Water-borne diseases, including cholera, typhoid, and dysentery, are caused by drinking water containing infectious viruses or bacteria, which often come from human or animal waste. Water-washed diseases, such as skin and eye infections, are caused by lack of clean water for washing.
An interaction wherein both species are harmed is called competition. They are competing for nutrient/habitat.
Some man-made fibres, too, are derived from naturally occurring polymers. For instance, rayon and acetate, two of the first man-made fibres ever to be produced, are made of the same cellulose polymers that make up cotton, hemp, flax, and the structural fibres of wood.
