What is an "algal bloom"? State its cause and any two harmful effects.

State any two harmful effects of acid rain.

What are algal blooms? How are they formed? Give two harmful effects of formation of algal blooms in an aquatic body.

Algal blooms in water bodies cause

State one use and one harmful effect of radioactivity.

What is Acid rain ? What are its harmful effects ?

Which of the following metals causes harmful effects?

State the cause of increase of green house effect.

What are harmful effects of sewage?

What is smog ? State its damaging effects.

What is hypertension? What are its causative factors ?