Geostatistical analysis of relationship metal content–grain size in lagoonal sediment cores using multivariate analysis

This work analyzes the relationship between heavy metal concentrations and other physical parameters, such as particle size and organic matter content, in sediment cores retrieved from the Oualidia lagoon. The samples were analyzed for Pb, Cd, As, Cr, Co, V, Zn, Al, Fe, and Mn using inductively coupled plasma mass spectrometry, while the particle size distribution was determined using a grain size analyzer (Malvern, Mastersizer) in CNESTEN. Correlation coefficient and principal component analysis were applied to the obtained data. The statistical analysis exhibited a strong relationship between fine particles and heavy metals, suggesting that the particle size mainly controls their accumulation in the studied samples. At the same time, organic matter content is negatively correlated with metals. Principal component analysis can effectively identify the comprehensive and single pollution levels of heavy metals in sediments, thus making it essential to measure heavy metal pollution in sediments. Besides, the recorded correlations between analyzed heavy metals and fine fractions suggest that hydrodynamic conditions along the lagoon are the main factors controlling the distribution and accumulation of pollutants. Such findings help in understanding the accumulation mode, deposition, and pollutant distribution along the lagoon.