Sediment-bound heavy metals as indicators of human influence and biological risk in coastal water bodies

Abstract

Birch, G. F., and Olmos, M. A. 2008. Sediment-bound heavy metals as indicators of human influence and biological risk in coastal water bodies. – ICES Journal of Marine Science, 65: 1407–1413. Currently, many institutions are conducting or planning large, regional-scale ecosystem assessments of estuarine health. A full, integrated assessment of these environments requires a large suite of biological, physical, and chemical indicators, including sedimentary chemistry, ecotoxicology, benthic community structure, and bioaccumulation. This commitment is beyond the capacity of most organizations, and a simpler approach is required to accommodate limited financial resources. A case is made for the use of sedimentary heavy metals as an easy and inexpensive indicator. The advantages are that sediments identify the “pristine” condition and give baseline information against which future management strategies may be benchmarked, and that they differentiate solely human-induced change from natural variation. Sediment indicators in depositional environments are also less dynamic than those associated with water and biota. Our objective is to demonstrate that sediment-bound heavy metals data provide the spatial extent and magnitude of chemical change, as well as the risk of biological stress attributable to contamination in estuarine ecosystems. An assessment of this scheme involving seven New South Wales (Australia) estuaries suggests that sedimentary heavy-metal indicators used in a weight-of-evidence approach, with data collected during the recent Australian National Land and Water Resources Audit, enhances estuarine condition assessment.

Apportionment of Hazardous Elements in Agricultural Soils Around the Vicinity of Brick Kiln in Bangladesh

“…It is stating a fact of human interference if enrichment factor of samples is more than 1.5. An EF of 1.5-3, 3-5, 5-10 and >10 is considered the evidence of minor, moderate, severe, and very severe modification [21].…”

Heavy metals contamination in water and sediments of an urban river in a developing country

“…The following equation was used to calculate the EFc: Earth's crust Where, (C M /C Al ) sample is the ratio of concentration of heavy metal (C M ) to that of aluminum (C Al ) in the Heavy metals contamination in river sediment sample, and (C M /C Al ) Earth's crust is the same reference ratio in the Earth's crust. Samples having enrichment factor >1.5 was considered indicative of human influence and (arbitrarily) an EF of 1.5-3, 3-5, 5-10 and >10 is considered evidence of minor, moderate, severe, and very severe modification (Birch and Olmos, 2008). Average shale values taken from Turekian and Wedepohl (1961).…”

Classifying Ecological Quality and Integrity of Estuaries

“…As a result, Ward et al (1998) reviewed 61 possible indicators for Australian estuaries and the seas, making recom mendations and identifying possible data sources. Despite this early work, and a host of related scientific studies (Fairweather, 1997;Deeley and Paling, 1999;Harris and Silveira, 1999;Kennedy and Jacoby, 1999;Edgar and Barrett, 2000;Ward, 2000;Melville and Pulkownik, 2006;Hirst and Kilpatrick, 2007;Scanes et al, 2007;Birch and Olmos, 2008), a clear set of national guidelines for monitoring Australian estuaries and marine waters have not been developed. A major obstacle in developing a consistent approach to monitoring of natural resources in Australia has been the complex and often confus ing process of coastal zone management, which is well documented (e.g., Zann, 2000).…”