What is the most likely cause of lead poisoning in a child admitted to the pediatric unit?

The most likely cause of lead poisoning in a child is often associated with exposure to old, collectible toys, especially those manufactured before certain regulations came into effect. Many older toys are painted with lead-based paint, and children frequently put toys in their mouths, increasing the risk of lead ingestion. The paint can deteriorate over time, creating dust or small chips that can be ingested or inhaled. Collectible items may be more at risk due to their age and potential use of lead in their manufacturing process, which was more common prior to the ban on lead in paint.

While other sources, such as contaminated water, soil, or newly painted houses, can also be contributors to lead exposure, the specificity and direct correlation of lead in old toys to childhood lead poisoning make this the most likely cause. Additionally, many residential buildings built before 1978 may contain lead-based paint, yet the prevalence of leaded toys, particularly ones that might be popular for play and less regularly monitored for safety, stands out as a significant risk factor.