Thirty-five lung pairs obtained during autopsy from randomly selected patients were investigated by particle induced X-ray emission for overall and regional elemental content determination. In each case the interbronchial lymph node was simultaneously processed. While homogenous distribution has been consistently observed for potassium, calcium, iron, copper, zinc, and rubidium, a very different distribution was recorded for titanium, chromium, nickel, and strontium. The significance of these results is discussed with regard to pollution hazards. Regional accumulation of this second group of elements seems to be related to air pollution peculiar to Liège. Advantages and limitations of the technique and the need for further research are stressed.