Can longtime breathing exposure (15 years +) to mold from bread cause cancer such as lymphoma? found in old backpack in a desk which was mostly closed

NO: Old Moldy bread in a back pack that was in a desk in a closed drawer wold not cause lymphoma.

Mold not cause: Everyone breathes mold spores. The amount inhaled from an old backpack in a drawer was probably a small exposure. Cancer Institute website identifies known risk, mold is not one of them: https://www.cancer.gov/about-cancer/causes-prevention/patient-prevention-overview-pdq#section/_199