Personal Exposure To Particulate Matter And Heart Rate Variability Among Informal Electronic Waste Workers At Agbogbloshie: A Longitudinal Study

Background: Informal electronic waste recycling activities are major contributors to ambient air pollution, yet studies assessing the effects or relationship between direct/continuous exposure of informal e-waste workers to particulate matter and cardiovascular function are rare. Methods: : Repeated measurements of fractions of PM 2.5 , PM 10-2.5 , and PM 10 in personal air of informal e-waste workers, (n=142) and a comparable group (n=65) were taken over a period of 20 months (March 2017 to November, 2018). Concurrently, 5-minute resting electrocardiogram was performed on each participant to assess resting heart rate variability indices. Linear mixed-effects models were used to assess the association between PM fractions and cardiac function. Results: SDNN, RMSSD, LF, HF and LH/HF ratio were all associated with PM. Significant associations were observed for PM 2.5 and MEANNN ( p = 0.039), PM10 and SDNN ( p = 0.035) and PM 10-2.5 and LH/HF ( p = 0.039). A 10µg/m 3 increase in the concentrations of PM 2.5 , PM 10-2.5 , and PM 10 in personal air was associated with reduced HRV indices and increased resting HR. A 10µg/m 3 per interquartile (IQR) increase in PM 10-2.5 and PM 10 , decreased SDNN by 11% [(95% CI: -0.002- 0.000); ( p = 0.187)] and 34% [(95% CI:-0.002-0.001); ( p = 0.035)] respectively. However, PM 2.5 increased SDNN by 34 % (95% CI: -1.32-0.64); ( p = 0.493). Also, 10µg/m 3 increase in PM 2.5 , PM 10-2.5 and PM 10 decreased RMSSD by 27% [(-1.34-0.79); ( p = 0.620)], 11% [(-1.73, 0.95); ( p = 0.846)] and 0.57% [(-1.56-0.46); ( p = 0.255%)]. Conclusion: Informal e-waste workers are at increased risk of developing cardiovascular disease from cardiac autonomic dysfunction as seen in reduced HRV and increased heart rate.