Effects of microplastics and nanoplastics on agricultural plants

Mikroplastika je globalno prisutna u poljoprivrednim tlima. Jednokratni plastični materijali za prekrivanje tla, primjena otpadnog mulja kao dodatka gnojivima i navodnjavanje su glavni izvori mikroplastike u poljoprivrednim tlima. Prisutnost mikroplastike u tlu uglavnom smanjuje kapacitet tla za vodu, a biljke koje rastu u tlu zagađenom mikroplastikom i nanoplastikom većinom imaju smanjen rast, dolazi do oksidacijskog stresa i smanjena im je klijavost sjemena. Mikroplastika vrlo malih dimenzija i nanoplastika mogu ulaziti u korijen i listove biljaka, akumulirati se u provodnim elementima i prenositi u druge dijelove biljke. Vršak korijena te mjesta ozljeda i odvajanja bočnog korijenja su kritična mjesta ulaska plastike u korijen. Dodatan izvor zagađenja predstavljaju aditivi prisutni u plastici koji se otpuštaju iz plastike u okoliš. Nadalje, mikroplastika može adsorbirati teške metale u tlu i smanjiti njihovu biološku dostupnost. Prisutnost mikroplastike i nanoplastike u jestivim dijelovima biljaka ukazuje na potrebu daljnjeg istraživanja njihovog učinka, ne samo na poljoprivredne prinose nego i na ljude i životinje koji konzumiraju biljke izložene plastici.Microplastics are present in agricultural soils worldwide. Single-use plastic mulch films, sewage sludge used as supplement to fertilisers and irrigation are the largest sources of microplastics in agricultural soils. The presence of microplastics in soil generally reduces the water capacity of the soil, and plants growing in soils contaminated with microplastics and nanoplastic generally have reduced growth, experience oxidative stress, and have reduced seed germination rates. Nanoplastics and very small microplastics can enter plant roots and leaves, accumulate in transport elements, and translocate to other plant organs. Root tips, wounds, and sites where lateral roots emerge are the most critical points for uptake of plastics into roots. Additives present in plastics can leach into the environment and also pose a pollution risk. In addition, microplastics can adsorb heavy metals, and reduce their bioavailability. The presence of microplastics and nanoplastics in edible parts of commonly consumed plants indicates the need for further research on the effects of these substances, not only on agricultural yields, but also on humans and animals that consume plants contaminated with plastics