# Seasonal Pollution Levels and Heavy Metal Contamination in the Jukskei River, South Africa
## 3 Results and Discussion
### Source Apportionment Using of PCA  
PCA was used to identify the origins of heavy metals in water samples [88]. The goal of PCA was to decrease the dimensionality of a multivariate dataset to a smaller number of components that best characterize and explain the majority of the data's content. With absolute loading levels of >0.75, 0.75-0.50, and 0.50-0.30, respectively, the factor loadings are classified as \"strong\", \"moderate\", and \"weak\", since most hydrochemical factors, particularly heavy metals, exhibited comparable behavior [89]. For the wet season (Table 10) factor 1 having an eigenvalue 2.638, it explained 46.571 of the variation, and it obtains strong loading for As with 0.873, moderate for Pb with 0.749, and strong loading for Cd with 0.837. Hg shows moderate loading with 0.500. Strong loading for As, Cd, and Pb suggests an anthropogenic source due to wastewater and agricultural pesticide application. The critical important cause of As pollution is agricultural activities which are dominating the downstream of the study area. There are a number of agricultural operations in the downstream area. Compounds based on As are most likely utilized as pesticides, fungicides, herbicides, and insecticides in agricultural and livestock production [90]. Underground \begin{table}
\begin{tabular}{l c c} \hline \hline
**Sampling Points** & *** RI Wet Season** & *** RI Dry Season** \\ \hline Juk-P1 & 193 & 7502 \\ Juk-P2 & 302 & 16,094 \\ Juk-P3 & 60.6 & 15,239 \\ Juk-P4 & 33.4 & 22,148 \\ Juk-P5 & 50.7 & 23,369 \\ Juk-DS-1 & 51.4 & 23,159 \\ Juk-DS-6 & 26.6 & 24,129 \\ Juk-DS-8 & 135 & 23,899 \\ Juk-DS-9 & 60.4 & 15,095 \\ \hline \hline \end{tabular}  
* RI: risk index.  
\end{table} 
Table 9: The potential ecological risk index. water used for irrigation is often linked to As contamination of crops [91]. The study area includes areas with high population density with poor hygiene and infestation with rats and cockroaches [34]. Unregulated pesticides are flooding the market with deadly consequences rising to the level of national disaster [34; 35]. Some reports of pesticides that contain Cd and Pb are applied to deal with pests and the random usage of pesticides results in sediment contamination [92]. Cd and Pb in the study area might be coming from diverse sources like fertilizer application in the farms and golf courses, battery production, and burning of coal from the nearby coal-fired power station. Industrial wastewater and sewage discharge is another major pathway for As, Cd, and Pb to enter the studied area. This is due to the mushrooming of informal settlements and failing wastewater infrastructure, which results in uncontrolled waste spillages through frequent bursts [58]. The presence of Hg in the river water system has long been associated with legacy mining activities and rampant informal and unregulated mining activities [32]. Hg is used in gold processing and with the rampant informal gold mining activities, Hg is a health hazard of concern in the mining communities [93; 94]. Factor 2 has an eigenvalue of 1.779, explaining 25.408 of the variation, and obtains 0.825 for Th and 0.819 for U, displaying strong loading, indicating similar distribution channels and anthropogenic origin and pollution can be attributed to the gold mining activities. For the dry season (Table 11), factor 1 is responsible for 70.897% of the variance and an eigenvalue value of 4. Factor 1 indicates anthropogenic sources, and it showed that there is no correlation between Hg and Pb, As, Cd, Th, and U. The lack of correlation of Hg and other heavy metals can be explained by the fact that the fate of metallic mercury that is manually added to sediments during gold extraction processes does not always follow that of the heavy metals that are already present in geological matrices and that are mobilized with sediment dredging and digging activities; this can be observed by the factor loadings in the dry season and also the correlation factor in the dry season [95].