Spatial and temporal variation of in vitro Bioaccessibility of chromium in playground soils of ancient bell metal industrial town, Khagra, West Bengal

Present study was designed to study the seasonal variation of Chromium (Cr) in playground soil of Khagra City located in West Bengal, India from 16 different playgrounds. Sequential extraction techniques had been carried out to evaluate the relative dispersal of Cr in exchangeable, carbonate, Fe-Mn oxide, and organic bound as well as residual fractions. The ?1 Pseudo total concentration of Cr had its average value of 19.85±7.94 mg kg in pre-monsoon and ?1 in case of post-monsoon an average of 115.17±192.17 mg kg . Sequential extraction was performed to evaluate the bioavailable fraction. Cr was mostly associated with residual phase (F5). Mean mobility factor (MF) for Cr in playground soil of Khagra was only 5.02 %. Geo-chemical indices such as Enrichment factor (EF), Geo-accumulation index (I ) and Contamination factor geo (CF), Ecological risk (ER) indicated very low pollution levels. Bioaccessible-Cr was most 2 2 significantly correlated (R2 0.85) in pre-monsoon and (R2 0.98) post-monsoon indicated, when the total amount of Cr is increased leading to increase in bioaccessible fraction.