In its account of the event, the state-run China News Service said that some of the residents who lined up for the chance to inhale—they were limited to a few minutes each—tried to wring the bags in order to extract every bit of air possible.

“I felt my baby move right when I breathed in,” one pregnant woman who participated in the event told the agency. “I would love to walk in the mountain’s forests after my child is born,” Sun added. China’s environmental ministry announced last week that Zhengzhou was among the country’s top 10 most-polluted cities. Its AQI on Monday was an unhealthy 158. By contrast, the Monday AQI forecast for Bakersfield, CA, the most polluted city in the U.S., was 45.