Table 2.
Analyses of factors influencing lead concentration in blood by study, showing the numbers in categories (N), the regression coefficient (β) and its standard error (S.E.), and the intercept and unadjusted and adjusted R2 at the bottom of the table.
| French National Birth Cohort Study (Elfe) |
German Environmental Specimen Bank (ESB) |
Japan Environment and Children’s Study (JECS) |
Norwegian Mother and Child Cohort Study (MoBa) |
Shanghai Birth Cohort Study |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample size for the lead analysis | 1,670 | 1,842 | 17,998 | 2,982 | 423 | |||||||||||
| Timing and type of sampling for lead |
Cord blood 2011 |
Whole blood from women aged 20–29 2010–2016 |
Maternal blood (mid–late trimester) 2011–2014 |
Maternal blood (week 18 of pregnancy) 2002–2008 |
Cord blood 2014–2015 |
|||||||||||
| Variable | N | β | S.E. | N | β | S.E. | N | β | S.E. | N | β | S.E. | N | β | S.E. | |
| Smoking | Never | 701 | 1.00 | - | 1081 | 1.00 | - | 7032 | 1.00 | - | 1552 | 1.00 | - | 335 | 1.00 | - |
| Passive | 20 | 0.08 | 1.87 | 332 | 0.84 | 0.30 | 2894 | 0.17 | 0.07 | 100 | 0.35 | 0.46 | 74 | 1.43 | 0.88 | |
| Former | 399 | −0.09 | 0.42 | 200 | 1.65 | 0.36 | 6729 | 0.34 | 0.05 | 1157 | 0.20 | 0.19 | 12 | 3.98 | 2.60 | |
| Current | 380 | 1.13 | 0.49 | 213 | 3.33 | 0.35 | 884 | 1.27 | 0.11 | 173 | 1.19 | 0.39 | 2 | NA | NA | |
| Maternal age& | <25 years | 255 | 1.00 | - | 1224 | 1.00 | - | 1403 | 1.00 | - | 241 | 1.00 | - | 25 | 1.00 | - |
| 25-34 years | 1144 | 0.81 | 0.56 | 618 | 0.66 | 0.24 | 9149 | 0.21 | 0.08 | 2257 | −0.003 | 0.32 | 352 | 0.69 | 1.67 | |
| 35+ years | 261 | 1.98 | 0.68 | 0 | NA | NA | 4000 | 0.60 | 0.09 | 484 | 0.53 | 0.38 | 46 | 0.58 | 2.10 | |
| BMI | <18.5 kg/m2 (underweight) | 123 | 1.00 | - | 112 | 1.00 | - | 2573 | 1.00 | - | 94 | 1.00 | - | 56 | 1.00 | - |
| ≥18.5 and 25 kg/m2 (healthy) | 1032 | 0.80 | 0.69 | 1494 | 0.43 | 0.56 | 11579 | 0.07 | 0.06 | 1913 | −0.22 | 0.47 | 320 | 1.68 | 1.20 | |
| ≥25 kg/m2 (overweight and obese) | 494 | 1.72 | 0.73 | 228 | 0.48 | 0.61 | 1691 | 0.36 | 0.09 | 918 | −0.46 | 0.49 | 47 | 1.10 | 1.75 | |
| Coffee consumption* | Less than 1 time per week | 790 | 1.00 | - | 653 | 1.00 | - | 13116 | 1.00 | - | 1489 | 1.00 | - | 0 | 1.00 | - |
| 1-2 times per week$ | 225 | 0.72 | 0.64 | 85 | 1.00 | 0.54 | 1309 | 0.27 | 0.08 | 410 | 0.60 | 0.26 | 0 | NA | NA | |
| More than 3 times per week$$ | 482 | 1.52 | 0.41 | 1101 | 0.27 | 0.25 | 1287 | 0.20 | 0.08 | 1083 | 0.91 | 0.20 | 0 | NA | NA | |
| Tea consumption** | Less than 1 time per week | 937 | 1.00 | - | 501 | 1.00 | - | 8822 | 1.00 | - | 2091 | 1.00 | - | 358 | 1.00 | - |
| 1-2 times per week$ | 233 | −0.07 | 0.60 | 160 | −0.14 | 0.39 | 2335 | 0.07 | 0.07 | 380 | 0.04 | 0.26 | 0 | NA | NA | |
| More than 3 times per week$$ | 205 | 1.95 | 0.52 | 1181 | 0.21 | 0.24 | 4686 | 0.31 | 0.05 | 511 | 1.07 | 0.23 | 65 | 0.32 | 1.16 | |
| Tap water consumption# | Less than 1 time per week | 640 | 1.00 | - | 37 | 1.00 | - | 10380 | 1.00 | - | 87 | 1.00 | - | 101 | 1.00 | - |
| 1-2 times per week$ | 80 | 0.56 | 0.83 | 12 | 0.69 | 1.60 | 1390 | 0.10 | 0.08 | 30 | −0.20 | 0.96 | 0 | NA | NA | |
| More than 3 times per week$$ | 781 | 0.68 | 0.44 | 1788 | 0.39 | 0.78 | 4073 | 0.25 | 0.05 | 2829 | −0.48 | 0.50 | 322 | 0.79 | 1.06 | |
| Bottle water consumption | Less than 1 time per week | 344 | 1.00 | - | NA | 1.00 | - | 7379 | 1.00 | - | 1800 | 1.00 | - | 165 | 1.00 | - |
| 1-2 times per week$ | 152 | 0.76 | 0.66 | NA | NA | NA | 1834 | −0.13 | 0.08 | 377 | −0.20 | 0.25 | 0 | NA | NA | |
| More than 3 times per week$$ | 999 | −0.89 | 0.48 | NA | NA | NA | 6630 | −0.21 | 0.05 | 640 | −0.26 | 0.21 | 258 | 2.28 | 1.58 | |
| Alcohol (when pregnancy was known) | Never | 1269 | 1.00 | - | NA | 1.00 | - | 8018 | 1.00 | - | 278 | 1.00 | - | 347 | 1.00 | - |
| Former | 105 | 0.16 | 0.70 | NA | NA | NA | 7320 | 0.15 | 0.05 | 2599 | 0.57 | 0.30 | 43 | −1.04 | 1.38 | |
| Current | 283 | −0.13 | 0.46 | NA | NA | NA | 505 | 0.81 | 0.13 | 79 | 1.91 | 0.61 | 2 | NA | NA | |
| Chocolate consumption## | Less than 1 time per week | 212 | 1.00 | - | 196 | 1.00 | - | 2773 | 1.00 | - | 880 | 1.00 | - | 0 | 1.00 | - |
| 1-2 times per week | 174 | 0.39 | 0.71 | 173 | 0.20 | 0.43 | 4797 | −0.12 | 0.05 | 1244 | −0.19 | 0.20 | 0 | NA | NA | |
| More than 3 times per week | 1087 | −0.70 | 0.52 | 1472 | −0.52 | 0.32 | 8358 | −0.23 | 0.05 | 794 | −0.25 | 0.22 | 0 | NA | NA | |
| Works at home | No renovation of residential home+ | 887 | 1.00 | - | NA | 1.00 | - | 17044 | 1.00 | - | NA | 1.00 | - | 356 | 1.00 | - |
| Renovation of residential home++ | 616 | 0.33 | 0.35 | NA | NA | NA | 564 | 0.28 | 0.06 | NA | NA | NA | 16 | −3.22 | 2.20 | |
| Value | Value | Value | Value | Value | ||||||||||||
| Intercept (α) | 6.23 | 11.11 | 6.11 | 8.57 | 12.43 | |||||||||||
| R2 | 0.09 | 0.04 | 0.03 | 0.03 | 0.05 | |||||||||||
| R2 (adjusted) | 0.08 | 0.04 | 0.03 | 0.03 | 0.00 | |||||||||||
NA: not applicable
&
age (Germany)
*
from leaf (Japan)
**
green tea (China, Japan and Norway)
#
all types of water (Germany)
##
sweets including chocolate (Germany)
$
weekly (France)
$$
daily (France and China, except for coffee)
+
after becoming pregnant (Japan)
++
after becoming pregnant (Japan)