Although the origin and manifestation of developmental disabilities and adverse health effects reflect complex interactions among many factors, the role of the environment cannot be ignored. Environmental health scientists have long established that the developing nervous system is particularly vulnerable to environmental pollutants. Many substances easily penetrate the placenta during prenatal development, and because the fetal blood-brain barrier is not fully formed, toxicants can enter and impact brain development through direct toxicity or through altering critical regulatory systems in the body. In addition, environmental chemicals can interfere with fetal development by disrupting the growth of the placenta and affecting the transfer of nutrients from the placenta to the fetus.
This may result in genetic damage, which when acquired during the fetal period have the potential to have long term effects than those acquired later in life. They are less capable than adults are of detoxifying harmful substances and repairing damage as their biological defense mechanisms are still forming.
Young children also engage their environments differently than adults; they eat more, drink more, and breathe more than adults in proportion to their body weight. They place things in their mouths and play on the ground, thus increasing their exposure. Therefore, it is imperative that interventions are conducted in the earliest stages of a child’s life, in order to prevent the developmental and health deficits that our research has linked to common environmental hazards.