The concentration of lead, iron and potassium were determined in suspended particulates matters (SPM) in the atmosphere Dhaka, Bangladesh between January and June, 2008. The sampling areas are Khandakar Mukarram Hossain Biggan Bhaban, University of Dhaka, Tejgaon, Hazaribagh, Uttara and Agargaon new colony. The average concentrations of TSP, PM10 and PM2.5 were 68, 43 and 35 µg m-3, respectively. About 82% particles were from fine fraction (PM2.5) and 18% were from coarse fraction (PM10-2.5), which indicates mechanical processes are one of the main sources for the particulate matters in air of Dhaka. The concentration of lead, iron and potassium were determined by using atomic absorption spectrophotometer (AAS) for the size fraction of PM10 with highest concentrations recorded for iron (10.8 g/m3) and lowest for lead (0.10 g/m3). The average concentration of NOx, O3 and SOx with eight hours sampling were 82.8, 22.5 and 25.5 g/m3 respectively. This study revealed that the concentrations of Pb, K, Fe, CO, NOx, O3 and SOx in Dhaka City were higher than the WHO (World Health Organization) guideline values.

Boreholes sediments (1-6 m depth) of the river Tista and Jamuna in Bangladesh were collected for the analysis of As, Fe, Mn, Cu and organic carbon. Chemical analysis reveals that Mn and Fe hydroxides and organic matter are the major leachable solids which carrying As. High levels of arsenic concentration in aquifers are associated with fine grained sediments at the lower depth of the sediment layer. The highest As containing sediment was gray and texture of sediment was clay type. The colour of the least As containing sediment was white and texture of sediment was sandy. In addition, this study indicate that As is closely associated with Fe and slightly correlated with Mn and Cu in the sediment of the river Tista and Jamuna. Arsenic was distributed regularly in sediments with Fe, Mn, Cu and organic matter from upper stream to lower stream of Tista and Jamuna river belt in Bangladesh.

Boreholes sediments (to a depth of 1-6 m) from the Jamuna River area in Bangladesh were collected for arsenic concentration and geochemical analysis. Chemical analysis reveals that Mn and Fe hydroxides and organic matter are the major leachable solids carrying As. High levels of arsenic concentration in aquifers are associated with fine grained sediments. Moreover, it is clearly shows that As is closely associated with Fe and Mn in sediments. Arsenic mobilized in sediments with Fe, Mn and organic matter from upper stream to lower stream of the river Jamuna. There was no significant relationship observed between arsenic and Cu in borehole sediments.