Table 5.
Maternal exposure to background pollutants and BETX
| Total study sample | Non-smoking mothers with BETX assessment | |||||
|---|---|---|---|---|---|---|
| Mean ± SD (μg/m3) | NO2 | PM10 | Benzene | Toluene | Ethylbenzene | Xylenes* |
| Window of exposure time | n = 370 | n = 56 | ||||
| Before pregnancy | ||||||
| 3 months bf | 27.6 ± 13.0 | 22.0 ± 6.7 | ||||
| During pregnancy | ||||||
| 1st trimester | 28.2 ± 12.7 | 21.8 ± 5.8 | ||||
| 2nd trimester | 28.2 ± 11.3 | 21.8 ± 5.2 | 3.3 ± 2.0 | 41.5 ± 16.5 | 5.1 ± 2.0 | 23.3 ± 8.7 |
| 3rd trimester | 26.7 ± 12.1 | 21.9 ± 6.4 | ||||
* Sum of o-xylene, m-xylene and p-xylene. SD, standard deviation; bf, before; BETX, benzene, ethylbenzene, toluene, xylenes.