pollution occurs when\no there is too much of any substance.\no a harmful substance is detected.\no harmful…

pollution occurs when\no there is too much of any substance.\no a harmful substance is detected.\no harmful substances build to unhealthy levels.\no too many people handle the substances.

pollution occurs when\no there is too much of any substance.\no a harmful substance is detected.\no harmful substances build to unhealthy levels.\no too many people handle the substances.

Answer

Answer:

C. harmful substances build to unhealthy levels.

Brief Explanations:

Pollution is defined as the presence or introduction into the environment of harmful substances at levels that can cause damage, which means harmful substances building to unhealthy levels.