A University of Johannesburg (UJ) study has uncovered dangerously high levels of cancer-causing chemicals in the Klip River in Gauteng. The research highlights a serious environmental and public health threat, as the detected levels of polycyclic aromatic hydrocarbons (PAHs) exceed safe limits. According to UJ researchers, sediment samples collected from the Klip River during the high and low flow seasons were found to contain 16 chemicals listed by the US Environmental Protection Agency as priority PAHs, with the varying concentrations depending on pollution level at different sites.