Surface air concentration and deposition of lead-210 in French Guiana: two years of continuous monitoring.
To make up for the lack of data on (210)Pb aerosol deposition in tropical regions and to use this radionuclide as an aerosol tracer, a monitoring station was run for two years at Petit-Saut, French Guiana. Lead-210 concentration in air at ground level was monitored continuously together with atmospheric total deposition. The air concentration has a mean value of 0.23+/-0.02 mBq m(-3) during both wet and dry seasons, and it is only weakly affected by the precipitation mechanism. This result was unexpected in a wet tropical region, with a high precipitation rate. In contrast, deposition clearly correlates with precipitation for low/moderate rainfall (<15 cm per 15-day), while this correlation is masked by strong fluctuations at high rainfall. The estimated mean annual deposition over the last ten years is 163+/-75 Bq m(-2) y(-1). This provides a procedure for estimating this mean flux at other sites in French Guiana.
Mélières
Marie-Antoinette
MA
Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS, Université J Fourier, BP 96, 38402, St Martin d'Hères, France. melieres@glaciog.ujf-grenoble.fr
Pourchet
Michel
M
Richard
Sandrine
S
D000336:Aerosols; D000392:Air Movements; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D004784:Environmental Monitoring; D005616:French Guiana; D007856:Lead Radioisotopes / Q000032:analysis*
D000336:Aerosols; D000396:Air Pollutants, Radioactive; D007856:Lead Radioisotopes