Biophysical matter in a marine estuary identified by the Sentinel-3B OLCI satellite and the presence of terrestrial iron (Fe) nanoparticles

Highlights: • Identification of elements present in water by unpublished satellite images • Nanoparticles frequently occur in natural media and may control key biogeochemical developments. • Sediments contained rather several iron nanoparticles containing potential hazardous elements. • There was human health risks associated to the presence of iron nanoparticles on suspended sediments. The analysis of marine matter using the Sentinel-3B OLCI (Ocean Land Color Instrument) satellite is the most advanced technique for evaluating: the absorption of colored detrital and dissolved material (ADG₄43_NN), total suspended matter concentration (TSM_NN) and of chlorophyll-a (CHL_NN) on a global scale. The objective is to analyze ADG₄43_NN, TSM_NN and CHL_NN using the Sentinel-3B OLCI satellite and the presence of Fe-nanoparticles (NPs) + hazardous elements (HEs) in suspended sediments (SSs) in the maritime estuary of the Colombian city of Barranquilla. The study used the unpublished image of the Sentinel-3B OLCI satellite in the evaluation of ADG₄43_NN, TSM_NN and CHL_NN in 72 sampled points. Subsequently, 36 samples of SSs were carried out in the Magdalena River, in the identification of Fe-NPs by advanced electron microscopies. The Sentinel-3B satellite revealed particulate accumulations in OCE1 through the intensity of OLCI in ocean. There was also a high Fe-NPs intensity of SSs in the Magdalena channel, spreading contamination to large regions.