An analysis of the genotoxicity of e-waste dumpsites in and around Metro Manila, Philippines using allium cepa assay as a bioindicator

Date of Publication

3-2017

Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Biology

Subject Categories

Toxicology

College

College of Science

Department/Unit

Biology

Thesis Adviser

Zeba F. Alam

Abstract/Summary

Increase in the usage of electronic gadgets and their improper disposal has led to the massive problem of electronic waste management in the Philippines. The improper disposal of e-waste can lead to the exposure to the hazardous substances that can be harmful to the humans as well as to the environment. Genotoxicity of e-waste from three different e-waste landfills sites in and around Metro Manila, were investigated using the Allium cepa bioassay. Morphological modifications of the Allium cepa roots, inhibition of root growth, mitotic index and the induction of high frequency of chromosomal aberrations were observed in the Allium cepa roots exposed to e-waste leachates prepared from the soil samples collected from all three sites tested as compared to the control. Since heavy metals are one of the hazardous components released during e-waste recycling, environmental contamination was further detected by Atomic Absorption Spectroscopy to detect the presence of heavy metals (Cd, Cu, Ni, Pb and Zn) in the soil samples of the e-waste recycling sites and in the hair of the informal recyclers. In the soil samples, the concentrations of heavy metals in the e-waste site were in the rank order Ni > Cu > Pb > Zn > Cd according to their means. These concentrations of heavy metals were found to be many folds higher than the maximum permissible limits recommended by WHO though statistically insignificant. In the hair samples, the levels of all heavy metals in rank order according to their means were: Zn > Ni > Cd > Cu > Pb for both the control and experimental groups. The results are among the first few in the Philippines that establish the genotoxicity of e-waste as well as trace the route of the heavy metal component of e-waste into the human subjects through the exposure to the environmental contamination by e-waste. Hence, a proper e-waste management is an absolute priority to minimize the risk to the Filipino population and the environment.

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTU021789

Shelf Location

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

Keywords

Electronic waste--Philippines--Metro Manila; Genetic toxicology; Heavy metals; Plant bioassay; Onions

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Embargo Period

5-28-2025

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