Which of the following locations is most at risk for lead exposure?

The location most at risk for lead exposure is homes built before 1978 with lead-based paint. This is due to the fact that lead-based paint was commonly used in residential properties until the U.S. Consumer Product Safety Commission banned its use in residential properties in 1978. In homes constructed before this year, there is a high likelihood that lead paint was applied to walls, doors, and other surfaces.

As the paint deteriorates over time, especially in older homes, it can create lead dust or peeling lead paint, both of which pose significant health risks, particularly to children and pregnant women. These populations are particularly vulnerable to the effects of lead exposure, which can result in a variety of health issues, including developmental delays and cognitive impairments. Therefore, homes built before 1978 are recognized as high-risk environments for lead exposure.

The other options present lower risks for lead exposure; for instance, newly constructed homes typically use modern materials and practices that are compliant with regulations against lead. Commercial buildings with modern paint similarly utilize contemporary materials that do not contain lead. Meanwhile, agricultural fields with chemical runoff may pose risks related to pesticides and other chemicals, but they are generally not associated with lead exposure specifically.