Monitoring indoor TVOC with novel continuous real-time sensor in low-income urban public housing in Boston, MA

This investigation on indoor residential environment of urban low-income public housing focuses on exploring the indoor TVOC concentration level and its association with renovation status. 49 Boston public housing homes were enrolled and each household was followed for one-year with three home visits. Two hourly measurements of indoor TVOC were collected during each home visit and other indoor environmental parameters, such as temperature, relative humidity and air exchange rate, were monitored over 4-day period during each home visit. Field technicians interviewed family's primary caregivers (e.g. mother) to collect household information. Descriptive statistics was used to summarize indoor TVOC concentration and mixed effects models were applied to analyse association between indoor TVOC concentration and major variable of interest, such as renovation status. Indoor TVOC concentration was significantly associated with renovation status (p=0.02); renovated homes reported higher indoor TVOC concentration (median=511 ppb) compared to non-renovated homes (median=242 ppb). Renovation status was also significantly associated with lower air exchange rate (p=0.01). Within-household variance (Σ² _w=8.11 ppb) was 7 times greater than between-household variance (Σ² _w=1.36 ppb); seasonality and air exchange collectively explain 53% variability. Although indoor TVOC concentration did not exceed any known reference concentration, the concentration difference of indoor TVOC between renovated and non-renovated households could be of concern as more Boston public housing communities receive weatherization-based renovation.