Formaldehyde vapour effects in chicken embryo

A total of 763 fertile chicken eggs were divided in two groups. The eggs of the first group were manipulated intact. The shell of each egg of the second group was drilled at the air chamber position. The eggs of both groups were divided in 6 subgroups and they were placed in an automatic incubator. Between the second and the fourth day of incubation each subgroup of eggs was moved to another incubator saturated with formaldehyde vapour, and it was exposed for a certain time. The hatched chicks were examined, measured, and processed, in order to search for any external, visceral, and skeletal malformation. Although the chicks of the first group did not show any particular abnormalities after their exposure to formaldehyde vapours, those of the second group were found to be affected in a rate of about 29:100. The observed embryotoxic effects of the hatched chicks of the second group were mainly early and late prenatal deaths, extensive and limited congenital anomalies as well as reduction deformities.