Microplastics and human health

This research aims to provide evidence-based recommendations to mitigate the adverse health effects of NPs, thereby informing future regulatory and policy decisions.

[9] The major pathways of human exposure to MNPs are ingestion, inhalation, and dermal contact, with bioaccumulation varying based on particle size, composition, and physicochemical characteristics.

Studies show that MNPs are detected in a variety of consumables, including drinking water,[14][15] beer,[16] honey, sugar,[17] table salt,[18][19] and even airborne particles that settle on food.

Fish, bivalves, and other seafood are frequently contaminated with MNPs ingested through water and food, and humans consuming these animals are thus directly exposed to MPs embedded in tissue.

[13] Contamination is further compounded by plastic packaging and storage materials, which can leach MNPs over time, leading to additional ingestion from common foods and drinks.

A 2022 study[34] detected MPs smaller than 5 mm in 75% of analyzed breast milk samples, raising concerns about infant exposure during critical developmental windows.

For some native population in North Canada and people who live near industrial factories, it is sometimes suggested by pediatricians that mothers not nurse their children,[37] over fear of ingestion of MPs and other potentially harmful chemicals.

Studies on dermal exposure highlight the potential for these particles to enter systemic circulation, especially if the skin barrier is disrupted by wounds or conditions that increase permeability, like pores such as sweat glands and hair follicles.

[10] Inhalation is a critical but understudied route of MNP exposure, with airborne MNPs originating from urban dust, synthetic fibers from textiles, rubber tires, and household plastic items.

[43][10] These airborne particles may become suspended in the air due to wave action in aquatic environments or the spread of wastewater treatment sludge on agricultural fields.

[4] Annual inhalation exposure rates are estimated at around 39,000–52,000 MP particles, with studies highlighting the significant contributions from synthetic textiles and urban dust sources.

[6] These findings collectively suggest that MNPs may accumulate in multiple organ systems depending on the exposure route, potentially leading to long-term health consequences as their presence in human tissues becomes more pervasive over time.

The potential health impacts of MPs vary based on factors, such as their particle sizes, shape, exposure time, chemical composition (enriched with heavy metals, polycyclic aromatic hydrocarbons [PAHs], etc.