Question

why is hazardous waste a concern?

because it is very easy to handle and dispose of

because it is easy to recycle and reuse in factories

because it is a risk to humans and the environment

Explanation:

Hazardous waste is dangerous. It can harm humans (e.g., through exposure causing illness) and the environment (e.g., polluting soil, water). Handling and disposal are complex (not easy), and recycling/reusing is often difficult due to its hazardous nature. So the key reason it's a concern is its risk.

Answer:

because it is a risk to humans and the environment