Using Low-Cost Sensors to Assess Fine Particulate Matter Infiltration (PM2.5) during a Wildfire Smoke Episode at a Large Inpatient Healthcare Facility

Abstract

Wildfire smoke exposure is associated with a range of acute health outcomes, which can be more severe in individuals with underlying health conditions. Currently, there is limited information on the susceptibility of healthcare facilities to smoke infiltration. As part of a larger study to address this gap, a rehabilitation facility in Vancouver, Canada was outfitted with one outdoor and seven indoor low-cost fine particulate matter (PM2.5) sensors in Air Quality Eggs (EGG) during the summer of 2020. Raw measurements were calibrated using temperature, relative humidity, and dew point derived from the EGG data. The infiltration coefficient was quantified using a distributed lag model. Indoor concentrations during the smoke episode were elevated throughout the building, though non-uniformly. After censoring indoor-only peaks, the average infiltration coefficient (range) during typical days was 0.32 (0.22–0.39), compared with 0.37 (0.31–0.47) during the smoke episode, a 19% increase on average. Indoor PM2.5 concentrations quickly reflected outdoor conditions during and after the smoke episode. It is unclear whether these results will be generalizable to other years due to COVID-related changes to building operations, but some of the safety protocols may offer valuable lessons for future wildfire seasons. For example, points of building entry and exit were reduced from eight to two during the pandemic, which likely helped to protect the building from wildfire smoke infiltration. Overall, these results demonstrate the utility of indoor low-cost sensors in understanding the impacts of extreme smoke events on facilities where highly susceptible individuals are present. Furthermore, they highlight the need to employ interventions that enhance indoor air quality in such facilities during smoke events.

Outdoor and indoor fine particulate matter at skilled nursing facilities in the western United States during wildfire and non‐wildfire seasons

“…Similar results were also seen in a 12 days study conducted in a retirement community, where Buczynska et al found no significant indoor sources of air pollution but did see a positive relationship between outdoor and Indoor Air Quality 5 . Another group recently published an investigation of a single healthcare building during a two‐month period of the 2020 wildfire season where they deployed two outdoor and seven indoor PM 2.5 sensors 41 . Their results indicate that PM 2.5 infiltrates the indoor space to a greater degree during a smoke event and is variable by location within the building.…”

“…5 Another group recently published an investigation of a single healthcare building during a two-month period of the 2020 wildfire season where they deployed two outdoor and seven indoor PM 2.5 sensors. 41 Their results indicate that PM 2.5 infiltrates the indoor space to a greater degree during a smoke event and is variable by location within the building.…”

Protecting Cardiovascular Health From Wildfire Smoke

“…Health facilities should continuously monitor and compare outdoor and indoor PM concentrations to assess the effectiveness of cleaner air interventions. 83 Changes in indoor pollutant concentrations can signal building managers to adjust HVAC systems and other interventions.…”

Cumulative Impacts of Diverse Land Uses in British Columbia, Canada: Application of the “EnviroScreen” Method

“…With the inclusion of future climate data, northern BC LHAs score higher given the faster rate of warming being experienced relative to coastal and southern regions of the province. The inclusion of climate data is an increasingly important function of environmental exposures in BC given recent risks associated with flooding [ 33 ], wildfires [ 34 ] and extreme heat [ 35 ]. Notably, the inclusion of these and other variables in the BCEnviroScreen perhaps requires a change in moniker from a ‘pollution burden’ score to something that approximates a cumulative measure of ‘landscape burden’.…”