The major cause of lead poisoning in children is primarily due to which of the following?

The major cause of lead poisoning in children is primarily due to inhaling lead-contaminated household dust. This dust can originate from lead-based paint that deteriorates over time, particularly in older homes built before 1978 when lead-based paints were commonly used. Children are particularly vulnerable because they frequently engage in behaviors such as crawling and playing on the floor, where lead dust can accumulate.

When children inhale or ingest this contaminated dust, it can lead to significant health issues, as even low levels of lead exposure can adversely affect a child's development, learning, and behavior. Moreover, lead can also be absorbed through the skin, but inhalation of dust is often considered a more significant pathway due to how widespread and easily accessible it is in a home environment where lead-based paint was used.

Other options may contribute to lead exposure as well, but the dust presents a more pervasive risk, especially in settings where children frequently play or spend time. Lead-contaminated food is less common, as food sources are typically monitored for lead levels. Similarly, while putting dirty fingers into their mouths can be a potential exposure route, it is often the presence of household dust that presents the most consistent and significant source of lead for young children.