Effects of concrete and wood building environments on pregnant dams and embryo-fetal development in rats

We have recently reported that the continuous exposure of rats to a concrete building environment under cool temperatures had adverse effects on general health parameters and embryo-fetal development. This study examined to compare the potential effects of concrete and wood building environments on pregnant dams and embryo-fetal development in rats. Groups of 10 mated females were exposed to polycarbonate (control), concrete, or wood cages from gestational days (GO) 0 to 20 under cool temperatures (11.9-12.3°C). All the females underwent a caesarean section on GO 20, and their fetuses were examined for any morphological abnormalities. The temperatures in the cages were similar in all groups but the relative humidity in the concrete and wood groups were higher than in the control group. The concentration of volatile organic compounds in the wood group was higher than in the control group. In the concrete group, maternal effects manifested as an increase in the incidence of clinical signs, a lower body weight, and a decrease in the thymus and ovary weights. Developmental effects included increased post-implantation loss and decreased litter size. Infrared thermal analysis showed that the skin temperature of the rats in the concrete group was lower than that in the control group. In contrast, there were no exposure-related adverse effects on the maternal and developmental parameters in the wood group. Overall, the exposure of pregnant rats to a concrete building environment under cool temperatures has adverse effects on the clinical signs, body weight, skin temperature, organ weight, and embryo-fetal development. On the other hand, exposure to a wood building environment does not have any adverse effects in rats.