Developmental neurotoxicity of polybrominated biphenyls

Area of Science:

• Environmental Toxicology
• Developmental Toxicology
• Neurotoxicology

Background:

• Polybrominated biphenyls (PBBs) are persistent organic pollutants with known toxic effects.
• Exposure during critical developmental windows can lead to long-term health consequences.

Purpose of the Study:

• To investigate the developmental and neurobehavioral effects of PBB exposure in Sprague-Dawley rats.
• To assess PBB toxicity across maternal and offspring generations.

Main Methods:

• Pregnant rats received daily oral doses of PBB (0, 0.2, or 2 mg/kg) from gestation day 6 to postpartum day 24.
• Maternal parameters, offspring growth, survival, and physical/behavioral development were evaluated.
• Neurobehavioral assessments included locomotion, cliff avoidance, cage emergence, and open-field activity.

Main Results:

• No adverse maternal effects or impact on offspring survival/developmental landmark acquisition were observed.
• Significant growth retardation (reduced crown-rump length and weight gain) was noted in male and female offspring exposed to 2 mg/kg PBB.
• Significant neurobehavioral effects, including delayed locomotion and suppressed open-field activity, were observed in offspring from dams receiving 2 mg/kg PBB.

Conclusions:

• Prenatal and early postnatal PBB exposure can cause growth retardation and neurobehavioral toxicity in offspring.
• Observed effects occurred at PBB concentrations in offspring body fat similar to those in highly exposed humans with neurological sequelae.
• These findings highlight the potential risks of PBB exposure during development.