Atmospheric pollution caused by toxic elements is an emerging problem of concern. Tree leaves have
been widely used as indicator of atmospheric pollutions and they are effective alternatives to the more
usual biomonitoring methods. Tree leaves can be used as natural traps of atmospheric deposition.
Elemental composition of dust deposited onto leaf surfaces can be used to characterize the urban
environment. A pilot survey including 16 Romanian settlements was carried out in order to evaluate
the characteristics and sources of air pollutants. Tree leaves (Tilia tomentosa, Tilia cordata, Tilia
platyphyllos) were collected and used for the measurements. Elemental analyses were carried out by
ICP-OES and ICP-MS. Principal component and discriminant analyses were used to characterizing
and estimating the level of pollution. Settlements were grouped on the basis of discriminant function
values. Multivariate comparison of chemical data ordered the settlements into 3 main groups, which
showed a systematic geographic distribution.