A study was undertaken to assess the air quality of Lahore by the elemental analysis of air conditioner (AC) filter dust samples
collected from 15 different commercial sites. Samples were prepared using the Leeds Public Analyst Method and were analyzed
using instrumental neutron activation analysis (INAA) for up to 31 elements. The elements Al, As, Ba, Ce, Co, Cr, Cs, Fe,
Hf, K, La, Lu, Mn, Na, Nd, Rb, Sc, Sm, Sn, Ta, Th, Yb and Zn were detected in all 15 samples whereas the remaining elements
have been detected in fewer samples; i.e. Mg, Sb and Tb were detected in 14 samples, Br and V in ten samples, U in nine samples
and Ca and Ti in eight samples only. Al, Ca, Fe, K, Mg and Na were determined in all samples at percentage levels. The concentrations
of most elements were found to lie around the mean values for the 15 samples studied and were not orders of magnitude different.
However the concentrations of Ca, Mg, Sn and Zn were found to be more variable and were found to be dependant on activities
such as construction, fruit and vegetable handling, tin plating and transport, respectively.