Pollution caused by synthetic detergents and its minimisation: Detergents having highly branched hydrocarbon chains are not biodegradable. The reason being that side-chains stop bacteria from attacking and breaking the chains. . Such detergents are therefore accumulated in rivers and ponds and make the water polluted. Since unbranched hydrocarbon chains are easily attacked by bacteria, therefore, in most of the detergents used these days, the branching of the hydrocarbon chain is kept to a minimum so that detergents become easily biodegradable and hence pollution is prevented.