Final answer:
The 2-year-old child is at the greatest risk for poisoning due to their curiosity, mobility, and tendency to explore the world orally without the ability to discern harm.
Step-by-step explanation:
The nurse recognizes that a 2-year-old child is at the greatest risk for poisoning. This age group is particularly curious and has developed enough mobility to access various substances but lacks the ability to recognize danger. Additionally, developmental milestones reveal that children at this age frequently explore their environment by putting objects in their mouths, which increases the risk of ingesting harmful substances.
Younger infants, while also placing objects in their mouths, are usually less mobile and more closely supervised, which often reduces their exposure to potential poisons. Older children have typically begun to understand the dangers of certain substances and are less likely to ingest them mistakenly.
According to the Centers for Disease Control and Prevention (CDC), there is a concern about lead poisoning in children, especially between the ages of one and five. Considering that children at two years of age are at a peak of exploring their environment orally and still developing cognitive abilities to discern harmful items, this makes them particularly vulnerable to poisoning hazards.