Table 1. Cohort Characteristics and Results from Bivariate Mixed-Effect Models for Blood and Hair Mn Concentrationsa.
| overall | blood
Mn (μg/L) (n = 664, k = 418) |
hair
Mn (μg/g) (n = 800, k = 449) |
|||
|---|---|---|---|---|---|
| N (%) | mean (95% CI) | pME | GM (95% CI) | pME | |
| Demographic and Pregnancy-Related Characteristics | |||||
| age (years) | |||||
| <18 | 78 (17.4) | 25.3 (24.0, 26.7) | - | 1.8 (1.4, 2.2) | - |
| 18–24 | 208 (46.3) | 24.4 (23.6, 25.2) | 0.24 | 1.7 (1.5, 2.0) | 0.86 |
| 25–29 | 84 (18.7) | 23.0 (21.7, 24.3) | 0.02 | 1.7 (1.3, 2.1) | 0.71 |
| 30–34 | 42 (9.4) | 24.7 (22.8, 26.6) | 0.60 | 2.0 (1.4, 2.7) | 0.63 |
| ≥35 | 37 (8.2) | 24.9 (22.9, 27.0) | 0.75 | 2.1 (1.5, 2.9) | 0.43 |
| education level | |||||
| ≤6th grade | 235 (52.3) | 24.4 (23.6, 25.2) | - | 1.9 (1.6, 2.2) | - |
| 7–11th grade | 201 (44.8) | 24.4 (23.6, 25.2) | 0.99 | 1.7 (1.5, 2.0) | 0.26 |
| completed high school | 13 (2.9) | 23.3 (20.1, 26.6) | 0.54 | 1.2 (0.6, 2.0) | 0.10 |
| marital status | |||||
| single | 109 (24.3) | 24.6 (23.4, 25.8) | - | 1.5 (1.2, 1.8) | - |
| married/living as married | 340 (75.7) | 24.3 (23.6, 25.0) | 0.66 | 1.9 (1.7, 2.1) | 0.07 |
| country of birth | |||||
| Costa Rica | 364 (81.1) | 24.3 (23.6, 24.9) | - | 1.6 (1.5, 1.8) | - |
| other Central American countries | 85 (18.9) | 24.8 (23.5, 26.1) | 0.49 | 2.4 (1.9, 2.9) | 0.004 |
| family incomeb | |||||
| above poverty line | 169 (40.6) | 24.1 (23.2, 25.0) | 1.7 (1.4, 2.0) | - | |
| below poverty line and above extreme poverty | 170 (40.9) | 24.4 (23.5, 25.4) | 0.61 | 1.8 (1.5, 2.1) | 0.52 |
| below extreme poverty line | 77 (18.5) | 24.1 (22.7, 25.5) | 0.98 | 1.9 (1.5, 2.4) | 0.33 |
| language at home | |||||
| Spanish only | 417 (92.9) | 24.5 (23.9, 25.1) | - | 1.8 (1.6, 2.0) | - |
| Spanish and other language | 32 (7.1) | 23.2 (21.2, 25.3) | 0.25 | 1.8 (1.3, 2.6) | 0.90 |
| parityb | |||||
| 0 | 154 (35.6) | 24.3 (23.3, 25.2) | - | 1.7 (1.5, 2.0) | - |
| ≥1 | 279 (64.4) | 24.4 (23.7, 25.1) | 0.87 | 1.8 (1.6, 2.0) | 0.71 |
| smoking during pregnancy | |||||
| no | 431 (96.0) | 24.5 (23.9, 25.1) | - | 1.8 (1.6, 2.0) | - |
| yes | 18 (4.0) | 21.4 (18.6, 24.1) | 0.03 | 1.6 (1.0, 2.6) | 0.70 |
| Occupational Characteristics | |||||
| agricultural workers in household during pregnancy | |||||
| 0 | 117 (26.0) | 23.7 (22.6, 24.8) | - | 1.5 (1.2, 1.8) | - |
| 1 | 241 (53.7) | 24.4 (23.6, 25.1) | 0.34 | 1.8 (1.6, 2.1) | 0.07 |
| ≥2 | 91 (20.3) | 25.3 (24.0, 26.5) | 0.06 | 2.0 (1.6, 2.5) | 0.03 |
| occupation before pregnancy | |||||
| none/not agriculture | 339 (75.5) | 24.5 (23.8, 25.1) | - | 1.6 (1.5, 1.8) | - |
| agriculture | 110 (24.5) | 24.1 (22.9, 25.2) | 0.58 | 2.3 (1.9, 2.8) | 0.002 |
| occupation during pregnancyc | |||||
| none/not agriculture | 412 (91.8) | 24.5 (23.9, 25.1) | - | 1.7 (1.6, 1.9) | - |
| agriculture | 37 (8.2) | 22.4 (20.5, 24.4) | 0.04 | 2.2 (1.6, 3.0) | 0.22 |
| husband/partner’s occupation before pregnancyb | |||||
| none/not agriculture | 152 (35.9) | 24.5 (23.5, 25.4) | - | 1.4 (1.2, 1.6) | - |
| agriculture | 271 (64.1) | 24.3 (23.6, 25.0) | 0.78 | 2.0 (1.8, 2.3) | <0.001 |
| husband/partner’s occupation during pregnancyc | |||||
| none/not agriculture | 175 (39.0) | 23.9 (23.0, 24.8) | - | 1.5 (1.3, 1.7) | - |
| agriculture | 274 (61.0) | 24.6 (23.9, 25.4) | 0.24 | 2.0 (1.8, 2.3) | 0.001 |
| Environmental Characteristics | |||||
| residential distance from banana plantations during pregnancy (meters) | |||||
| <50 | 114 (25.4) | 23.6 (22.4, 24.7) | - | 2.5 (2.0, 3.0) | - |
| 50-<600 | 230 (51.2) | 24.8 (24.0, 25.6) | 0.09 | 1.5 (1.3, 1.7) | <0.001 |
| ≥600 | 105 (23.4) | 24.4 (23.2, 25.5) | 0.32 | 1.8 (1.5, 2.2) | 0.02 |
| source of drinking water in the home | |||||
| aqueduct | 354 (78.8) | 24.6 (24.0, 25.3) | - | 1.5 (1.3, 1.6) | - |
| well (banana company or private) | 72 (16.0) | 23.3 (21.9, 24.7) | 0.10 | 3.7 (3.0, 4.7) | <0.001 |
| other source (river, rain, tank, bottled water) | 23 (5.2) | 23.9 (21.5, 26.3) | 0.58 | 2.3 (1.5, 3.3) | 0.04 |
| drinking water Mn concentrations (μg/L)b | |||||
| first quartile: 0.0–0.5 | 36 (26.1) | 25.0 (23.2, 26.9) | - | 0.7 (0.5, 1.0) | - |
| second quartile: 0.6–9.8 | 33 (23.9) | 23.7 (21.7, 25.7) | 0.32 | 1.5 (1.1, 2.1) | 0.002 |
| third quartile: 9.9–157.7 | 35 (25.4) | 25.7 (23.7, 27.6) | 0.64 | 2.0 (1.5, 2.8) | <0.001 |
| fourth quartile: 157.8–1600.0 | 34 (24.6) | 24.2 (22.3, 26.1) | 0.54 | 3.6 (2.6, 5.0) | <0.001 |
| wall and floor materials of the houseb | |||||
| both made of nonpermeable and easy-to-clean materials | 119 (40.5) | 22.5 (21.4, 23.6) | - | 1.4 (1.2, 1.8) | - |
| one or both made of permeable and difficult-to-clean materials | 175 (59.5) | 25.4 (24.5, 26.3) | <0.001 | 1.5 (1.3, 1.8) | 0.61 |
| reported aerial spraying near the homec | |||||
| day before sample collection | |||||
| no | 333 (74.2) | 24.5 (23.9, 25.2) | - | 1.7 (1.5, 1.9) | - |
| yes | 116 (25.8) | 23.6 (22.6, 24.6) | 0.10 | 1.9 (1.6, 2.3) | 0.15 |
| day of sample collection | |||||
| no | 334 (74.4) | 24.4 (23.8, 25.0) | - | 1.7 (1.5, 1.9) | - |
| yes | 115 (25.6) | 24.2 (23.1, 25.3) | 0.72 | 2.1 (1.8, 2.5) | 0.01 |
| reported washing work clothes of agricultural workersc | |||||
| day before sample collectionb | |||||
| no | 335 (80.2) | 24.3 (23.7, 25.0) | - | 1.7 (1.6, 1.9) | - |
| yes | 83 (19.8) | 24.3 (23.2, 25.5) | 0.97 | 2.0 (1.7, 2.4) | 0.16 |
| day of sample collection | |||||
| no | 360 (80.1) | 24.6 (23.9, 25.2) | - | 1.7 (1.5, 1.9) | - |
| yes | 89 (19.9) | 23.6 (22.4, 24.7) | 0.13 | 2.2 (1.8, 2.6) | 0.01 |
a
Abbreviations: n, number of samples; k, number of women; CI, confidence interval; ME, mixed-effect models; GM, geometric mean.
b
Information was missing for several women with at least one blood sample (k = 31 for family income, k = 15 for parity, k = 24 for husband/partner’s occupation before pregnancy, k = 287 for drinking water Mn concentrations, k = 143 for wall and floor materials of the house, and k = 26 for washing work clothes the day before sample collection) and for several women with at least one hair sample (k = 33 for family income, k = 16 for parity, k = 26 for husband/partner’s occupation before pregnancy, k = 311 for drinking water Mn concentrations, k = 155 for wall and floor materials of the house, and k = 31 for washing work clothes the day before sample collection).
c
Variables were analyzed as time-varying characteristics in the bivariate and multivariate linear mixed-effects models.