A lot of plastic is used in agriculture it breaks down in the sunshine and gets into everything even I know this and I'm just the best golfer!

Also « some pesticides used in food production may contain plastic. Pesticides are chemical substances used to protect plants from pests and diseases. Some of these substances may be formulated with additives that include plastic-like materials to improve their effectiveness and durability.»

Airborne microplastics settle on fruit and vegetables. Animals sweat and move around so the plastic is not just sitting on their skin. But yes animals actually have microplastics in their flesh rather than just sitting on their skin like with plants