"In this truly comparative social and environmental history of air pollution, Greenlees deftly weaves public health, regulatory politics and labor relations into a prescient reminder that protecting workers from hazardous workplaces remains a pressing issue on a global scale."— Graham Mooney, Johns Hopkins University, and author of Instrusive Interventions: Public Health, Domestic Space, and"This is a promising, important, and long-awaited project—the first comparative history of industry-related hazards in the United States and Britain. The author has synthesized a vast body of research, much of it her own original work. At once comprehensive and selective, When the Air Became Important is illuminating scholarship." — Chris Sellers, Stony Brook University