Table 1. Maternal, paternal, and child characteristics by RF-EMF a .
RF-EMF exposure from base stations, age 5 | RF-EMF exposure from WiFi/cordless phones, age 5 | mobile phone owernership at age 7 | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Low | Medium | High | P-trend | both | WiFi no, CP yes | WiFi yes, CP no | neither | P-diff | no | yes | P-diff | |
Child characteristics | ||||||||||||
N | 1094 | 919 | 237 | 1607 | 438 | 158 | 108 | 2223 | 108 | |||
Age (years) | 7.4 | 7.4 | 7.4 | 0.68 | 7.4 | 7.4 | 7.3 | 7.5 | 0.03 | 7.4 | 7.6 | <0.001 |
Sex (% girls) | 50 | 47 | 52 | 0.94 | 50 | 46 | 46 | 44 | 0.24 | 48.6 | 49.1 | 0.928 |
Maternal characteristics | ||||||||||||
Age (years) | 39.7 | 39.8 | 39.6 | 0.55 | 40 | 39.7 | 38.6 | 37.5 | <0.001 | 39.8 | 38.6 | 0.006 |
Country of birth (% non Dutch) | 17 | 23 | 19 | 0.01 | 16 | 25 | 20 | 44 | 19 | 36.1 | <0.001 | |
Educational level (%) high | 74 | 69 | 77 | 78 | 62 | 65 | 46 | 73.5 | 41.7 | |||
medium | 19 | 20 | 13 | 17 | 25 | 22 | 27 | 18.9 | 27.8 | |||
low | 7 | 11 | 9 | 0.35 | 6 | 13 | 13 | 28 | <0.001 | 7.7 | 30.6 | <0.001 |
Paternal characteristics | ||||||||||||
Age (years) | 42.2 | 42.6 | 42.7 | 0.13 | 42.3 | 43.3 | 41.1 | 41.9 | 0.000 | 42.4 | 42.2 | 0.775 |
Country of birth (% non Dutch) | 21 | 25 | 24 | 0.10 | 18 | 32 | 31 | 51 | <0.001 | 21.8 | 49.5 | <0.001 |
Parental financial situation | ||||||||||||
A lot to spare | 27 | 26 | 30 | 31 | 18 | 22 | 14 | 27.5 | 12 | |||
A little to spare | 40 | 39 | 37 | 41 | 38 | 40 | 26 | 40.1 | 36.1 | |||
Just enough | 22 | 23 | 20 | 18 | 30 | 26 | 43 | 21.7 | 29.6 | |||
To use or dip into the savings | 5 | 5 | 7 | 6 | 5 | 3 | 6 | 4.9 | 8.3 | |||
To go into the red or into debt | 6 | 7 | 6 | 0.64 | 5 | 9 | 10 | 12 | <0.001 | 5.8 | 13.9 | <0.001 |
aValues are percentages for the categorical variables and arithmetic means for the continuous variables
CP: Cordless phone; P-diff = P-value for group differences based on chi-square or Kruskal-Wallis tests; P-trend = P-value for non-parametric test for trend