Source characterization using molecular distribution and stable carbon isotopic composition of n-alkanes in sediment cores from the tropical Mundaú-Manguaba estuarine-lagoon system, Brazil

► First report of temporal variation in hydrocarbons of this system. ► Contribution and source characterization of n-alkanes over the past 40 yr. ► The δ13C of individual n-alkanes indicative of C3 plants and lacustrine algae. ► The system has been subject to multiple anthropogenic activities. ► Major pollution sources are sugar cane monoculture and waste effluent.