A community-based study on associations between PM and PM exposure and heart rate variability using wearable low-cost sensing devices.

Few studies have investigated the effect of personal PM and PM exposures on heart rate variability (HRV) for a community-based population, especially in Asia. This study evaluates the effects of personal PM and PM exposure on HRV during two seasons for 35 healthy adults living in an urban community in Taiwan. The low-cost sensing (LCS) devices were used to monitor the PM levels and HRV, respectively, for two consecutive days. The mean PM and PM concentrations were 13.7 ± 11.4 and 12.7 ± 10.5 μg/m (mean ± standard deviation), respectively. Incense burning was the source that contributed most to the PM and PM concentrations, around 9.2 μg/m, while environmental tobacco smoke exposure had the greatest impacts on HRV indices, being associated with the highest decrease of 20.2% for high-frequency power (HF). The results indicate that an increase in PM concentrations of one interquartile range (8.7 μg/m) was associated with a change of -1.92% in HF and 1.60% in ratio of LF to HF power (LF/HF). Impacts on HRV for PM were similar to those for PM. An increase in PM concentrations of one interquartile range (8.7 μg/m) was associated with a change of -0.645% in SDNN, -1.82% in HF and 1.54% in LF/HF. Stronger immediate and lag effects of PM exposure on HRV were observed in overweight/obese subjects (body mass index (BMI) ≥24 kg/m) compared to the normal-weight group (BMI <24 kg/m). These results indicate that even low-level PM concentrations can still cause changes in HRV, especially for the overweight/obese population.