Figure 2.

Pathways of human exposure to microplastics mainly include ingestion, inhalation, and dermal contact. Ingestion is the most important route of exposure, and dermal contact is considered the least important route of exposure. For example, micro- and nanoplastics in salt, commercial fish, bottled water, and canned food can enter the human body through ingestion, those in floating fibers and dust in the air can enter the human body through inhalation, and those in toothpaste and skin-cleaning products can enter the human body through skin contact.