Children and PCBs
How Behavioral Effects Are Measured in Infants and Children

Major sources of PCB exposure in children include eating contaminated food, drinking contaminated water, and breathing contaminated air near some hazardous waste sites or in buildings with old electrical appliances that use PCBs. PCBs accumulate in pregnant womens' bodies and are released during pregnancy, passing through the placenta, and thus exposing fetuses in utero. Infants may also be exposed through nursing; because PCBs dissolve in fat, they can accumulate in the mothers' breast milk and be transferred through breastfeeding. 

Adverse effects in infants and children include:

• low birth weight
• shorter gestational period
• smaller head size

abnormal neurodevelopment (e.g., abnormal reflexes, motor immaturity, permanent  learning disabilities, mental retardation, impaired cognitive skills, problems with memory, and depressed responsiveness) 
 increased hyperactivity)
immunologic effects (e.g., less wheezing, fewer allergic reactions, higher prevalence of recurrent middle ear infections, and higher prevalence of chicken pox)
problems with thyroid function
facial abnormalities
birth defects

How Behavioral Effects Are Measured in Infants and Children

Some of the tests used to measure infant/child behavioral effects are the Fagan Test of Visual Recognition (also known as the Fagan Test of Infant Intelligence), Bayley Scales of Infant Development, Wechsler Intelligence Scale for Children-Revised (WISC-R), and Neonatal Behavioral Assessment Scale (NBAS). 
The Fagan test involves showing an infant or child two identical photos of human faces for about 20 seconds, then changing one of the photos for a new one and presenting the new combination of photos. Normal babies spend more time looking at the photo of the new face. Children with memory problems cannot remember the first two photos well enough to recognize that the second two photos are different.

The Bayley test is a standardized test gauging small children's development
(children aged 1 month to 3.5 years). It includes a mental development index (MDI) and a psychomotor development index (PDI). MDI measures memory, the ability to solve simple problems, and language capabilities. PDI measures body control, coordination, and fine motor movement. Both indexes are scaled like a standard intelligence quotient (IQ) test.

The Wechsler Intelligence Scales for Children-Revised (WISC-R) measures verbal and nonverbal performance skills.

The Neonatal Behavioral Assessment Scale measures behavioral development. The scale evaluates 28 behavioral and 18 reflex items (e.g., assessing an infant's reactions to a variety of stimuli, such as a light in the eyes, a rattle, or a moving ball).