I do not have a point that needs sourcing. The article quite simply does not discuss other sources of microplastics. It does not dismiss them either.

edit: Allow me to elaborate a little less formally. OP’s initial comment straight up sounds like whatabaoutism by Big Bottled Water. It dismisses the microplastics in water bottles, pointing to other sources of microplastics. OP then claims that the article dismisses other sources, failing to provide any relevant quotes. Have I gone insane?