The Bhopal gas tragedy in $1984$ was caused by the leakage of which gas?

Brewery and sugar factory waste alters the quality of a water body by increasing

Due to the attack of fumes of sulphur dioxide and sulphuric acid,the marble of the Taj Mahal and the red stone of the Red Fort changed into calcium sulphate,which causes:

What does '$X$' represent in the given figure?

$DDT$ residues are rapidly passed through food chains causing biomagnification. What is the reason for this?

Differentiate between biodegradable pollutants and non-biodegradable pollutants.