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The organic fraction associated to sands of five localities of Algerian Sahara Desert was characterized with regards to n-alkanes polynuclear aromatic hydrocarbons (PAH) and mono/dicarboxylic acids Huge differences were observed among total contents of the three groups in the sands and within each group with regard to percent distribution patterns of congeners Mutagenic nitro-PAH were virtually absent Organic acids were identified as the most abundant compounds in all samples (up to 4800 ng g(-1) vs less than 700 of n-alkanes and 22 ng g(-1) of PAH) their presence was overall related to biogenic sources except for the Hassi Messaoud petroleum area where an important contribution of anthropogenic emission was present The sand composition at Hassi Messaoud (and at lesser extent Tougguort) seemed to indicate that environmental conditions promote there the oxidative decomposition of organics by con trast at Laghouat Hassi Bahbah and Gardara oases the deposition involved fresh (non-reacted) air pollutants The sand composition at the Hassi Messaoud was compared to that of airborne particulates of the industrial district and city Airborne n-alkanes (approximate to 500 ng m(-3)) and fatty acids (approximate to 15 000 ng m(-3)) were very high compared to Algiers city whilst PAH contents (10-60 ng m(-3)) were typical of polluted areas in winter similarly the sands were reach of the two aliphatic groups and relatively poor of PAH (C) 2010 Elsevier Ltd All rights reserved