Arsenic and mercury contamination of sediments of geothermal springs, mangrove lagoon and the Santispac bight, Bahía Concepción, Baja California Peninsula

Abstract

In order to find out the environmental impact on the coastal zone, the composition of sediments of the intertidal hot spring zone and adjacent area of the Playa Santispac in the pristine Bahía Concepción (Baja California peninsula) was studied. High concentrations of As (13-111 mg/kg) and Hg (0.55-25.2 mg/kg) were found in the sediments of geothermal sources. Arsenic and Hg concentrations decrease rapidly in the adjacent small mangrove lagoon sediments and reach background levels (0.7- 2.6 mg/kg and 6-60 ug/kg for as and Hg respectively) in the marine sediments collected in front of Playa Santispac.