Cytogenetic Analysis among Train Depot Workers Exposed to Total Volatile Organic Compounds

Abstract

Occupational exposure to toxic chemicals such as Total Volatile Organic Compounds (TVOC) from diesel engine exhaust implicates genotoxic risk. The objective of this study was to determine the DNA damage among KL Sentral depot workers exposed to TVOC by means of cytogenetic analysis. Data were obtained partially from disseminated questionnaires and buccal cells samples were collected from a total of 27 depot workers and 10 office workers by using wooden tongue depressor. TVOC measurement was carried out by using Photoionisation Detector (PID). 4 sampling points were selected, namely Locomotive (LOCO), Power Generating Car (PGC), refuelling of diesel and coach. Cytogenetic analysis was done by using Acridine Orange (AO) staining. Micronucleus (MN) frequency as a biomarker for DNA damage was scored from 1,000 cells per sample observed under fluorescence microscope. The results showed that the overall means of concentrations for TVOC were 0.1±0.1, 0.0±0.0, 0.1±0.0 and 0.1±0.0 in LOCO, PGC, refuelling of diesel and coach, respectively. TVOC concentration measured did not exceed the permissible level based on DOSH 2010. For the cytogenetic analysis, depot workers showed significantly higher MN (p<0.001) than the office workers. Besides that, the sociodemographic factors (e.g., age, smoking status) and the MN frequency of the depot workers were also significantly higher than the office workers. However, there was no significant difference in MN frequency between workers wearing Personal Protective Equipment (PPE) and without wearing PPE [MN (p=0.491)]. In addition, there was a positive correlation between the working period (year) and the frequency of MN with r²=0.54, p<0.01. The result also showed that exposure to TVOC was a significant predictor of the MN frequency (p<0.001). On the other hand, smoking status did not show any significant association with the frequency of MN. These findings showed that depot workers exposed to TVOC were prone to DNA damage. Therefore, biomonitoring of DNA damage among depot workers is recommended in order to improve occupational health and safety condition in their workplace.