Elevation of selenium levels in air by xerography.
D000393:Air Pollutants / Q000032:analysis*; D000395:Air Pollutants, Occupational / Q000032:analysis*; D003308:Copying Processes; D012643:Selenium / Q000032:analysis*
D000393:Air Pollutants; D000395:Air Pollutants, Occupational; D012643:Selenium