Assessment of trace element contamination of urban surface soil at informal industrial sites in a low-income country
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Trace elements released by human activity are ubiquitously detected in surface soil. The trace element contamination statuses of 20 sampling stations at two busy informal industrial sites of Harare city, Zimbabwe, were evaluated using geochemical indices. Spectrophotometric determinations of concentrations of trace elements in surface soil indicated generally higher values than the reference site and the average upper earth’s crust. High contamination factors were observed for trace elements across sampling stations at Gazaland and Siyaso informal industrial sites. Concentrations exhibited heterogeneous distribution of trace elements in surface soil varying with the nature of activity at a sampling station. The pollution load index and degree of contamination suggested highly contaminated surface soil with Cd, Cu and Pb particularly where the following activities were done: (1) welding, (2) automobile maintenance and (3) waste dumping. These results may be very important to reduce soil contamination. Paving surfaces may help to reduce dispersal of trace elements deposited on surface soil to other stations and minimise human exposure via inhalation and contact.
KeywordsInformal industry Potential ecological risk Trace element Urban soil geochemistry Zimbabwe
We thank Mr. R. Richakara and Mr. K. Kadema for the chemical analyses done. We acknowledge the financial assistance we got from the Postgraduate Centre of Bindura University of Science Education in the form of block grants. We appreciate the assistance we got from colleagues in the form of preliminary manuscript reviews.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest for the current work.
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