Nomura T, Tanaka S, Kurokawa N, Shibata K, Nakajima H, Kurishita A, Hongyo T, Ishii Y
Department of Radiation Biology, Faculty of Medicine, Osaka University, Japan.
Mutat Res. 1996 Jul 10;369(1-2):59-64. doi: 10.1016/s0165-1218(96)90048-8.
Urethane (ethyl carbamate) which has long been used for commonly used drugs and has proven to be useful in the formation of products in every-day use, is volatile, and small amounts sublime spontaneously. Pregnant ICR mice were maintained in the vinyl chamber (45 liter) which was ventilated 4 times per hour. To inhale urethane gas, air was passed first through a glass bottle containing 500 g of crystalline urethane and then into the vinyl chamber. Concentration of the sublimed urethane gas in the chamber was 1.28 +/- 0.08 mg/l, and sublimed urethane gas produced significantly high incidence of chromosomal aberrations in the cells of whole embryo, when mice inhaled it for 48 h from day 9 to day 11 of pregnancy. High and significant incidence of chromosomal aberrations (36.0%) was detected in the embryo 3 h after urethane gas inhalation, but decreased to 5.3% at 24 h after exposure and showed no significant differences from controls after 48 h, while the incidence in bone marrow cells from the adult (pregnant) mice was lower (21.5%) at 3 h after exposure but a significant increase remained until 72 h after exposure. A majority of chromosomal aberrations was chromatid types. As a consequence of cellular damages by urethane gas inhalation during pregnancy, significantly high incidence of fetal deaths and congenital malformations (cleft palate, polydactyly, tail anomaly etc.) was induced in the offspring. Thus, we must be aware of the risk of volatile chemicals, because it is difficult to perceive and avoid hazardous exposure via respiration.
长期以来一直用于常用药物且已被证明在日常用品生产中有用的氨基甲酸乙酯（尿烷）具有挥发性，少量会自发升华。将怀孕的ICR小鼠饲养在每小时换气4次的乙烯基饲养箱（45升）中。为了让小鼠吸入氨基甲酸乙酯气体，空气先通过一个装有500克结晶氨基甲酸乙酯的玻璃瓶，然后进入乙烯基饲养箱。饲养箱中升华的氨基甲酸乙酯气体浓度为1.28±0.08毫克/升，当小鼠在怀孕第9天至第11天吸入该气体48小时后，升华的氨基甲酸乙酯气体在全胚胎细胞中产生了显著高的染色体畸变发生率。在吸入氨基甲酸乙酯气体3小时后，胚胎中检测到高且显著的染色体畸变发生率（36.0%），但在接触后24小时降至5.3%，48小时后与对照组无显著差异，而成年（怀孕）小鼠骨髓细胞在接触后3小时的染色体畸变发生率较低（21.5%），但直到接触后72小时仍有显著增加。大多数染色体畸变是染色单体类型。由于孕期吸入氨基甲酸乙酯气体造成细胞损伤，后代中胎儿死亡和先天性畸形（腭裂、多指、尾巴异常等）的发生率显著升高。因此，我们必须意识到挥发性化学物质的风险，因为通过呼吸很难察觉和避免有害暴露。
