Cooking, Health, and Daily Exposure to Pollution Spikes

Many routine daily activities—such as cooking and commuting—cause large recurring pollution spikes that may impact health without significantly affecting average exposure. We study pollution spikes by combining experimental variation in cooking technology with high-frequency data on individual pollution exposure and time-use in Kenya. Improved cookstoves reduce PM2.5 spikes while cooking by 51.3 μg/m 3 (41 percent) and cause a 0.24 standard deviation reduction in self-reported respiratory symptoms. However, even after more than three years of daily use, we find no clinical health improvements, possibly because we detect no impact on average exposure. Clinical health improvements may require reductions in ambient concentrations. (JEL I12, O12, O13, Q51, Q53)