-- What are the hidden costs of laundry? --
Well, aside from the obvious costs including detergents and dryer sheets... and their packaging... and the energy used to power the machines - laundry can have some hidden costs to the environment as well.
Choice of fabric can play a role on the impact on the environment. Synthetic fabrics release tiny plastic fibers that end up in the ocean. So do bits of plastic pellets (used in paint removals, skin cleansers...) and these types of 'microplastic' fibers end up polluting marine environments, where it can act like a sponge - absorbing other pollutants, and once ingested by marine life, these toxic-laden fibers may very well cause genetic mutations, diseases and other changes.