Reduction in fluoride levels in the old Warta reservoir near Lubon, Poland

Earlier reports showed that the extensive pollution of the old Warta reserv oir near Lubon, Poland was caused by fluoride emissions from a nearby phosp hate fertilizer plant. In this paper, we provide new determinations of fluo ride levels in the reservoir. After reduction of emissions in the early 199 0s, our measurements revealed that fluoride concentrations had decreased fr om an average of 75 mg/L in 1978 and 23 mg/L in 1984 to 2.5-2.6 mg/L in 199 5-1996 with a range of 1.32 to 4.1 mg/L, depending of the season of the yea r and the location in the reservoir.