Pollution assessment models of surface soils in Port Harcourt city, Rivers State, Nigeria

Abstract

Environmental pollution has resulted in several health and physiological problems in both plants and animals. This has witnessed growing number of models for assessment purposes. Some of these provide useful information, and reduce large data for easier understanding by policy-makers. In the current study of pollution, we used data from four locations: Oil Market, Trans Amadi, Borrokiri and GRA in Port Harcourt and a control taken from Federal Land Resource Umuahia (FLRU). A total of 25 composite soil samples were analyzed for physicochemical parameters and heavy metals, by means of a 969 Unicam AAS model series. The data obtained were then subjected to index models. Results showed iron (Fe) to be most abundant metal, ranging from 10.44 to 19.54 mg/kg, then Ni (8.03 to 13.6mg/kg), Cd (3.96 to 5.41 mg/kg), Pb (1.36 to 7.64 mg/kg), Zn (0.09 to 7.24 mg/kg), Cu (0.16 to 0.32) and As (0.07 to 0.11 mg/kg). All metal concentrations were below permissible limits set by NESRA. Contamination factor (Cf) and Igeo revealed moderate to heavy contamination by Cd and Zn. Anthropogenicity revealed that increasing metals in the environment are largely from anthropogenic inputs. The Pollution Index revealed that soils were unpolluted (PLI < 1) with the heavy metals. Furthermore, the Sodium absorption ratio showed that the soils are less sodic and could be good soils for plant growth. All four sites showed a linear relationship between anthropogenicity and geoaccumulation indexes, and so both indexes furnish basically the same information However, pollution from these metals in the study area should be under routine check for possible pollution in the near future, as some metals showed elevated concentrations above background values