effect (n)

The radiation leak has had a disastrous effect on/upon the environment.
I tried taking tablets for the headache but they didn't have any effect.
I think I'm suffering from the effects of too little sleep.
The new law had a positive effect on reducing air pollution in the city.
The medication had a calming effect on the patient's anxiety symptoms.
The economic downturn had a cascading effect on various industries, leading to layoffs and reduced consumer spending.
The teacher's encouragement had a lasting effect on the student's confidence and academic performance.