The impact of pollen on the respiratory mucosa was modeled by studying the process by which solutes are eluted from pollen grains. Rye grass (Lolium perenne), short ragweed (Ambrosia artemisiifolia), and white oak (Quercus alba) pollens were packed between glass wool plugs in small columns. Water was pumped through the columns and the eluate solute yield was determined by measurement of the dry solute weight. Solute separation was rapid, and concentrations and osmolalities of the eluate decreased exponentially. Theoretical initial solute concentrations were 179 g/l for rye grass, 55 g/l for short ragweed and 349 g/l for oak pollen eluates. Theoretical initial osmolarities of the same eluates were 321 mOsm/kg for rye grass, 196 mOsm/kg for ragweed and 424 mOsm/kg for oak pollen. Sequential separation of allergens (Lol p I, Amb a I, Amb a V), enzymes and proteins was demonstrated by specific assays. These observations suggest that the complex stimulus produced immediately after pollen grain hydration at the respiratory mucosal fluid interface is much more intense than previously envisioned. Sequential separation of pollen components has important implications for the production of improved allergenic extracts.