M.Sc Thesis

M.Sc StudentGutman Ravit
SubjectCharacterization of Anthropogenic Components in Mineral
Dust during Dust StormsOover the East
DepartmentDepartment of Civil and Environmental Engineering
Supervisor PROFESSOR EMERITUS Yaacov Mamane
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Israel is affected by Saharan and Arabian dust storms, sea salt and anthropogenic sources. It is the purpose of this study to determine the enrichment of Saharan and Arabian dust by anthropogenic pollution. Data were collected in different studies, using dichotomous samplers that separate PM10 into fine and coarse particles. Twenty four hours filters were analyzed for the elemental content. The sampling took place at Neve Yam, Ashdod, Haifa and Tel Aviv. Dust storm days were compared with clear days to determine the enrichment by anthropogenic sources. Fine and coarse particle fractions were compared to gain more insight on the particle make up. The study focused on nine dust events from Ashdod and Tel Aviv. For the other sampling sites an inter comparison is included. As expected, coarse and fine concentrations were significantly higher. Elements of geological and marine origin also increased during the dust events. The Cl to Na ratio in the coarse fraction was higher than found in sea water. A possible explanation was suggested. An increase of concentrations of anthropogenic elements during dust storm events in both particle size fractions was the main finding of this study. High concentrations of fine sulfates were observed during clear days. But high sulfates in the coarse fraction during dust episodes were either part of the gypsum matrix, or reaction of SO2 on mineral surfaces. In order to differentiate between anthropogenic and natural sources, enrichment factor (EF) was calculated. Enrichment of S, Co, Zn, Se, Br, Pb in the coarse fraction during dust events and in clear days was observed. Sulfur, V, Co, Ni, Zn, As, Se, Br, Pb were enriched in the fine fraction during both dusty and clear days. Low EF values of crustal elements in both size fractions were observed. Cluster Analysis was performed to identify strong associations among elements. Results pointed at the existence of different clusters for elements in coarse and fine particles during dusty and clear days. In both fractions the clusters represented elements related to crustal, marine, and few anthropogenic sources. During dust storm events, the anthropogenic elements in the coarse fraction seem to be all connected, and are related to the crustal group. This study shows that dust particles, during their transport from the Saharan desert and from Arabian deserts to Israel, are enriched with anthropogenic pollution that may have potential health implication.