Levels of formaldehyde and TVOCs and influential factors of 100 underground station environments from 2013 to 2015

Abstract

In this study, the environmental factors that affect airborne formaldehyde and total volatile organic compounds (TVOCs) were evaluated and the monthly variations in formaldehyde and TVOC levels in underground platforms of subway stations were compared. Formaldehyde level was determined from May 2013 to September 2015 for lines 1 to 4 of Seoul Metro. Samples for formaldehyde and TVOCs were collected at intervals of 30 min during a 60 min period, and then analyzed via high-performance liquid chromatography (HPLC) for formaldehyde and gas chromatography for TVOCs. Formaldehyde levels were correlated with depth of platform, whereas TVOC levels were negatively correlated with depth of platform. There were significant differences in levels of formaldehyde and TVOCs in 2013 and 2015 in the underground platforms. The highest levels of formaldehyde and TVOCs were in July from May to September, respectively (p < 0.05). Formaldehyde and TVOC levels varied greatly, depending on monthly variation and correlated with depth of platform. Therefore, Seoul Metro might need to manage the underground platforms at depth more carefully and further study the reasons behind the relatively high levels of formaldehyde and TVOC ranging from 12 to 22 m.