Question

1 asbestos and lead have not been used in residential construction materials for decades. why are they still public health risks? asbestos and lead that have been removed from buildings leak into the groundwater. bad contractors still use these materials to construct homes and apartment buildings. many people live in older homes and apartment buildings that contain these materials. older people who were exposed to these substances can expose friends and family members

Explanation:

Asbestos and lead were commonly used in older construction. Even though their use has stopped, many older homes and buildings still have these materials. Exposure can occur during renovation, deterioration, etc. Bad contractors using them (if true) would be a new - use risk, but the more widespread and long - term risk is from existing structures. Removal - related groundwater leakage is a more limited pathway compared to the presence in buildings. And the risk from older people's past exposure (unless there is some unique transfer mechanism not in common knowledge) is less significant than the physical presence in buildings.

Answer:

Many people live in older homes and apartment buildings that contain these materials.