteristic | N = 3,413 | N | Mean Difference | 95% CI | p-value | Overall N = 3,413 |
<4 N = 2,437 |
>6 N = 976 |
p-value | PR | 95% CI | p-value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Electricity Available | 3,397 | >0.9 | ||||||||||
| No | 4.0 (3.4) | — | — | 16 (100%) | 12 (75%) | 4 (25%) | — | — | ||||
| Yes | 4.7 (4.4) | 0.70 | -1.5, 2.9 | 0.5 | 3,381 (100%) | 2,413 (71%) | 968 (29%) | 1.15 | 0.58, 3.36 | 0.8 | ||
| Electric Fan | 3,399 | 0.012 | ||||||||||
| No | 4.3 (4.4) | — | — | 377 (100%) | 290 (77%) | 87 (23%) | — | — | ||||
| Yes | 4.8 (4.4) | 0.48 | 0.01, 0.95 | 0.044 | 3,022 (100%) | 2,137 (71%) | 885 (29%) | 1.27 | 1.06, 1.55 | 0.015 | ||
| Black and White Television | 3,399 | 0.027 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,167 (100%) | 2,276 (72%) | 891 (28%) | — | — | ||||
| Yes | 5.2 (4.5) | 0.55 | -0.04, 1.1 | 0.068 | 232 (100%) | 151 (65%) | 81 (35%) | 1.24 | 1.02, 1.48 | 0.022 | ||
| Colour Television | 3,399 | 0.11 | ||||||||||
| No | 5.1 (5.1) | — | — | 1,100 (100%) | 766 (70%) | 334 (30%) | — | — | ||||
| Yes | 4.5 (4.0) | -0.60 | -0.91, -0.28 | <0.001 | 2,299 (100%) | 1,661 (72%) | 638 (28%) | 0.91 | 0.82, 1.02 | 0.11 | ||
| Radio/Transistor | 3,399 | 0.022 | ||||||||||
| No | 4.8 (4.5) | — | — | 3,152 (100%) | 2,235 (71%) | 917 (29%) | — | — | ||||
| Yes | 3.7 (2.9) | -1.0 | -1.6, -0.46 | <0.001 | 247 (100%) | 192 (78%) | 55 (22%) | 0.77 | 0.59, 0.96 | 0.029 | ||
| Pressure Cooker | 3,399 | <0.001 | ||||||||||
| No | 5.7 (5.4) | — | — | 810 (100%) | 514 (63%) | 296 (37%) | — | — | ||||
| Yes | 4.4 (4.0) | -1.3 | -1.6, -0.92 | <0.001 | 2,589 (100%) | 1,913 (74%) | 676 (26%) | 0.71 | 0.64, 0.80 | <0.001 | ||
| Cot/Bed | 3,399 | <0.001 | ||||||||||
| No | 5.5 (4.8) | — | — | 470 (100%) | 292 (62%) | 178 (38%) | — | — | ||||
| Yes | 4.6 (4.3) | -0.92 | -1.3, -0.49 | <0.001 | 2,929 (100%) | 2,135 (73%) | 794 (27%) | 0.72 | 0.63, 0.82 | <0.001 | ||
| Mattress | 3,399 | <0.001 | ||||||||||
| No | 5.9 (5.2) | — | — | 886 (100%) | 529 (60%) | 357 (40%) | — | — | ||||
| Yes | 4.3 (4.0) | -1.6 | -2.0, -1.3 | <0.001 | 2,513 (100%) | 1,898 (76%) | 615 (24%) | 0.61 | 0.55, 0.68 | <0.001 | ||
| Chair | 3,399 | <0.001 | ||||||||||
| No | 5.5 (4.6) | — | — | 347 (100%) | 212 (61%) | 135 (39%) | — | — | ||||
| Yes | 4.6 (4.4) | -0.85 | -1.3, -0.36 | <0.001 | 3,052 (100%) | 2,215 (73%) | 837 (27%) | 0.70 | 0.61, 0.82 | <0.001 | ||
| Table | 3,399 | <0.001 | ||||||||||
| No | 5.5 (4.9) | — | — | 994 (100%) | 635 (64%) | 359 (36%) | — | — | ||||
| Yes | 4.4 (4.1) | -1.1 | -1.4, -0.78 | <0.001 | 2,405 (100%) | 1,792 (75%) | 613 (25%) | 0.71 | 0.63, 0.79 | <0.001 | ||
| Mobile Phone | 3,399 | 0.054 | ||||||||||
| No | 5.1 (4.3) | — | — | 171 (100%) | 111 (65%) | 60 (35%) | — | — | ||||
| Yes | 4.7 (4.4) | -0.45 | -1.1, 0.22 | 0.2 | 3,228 (100%) | 2,316 (72%) | 912 (28%) | 0.81 | 0.66, 1.01 | 0.044 | ||
| Landline Phone | 3,399 | 0.2 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,311 (100%) | 2,359 (71%) | 952 (29%) | — | — | ||||
| Yes | 4.2 (3.5) | -0.54 | -1.5, 0.39 | 0.3 | 88 (100%) | 68 (77%) | 20 (23%) | 0.79 | 0.51, 1.12 | 0.2 | ||
| Watch/Clock | 3,370 | 0.029 | ||||||||||
| No | 4.9 (4.6) | — | — | 1,038 (100%) | 714 (69%) | 324 (31%) | — | — | ||||
| Yes | 4.6 (4.3) | -0.28 | -0.60, 0.04 | 0.086 | 2,332 (100%) | 1,690 (72%) | 642 (28%) | 0.88 | 0.79, 0.99 | 0.028 | ||
| Washing Machine | 3,399 | <0.001 | ||||||||||
| No | 4.8 (4.5) | — | — | 2,521 (100%) | 1,760 (70%) | 761 (30%) | — | — | ||||
| Yes | 4.3 (4.2) | -0.50 | -0.83, -0.16 | 0.004 | 878 (100%) | 667 (76%) | 211 (24%) | 0.80 | 0.70, 0.91 | <0.001 | ||
| Refrigerator | 3,399 | <0.001 | ||||||||||
| No | 5.0 (4.6) | — | — | 1,779 (100%) | 1,220 (69%) | 559 (31%) | — | — | ||||
| Yes | 4.4 (4.1) | -0.62 | -0.92, -0.33 | <0.001 | 1,620 (100%) | 1,207 (75%) | 413 (25%) | 0.81 | 0.73, 0.90 | <0.001 | ||
| Computer | 3,399 | 0.022 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,195 (100%) | 2,267 (71%) | 928 (29%) | — | — | ||||
| Yes | 4.1 (3.6) | -0.60 | -1.2, 0.02 | 0.059 | 204 (100%) | 160 (78%) | 44 (22%) | 0.74 | 0.56, 0.95 | 0.029 | ||
| Internet | 3,399 | <0.001 | ||||||||||
| No | 5.0 (4.6) | — | — | 1,585 (100%) | 1,075 (68%) | 510 (32%) | — | — | ||||
| Yes | 4.5 (4.2) | -0.49 | -0.78, -0.19 | 0.001 | 1,814 (100%) | 1,352 (75%) | 462 (25%) | 0.79 | 0.71, 0.88 | <0.001 | ||
| Sewing Machine | 3,399 | 0.5 | ||||||||||
| No | 4.7 (4.4) | — | — | 2,866 (100%) | 2,040 (71%) | 826 (29%) | — | — | ||||
| Yes | 4.6 (4.3) | -0.08 | -0.48, 0.33 | 0.7 | 533 (100%) | 387 (73%) | 146 (27%) | 0.95 | 0.81, 1.10 | 0.5 | ||
| Air Conditioner/Cooler | 3,399 | 0.6 | ||||||||||
| No | 4.7 (4.3) | — | — | 2,821 (100%) | 2,019 (72%) | 802 (28%) | — | — | ||||
| Yes | 4.9 (4.7) | 0.24 | -0.15, 0.64 | 0.2 | 578 (100%) | 408 (71%) | 170 (29%) | 1.03 | 0.90, 1.18 | 0.6 | ||
| Bicycle | 3,399 | 0.7 | ||||||||||
| No | 4.7 (4.2) | — | — | 2,181 (100%) | 1,552 (71%) | 629 (29%) | — | — | ||||
| Yes | 4.7 (4.7) | 0.07 | -0.24, 0.37 | 0.7 | 1,218 (100%) | 875 (72%) | 343 (28%) | 0.98 | 0.87, 1.09 | 0.7 | ||
| Motorcycle/Scooter | 3,399 | 0.031 | ||||||||||
| No | 4.6 (4.5) | — | — | 1,603 (100%) | 1,173 (73%) | 430 (27%) | — | — | ||||
| Yes | 4.8 (4.3) | 0.16 | -0.14, 0.45 | 0.3 | 1,796 (100%) | 1,254 (70%) | 542 (30%) | 1.13 | 1.01, 1.25 | 0.031 | ||
| Car/Four Wheeler | 3,399 | <0.001 | ||||||||||
| No | 4.8 (4.5) | — | — | 2,988 (100%) | 2,087 (70%) | 901 (30%) | — | — | ||||
| Yes | 3.7 (3.6) | -1.1 | -1.6, -0.69 | <0.001 | 411 (100%) | 340 (83%) | 71 (17%) | 0.57 | 0.46, 0.71 | <0.001 | ||
| Animal Drawn Cart | 3,399 | 0.10 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,218 (100%) | 2,288 (71%) | 930 (29%) | — | — | ||||
| Yes | 4.1 (3.4) | -0.66 | -1.3, 0.00 | 0.048 | 181 (100%) | 139 (77%) | 42 (23%) | 0.80 | 0.60, 1.03 | 0.11 | ||
| Water Pump | 3,399 | 0.5 | ||||||||||
| No | 4.7 (4.3) | — | — | 2,924 (100%) | 2,082 (71%) | 842 (29%) | — | — | ||||
| Yes | 4.7 (4.8) | -0.02 | -0.44, 0.41 | >0.9 | 475 (100%) | 345 (73%) | 130 (27%) | 0.95 | 0.81, 1.11 | 0.5 | ||
| Tractor | 3,399 | 0.2 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,293 (100%) | 2,357 (72%) | 936 (28%) | — | — | ||||
| Yes | 5.0 (4.8) | 0.36 | -0.49, 1.2 | 0.4 | 106 (100%) | 70 (66%) | 36 (34%) | 1.19 | 0.89, 1.53 | 0.2 | ||
| Thresher/Seed Removal Machine | 3,399 | 0.8 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,359 (100%) | 2,399 (71%) | 960 (29%) | — | — | ||||
| Yes | 4.9 (5.1) | 0.18 | -1.2, 1.5 | 0.8 | 40 (100%) | 28 (70%) | 12 (30%) | 1.05 | 0.61, 1.59 | 0.8 | ||
| Home Theatre | 3,399 | 0.7 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,321 (100%) | 2,373 (71%) | 948 (29%) | — | — | ||||
| Yes | 4.5 (3.3) | -0.24 | -1.2, 0.75 | 0.6 | 78 (100%) | 54 (69%) | 24 (31%) | 1.08 | 0.74, 1.46 | 0.7 | ||
| Vacuum Cleaner | 3,399 | 0.059 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,333 (100%) | 2,373 (71%) | 960 (29%) | — | — | ||||
| Yes | 3.2 (2.7) | -1.5 | -2.6, -0.44 | 0.006 | 66 (100%) | 54 (82%) | 12 (18%) | 0.63 | 0.35, 1.00 | 0.080 | ||
| Microwave/Electric Oven | 3,399 | <0.001 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,307 (100%) | 2,346 (71%) | 961 (29%) | — | — | ||||
| Yes | 3.2 (3.7) | -1.5 | -2.4, -0.62 | <0.001 | 92 (100%) | 81 (88%) | 11 (12%) | 0.41 | 0.22, 0.68 | 0.002 | ||
| Treadmill/Exercise Equipment | 3,399 | 0.11 | ||||||||||
| No | 4.7 (4.4) | — | — | 3,387 (100%) | 2,421 (71%) | 966 (29%) | — | — | ||||
| Yes | 5.0 (2.6) | 0.35 | -2.1, 2.8 | 0.8 | 12 (100%) | 6 (50%) | 6 (50%) | 1.75 | 0.83, 2.68 | 0.053 | ||
| Type of PDS/Ration Card | 3,395 | 0.019 | ||||||||||
| APL | 4.4 (4.5) | — | — | 720 (100%) | 542 (75%) | 178 (25%) | — | — | ||||
| No card | 4.8 (4.3) | 0.38 | -0.08, 0.85 | 0.11 | 652 (100%) | 469 (72%) | 183 (28%) | 1.14 | 0.95, 1.36 | 0.2 | ||
| BPL/AAY/TPDS | 4.8 (4.4) | 0.40 | 0.03, 0.78 | 0.035 | 2,023 (100%) | 1,412 (70%) | 611 (30%) | 1.22 | 1.06, 1.42 | 0.006 | ||
| Any Woman Enrolled in a Self-Help Group | 3,381 | 0.3 | ||||||||||
| No | 4.6 (4.3) | — | — | 2,344 (100%) | 1,687 (72%) | 657 (28%) | — | — | ||||
| Yes | 4.8 (4.5) | 0.20 | -0.12, 0.52 | 0.2 | 1,037 (100%) | 727 (70%) | 310 (30%) | 1.07 | 0.95, 1.19 | 0.3 | ||
| Any Household Member with Disability | 3,393 | 0.7 | ||||||||||
| No | 4.6 (4.2) | — | — | 2,526 (100%) | 1,808 (72%) | 718 (28%) | — | — | ||||
| Yes | 4.9 (4.8) | 0.25 | -0.09, 0.59 | 0.14 | 867 (100%) | 614 (71%) | 253 (29%) | 1.03 | 0.91, 1.16 | 0.7 | ||
| Household Covered by Insurance | 3,396 | 0.009 | ||||||||||
| No | 4.9 (4.4) | — | — | 1,581 (100%) | 1,095 (69%) | 486 (31%) | — | — | ||||
| Yes | 4.5 (4.4) | -0.32 | -0.62, -0.02 | 0.034 | 1,815 (100%) | 1,331 (73%) | 484 (27%) | 0.87 | 0.78, 0.96 | 0.009 | ||
| Household Owns Agricultural Land | 3,324 | <0.001 | ||||||||||
| No | 4.5 (4.2) | — | — | 2,336 (100%) | 1,715 (73%) | 621 (27%) | — | — | ||||
| Yes | 5.1 (4.7) | 0.59 | 0.27, 0.92 | <0.001 | 988 (100%) | 661 (67%) | 327 (33%) | 1.25 | 1.11, 1.39 | <0.001 | ||
| Owns Livestock | 3,273 | 0.2 | ||||||||||
| No | 4.6 (4.1) | — | — | 2,453 (100%) | 1,765 (72%) | 688 (28%) | — | — | ||||
| Yes | 5.0 (5.0) | 0.38 | 0.03, 0.72 | 0.033 | 820 (100%) | 571 (70%) | 249 (30%) | 1.08 | 0.96, 1.22 | 0.2 | ||
| Cows/Bulls/Buffaloes/Yaks | 748 | >0.9 | ||||||||||
| No | 5.2 (5.8) | — | — | 131 (100%) | 91 (69%) | 40 (31%) | — | — | ||||
| Yes | 5.0 (5.0) | -0.20 | -1.2, 0.76 | 0.7 | 617 (100%) | 427 (69%) | 190 (31%) | 1.01 | 0.77, 1.36 | >0.9 | ||
| Camels | 569 | >0.9 | ||||||||||
| No | 4.8 (4.9) | — | — | 566 (100%) | 406 (72%) | 160 (28%) | — | — | ||||
| Yes | 4.3 (2.2) | -0.48 | -6.0, 5.0 | 0.9 | 3 (100%) | 2 (67%) | 1 (33%) | 1.18 | 0.24, 5.87 | 0.8 | ||
| Horses/Donkeys/Mules | 565 | 0.5 | ||||||||||
| No | 4.8 (4.8) | — | — | 563 (100%) | 404 (72%) | 159 (28%) | — | — | ||||
| Yes | 6.0 (3.0) | 1.2 | -5.5, 7.9 | 0.7 | 2 (100%) | 1 (50%) | 1 (50%) | 1.77 | 0.44, 7.12 | 0.4 | ||
| Goats/Sheep | 659 | 0.077 | ||||||||||
| No | 4.6 (4.4) | — | — | 366 (100%) | 268 (73%) | 98 (27%) | — | — | ||||
| Yes | 5.3 (5.4) | 0.76 | 0.01, 1.5 | 0.046 | 293 (100%) | 196 (67%) | 97 (33%) | 1.24 | 0.98, 1.57 | 0.077 | ||
| Pigs | 577 | 0.2 | ||||||||||
| No | 4.9 (4.9) | — | — | 524 (100%) | 370 (71%) | 154 (29%) | — | — | ||||
| Yes | 4.4 (5.5) | -0.53 | -1.9, 0.87 | 0.5 | 53 (100%) | 42 (79%) | 11 (21%) | 0.71 | 0.38, 1.14 | 0.2 | ||
| Chickens/Ducks | 645 | 0.019 | ||||||||||
| No | 5.1 (4.8) | — | — | 379 (100%) | 257 (68%) | 122 (32%) | — | — | ||||
| Yes | 4.6 (5.2) | -0.51 | -1.3, 0.27 | 0.2 | 266 (100%) | 203 (76%) | 63 (24%) | 0.74 | 0.56, 0.95 | 0.021 | ||
| Wealth Index | 3,399 | <0.001 | ||||||||||
| Highest | 4.2 (4.1) | — | — | 641 (100%) | 499 (78%) | 142 (22%) | — | — | ||||
| Higher | 4.6 (4.2) | 0.37 | -0.10, 0.84 | 0.12 | 680 (100%) | 493 (73%) | 187 (28%) | 1.24 | 1.03, 1.50 | 0.025 | ||
| Middle | 4.3 (3.6) | 0.08 | -0.39, 0.56 | 0.7 | 659 (100%) | 494 (75%) | 165 (25%) | 1.13 | 0.93, 1.38 | 0.2 | ||
| Lower | 4.5 (4.1) | 0.35 | -0.11, 0.81 | 0.14 | 718 (100%) | 510 (71%) | 208 (29%) | 1.31 | 1.09, 1.58 | 0.004 | ||
| Lowest | 5.9 (5.4) | 1.7 | 1.2, 2.2 | <0.001 | 701 (100%) | 431 (61%) | 270 (39%) | 1.74 | 1.47, 2.07 | <0.001 | ||
| Unknown | 16 | 12 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 43 | 33 | 10 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| Unknown | 18 | 14 | 4 | |||||||||
| Unknown | 32 | 23 | 9 | |||||||||
| Unknown | 20 | 15 | 5 | |||||||||
| Unknown | 17 | 11 | 6 | |||||||||
| Unknown | 89 | 61 | 28 | |||||||||
| Unknown | 140 | 101 | 39 | |||||||||
| Unknown | 2,665 | 1,919 | 746 | |||||||||
| Unknown | 2,844 | 2,029 | 815 | |||||||||
| Unknown | 2,848 | 2,032 | 816 | |||||||||
| Unknown | 2,754 | 1,973 | 781 | |||||||||
| Unknown | 2,836 | 2,025 | 811 | |||||||||
| Unknown | 2,768 | 1,977 | 791 | |||||||||
| Unknown | 14 | 10 | 4 | |||||||||
| 1 Blood Pb Levels (μg/dL): Mean (SD) | ||||||||||||
| 2 n (%) | ||||||||||||
| 3 Fisher's exact test; Pearson's Chi-squared test |
Findings: Largely ownership of assets is associated with lower blood lead levels, except for a few such as agricultural land and livestock. This needs to be explored further in the future case-control data where livestock and feed/water may be additionally tested for lead contamination. There is a clear dose-response type relationship between wealth index and blood lead levels, with lower income being associated with higher blood lead levels. This may be due to poorer living conditions, lack of access to cleaner water, and higher exposure to lead-containing products among lower-income households.
C1. Household income
C2. Agricultural land ownership
D. Blood micro-nutrient levels
| Characteristic | N = 3,413 | N | Mean Difference | 95% CI | p-value | Overall N = 3,413 |
<4 N = 2,437 |
>6 N = 976 |
p-value | PR | 95% CI | p-value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Anemia status | 3,413 | <0.001 | ||||||||||
| No Anemia | 4.5 (4.1) | — | — | 2,213 (100%) | 1,624 (73%) | 589 (27%) | — | — | ||||
| Any Anemia | 5.1 (4.8) | 0.68 | 0.38, 0.99 | <0.001 | 1,200 (100%) | 813 (68%) | 387 (32%) | 1.21 | 1.09, 1.35 | <0.001 | ||
| Anaemia Status (Any, New) | 3,413 | <0.001 | ||||||||||
| No Anemia | 4.5 (4.1) | — | — | 2,213 (100%) | 1,624 (73%) | 589 (27%) | — | — | ||||
| Mild Anemia | 4.9 (4.7) | 0.49 | 0.12, 0.87 | 0.010 | 685 (100%) | 479 (70%) | 206 (30%) | 1.13 | 0.99, 1.29 | 0.073 | ||
| Moder+Sev Anemia | 5.4 (4.9) | 0.94 | 0.52, 1.4 | <0.001 | 515 (100%) | 334 (65%) | 181 (35%) | 1.32 | 1.15, 1.51 | <0.001 | ||
| Iron Deficiency Status | 741 | 0.001 | ||||||||||
| No Iron Deficiency | 4.2 (3.7) | — | — | 571 (100%) | 434 (76%) | 137 (24%) | — | — | ||||
| Iron Deficiency (ID) | 5.5 (4.9) | 1.3 | 0.56, 1.9 | <0.001 | 170 (100%) | 108 (64%) | 62 (36%) | 1.52 | 1.18, 1.93 | <0.001 | ||
| iron_def_adj | 714 | 0.009 | ||||||||||
| No Iron Deficiency | 4.1 (3.8) | — | — | 410 (100%) | 321 (78%) | 89 (22%) | — | — | ||||
| Iron Deficiency | 4.8 (4.2) | 0.70 | 0.11, 1.3 | 0.021 | 304 (100%) | 212 (70%) | 92 (30%) | 1.39 | 1.08, 1.79 | 0.009 | ||
| Anaemia Adjusted for Iron | 739 | 0.066 | ||||||||||
| No Anemia + Iron Deficiency | 3.2 (2.2) | — | — | 33 (100%) | 29 (88%) | 4 (12%) | — | — | ||||
| Anemia + No Iron Deficiency | 4.3 (3.7) | 1.1 | -0.37, 2.6 | 0.14 | 223 (100%) | 166 (74%) | 57 (26%) | 2.11 | 0.95, 6.62 | 0.12 | ||
| No Anemia + No Iron Deficiency | 4.7 (4.3) | 1.4 | -0.01, 2.9 | 0.051 | 457 (100%) | 330 (72%) | 127 (28%) | 2.29 | 1.05, 7.13 | 0.081 | ||
| Anemia + Iron Deficiency | 5.3 (4.0) | 2.0 | -0.06, 4.1 | 0.057 | 26 (100%) | 15 (58%) | 11 (42%) | 3.49 | 1.37, 11.5 | 0.017 | ||
| Vitamin B12 Status | 708 | 0.8 | ||||||||||
| Normal (≥203 pg/mL) | 4.5 (4.0) | — | — | 441 (100%) | 324 (73%) | 117 (27%) | — | — | ||||
| Deficient (<203 pg/mL) | 4.6 (4.4) | 0.08 | -0.55, 0.71 | 0.8 | 267 (100%) | 194 (73%) | 73 (27%) | 1.03 | 0.80, 1.32 | 0.8 | ||
| Serum Folate Status | 707 | 0.4 | ||||||||||
| Normal (≥4 ng/mL) | 4.5 (4.1) | — | — | 612 (100%) | 445 (73%) | 167 (27%) | — | — | ||||
| Deficient (<4 ng/mL) | 4.3 (4.1) | -0.25 | -1.1, 0.65 | 0.6 | 95 (100%) | 73 (77%) | 22 (23%) | 0.85 | 0.56, 1.22 | 0.4 | ||
| Vitamin D Status | 705 | 0.3 | ||||||||||
| Normal (≥12 ng/mL) | 4.5 (3.8) | — | — | 576 (100%) | 426 (74%) | 150 (26%) | — | — | ||||
| Deficient (<12 ng/mL) | 4.9 (5.3) | 0.43 | -0.36, 1.2 | 0.3 | 129 (100%) | 89 (69%) | 40 (31%) | 1.19 | 0.87, 1.57 | 0.2 | ||
| Unknown | 2,672 | 1,895 | 777 | |||||||||
| Unknown | 2,699 | 1,904 | 795 | |||||||||
| Unknown | 2,674 | 1,897 | 777 | |||||||||
| Unknown | 2,705 | 1,919 | 786 | |||||||||
| Unknown | 2,706 | 1,919 | 787 | |||||||||
| Unknown | 2,708 | 1,922 | 786 | |||||||||
| 1 Blood Pb Levels (μg/dL): Mean (SD) | ||||||||||||
| 2 n (%) | ||||||||||||
| 3 Pearson's Chi-squared test |
| Correlation between Blood micronutrient and Blood Pb levels | ||
| Micronutrient | Correlation Coefficient (r) | P-value |
|---|---|---|
| ferritin_clean | -0.110 | 0.0026 |
| log_ferritin | -0.164 | 0.0000 |
| ferritin_adj | -0.079 | 0.0344 |
| log_ferritin_adj | -0.103 | 0.0059 |
| folate_ng_ml | 0.053 | 0.1614 |
| rbc_folate_ng_ml | -0.038 | 0.3336 |
| b12_pg_ml | -0.069 | 0.0665 |
| vitd_ng_ml | 0.029 | 0.4373 |
Findings: Anemia and iron deficiency are clearly associated with higher blood lead levels. This supports our hypothesis that this leads to increased absorption of lead in the gut. But it is also possible that lead exposure contributes to these deficiencies. In addition, the continuous variables of blood levels of ferritin and vitamin B12 have a weak negative correlation with blood lead but others like folate and vitamin D are not associated.
These indicators of longer term nutritional status and micronutrient deficiency are more relevant for lead absorption. In simple words, lower intake of micronutrients in diet over a longer period leads to lower blood levels of these micronutrients which in turn leads to higher absorption of lead in the gut and higher blood lead levels.
E. Inflammation
| Characteristic | N = 3,413 | N | Mean Difference | 95% CI | p-value | Overall N = 3,413 |
<4 N = 2,437 |
>6 N = 976 |
p-value | PR | 95% CI | p-value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CRP Status | 748 | 0.040 | ||||||||||
| Inflammation | 3.6 (2.9) | — | — | 58 (100%) | 49 (84%) | 9 (16%) | — | — | ||||
| No Inflammation | 4.6 (4.1) | 1.0 | -0.08, 2.1 | 0.069 | 690 (100%) | 497 (72%) | 193 (28%) | 1.80 | 1.05, 3.63 | 0.059 | ||
| AGP Status | 746 | 0.2 | ||||||||||
| Inflammation | 4.0 (3.2) | — | — | 95 (100%) | 74 (78%) | 21 (22%) | — | — | ||||
| No Inflammation | 4.6 (4.2) | 0.59 | -0.29, 1.5 | 0.2 | 651 (100%) | 470 (72%) | 181 (28%) | 1.26 | 0.87, 1.94 | 0.3 | ||
| Inflammation Status | 747 | 0.050 | ||||||||||
| Inflammation | 3.8 (3.0) | — | — | 117 (100%) | 94 (80%) | 23 (20%) | — | — | ||||
| No Inflammation | 4.7 (4.2) | 0.90 | 0.10, 1.7 | 0.027 | 630 (100%) | 451 (72%) | 179 (28%) | 1.45 | 1.01, 2.20 | 0.062 | ||
| Unknown | 2,665 | 1,891 | 774 | |||||||||
| Unknown | 2,667 | 1,893 | 774 | |||||||||
| Unknown | 2,666 | 1,892 | 774 | |||||||||
| 1 Blood Pb Levels (μg/dL): Mean (SD) | ||||||||||||
| 2 n (%) | ||||||||||||
| 3 Pearson's Chi-squared test |
| Correlation between Inflammation markers and Blood Pb levels | ||
| Inflammation markers | Correlation Coefficient (r) | P-value |
|---|---|---|
| crphs_clean | -0.067 | 0.0662 |
| agp_clean | -0.081 | 0.0272 |
| log_crp | -0.098 | 0.0081 |
| log_agp | -0.080 | 0.0281 |
Findings: Generally lack of inflammation is associated with higher blood lead levels. This may be because inflammation leads to sequestration of lead in the liver and other tissues, leading to lower blood lead levels. The biological plausibility of this association needs to be assessed further. Whether to use these variables to adjust for the relationship between blood micronutrients and blood lead levels needs to be assessed.
F. Anthropometric
| Characteristic | N = 3,413 | N | Mean Difference | 95% CI | p-value | Overall N = 3,413 |
<4 N = 2,437 |
>6 N = 976 |
p-value | PR | 95% CI | p-value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Stunting status | 2,787 | <0.001 | ||||||||||
| No Stunting | 4.5 (4.1) | — | — | 1,982 (100%) | 1,438 (73%) | 544 (27%) | — | — | ||||
| Stunting | 5.1 (4.7) | 0.57 | 0.15, 0.99 | 0.008 | 530 (100%) | 352 (66%) | 178 (34%) | 1.22 | 1.06, 1.40 | 0.005 | ||
| Severe Stunting | 6.0 (5.5) | 1.5 | 0.95, 2.1 | <0.001 | 275 (100%) | 167 (61%) | 108 (39%) | 1.43 | 1.21, 1.67 | <0.001 | ||
| Wasting status | 2,761 | 0.6 | ||||||||||
| No Wasting | 4.7 (4.3) | — | — | 2,384 (100%) | 1,682 (71%) | 702 (29%) | — | — | ||||
| Wasting | 5.1 (5.0) | 0.36 | -0.16, 0.89 | 0.2 | 305 (100%) | 209 (69%) | 96 (31%) | 1.07 | 0.89, 1.27 | 0.5 | ||
| Severe Wasting | 4.9 (4.0) | 0.23 | -0.80, 1.3 | 0.7 | 72 (100%) | 48 (67%) | 24 (33%) | 1.13 | 0.78, 1.53 | 0.5 | ||
| Underweight status | 2,807 | <0.001 | ||||||||||
| No Underweight | 4.5 (4.2) | — | — | 2,105 (100%) | 1,520 (72%) | 585 (28%) | — | — | ||||
| Underweight | 5.4 (5.0) | 0.90 | 0.47, 1.3 | <0.001 | 519 (100%) | 342 (66%) | 177 (34%) | 1.23 | 1.07, 1.40 | 0.004 | ||
| Severe Underweight | 5.6 (4.8) | 1.1 | 0.40, 1.7 | 0.002 | 183 (100%) | 111 (61%) | 72 (39%) | 1.42 | 1.15, 1.70 | <0.001 | ||
| MUAC Group | 2,815 | 0.064 | ||||||||||
| Normal | 4.7 (4.4) | — | — | 2,753 (100%) | 1,942 (71%) | 811 (29%) | — | — | ||||
| severewasting | 5.0 (3.6) | 0.27 | -0.84, 1.4 | 0.6 | 62 (100%) | 37 (60%) | 25 (40%) | 1.37 | 0.97, 1.80 | 0.046 | ||
| Unknown | 626 | 480 | 146 | |||||||||
| Unknown | 652 | 498 | 154 | |||||||||
| Unknown | 606 | 464 | 142 | |||||||||
| Unknown | 598 | 458 | 140 | |||||||||
| 1 Blood Pb Levels (μg/dL): Mean (SD) | ||||||||||||
| 2 n (%) | ||||||||||||
| 3 Pearson's Chi-squared test |
Findings: Stunting, and underweight which are chronic malnutrition indicators are associated with higher blood lead levels. This may be because malnutrition leads to increased absorption of lead in the gut. But it is also possible that lead exposure contributes to malnutrition. The direction of causality cannot be determined from this cross-sectional analysis.
G. Dietary nutrient intake
| Correlation between Nutritional Variables and Blood Pb Levels | ||
| Nutritional Variable | Correlation Coefficient (r) | P-value |
|---|---|---|
| Energy Intake (kcal/day) | -0.058 | 0.0032 |
| Protein Intake (g/day) | -0.092 | 0.0000 |
| Carbohydrate Intake (g/day) | -0.039 | 0.0482 |
| Total Fat Intake (g/day) | -0.054 | 0.0055 |
| Iron Intake (mg/day) | -0.081 | 0.0000 |
| Zinc Intake (mg/day) | -0.091 | 0.0000 |
| Calcium Intake (mg/day) | -0.084 | 0.0000 |
| Thiamine (B1) Intake (mg/day) | -0.089 | 0.0000 |
| Riboflavin (B2) Intake (mg/day) | -0.086 | 0.0000 |
| Niacin (B3) Intake (mg/day) | -0.064 | 0.0011 |
| Total Folate (B9) Intake (ug/day) | -0.105 | 0.0000 |
| Vitamin C Intake (mg/day) | -0.051 | 0.0089 |
| Vitamin A Intake (ug/day) | -0.061 | 0.0018 |
| Vitamin B12 Intake (ug/day) | -0.010 | 0.5955 |
| Birth Weight (grams) | 0.041 | 0.4723 |
| Blood Parameter | Odds Ratio (per 10-unit increase) | 95% CI Lower | 95% CI Upper | P-value |
|---|---|---|---|---|
| Energy Intake (kcal/day) | 0.998 | 0.996 | 0.999 | 0.0110 |
| Protein Intake (g/day) | 0.889 | 0.841 | 0.939 | 0.0000 |
| Carbohydrate Intake (g/day) | 0.989 | 0.977 | 0.999 | 0.0467 |
| Total Fat Intake (g/day) | 0.959 | 0.915 | 1.003 | 0.0708 |
| Iron Intake (mg/day) | 0.612 | 0.491 | 0.758 | 0.0000 |
| Zinc Intake (mg/day) | 0.381 | 0.252 | 0.570 | 0.0000 |
| Calcium Intake (mg/day) | 0.993 | 0.989 | 0.997 | 0.0004 |
| Thiamine (B1) Intake (mg/day) | 0.002 | 0.000 | 0.027 | 0.0000 |
| Riboflavin (B2) Intake (mg/day) | 0.001 | 0.000 | 0.028 | 0.0000 |
| Niacin (B3) Intake (mg/day) | 0.698 | 0.531 | 0.905 | 0.0084 |
| Total Folate (B9) Intake (ug/day) | 0.963 | 0.948 | 0.976 | 0.0000 |
| Vitamin C Intake (mg/day) | 0.965 | 0.937 | 0.993 | 0.0163 |
| Vitamin A Intake (ug/day) | 0.992 | 0.986 | 0.998 | 0.0137 |
| Vitamin B12 Intake (ug/day) | 0.871 | 0.132 | 2.323 | 0.8087 |
| Birth Weight (grams) | 1.000 | 0.996 | 1.005 | 0.9624 |
Findings: There is a weak negative correlation between intake of macro and micro- nutrients in diet and blood lead levels. We find corroborative evidence in the fact that iron deficiency and anemia also had similar association as in Part 2D. However, these are measured at a single time point and may not be the best indicators of long term nutritional status which is more relevant for lead absorption. Also, birth weight does not seem to be associated.
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H. CBC parameters
| Correlation between Blood Parameters and Blood Pb Levels | ||
| Nutritional Variable | Correlation Coefficient (r) | P-value |
|---|---|---|
| wbc | 0.094 | 0.0000 |
| lym_perc | 0.035 | 0.0414 |
| mono_perc | -0.033 | 0.0554 |
| gran_perc | -0.025 | 0.1434 |
| lym_mm | 0.111 | 0.0000 |
| mono_mm | 0.024 | 0.1636 |
| gra_mm | 0.037 | 0.0320 |
| rbc | 0.120 | 0.0000 |
| hgb | -0.090 | 0.0000 |
| hct | -0.056 | 0.0010 |
| mcv | -0.163 | 0.0000 |
| mch | -0.116 | 0.0000 |
| mchc | -0.044 | 0.0096 |
| rdwcv | 0.130 | 0.0000 |
| rdwsd | -0.044 | 0.0094 |
| plt | 0.143 | 0.0000 |
| tht | 0.130 | 0.0000 |
| mpv | -0.060 | 0.0005 |
| pdw | -0.112 | 0.0000 |
| eag | 0.074 | 0.5479 |
| Blood Parameter | Odds Ratio (per 10-unit increase) | 95% CI Lower | 95% CI Upper | P-value |
|---|---|---|---|---|
| wbc | 1.89 | 1.49 | 2.41 | 0.00 |
| lym_perc | 1.10 | 1.04 | 1.18 | 0.00 |
| mono_perc | 0.75 | 0.58 | 0.95 | 0.02 |
| gran_perc | 0.93 | 0.87 | 0.99 | 0.01 |
| lym_mm | 4.30 | 2.86 | 6.50 | 0.00 |
| mono_mm | 2.92 | 0.47 | 17.46 | 0.24 |
| gra_mm | 1.27 | 0.91 | 1.77 | 0.16 |
| rbc | 71.03 | 19.04 | 269.73 | 0.00 |
| hgb | 0.32 | 0.20 | 0.51 | 0.00 |
| hct | 0.79 | 0.67 | 0.93 | 0.01 |
| mcv | 0.72 | 0.66 | 0.78 | 0.00 |
| mch | 0.52 | 0.43 | 0.63 | 0.00 |
| mchc | 0.67 | 0.48 | 0.90 | 0.01 |
| rdwcv | 3.40 | 2.38 | 4.87 | 0.00 |
| rdwsd | 0.84 | 0.71 | 0.98 | 0.03 |
| plt | 1.03 | 1.02 | 1.04 | 0.00 |
| tht | 63492439165171.31 | 15558399243.04 | 289524393857163328.00 | 0.00 |
| mpv | 0.25 | 0.14 | 0.45 | 0.00 |
| pdw | 0.51 | 0.42 | 0.62 | 0.00 |
| eag | 22.28 | 0.00 | 8984057.05 | 0.63 |
Findings: Complete blood count parameters such as hemoglobin, hematocrit, red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet count and white blood cell count are all negatively correlated with blood lead levels. These are possible consequences of high blood lead levels.
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High level causal diagram for high blood levels (Simplified)
Part 3A. Revised adjusted regression analysis for factors associated
We selected four groups of modifiable risk factors for adjusted analysis based on the literature and our unadjusted analysis: 1) drinking water source, 2) micronutrient deficiency, 3) malnutrition status, and 4) diet poor in micronutrients. We ran a separate regression model for each of the exposure variables in these groups adjusted for a set of variables based on the causal diagram shown above.
A. Drinking water source
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Drinking Water | 3,395 |
|
|
|
| Bore well |
|
— | — |
|
| Open well |
|
0.68 | 0.46, 0.98 | 0.042 |
| Others |
|
1.32 | 0.91, 1.89 | 0.14 |
| RO/Bottled/Purchased water |
|
1.81 | 1.38, 2.38 | <0.001 |
| Surface/Spring water |
|
0.93 | 0.60, 1.41 | 0.7 |
| Tap water |
|
1.02 | 0.84, 1.24 | 0.8 |
| Water tanker |
|
1.70 | 1.06, 2.71 | 0.026 |
| age_gp | 3,395 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.75 | 0.59, 0.97 | 0.026 |
| 3-4 |
|
0.75 | 0.59, 0.95 | 0.018 |
| 4-5 |
|
0.70 | 0.56, 0.89 | 0.003 |
| Gender | 3,395 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.23 | 1.06, 1.43 | 0.008 |
| Type of House | 3,395 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.93 | 0.76, 1.12 | 0.4 |
| Kutcha |
|
0.79 | 0.61, 1.01 | 0.067 |
| PSU Rural/Urban | 3,395 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.38 | 1.16, 1.64 | <0.001 |
| Wealth Index | 3,395 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.40 | 1.08, 1.81 | 0.011 |
| Middle |
|
1.37 | 1.05, 1.79 | 0.022 |
| Lower |
|
1.77 | 1.36, 2.32 | <0.001 |
| Lowest |
|
3.12 | 2.37, 4.14 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
B. Micronutrient deficiency
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Iron Deficiency Status | 736 |
|
|
|
| No Iron Deficiency |
|
— | — |
|
| Iron Deficiency (ID) |
|
1.70 | 1.15, 2.50 | 0.008 |
| age_gp | 736 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
1.27 | 0.67, 2.47 | 0.5 |
| 3-4 |
|
0.97 | 0.53, 1.82 |
0.9 |
| 4-5 |
|
0.99 | 0.56, 1.83 |
0.9 |
| Gender | 736 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.38 | 0.99, 1.94 | 0.059 |
| Type of House | 736 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.75 | 0.46, 1.19 | 0.2 |
| Kutcha |
|
0.90 | 0.52, 1.54 | 0.7 |
| PSU Rural/Urban | 736 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.41 | 0.97, 2.06 | 0.069 |
| Wealth Index | 736 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.25 | 0.74, 2.11 | 0.4 |
| Middle |
|
1.16 | 0.67, 1.99 | 0.6 |
| Lower |
|
1.76 | 1.00, 3.10 | 0.049 |
| Lowest |
|
2.59 | 1.46, 4.65 | 0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Anemia status | 3,397 |
|
|
|
| No Anemia |
|
— | — |
|
| Any Anemia |
|
1.25 | 1.07, 1.47 | 0.005 |
| age_gp | 3,397 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.76 | 0.60, 0.98 | 0.032 |
| 3-4 |
|
0.76 | 0.60, 0.97 | 0.026 |
| 4-5 |
|
0.74 | 0.58, 0.93 | 0.010 |
| Gender | 3,397 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.23 | 1.06, 1.44 | 0.007 |
| Type of House | 3,397 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.95 | 0.78, 1.14 | 0.6 |
| Kutcha |
|
0.77 | 0.60, 0.99 | 0.040 |
| PSU Rural/Urban | 3,397 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.47 | 1.24, 1.74 | <0.001 |
| Wealth Index | 3,397 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.35 | 1.04, 1.74 | 0.022 |
| Middle |
|
1.26 | 0.97, 1.64 | 0.087 |
| Lower |
|
1.62 | 1.25, 2.10 | <0.001 |
| Lowest |
|
2.77 | 2.12, 3.64 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Vitamin B12 Status | 703 |
|
|
|
| Normal (≥203 pg/mL) |
|
— | — |
|
| Deficient (<203 pg/mL) |
|
0.95 | 0.66, 1.35 | 0.8 |
| age_gp | 703 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
1.29 | 0.67, 2.54 | 0.4 |
| 3-4 |
|
0.93 | 0.51, 1.77 | 0.8 |
| 4-5 |
|
0.93 | 0.52, 1.72 | 0.8 |
| Gender | 703 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.36 | 0.97, 1.92 | 0.080 |
| Type of House | 703 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.72 | 0.45, 1.14 | 0.2 |
| Kutcha |
|
0.82 | 0.47, 1.41 | 0.5 |
| PSU Rural/Urban | 703 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.39 | 0.95, 2.03 | 0.090 |
| Wealth Index | 703 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.23 | 0.73, 2.10 | 0.4 |
| Middle |
|
1.18 | 0.68, 2.06 | 0.6 |
| Lower |
|
1.71 | 0.97, 3.04 | 0.066 |
| Lowest |
|
2.53 | 1.39, 4.63 | 0.002 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Serum Folate Status | 702 |
|
|
|
| Normal (≥4 ng/mL) |
|
— | — |
|
| Deficient (<4 ng/mL) |
|
0.77 | 0.44, 1.30 | 0.3 |
| age_gp | 702 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
1.24 | 0.65, 2.45 | 0.5 |
| 3-4 |
|
0.92 | 0.50, 1.74 | 0.8 |
| 4-5 |
|
0.92 | 0.51, 1.70 | 0.8 |
| Gender | 702 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.35 | 0.96, 1.90 | 0.090 |
| Type of House | 702 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.72 | 0.44, 1.14 | 0.2 |
| Kutcha |
|
0.85 | 0.48, 1.47 | 0.6 |
| PSU Rural/Urban | 702 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.42 | 0.97, 2.08 | 0.070 |
| Wealth Index | 702 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.22 | 0.72, 2.08 | 0.5 |
| Middle |
|
1.14 | 0.65, 1.98 | 0.6 |
| Lower |
|
1.67 | 0.94, 2.97 | 0.079 |
| Lowest |
|
2.42 | 1.33, 4.43 | 0.004 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Vitamin D Status | 700 |
|
|
|
| Normal (≥12 ng/mL) |
|
— | — |
|
| Deficient (<12 ng/mL) |
|
1.22 | 0.78, 1.87 | 0.4 |
| age_gp | 700 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
1.28 | 0.66, 2.51 | 0.5 |
| 3-4 |
|
0.91 | 0.49, 1.72 | 0.8 |
| 4-5 |
|
0.91 | 0.51, 1.68 | 0.8 |
| Gender | 700 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.35 | 0.96, 1.91 | 0.085 |
| Type of House | 700 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.72 | 0.44, 1.13 | 0.2 |
| Kutcha |
|
0.81 | 0.46, 1.40 | 0.5 |
| PSU Rural/Urban | 700 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.36 | 0.93, 1.99 | 0.12 |
| Wealth Index | 700 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.23 | 0.73, 2.11 | 0.4 |
| Middle |
|
1.20 | 0.69, 2.08 | 0.5 |
| Lower |
|
1.75 | 0.99, 3.12 | 0.056 |
| Lowest |
|
2.55 | 1.41, 4.65 | 0.002 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Anaemia Adjusted for Iron | 734 |
|
|
|
| No Anemia + Iron Deficiency |
|
— | — |
|
| Anemia + No Iron Deficiency |
|
2.24 | 0.82, 7.94 | 0.2 |
| No Anemia + No Iron Deficiency |
|
2.73 | 1.03, 9.47 | 0.068 |
| Anemia + Iron Deficiency |
|
4.72 | 1.31, 20.1 | 0.023 |
| age_gp | 734 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
1.33 | 0.70, 2.57 | 0.4 |
| 3-4 |
|
0.97 | 0.53, 1.82 |
0.9 |
| 4-5 |
|
0.94 | 0.53, 1.72 | 0.8 |
| Gender | 734 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.40 | 1.00, 1.96 | 0.053 |
| Type of House | 734 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.67 | 0.42, 1.06 | 0.10 |
| Kutcha |
|
0.76 | 0.44, 1.30 | 0.3 |
| PSU Rural/Urban | 734 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.37 | 0.94, 2.00 | 0.10 |
| Wealth Index | 734 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.32 | 0.78, 2.22 | 0.3 |
| Middle |
|
1.22 | 0.71, 2.10 | 0.5 |
| Lower |
|
1.86 | 1.06, 3.29 | 0.032 |
| Lowest |
|
2.73 | 1.53, 4.90 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
C. Malnutrition status
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Stunting status | 2,777 |
|
|
|
| No Stunting |
|
— | — |
|
| Stunting |
|
1.28 | 1.03, 1.57 | 0.023 |
| Severe Stunting |
|
1.54 | 1.17, 2.01 | 0.002 |
| age_gp | 2,777 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.70 | 0.54, 0.92 | 0.010 |
| 3-4 |
|
0.74 | 0.57, 0.96 | 0.024 |
| 4-5 |
|
0.70 | 0.54, 0.90 | 0.006 |
| Gender | 2,777 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.15 | 0.97, 1.36 | 0.10 |
| Type of House | 2,777 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.93 | 0.76, 1.14 | 0.5 |
| Kutcha |
|
0.72 | 0.55, 0.94 | 0.019 |
| PSU Rural/Urban | 2,777 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.54 | 1.28, 1.85 | <0.001 |
| Wealth Index | 2,777 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.37 | 1.03, 1.84 | 0.031 |
| Middle |
|
1.27 | 0.95, 1.71 | 0.11 |
| Lower |
|
1.61 | 1.20, 2.17 | 0.001 |
| Lowest |
|
2.68 | 1.98, 3.65 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Wasting status | 2,751 |
|
|
|
| No Wasting |
|
— | — |
|
| Wasting |
|
1.06 | 0.81, 1.37 | 0.7 |
| Severe Wasting |
|
1.15 | 0.67, 1.89 | 0.6 |
| age_gp | 2,751 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.67 | 0.52, 0.88 | 0.004 |
| 3-4 |
|
0.72 | 0.56, 0.94 | 0.013 |
| 4-5 |
|
0.66 | 0.51, 0.85 | 0.001 |
| Gender | 2,751 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.16 | 0.98, 1.37 | 0.085 |
| Type of House | 2,751 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.92 | 0.75, 1.13 | 0.4 |
| Kutcha |
|
0.73 | 0.56, 0.96 | 0.025 |
| PSU Rural/Urban | 2,751 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.49 | 1.24, 1.79 | <0.001 |
| Wealth Index | 2,751 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.38 | 1.03, 1.84 | 0.030 |
| Middle |
|
1.29 | 0.96, 1.74 | 0.089 |
| Lower |
|
1.71 | 1.28, 2.29 | <0.001 |
| Lowest |
|
2.88 | 2.13, 3.92 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Underweight status | 2,797 |
|
|
|
| No Underweight |
|
— | — |
|
| Underweight |
|
1.26 | 1.02, 1.56 | 0.030 |
| Severe Underweight |
|
1.55 | 1.12, 2.12 | 0.007 |
| age_gp | 2,797 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.68 | 0.52, 0.89 | 0.005 |
| 3-4 |
|
0.72 | 0.56, 0.93 | 0.013 |
| 4-5 |
|
0.67 | 0.52, 0.86 | 0.002 |
| Gender | 2,797 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.15 | 0.98, 1.36 | 0.094 |
| Type of House | 2,797 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.93 | 0.76, 1.14 | 0.5 |
| Kutcha |
|
0.72 | 0.55, 0.95 | 0.019 |
| PSU Rural/Urban | 2,797 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.49 | 1.24, 1.79 | <0.001 |
| Wealth Index | 2,797 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.37 | 1.03, 1.82 | 0.033 |
| Middle |
|
1.27 | 0.95, 1.71 | 0.10 |
| Lower |
|
1.60 | 1.20, 2.15 | 0.002 |
| Lowest |
|
2.69 | 1.99, 3.66 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| MUAC Group | 2,805 |
|
|
|
| Normal |
|
— | — |
|
| severewasting |
|
1.56 | 0.91, 2.63 | 0.10 |
| age_gp | 2,805 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.68 | 0.52, 0.89 | 0.005 |
| 3-4 |
|
0.73 | 0.57, 0.95 | 0.017 |
| 4-5 |
|
0.67 | 0.52, 0.87 | 0.002 |
| Gender | 2,805 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.15 | 0.98, 1.36 | 0.090 |
| Type of House | 2,805 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.91 | 0.74, 1.12 | 0.4 |
| Kutcha |
|
0.73 | 0.55, 0.95 | 0.020 |
| PSU Rural/Urban | 2,805 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.48 | 1.23, 1.78 | <0.001 |
| Wealth Index | 2,805 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.38 | 1.04, 1.83 | 0.028 |
| Middle |
|
1.29 | 0.97, 1.73 | 0.083 |
| Lower |
|
1.67 | 1.25, 2.23 | <0.001 |
| Lowest |
|
2.85 | 2.11, 3.85 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
D. Diet poor in micronutrients
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Iron Intake (mg/day) | 2,603 | 0.96 | 0.94, 0.98 | <0.001 |
| age_gp | 2,603 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.78 | 0.59, 1.05 | 0.10 |
| 3-4 |
|
0.77 | 0.58, 1.02 | 0.067 |
| 4-5 |
|
0.74 | 0.56, 0.97 | 0.031 |
| Gender | 2,603 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.28 | 1.07, 1.52 | 0.006 |
| Type of House | 2,603 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.92 | 0.74, 1.13 | 0.4 |
| Kutcha |
|
0.73 | 0.55, 0.97 | 0.030 |
| PSU Rural/Urban | 2,603 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.56 | 1.29, 1.89 | <0.001 |
| Wealth Index | 2,603 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.53 | 1.14, 2.07 | 0.005 |
| Middle |
|
1.30 | 0.96, 1.76 | 0.091 |
| Lower |
|
1.81 | 1.34, 2.45 | <0.001 |
| Lowest |
|
2.65 | 1.93, 3.65 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Zinc Intake (mg/day) | 2,603 | 0.92 | 0.88, 0.96 | <0.001 |
| age_gp | 2,603 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.79 | 0.59, 1.06 | 0.11 |
| 3-4 |
|
0.77 | 0.58, 1.03 | 0.076 |
| 4-5 |
|
0.75 | 0.57, 1.00 | 0.048 |
| Gender | 2,603 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.27 | 1.07, 1.51 | 0.007 |
| Type of House | 2,603 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.91 | 0.74, 1.13 | 0.4 |
| Kutcha |
|
0.73 | 0.55, 0.96 | 0.028 |
| PSU Rural/Urban | 2,603 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.55 | 1.28, 1.88 | <0.001 |
| Wealth Index | 2,603 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.51 | 1.12, 2.04 | 0.007 |
| Middle |
|
1.28 | 0.95, 1.74 | 0.11 |
| Lower |
|
1.77 | 1.31, 2.40 | <0.001 |
| Lowest |
|
2.61 | 1.91, 3.60 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Calcium Intake (mg/day) | 2,603 | 1.00 | 1.00, 1.00 | 0.006 |
| age_gp | 2,603 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.75 | 0.56, 1.01 | 0.055 |
| 3-4 |
|
0.72 | 0.54, 0.95 | 0.021 |
| 4-5 |
|
0.67 | 0.51, 0.89 | 0.005 |
| Gender | 2,603 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.26 | 1.06, 1.50 | 0.008 |
| Type of House | 2,603 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.90 | 0.73, 1.12 | 0.3 |
| Kutcha |
|
0.70 | 0.53, 0.93 | 0.015 |
| PSU Rural/Urban | 2,603 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.56 | 1.29, 1.89 | <0.001 |
| Wealth Index | 2,603 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.50 | 1.11, 2.02 | 0.008 |
| Middle |
|
1.27 | 0.94, 1.72 | 0.13 |
| Lower |
|
1.75 | 1.30, 2.37 | <0.001 |
| Lowest |
|
2.57 | 1.87, 3.55 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
| Characteristic | N | OR1 | 95% CI | p-value |
|---|---|---|---|---|
| Vitamin C Intake (mg/day) | 2,603 | 1.00 | 0.99, 1.00 | 0.047 |
| age_gp | 2,603 |
|
|
|
| 1-2 |
|
— | — |
|
| 2-3 |
|
0.75 | 0.56, 1.00 | 0.053 |
| 3-4 |
|
0.72 | 0.54, 0.95 | 0.020 |
| 4-5 |
|
0.68 | 0.52, 0.90 | 0.006 |
| Gender | 2,603 |
|
|
|
| Female |
|
— | — |
|
| Male |
|
1.26 | 1.06, 1.49 | 0.009 |
| Type of House | 2,603 |
|
|
|
| Pucca |
|
— | — |
|
| Semi-pucca |
|
0.92 | 0.74, 1.13 | 0.4 |
| Kutcha |
|
0.74 | 0.56, 0.98 | 0.037 |
| PSU Rural/Urban | 2,603 |
|
|
|
| Rural |
|
— | — |
|
| Urban |
|
1.54 | 1.27, 1.86 | <0.001 |
| Wealth Index | 2,603 |
|
|
|
| Highest |
|
— | — |
|
| Higher |
|
1.53 | 1.14, 2.07 | 0.005 |
| Middle |
|
1.30 | 0.96, 1.76 | 0.093 |
| Lower |
|
1.81 | 1.34, 2.45 | <0.001 |
| Lowest |
|
2.73 | 1.99, 3.75 | <0.001 |
| 1 Adjusted for age group, gender, type of house, rural/urban, and wealth index | ||||
| Abbreviations: CI = Confidence Interval, OR = Odds Ratio | ||||
Note: Each variable is a separate logistic regression model adjusted for a common set of variables (age, gender, rural/urban and wealth index). Following are the potential risk factors for high blood lead levels in children:
RO/bottled/purchased water (OR = 1.81, 95% CI: 1.38–2.38, p < 0.001) and water tankers (OR = 1.70, 95% CI: 1.06–2.71, p = 0.026) were associated with higher odds of elevated blood lead levels.
Children with severe stunting (OR = 1.54, 95% CI: 1.17–2.01, p = 0.002) and severe underweight status (OR = 1.55, 95% CI: 1.12–2.12, p = 0.007) were associated with higher odds of elevated blood lead levels.
Iron deficiency (OR = 1.70, 95% CI: 1.15–2.50, p = 0.008) and any anaemia (OR = 1.25, 95% CI: 1.07–1.47, p = 0.005) were associated with higher odds of elevated blood lead levels.
Notably, the concurrent presence of both anaemia and iron deficiency amplified these odds nearly five-fold (OR = 4.72, 95% CI: 1.31–20.10, p = 0.023).
Consistent with the biomarker findings, higher daily dietary intakes of iron and zinc were protective, reducing the odds by 4% (OR = 0.96, 95% CI: 0.94–0.98, p < 0.001) and 8% (OR = 0.92, 95% CI: 0.88–0.96, p < 0.001) per 20 unit increase, respectively.
Comments from DG
Why don’t you try adjustment for age, gender, type of house, rural/urban, and wealth index for exposures 1) drinking water, 2) anthropometry, 3) micronutrient status, 4) dietary energy, protein and micronutrient intake. Of these 1) and 4) can be considered to be exposure factors. 2) and 3) are equally likely to be the cause or effect of high blood lead. Or that all modifiable and non modifiable factors are simply associated with environmental exposure to lead. Poor, urban, children who are malnourished, anemic and have poor energy, protein and micronutrient intake.