| heavy metals in sediments from the paraguay river: a preliminary study. | the first results ever obtained on heavy metal concentrations (fe, mn, cr, cu, zn and pb) in the paraguay river surface sediments are presented. samples collected at 11 locations, along a distance of 570 km, between the cities of bahia negra and alberdi in paraguay, for six different periods between november 1991 and 1993, were analyzed. the paraguay sediments appeared to have features of an unpolluted river even though significant amounts of domestic and industrial effluents are discharged near ... | 1998 | 9496666 |