Which of the following is a source of lead contamination in yards and playgrounds?

The presence of lead in yards and playgrounds is a significant concern, particularly in areas where older homes and buildings were painted with lead-based paints. Over time, this paint deteriorates, and the resulting dust can accumulate in the surrounding soil and outdoor spaces, including yards and playgrounds. This paint dust becomes a source of lead contamination when it is disturbed, making it accessible to children who play in these environments.

Lead exposure poses serious health risks, especially to young children, including developmental delays and other long-term health issues. Therefore, it is crucial to recognize paint dust as a primary contributor to lead contamination outside of homes, especially given the prevalence of older buildings in many communities where lead-based paints were commonly used.

The other options do not represent meaningful sources of lead contamination. Natural soil erosion typically does not have lead unless the soil itself is contaminated by other means. Animal droppings might contain harmful substances, but lead is unlikely to be one of them unless the animals have consumed lead-based materials, which is uncommon. Plastic waste generally does not contain lead, and while it can be an environmental concern, it does not contribute to lead contamination in the context being discussed.