COVID-19 Highlights an Environmental Injustice: Influence of Energy Insecurity on Urban Outdoor Air Pollution during Community Lockdown in South-Central Chile

Abstract

BACKGROUND AND AIM: In south-central Chile, outdoor air pollution primarily originates as household air pollution from wood burning for heating. The effect of COVID-19 lockdowns on ambient air pollution levels in urban south-central Chile, may therefore be different from trends observed in cities where transportation/industrial emission sources dominate. This study investigates the impact of COVID-19 lockdown on outdoor fine (PM2.5) and coarse (PM10) particulate matter concentrations in Temuco, Chile. METHODS: Hourly PM2.5 and PM10 measurements from six air monitoring stations (three reference-grade beta attenuation monitors and three low-cost sensors) in commercial and low- and middle-income residential areas of Temuco were compared during winter months (March-September) in 2019 and 2020 (spanning COVID-19 lockdown). RESULTS:Average monthly PM2.5 concentrations in low-income residential areas of Temuco during winter 2019 ranged from (36-53 µg/m3), approximately twice as high as concentrations in commercial areas (12-29 µg/m3). During COVID-19 lockdown, average monthly ambient PM2.5 concentrations in a commercial and middle-income residential area of Temuco were up to 50% higher (12 µg/m3 to 18 µg/m3) and 59% higher (22 µg/m3 to 35 µg/m3) than 2019 levels, respectively. Conversely, PM2.5 levels decreased by up to 52% (43 µg/m3 to 21 µg/m3) in three low-income neighborhoods. The night-time mass percent of PM10 that was PM2.5 in April 2020 increased by 48% above April 2017-2019 proportions (50% to 74%) in a commercial area. CONCLUSIONS:Wood burning was responsible for a significantly higher proportion of ambient PM2.5 pollution in commercial areas and a middle-income neighborhood of Temuco during COVID-19 lockdown, compared to winter months in 2019. Energy insecure households likely refrained from wood heating during lockdown, leading to PM2.5 concentration declines in low-income neighborhoods. To reduce ambient air pollution and energy insecurity resulting from reliance on wood for heating in south-central Chile, affordability of clean heating fuels (e.g. electricity, liquefied petroleum gas) should be a policy priority. KEYWORDS: COVID-19, residential heating, household air pollution, particulate matter, energy insecurity, PM2.5