Attention Deficit Hyperactivity Disorder (ADHD) Practice Test

The association between lead exposure and an increased risk of developing Attention Deficit Hyperactivity Disorder (ADHD) is well-documented in research. Lead is a neurotoxin that can adversely affect brain development, particularly in children. Exposure to lead, whether through contaminated water, old paint, or other sources, can interfere with neurological functioning, leading to cognitive deficits and behavioral issues that resemble ADHD symptoms. Studies have shown that even low levels of lead exposure can have significant detrimental effects on a child's attention span, impulse control, and overall behavior.

In contrast, factors such as regular exercise, a healthy diet during pregnancy, and a stable home environment have been associated with a lower risk of ADHD. Regular physical activity and a nutritious diet can contribute positively to brain health, while a stable and supportive home environment helps to foster emotional and psychological well-being. Thus, lead exposure stands out as a risk factor that directly correlates with the onset of ADHD symptoms, making it the correct answer.