Pollutant trends and hazard ranking in the desalination area of the Penghu Islands, Taiwan

►We examine the temporal and spatial trends of pollutant in seawater and sediment. ►The As concentration in seawater has high correlation with that in sediment. ►A hazard index (HI) is applied to assess the potential hazard of contaminants. ►Considering HIs in seawater and sediment, As is the highest-ranking trace element.