harmful, damaging
Fumar es dañino para la salud.
Smoking is harmful to your health.
El sacerdote dijo que este libro podría ser dañino para la juventud.
The priest said that this book could be harmful to young people.
Beber es dañino para tu salud.
Drinking is harmful to your health.
Este libro no sólo es inútil sino incluso dañino.
This book is not only useless but even harmful.