Excess emissions are air pollution releases that exceed permitted levels and occur during facility start-ups, shutdowns, or malfunctions. While they are violations of the federal Clean Air Act, states have historically granted violating facilities automatic exemptions; limiting enforcement and weakening existing regulation. Recent efforts to harmonize state and federal rules have ignited debate surrounding optimal excess emissions regulation. Using Texas data from 2002 to 2017, we show robust evidence on the costs of excess emissions. We find that excess emissions increase harmful nearby pollution and elderly mortality, and are responsible for an average of 35 annual deaths in Texas alone. Using excess emissions as an instrument for ozone concentrations, we find that a 10% increase in monthly average ozone increases elderly mortality by 3.9%, driven by increased deaths in the oldest age groups.

过量排放是指超出设施允许水平的空气污染排放，发生在工厂启动，关闭或故障期间。尽管它们违反了联邦《清洁空气法》，但从历史上看，各州都已授予违反设施的自动豁免权；限制执法并削弱现有法规。最近为协调州和联邦法规而做出的努力引发了围绕最佳超额排放法规的辩论。使用2002年至2017年的德克萨斯州数据，我们显示了过量排放成本的有力证据。我们发现，过量排放会增加附近有害的污染和老年人死亡率，仅德克萨斯州每年就造成35人死亡。使用过量排放作为臭氧浓度的一种手段，我们发现每月平均臭氧增加10％可使老年人死亡率增加3.9％，