1. (a) the environmental impact can control or fix because the danger is caused by not wearing a helmet is not pollution, it can destroy the environment.
1 (a) little environmental impact. Can be controlled or modified because of the danger that would result from not wearing a helmet is not a pollutant that can damage the environment.
1 (little) environmental impact a little control or edit it. Because danger happens from not wearing a helmet the pollution that can destroy the environment.