Proton-induced x-ray emission analysis--a promising technique for studying the metal content of plants and soils.

The ease of employing proton-induced X-ray emission analysis (PIXEA) to studies relating metal content of soils to metal uptake in plants was aptly demonstrated in an investigation concerning the effect of automotive pollution on the abundance of about 16 elements accumulated in ribwort plantain and its surrounding soil. Elemental concentrations were shown to be dependent on the age of the plant leaves, as well as the distance from the roadside.