Coastal sediment is a vital habitat for aquatic and marine life in coastal ecosystem. However, urbanization and economic development in coastal areas have resulted in environmental problems globally. Due to coastal development such as new industrial facilities and commercial port expansion, anthropogenic metals are introduced to the adjacent areas. Therefore, metal pollution in coastal areas is one of the focused environmental concerns. Sediment quality in coastal zone reflects the long-term environmental status because it keeps a record of the development in the area. In this review paper, sediment metal concentrations in 52 selected sites worldwide are summarized for evaluation of the coastal environmental quality. The results from this study can be applied to science-based policy formulation and ecological restoration/rehabilitation practices in an integrated coastal zone environmental management.Keywords Coastal sediment . Metal . Enrichment factor . Hazardous quotient . Risk assessment
OverviewMetals with different speciations and oxidation states are naturally present in the earth crust [1]. Depending on the rock type, geophysical condition, and geographical location around the world, metal concentrations in sediments, soils, and water present as naturally weathered products from the earth crust can be different from place to place [2, 3]. Trace amount of metals is essential micronutrients for the growth and metabolism of many organisms [4]. However, metals in excessive amount can be toxic to organism and cause ecological toxicity [4]. Anthropogenic metal input associated with the urbanization and industrialization in the twentieth century has increased dramatically in the coastal areas and is drawing increasing attention around the world because about 80 % of the pollutants from human activities are introduced into coastal environment [1,5]. Therefore, metal pollution in the coastal sediments has become a major environmental problem because it threatens the economic and ecological value of the coastal area.Coastal environment is a complex system involving physical, chemical, and biological processes that play important roles in metal biogeochemical cycle. However, anthropogenic input has caused metal pollution in the coastal area. The sources include mining, metal product fabrication, solid waste disposal, fossil fuel combustion, and municipal/industrial waste effluent [1, 6]. Industries, such as foundry, paper processing, laundry, tannery, and dye works, can emit toxic metals and discharge wastewater to the adjacent estuaries and coastal areas [7,8]. Acid rain can leach metals and increase the mobility of toxic metals from pollutant sources to the environment [9]. Once enter coastal environment, the toxic metals will mainly accumulate in the sediments because of particle Curr Pollution Rep (2015) 1:203-219 DOI 10.1007 scavenging and settling. Therefore, high concentrations of toxic metals are often found in sediments in many industrialized urban coastal areas as a consequence of industrializat...