Table 1.
Characteristics of nonpregnant, reproductive-aged (15–44 years) women from NHANES 2003−2004 by indicators of elevated neurodevelopmental toxicant (NDT) exposure a and allostatic load b.
| All Women n (Weighted %) |
Indicators of Elevated NDT Exposure a | Allostatic Load b | |||||
|---|---|---|---|---|---|---|---|
| HQPb > 1 n (Weighted %) |
HQMeHg > 1 n (Weighted %) |
HINDT > 1 n (Weighted %) |
Low n (Weighted %) |
Intermediate n (Weighted %) |
High n (Weighted %) |
||
| Total Population | 1,250 | 159 (11) | 19 (2) | 324 (25) | 330 (28) | 632 (54) | 210 (20) |
| Race/Ethnicity | |||||||
| Caucasian | 551 (74) | 46 (9) | 10 (2) | 119 (22) | 156 (28) * | 274 (54) | 88 (19) |
| African American | 373 (15) | 52 (14) | 6 (2) | 104 (32) * | 86 (18) | 194 (55) | 67 (26) * |
| Mexican American | 326 (11) | 61 (22) * | 3 (1) | 101 (36) * | 88 (21) | 164 (56) | 55 (23) |
| Country of Birth | |||||||
| United States | 1,049 (90) | 92 (8) | 15 (2) * | 225 (23) | 278 (25) | 533 (54) | 175 (20) |
| Foreign | 201 (10) | 67 (33) * | 4 (2) | 99 (48) * | 52 (26) | 99 (52) | 35 (22) |
| Age (years) | |||||||
| 15−19 | 520 (16) | 43 (5) | 4 (1) | 79 (11) | 191 (43) | 254 (49) | 40 (8) |
| 20−28 | 252 (26) | 29 (9) | 3 (1) | 59 (20) * | 66 (30) * | 136 (58) * | 31 (12) * |
| 29−44 | 478 (58) | 87 (14) * | 12 (2) | 184 (33) * | 73 (19) * | 242 (54) | 139 (28) * |
| Highest Education c | |||||||
| Less than high school graduate | 327 (15) | 70 (22) * | 4 (1) | 114 (39) | 68 (18) * | 170 (53) | 69 (29) * |
| High school graduate | 302 (27) | 37 (11) | 3 (1) | 67 (21) | 74 (20) * | 152 (53) | 55 (27) * |
| Some college | 383 (35) | 30 (7) | 3 (1) | 75 (19) | 107 (28) * | 197 (56) | 54 (17) |
| College graduate or above | 194 (23) | 17 (8) | 9 (5) * | 57 (31) * | 67 (33) | 90 (54) | 26 (13) |
| Smoking Status (serum cotinine) | |||||||
| Nonsmoker (≤10 ng/mL) | 943 (72) | 100 (8) | 14 (2) | 214 (22) | 270 (27) | 485 (54) | 147 (19) |
| Smoker (>10 ng/mL) | 282 (28) | 56 (18) * | 5 (2) | 105 (37) * | 60 (21) * | 147 (55) | 62 (25) * |
| Iron Status Indicator d | |||||||
| Normal | 870 (74) | 105 (11) | 17 (2) | 235 (28) | 247 (27) * | 449 (55) | 122 (18) * |
| Abnormal | 379 (26) | 54 (11) | 2 (0) | 89 (21) | 83 (19) | 183 (52) | 87 (28) |
Notes: a Hazard quotients (HQs) were calculated by dividing blood concentrations of lead (Pb) and methyl mercury (MeHg) by 1.76 µg/dL and 5.8 µg/L, respectively. The hazard index (HI) was calculated by summing individual hazard quotients for Pb and MeHg (Equation 1). b Allostatic load, a measure of physiological dysregulation, was used as an indicator of chronic stress exposure and was estimated based on the categorical classification of AL-clinical scores (0 = Low; 1−2 = Intermediate; ≥3 = High) and calculated by summing the number of 10 biomarkers above clinical high risk criteria (Equation 2). c If the participant was <18 years of age, head of household status was used. d Iron status was determined abnormal if any two of the following conditions were met: (1) serum ferritin <15 ng/mL, (2) transferrin saturation <16%, (3) red blood cell distribution width >15%, or (4) erythrocyte protoporphyrin >50 µg/dL red blood cells. * Denotes statistically significant within group differences between the indicated percentage and the lowest (or highest) percentage (p < 0.05) (e.g., Mexican Americans had a statistically significant higher percentage of women with an HQPb > 1 relative to Caucasians).