Heavy metal monitoring of beach sands through environmental magnetism technique: a case study from Vengurla and Aravali beaches of Sindhudurg district, Maharashtra, India

Mineral magnetic, geochemical and statistical analyses were carried on surface sediments collected from Vengurla and Aravali beach, along west coast of India, premonsoon (PreM), monsoon(M) and postmonsoon (PM). Magnetic concentration parameters (χlf, ARM, SIRM and HIRM) are strongly correlated within them PreM during M and PM. Thermomagnetic analysis identifies titanomagnetite, magnetite, maghemite and hematite as the dominant magnetic mineralogy of the sediments. Strong correlation was deciphered between magnetic parameters and heavy metal (Cu, Cr, Zn and Ni) PreM and PM which obliterated in M. This shows influx of magnetic minerals and heavy metals is more in M than PreM and PM. The monsoonal influx is more haphazard and random in M because of enhanced weathering resulting in weak correlation between different mineralogical and geochemical entities. This finding outlines the efficacy of simple, rapid and non-destructive magnetic measurement which can be used as an indicator for heavy metal contamination. It can act as a proxy for measuring of heavy metal content in the coastal and beach environment.