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.

The Port of Veracruz, the main port in the Gulf of Mexico, has experienced a significant increase in its import and export operations, such as petroleum coke (Petcoke), a solid waste, mainly used in the steel industry. During the period of 2010–2023, approximately 7,401,594 tons of coke were stored outdoors, generating PM₁₀ particulate emissions due to wind erosion. These particles were dispersed to urban areas, reaching an estimated total emission of 5077 tons. The study used geospatial analysis and environmental modeling tools (ALOHA^®) to evaluate the dispersion and concentration of PM₁₀ in the atmosphere, comparing them with the limits established by the Mexican Official Standard NOM-025-SSA1-2021. The results indicate that in years with high port activity, such as 2014, PM₁₀ concentrations exceeded the normative values, representing a potential risk to public health and urban infrastructure. This study provides critical evidence on the environmental impacts of coke handling in ports and suggests mitigation strategies, including processes for the confinement of materials and the implementation of advanced emissions monitoring systems.