The map service shows levels of heavy metals and other inorganic environmental indicators in surface sediments, as well as content of mud and TOC, which are important factors for binding and accumulation of heavy metals in the sediments. The term heavy metals includes all metallic elements that have a relatively high specific gravity. Heavy metals are natural constituents of the earth's crust and occur in varying concentrations in most natural materials. In addition, the content of microplastic particles in sediments is shown as one of the important environmental indicators.