Nationwide Assessment of Microplastic Contamination and Polymer Risk Indices in Brazilian Coastal Sands (2023–2024)

This dataset compiles georeferenced information on microplastic (MP) contamination in beach sands sampled across the Brazilian coastline between 2020 and 2024, as part of the MicroMar Project. The dataset includes 4,000+ sampling points distributed along 1,000 beaches, representing all coastal states of Brazil. For each sample, metadata include geographic coordinates (longitude and latitude), sample identification code, state, municipality, and beach name. Quantitative data comprise microplastic concentrations normalized by dry sand mass (MPs_kg, particles per kilogram), as well as three synthetic environmental risk indices: the Polymer Load Index (PLI), Polymer Hazard Index (PHI), and Pollution Ecological Risk Index (PERI). These indices were calculated from polymer composition and hazard weighting following established frameworks. This dataset provides a baseline for assessing spatial patterns, polymer-specific risks, and regional drivers of microplastic pollution in Brazilian coastal ecosystems. It supports national and international research efforts on marine litter and coastal contamination.