Rainwater samples were collected in Irbid city using 24 hour sampling perio
ds from December 1996 to April 1998. All samples were analyzed for major ca
tions (Na+, K+, Ca2+ and Mg2+), major anions (Cl-, NO3- and SO42-) and pH.
High levels of Ca2+ and SO42- were observed. Together, Ca2+ and SO42- made
up more than 52.4% of the total ion mass, while Ca2+ alone contributed over
39.0% of the total cation. The majority of the rain samples collected had
pH values higher than 5.6. The average pH was 6.4 +/- 0.9. High values of p
H are attributed to the neutralization by natural alkaline local dusts whic
h contain large fractions of calcite. Correlation and mineralogical analyse
s indicated that Ca2+, K+ and fractions of Na+, SO42- and Mg2+ are of crust
al origin. Results of the present study suggested that the atmospheric comp
osition in the city is strongly influenced by natural sources rather than a
nthropogenic.