Abstract: An airborne particle impaction system and a particle impaction cell for use therewith. The cell includes a device for holding a removable planar support sheet with a tacky surface. The cell includes an inlet slit adjacent to a support sheet in the cell and an outlet opposite the sheet. A flexible tube connects the cell outlet to a vacuum pump. Air is drawn in the cell inlet slit, travels across the support sheet, around sheet edges and out the cell outlet. Particles in the air stream are forced by inertial forces to impact the support sheet, where they are retained by the tacky layer. The cell further includes a base having a floor, a rim around the floor and the cell outlet and a cover having a top surface bearing the slit and a lip configured to fit within and engage the base rim in a substantially air tight arrangement. A ledge around the base interior supports the corners of a polyhedral sheet. The support sheet is clamped between the cover lip and the ledge. Ideally, the slit exit is spaced closely (e.g.