Developmental effects associated with exposure to xylene: a review

Area of Science:

• Toxicology
• Developmental Biology
• Environmental Health

Background:

• Xylene exposure during pregnancy is a concern due to potential adverse effects on fetal development.
• Rodent studies provide valuable insights into the toxicological profiles of xylene isomers and mixtures.

Purpose of the Study:

• To evaluate the fetotoxic and teratogenic potential of maternal exposure to mixed xylenes and individual xylene isomers in rodents.
• To determine if xylene exposure causes specific malformations, such as cleft palate.

Main Methods:

• Rodents were exposed to mixed xylenes or individual isomers (o-, m-, p-xylenes) via inhalation, dermal application, or oral administration.
• Fetuses were examined for signs of toxicity, including mortality, growth inhibition, malformations, and altered enzyme activities.

Main Results:

• Maternal xylene exposure led to fetotoxic effects, including prenatal mortality, growth retardation, and altered fetal enzyme activities.
• Oral exposure to mixed xylenes was associated with malformations, primarily cleft palate.
• Inhalation of individual isomers caused similar effects, except for cleft palate.
• The o- and p-isomers appeared more hazardous than the m-isomer.
• Malformations were generally observed at maternally toxic doses.

Conclusions:

• Maternal xylene exposure poses risks to conceptus development in rodents.
• While certain malformations like cleft palate were observed, a selective teratogenic effect of xylene has not been conclusively established.
• The findings highlight the importance of considering maternal toxicity when assessing developmental risks of chemical exposures.