Table 1 The connection between plastic trash discarded into the environment and human exposure to MNP, toxic additives and contaminants to plastic

A

Plastic pollution can be seen in landfills of plastic trash, as well as in piles of trash thrown in public spaces such as parks, beaches and nature preserves. The plastic trash gradually disintegrates, until it breaks down into MNP which pollute the atmosphere and contaminate the air we breathe. Other causes of the release of MNP into the atmosphere are more subtle: MNP created by abrasion of tires on roads, released into the atmosphere by ocean spray [20], fragmentation of synthetic grass [41, 42] and fragmentation of crumb rubber [43]

B

Plastic trash thrown into public spaces also enables leaching of toxic chemicals from the plastic into the ground, and from there into ground water, often used as a source of drinking water [144]. It has recently been documented that NP can migrate through soil to underground water sources, adding a new cause for concern [145]

C

Environmental plastic pollution causes fish, shellfish and marine salt to become contaminated with MNP and toxic chemicals. These enter the global food chain, and, if ingested by people, can have adverse effects on our health [146, 147]

D

The high levels of plastic pollution from SUPs indicate that much plastic is being produced in an unstainable way—Use Once and Throw Away. The cumulative amount of plastic produced since the first synthesis of plastic is estimated at 9.5 billion tons as of 2019 and predicted to increase to 34 billion tons by 2050 [148], of which most is buried in landfills, found in the depths of the ocean, or dispersed in aqueous environments, the air and land as fragmented plastic, including MNP. The rapidly growing plastic industry is highly energy-dependent and contributes significantly to global warming by its emission of greenhouse gases (GHG) [149]