Subacute toxicity evaluation in rats exposed to concrete and hwangto building environments.

This study examined the potential adverse effects of the subacute exposure of rats to concrete and hwangto building environments. Polycarbonate was used as a comparison. Groups of 10 male rats were exposed to polycarbonate, concrete, or hwangto cages for a 4-week period in summer or winter. During the study period, the clinical signs, mortality, skin temperature, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were examined. The concentration of total volatile organic compounds (VOCs), temperature, and relative humidity in the each cages were also measured. There were no exposure-related effects in any group of the study examined in the summer. The temperature, relative humidity, and the concentration of VOCs in the cages were similar in all groups. However, in the winter study, significant differences in several parameters were detected among the groups. In the concrete group, there was an increase in the clinical signs, a reduction in the body weight gain, food intake, and liver weight, an increase in the lung weight, and an increase in the histopathological alterations in the lung and thymus. Infrared thermal analysis showed that the skin temperature of the rats in the concrete group was lower than that in the polycarbonate group. However, in the hwangto group, there was a decrease in the clinical signs and an increase in the body weight, food intake, and the weights of the heart, lung, spleen, and epididymides. Overall, the 4-week exposure of the rats to the concrete building environment had adverse effects on the clinical signs, skin temperature, body weight, and some organs in the winter but not in the summer. On the other hand, the exposure of hwangto building environment did not have any exposure-related adverse effects on the general health parameters and skin temperature in rats.