R. Freydier, †, , B. Dupre†, J.P. Lacaux‡
Precipitation chemistry in intertropical Africa
Atmospheric Environment, Volume 32, Issue 4, February 1998, Pages 749–765
ISSN: 1352-2310
http://www.worldcat.org/oclc/610395849


R. Freydier

Author to whom correspondence should be addressed. Fax: (33)5-61-25-32-05

GRGS, OMP-UMR 5566 CNES/CNRS/UPS, 18, Avenue E. Belin, 31055 Toulouse,France

freydier@pontos.cst.cnes.fr



B. Dupre

GRGS, OMP-UMR 5566 CNES/CNRS/UPS, 18, Avenue E. Belin, 31055 Toulouse,France



J.P. Lacaux

Laboratoire d'Ae´rologie, OMP-UMR 5560 UPS/CNRS, 14, Avenue E. Belin, 31400 Toulouse,France





"Abstract
Rainwater samples from Kollo (Niger) and Lamto (Ivory Coast) were collected during the year 1994. Two phases were analyzed, the dissolved was obtained with a 0.2 µm filtration and the total was obtained after evaporation and an HF : HNO3 digestion. Mg, V, Cr, Mn, Co, Zn, Rb, Sr, Ba, Pb, U, Al, Fe, Cs, REEs and Th were analyzed in both phases and Na, K, Ca and Cl in the dissolved phase. Except for Zn in Lam to with a value of 53, enrichment factors EF, calculated with respect to Al normalization in the total phase, do not show any significant enriched values (EF > 10). However, event by event, at low Al amounts, some elements V, Cr, Mn, Co, Zn, Pb and Mg, Rb, Sr and Ba are obviously enriched. Anthropogenic activities for metals and Ba or natural emissions for Mg, Rb, Sr can explain these enriched values. The REE patterns of precipitation particles are almost flat with La/Yb values (16.5–21.5) higher than the upper-crust values (13.6). These values are comparable with those measured in suspended sediments from Congo rivers. Dissolved-total distributions are: Zn > Sr > Mn > Co > Mg > Ba > Cr > Rb > V > Ph > U > Th > Cs > La > Ce > Al > Fe for Lamto samples and Zn > Sr > Mg > Mn > Rb > Co > Ba > Cr > Pb > V > Cs > Th > U > Al > La > Ce > Fe for Kollo samples. The percentage of the dissolved fraction is conversely proportional to the amount of Al in precipitations. Precipitation particles in Lamto and Kollo are strongly depleted in Mg, Mn, Rb, Sr and Ba compared to the upper-crust composition. The Rb/La mean ratios of 1.62 in Lamto and 1.70 in Kollo differ from the upper-crust value (3.73) and indicate that these particles have already been involved in weathering processes. All the information obtained in this study shows that terrigeneous particle emission is the main source of trace elements, in this region. Nevertheless, the contribution from other sources (ocean, vegetation, human activities) become evident when the amount of crustal dust particles in the atmosphere is very low.

Author Keywords
Trace elements; intertropical Africa; terrigeneous particles; enrichment factors; weathering processes"
http://www.sciencedirect.com/science/article/pii/S1352231097003427

In comparison with stated normal amounts of aluminum found in the air.

(Quote) “…..Levels of aluminum in the air generally range from 0.005 to 0.18 micrograms (1 microgram, ?g, equals a millionth of a gram, 1 gram equals 0.0022 pound) of aluminum per cubic meter of air (0.005–0.18 ?g/m3 or 0.00018 mg/L) , depending on location, weather conditions, and level of industrial activity in the area. Most of the aluminum in the air is in the form of small suspended particles of soil (dust). Aluminum levels in urban and industrial areas may be higher and can range from 0.4 to 8.0 ?g/m3 ….”
http://www.eoearth.org/view/article/155461/

or (0.008 mg/l) [ 740.00 mg/L Alu content recorded in Rain water analysis from London- in studies from Wrights Patterson Airforce Laboratory just 5.0 mg/l caused harm to cellular function in the lungs]
http://www.dtic.mil/get-tr-doc/pdf?AD=ADA445568
https://mrmaxbliss.wordpress.com/2013/08...hemtrail-files/

http://www.worldcat.org/oclc/144877