Lead and lead-210 in some river waters of the southwestern part of France. Importance of the atmospheric contribution

Abstract

The Pb and Pb/sup 210/ concentrations in the waters of the Garonne, Ariege, and Hers Rivers in rural southwest France were measured during the period Dec. 1973-July 1974. The mean levels of total Pb and Pb/sup 210/ were 12 jg/l. and 0l38 counts/min/l., respectively. During a complete year, the lead content in some river waters varied from 14.4 jg/l. to less than 0.2 jg/l. The fallout of atmospheric lead, from fuel additives, due to rain leaching is higher than lead transport in the rivers. The circulation of Pb/sup 210/ shows that at least 87Vertical Bar3< of this atmospheric lead is retained by the soils. During the high flow rate period, this pollution corresponds to a maximum lead content of 0.4 jg/l. in river waters. Dry lead deposition on roads, which can be carried on to rivers, did not lead to a significant increase in water lead content during the low flow season, indicating that the lead is retained by the soils. During the high flow season, pollution from this source falls below a significant proportion in the Ariege and Garonne Rivers, and could be negligible in the Hers River. The Pb seems to originate from natural sources; it is easilymore » accounted for by the presence of particles with lead contents of up to 200 ppm during high flow rate periods.« less