Flow diagram to illustrate the potential human health effects of microplastics. Dotted lines represent current speculative research. (1) Latini et al. (2003), (2) Peretz et al. (2014), (3) Ait Bamai et al. (2014b), (4) Gasperi et al. (2018) (5) Tang et al. (2020), (6) Valavanidis et al. (2013), (7) Prata (2018), (8) Gallagher et al. (2015), (9) Lu et al. (2016), (10) Qiao et al. (2019), (11) Li et al. (2020a, b), (12) Morris and Acheson (2003), (13) Kirstein et al. (2016), (14) Yang et al. (2019a), (15) Lu et al. (2019)