Yarrow (Achillea millefolium L. ) was transplanted to four localities with different air pollution characteristics in and around Copenhagen. The experimental field set-up permitted the determination of the increase in Pb and Cd levels in the above-ground plant parts as well as the fraction being washed off from these by natural rain water during the same periods. Bulk precipitation values were measured for the periods too, and the Pb and Cd accumulation in in situ Yarrows at the localities were compared with the transplants and changes in soil levels with time.