Analysis of DNA damage among urban female street sweepers expose to vehicular exhaust

Date of Publication


Document Type


Degree Name

Doctor of Philosophy in Biology

Subject Categories



College of Science



Thesis Adviser

Glenn L. Sia Su

Defense Panel Chair

Florencia G. Claveria

Defense Panel Member

Maria Carmen A. Lagman
Noel F. Alfonso
Gliceria B. Ramos
Josephine D. Agapito


Occupational exposure to vehicular exhaust in Metro Manila, Philippines is a major human health risk concern because of the established DNA damaging potential of some of its components like PAHs. Hence, in this study, peripheral blood leucocytes of 50 urban female street sweepers/exposed subjects and an equal number of housekeepers and housewives/reference group were analyzed for DNA damage utilizing the Micronucleus (MN) test and the alkaline single cell gel electrophoresis (SCGE) or comet assay as biomarkers. This study also determined the influence of some demographic characteristics like age, length of fuel exhaust exposure, smoking and alcohol/coffee/tea drinking on DNA damage. Possible association of DNA damage and hematological parameters to include RBC count, WBC count, hematocrit, hemoglobin, lymphocytes and segmenters was also made. Results showed that exposure to vehicular exhaust has caused an increase in tail lengths (8.48±3.41 μm versus 19.35±8.79 μm) and tail moments (1.93±1.43 versus 8.02±5.71) of the leucocytes as demonstrated by the comet assay, but such increase was not observed in micronucleation. Differences in the demographic characteristics of the study population were not significant (p > 0.05) but comet assay results of the smokers, alcohol/coffee/tea drinkers with longer length of exposure to fuel exhaust recorded higher DNA damage compared to the smokers (p < 0.05), alcohol/coffee/tea drinkers of the reference group. Hematological parameters were not affected by fuel exhaust exposure (p > 0.05). Results of the current study suggest the possibility that constant exposure to fuel exhaust could lead to a transient increase in the levels of damage in the DNA of leucocytes and that the comet assay was a particularly sensitive technique in detecting such effects. Other studies are needed to better understand the degree of fuel exhaust exposure needed and the mechanism involved so that the DNA damage may be translated into micronucleus formation.

Abstract Format






Accession Number


Shelf Location

Archives, The Learning Commons, 12F Henry Sy Sr. Hall


DNA damage; Street cleaners; Women employees; Automobiles—Pollution control devices

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