Genotoxic Effect of Automobile Exhaust Exposure among Motorized Tricycle Drivers in Tuguegarao City, Cagayan, Philippines using Micronucleus Assay: A Retrospective Cohort Study

Abstract

Motorized tricycle drivers are among the populations of the transport industry who are very much prone to the effects of hazardous substances found in automobile exhausts. This research was aimed to determine the risk factors of cytogenetic damage brought about by automobile exhaust exposure among motorized tricycle drivers of Tuguegarao City. In this study, a total enumeration of motorized tricycle drivers from of Pengue Ruyu, Tuguegarao City was done. Out of 52 tricycle drivers, only 51 participants were included in the study. Most of the tricycle drivers of Pengue Ruyu were primarily middle-aged drivers; substantially exposed to automobile exhaust; cigarette smokers and alcoholic drinkers; non-users of protective masks; had no vitamin supplementation; and had routes that involved driving across Barangay Tanza. A high incidence of genotoxicity [76.47% (95% CI: 64.83% to 88.11%)] among the study participants was observed. Among the categorical variables, only automobile exhaust exposure and vitamin supplementation showed significant correlation (p<0.05) with the development of cytogenetic damage. Automobile exhaust exposure was found to be a risk factor, while intake of vitamins as a protective factor. Statistical analysis showed that tricycle drivers substantially exposed to combustion products in automobile exhaust had a significantly (p<0.05) higher mean frequency of micronuclei and were 2.13 (90% CI: 1.12 to 4.08) times more likely to develop cytogenetic damage than those tricycle drivers who have low confidence of exhaust exposure. Tricycle drivers who have vitamin supplementation tend to have a significantly (p<0.05) lower mean frequency of micronuclei and reduce their risk of developing cytogenetic damage by 44% (90% CI: 4% to 55%) than those who do not take any vitamins at all. Wearing protective masks could be a protective factor as it may reduce the risk of developing cytogenetic damage by 46% (90% CI: -46% to 72%) but was found to be statistically insignificant. Identifying factors that contribute to the pathogenesis of genotoxicity in vulnerable and susceptible groups can help to plan for effective prevention strategies.