Status of PAHs in Environmental Compartments of South Africa: A Country Report

Abstract

This article covers the status of PAH concentrations and composition patterns in surface water, air, sediment, and soil samples from South Africa. Despite South Africa being one of the largest economies in Africa, it is only recently that researchers have reported the presence and possible sources of these compounds in various environmental compartments. This article discusses the potential hotspots and possible sources of these compounds. It also compares the total PAH concentrations and percentage composition patterns of the individual PAHs. So far, total concentrations of five PAHs determined in sediment samples from the Johannesburg area, Gauteng Province, gave the highest concentrations ranging from 1233–136,276 μg kg⁻¹. The total concentration of six PAHs found in runoff water from the Venda region of the Limpopo Province, gave the highest concentration with a range of 28.7–3192.6 μg L⁻¹. The decreasing order of percentage composition of PAHs in water samples tended to follow 3-ring > 4-ring > 2-ring PAHs. In soil samples the decreasing order of percentage composition followed 4-ring > 3-ring > 5-ring > 2-ring > 6-ring PAHs. The total freely dissolved PAHs followed solubility of the compounds with 2-ring > 3-ring > 4-ring > 5-ring > 6-ring PAHs. Some of the identified sources of PAHs using molecular ratios include petrogenic emissions such as from petroleum combustion from vehicles and pyrolytic sources such as coal combustion by coal powered power stations, as well as iron and steel production industries. Oil spills were also identified as major PAH contributor in runoff water from the Venda region of the Limpopo Province.

Key Words:

• air
• polycyclic aromatic hydrocarbons
• soil and sediments
• South Africa
• water