Field evidence for transfer of plastic debris along a terrestrial food chain

Although plastic pollution happens globally, the micro-(<5 mm) and macroplastic (5-150 mm) transfer of plastic to terrestrial species relevant to human consumption has not been examined. We provide first-time evidence for micro-and macroplastic transfer from soil to chickens in traditional Mayan home gardens in Southeast Mexico where waste mismanagement is common. We assessed micro-and macroplastic in soil, earthworm casts, chicken feces, crops and gizzards (used for human consumption). Microplastic concentrations increased from soil (0.87 +/- 1.9 particles g(-1)), to earthworm casts (14.8 +/- 28.8 particles g(-1)), to chicken feces (129.8 +/- 82.3 particles g(-1)). Chicken gizzards contained 10.2 +/- 13.8 microplastic particles, while no microplastic was found in crops. An average of 45.82 +/- 42.6 macroplastic particles were found per gizzard and 11 +/- 15.3 macroplastic particles per crop, with 1-10 mm particles being significantly more abundant per gizzard (31.8 +/- 27.27 particles) compared to the crop (1 +/- 2.2 particles). The data show that micro-and macroplastic are capable of entering terrestrial food webs.