Field investigation of indoor air quality and its association with heating lifestyles among older people in severe cold rural China

Persistent extreme cold in Northeast China, spanning six months, has led to unique adaptive heating practices among rural residents. Practices such as using solid fuels and maintaining airtight living spaces are linked to compromised indoor air quality (IAQ) and have implications for public health. This study investigated the IAQ and heating lifestyles in six typical rural dwellings in Northeast China over one week. We documented the dynamic profiles of indoor pollutants and examined the influence of heating habits on these patterns. Our findings reveal alarmingly high levels of PM_2.5, averaging 272 μg/m³, and peak concentrations of CO₂ and CO reaching about 2500 ppm and 75 ppm, respectively. Although these dwellings presented similar time-varying air pollution patterns, the use of different fuels and variations in dwelling construction resulted in significant differences in air quality. Factors such as fuel use ratios and the permeability of building inner envelopes were found to be critical parameters in determining the IAQ. Through correlation analysis between the IAQ metrics and these factors, we derived multiple linear regression models. This investigation provides solid evidence explaining the relationship between the local heating lifestyle of older rural people in Northeast China and poor IAQ. The research results can guide appropriate control measures to improve IAQ during the half-year heating season in this region.