The low cost of production and the widespread use of plastics has brought about a problem that is difficult to measure; microplastics are considered emerging pollutants because their presence can pose a risk to the environment. This study focuses on the characterization of microplastics (MPs) in the nesting area of green (Chelonia mydas) and Kemp’s ridley (Lepidochelys kempii) sea turtles, on the coastal municipalities of Nautla and Vega de Alatorre, Veracruz, Mexico. Five beaches along 15.5 km of coastline were analyzed and samples were taken in the intertidal zone. In this work, only microplastics in sizes from one to five mm were analyzed. A characterization of the potential sources of microplastics at the basin level was carried out and 94% of the samples analyzed presented MPs, the greatest amount was at site Playa Navarro (B32) (1.2 Item/kg dw), and in the high tide zone (4.86 ± 2.79 Item/kg dw). The predominant color of the MPs was white (42%), the most representative form were fragments (31%), while most of the MPs presented sizes of 4–5 mm (35%) followed by 1–2 mm (34%). The chemical composition of most of the MPs was polyethylene (55%). Regarding the sources of the MPs generation, livestock, agriculture, fishing, tourism, wastewater discharges, urban solid waste and, to a lesser extent, the plastic industry were identified. The mobilization factors of the MPs turned out to be the Colipa and Misantla rivers with runoff from the basin, wind, waves and marine currents.

Oil activity has generated severe problems of soil contamination. Different techniques have been employed for the removal of pollutants, which are mainly used separately as treatments, but if combined, removal could be improved. The aim of this study was to remove total petroleum hydrocarbons (TPH) from soil artificially contaminated with crude oil using Fenton oxidation followed by biostimulation with nutrients and oil palm bagasse (OPB) used as an amendment. Microcosm units of soil with hydrocarbons were treated with H₂O₂ and Fe citrate at 30% humidity and 25 °C. Samples were taken at 0, 10, and 30 days. Each unit was then adjusted to a C:N:P ratio of 100:10:1, which is considered optimal for remediation of soils contaminated with petroleum hydrocarbons, and mixed with OPB at a ratio of 96:4, 30% humidity, and 25 °C. Samples were taken at 0, 10, 30, and 40 days. Physicochemical parameters, TPH, microbial population, and lipase and dehydrogenase activity were monitored. Slight TPH removal (20.3%), a decrease in enzymatic activities, and a reduction in bacterial population were observed with Fenton oxidation. In the case of the biostimulation-amendment treatment, TPH removal was of 55%, with an increase in enzymatic activities and microbial population.