Spatial Distribution of Minor Elements in the Tazlău River Sediments: Source Identification and Evaluation of Ecological Risk

Minor elements received more attention in recent years due to their contamination susceptibility and environmental impact. Surface sediment samples were collected from 29 sites and total contents of eight minor elements (Cr, Co, Ni, Cu, Zn, As, Cd, and Pb) were investigated in order to determine the geostatistical distribution and to predict ecological implications. The relationship between metals and ecological implications was analyzed by using the geochemical normalization approach and ecological prediction indicators such as the enrichment factor (EF), the contamination degree (CD), the environmental toxicity quotient (ETQ), and the health risk assessment. Based on the studied toxic metals, it was observed that the most toxic element in Tazlău River sediments is Cr. The assessment results of carcinogenic and non-carcinogenic risks via dermal contact indicate that the study area shows no human health risk. The correlation matrix and principal component analysis (PCA) provide an overview of the major sources, anthropogenic versus geogenic, where Cr and Cd mainly originate from anthropogenic sources, while Pb is derived from a geogenic source. The approaches used in this study will provide a baseline regarding the accumulation of minor elements in the sediment and will be useful for other studies to easily identify the major contaminates and to estimate the health human risk.

Temporal and spatial variability of heavy metals in Marudu Bay, Malaysia

The current study was conducted to estimate the baseline concentration of heavy metals in the surface sediment of Marudu Bay. Environmental parameters were measured at the seafloor and samples of the surface sediment were collected at monthly intervals for the period of 12 months. The organic content, total N, total P and concentration of 16 trace metals in the surface sediment were analyzed. The baseline concentration of metals was estimated by geochemical normalization. Anthropogenic inputs of metals were then estimated by calculating the enrichment factor for each element. The result demonstrated that the C/N ratio of sediment at Marudu Bay varies from 15 to 342, which indicates the dominance of terrestrial organic matter. The baseline concentration of V, Fe, Mn, Zn, Ti, Rb and Sr were 26.74 mg kg