The possibility of selecting clones of eastern white pine (Pinusstrobus L.) with specific sensitivities to different air pollution regimes was investigated. Field screening was carried out by exposing potted seedlings to field conditions for 1 year or longer in each of three areas where a particular phytotoxicant was known to predominate. The areas were characterized by the following pollution sources and major phytotoxicants: (1) power plant, sulfur dioxide; (2) fertilizer plant, fluorides; and (3) vehicular traffic, oxidants. Selections were made of: (1) trees injured during only one season in one area; (2) trees injured during both the summer and winter, but only in one area; (3) trees resistant to air pollution in all three areas; and (4) trees sensitive to air pollution in all three areas. These selections are being propagated for use as specifically sensitive bioindicators of air pollution and as resistant lines for use in seed orchards of white pine.