Journal of Cold Regions Engineering

Interior Alaska has indoor air quality (IAQ) issues similar to those of other far northern communities associated with long cold winters and reduced ventilation rates. We also have some interesting issues associated with elevated radon in homes built in the hills around Fairbanks, as well as elevated particulate levels created by smoke from forest fires that occur in the vast uninhabited portions of the state. To better understand the influences of critical variables such as indoor source strengths and ventilation rates on IAQ associated with forest fires and radon, we have developed a Simulink-based mass conservation model. Using data gathered at two homes in Fairbanks during 2003, we have used this model to predict indoor radon and ${\mathrm{PM}}_{2.5}$ levels (particles less than $2.5\mu \mathrm{m}$ in diameter). We find that we are able to predict both the rise of radon following the shutdown of a radon mitigation system and the variation of indoor ${\mathrm{PM}}_{2.5}$ by using ventilation rates consistent with what we have measured, ${\mathrm{PM}}_{2.5}$ source strengths associated with individuals in residences, and penetration and deposition rates compatible with what others have found. We have used situation-specific algorithms for subsurface radon source strength as well as particulate generation associated with cooking.

Advances have been made in engineering–geological studies of roadbeds in permafrost areas of the Qinghai–Tibet Plateau. The methodology used in engineering–geologic investigations has been greatly improved and provisions and regulations have been devised to guide engineering activities. Special attention has been paid to ground temperature and ice content because they are two of the most important and unique parameters for permafrost. Based on the data collected from recent studies, recommendations are made to enhance the stability of roadbeds. Under climate warming, a “roadbed cooling” approach is suggested for road constructions in “warm” permafrost. Advances have been also made in the prediction of changes in the permafrost engineering–geological environment, as induced by climate warming.