Question

why do we need to observe health and safety measures in planting trees/seedlings?

Answer 1

You also keep dirt, fertilizer, grass and other potential irritants away from your body. Shoes with closed toes prevent injury to your feet from shovels or other implements used while planting.

because the plant you are going to grow maybe helpful to animals or other living organism.. and if they cause any harm in their body then there can be a problem also..