Pollution from wildfires constitutes a growing source of poor air quality globally. To protect health, governments largely rely on citizens to limit their own wildfire smoke exposures, but the effectiveness of this strategy is hard to observe. Using data from private pollution sensors, cell phones, social media posts and internet search activity, we find that during large wildfire smoke events, individuals in wealthy locations increasingly search for information about air quality and health protection, stay at home more and are unhappier. Residents of lower-income neighbourhoods exhibit similar patterns in searches for air quality information but not for health protection, spend less time at home and have more muted sentiment responses. During smoke events, indoor particulate matter (PM_2.5) concentrations often remain 3–4× above health-based guidelines and vary by 20× between neighbouring households. Our results suggest that policy reliance on self-protection to mitigate smoke health risks will have modest and unequal benefits.

野火造成的污染是全球空气质量差的一个日益严重的来源。为了保护健康，政府在很大程度上依靠公民来限制他们自己的野火烟雾暴露，但这种策略的有效性很难观察到。使用来自私人污染传感器、手机、社交媒体帖子和互联网搜索活动的数据，我们发现在大型野火烟雾事件期间，富裕地区的人们越来越多地搜索有关空气质量和健康保护的信息，更多地呆在家里并且更不快乐。低收入社区的居民在搜索空气质量信息而非健康保护方面表现出类似的模式，他们在家的时间更少，情绪反应也更温和。在烟雾事件期间，室内颗粒物 (PM _2.5) 浓度通常比基于健康的指南高出 3-4 倍，并且在相邻家庭之间相差 20 倍。我们的结果表明，依靠自我保护来减轻烟雾健康风险的政策将产生适度且不平等的收益。