Association between microenvironment air quality and cardiovascular health outcomes.

Abstract

Exposure to fine particulate matter (PM2.5) is associated with cardiovascular disease risk. To date, there are few studies on short-term PM2.5 exposure in different microenvironments and its impact on immediate health effects, particularly in the Southeast Asia region. This study assessed PM2.5 concentrations in different microenvironments in a densely populated city in the tropics using low-cost personal PM2.5 sensors as well as their associations with acute cardiovascular health outcomes. A total of 49 adult participants affiliated with the National University of Singapore (NUS) community were recruited. Personal low-cost sensors were used to measure PM2.5 concentrations between September 2017 and March 2019. Demographic information and time-activity patterns were collected using questionnaires. Wilcoxon pairwise comparisons were used to determine statistical differences between PM2.5 exposures at 18 different microenvironments. Generalized Estimating Equations (GEE) models were used to assess the association between PM2.5 exposure and blood pressure as well as heart rate. All models were adjusted for age, sex, body mass index, physical activity, temperature, duration of exposure, and baseline cardiovascular parameters. Significant differences in PM2.5 concentrations were observed across different microenvironments. Air-conditioned offices and tertiary teaching spaces had the lowest (median=13.1μg/m3) and hawker centres had the highest (median=32.0μg/m3) PM2.5 concentrations. Significant positive associations between PM2.5 exposure and heart rate (β=0.40, p=4.6×10-5) as well as diastolic blood pressure (β=0.16, p=0.0077) were also observed. Short-term exposure to PM2.5 was significantly associated with higher heart rate and blood pressure. Further work is needed to investigate the variations within each type of microenvironment and expand the study to other sub-populations such as the elderly and children.