A study by the National Sleep Foundation reveals that unwashed pillowcases can harbor more bacteria than a toilet seat within just one week. Dirty pillowcases can expose you to harmful bacteria, fungi, and allergens, potentially causing skin irritation, respiratory problems, and infections. Regular washing of bedding is crucial for health and quality sleep.A study by the National Sleep Foundation reveals that unwashed pillowcases can harbor more bacteria than a toilet seat within just one week. Dirty pillowcases can expose you to harmful bacteria, fungi, and allergens, potentially causing skin irritation, respiratory problems, and infections. Regular washing of bedding is crucial for health and quality sleep.