Occurrence, distribution, and ecological risk assessment of DDTs and heavy metals in surface sediments from Lake Awassa—Ethiopian Rift Valley Lake

• Published in: Environmental science and pollution research international Vol. 20; no. 12; pp. 8663 - 8671
• Main Authors: Yohannes, Yared Beyene, Ikenaka, Yoshinori, Saengtienchai, Aksorn, Watanabe, Kensuke P., Nakayama, Shouta M. M., Ishizuka, Mayumi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2013; Springer Nature B.V
• Subjects: Animals; Anthropogenic factors; Aquatic environment; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bans; Bioaccumulation; Coastal zone; Contaminants; Contaminated sediments; Correlation analysis; DDD; DDE; DDT - analysis; Developing Countries; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental science; Ethiopia; Factories; Geologic Sediments - chemistry; Heavy metals; Humans; Laboratories; Lake sediments; Lakes; Lakes - chemistry; LDCs; Metal concentrations; Metals; Metals, Heavy - analysis; Nitrous oxide; Pesticides; Principal components analysis; Research Article; Rift valleys; Risk Assessment; Sediment samplers; Sediments; Side effects; Studies; Toxicology; Veterinary colleges; Veterinary medicine; Waste Water Technology; Water bodies; Water inflow; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control; Ethiopia; DDTs; Lake Awassa; Sediment; Spatial distribution; Correlation analysis; Heavy metals; Ecological risk assessment
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-013-1821-8

Dichlorodiphenyltrichloroethanes (DDTs) and heavy metals are ubiquitous contaminants with high bioaccumulation and persistence in the environment, which can have adverse effects on humans and animals. Although applications of DDTs have been banned in many countries, developing countries like Ethiopia are still using these for agricultural and medicinal purposes. In addition, heavy metals are naturally present in the aquatic environment and distributed globally. In this study, the occurrence, distribution, and ecological risk of DDTs and heavy metals in surface sediments from one of the Ethiopian rift valley lakes were studied. Twenty-five surface sediment samples from Lake Awassa, Ethiopia were collected and analyzed for DDTs and heavy metals. Results showed that concentrations of total DDTs ranged from 3.64 to 40.2 ng/g dry weight. High levels of DDTs were observed in the vicinity of inflow river side and coastal areas with agricultural activities. The heavy metals content were followed the order Zn > Ni > Pb > Cu > Cr > Co > As > Cd > Hg. Correlation analysis and principal components analysis demonstrated that heavy metals were originated from both natural and anthropogenic inputs. The levels of DDE and DDD in surface sediments exceeded the sediment quality guideline values, indicating that adverse effects may occur to the lake. A method based on toxic-response factor for heavy metals revealed that the calculated potential ecological risk indices showed low ecological risk for the water body.