Winter indoor environment of elderly households: A case of rural regions in northeast and southeast China

To study the winter indoor environment in the rural homes with elderly individuals in different climate regions, households with elderly individuals in Qiqihar (northeast China) and Shanghai (southeast China), were selected for questionnaire surveys (50 and 60 households in Qiqihar and Shanghai, respectively) and field measurements (10 and 5 households in Qiqihar and Shanghai, respectively). The field measurements included the monitoring of air temperature, relative humidity (RH), carbon dioxide (CO2), particulate matter (PM) with an aerodynamic diameter of 2.5 mu m or less (PM2.5), carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs) concentration. The results indicated that elderly individuals in Qiqihar had large temperature steps ranging from 15 to 35 degrees C between the indoor and outdoor, and experienced unsteady thermal environment, but those in Shanghai experienced low temperature, high RH, and steadier thermal environment. Additionally, the thermal neutral temperatures in Qiqihar and Shanghai were 17.32 degrees C and 16.91 degrees C, higher than air temperatures for living-bedrooms/kitchens (14.5 +/- 4.3 degrees C/12.8 +/- 4.7 degrees C) and for living rooms/bedrooms (10.4 +/- 1.5 degrees C/10.5 +/- 1.5 degrees C). Moreover, the older people had higher blood pressure in lower temperature. Qiqihar households showed more serious air pollution than Shanghai. For Qiqihar households, the concentration of PM2.5 and total VOCs (TVOC), which exceeded the standard, accounted for 90%, while PM2.5 concentrations in 4 households were 6 times higher than the standard. This study provides valuable data for future work on environmental risk assessment in elderly households in rural areas.