LEVELS AND RISK ASSESSMENTS OF POLYCYCLIC AROMATIC HYDROCARBONS IN SURFACE DUST FROM ELECTRONICS AND ELECTRICAL MATERIALS MAINTENANCE SHOPS

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are toxic organic compounds causing health related risks. They can be present in, air, surface dust and soil having natural and anthropogenic sources like incomplete combustion of electronic waste (E-waste). Surface dust from electronics and electrical material maintenance shops may contribute organic pollutants to the environment due to the E-waste processing activities. These indicate that investigating the levels and risk assessments of PAHs associated to such activities is crucial. Herein, the levels of selected PAHs, fluorene, naphthalene, and phenanthrene, in surface dust collected from selected electronic and electrical materials maintenance workshops in Dire Dawa, Harar city, Haramaya University and Haramaya town were investigated using an optimized QuEChERS method prior to the HPLC analysis. The obtained results showed that the investigated surface dust samples contained high concentration of PAHs, 1.50–2.04, ND–1.58, and 1.43–5.2, µg g-1 fluorene, naphthalene, and phenanthrene, respectively. The highest concentration of total PAHs (8.33 µg g-1 ) was found in samples collected from the workshop in Dire Dawa city, followed by Haramaya University (4.98 µg g-1 ), Haramaya town (4.85 µg g-1 ), and Harar city (3.24 µg g-1 ). The obtained adult daily intake dosage values were in the range of 2.88–7.40 ng kg−1 d−1 , suggesting that E-waste processing activities may increase a substantial risk of non dietary PAHs to exposed workers under poor labor protection conditions. The obtained hazard quotient ≤2.60 × 10−3 and hazardous Index ≤3.02 × 10−3 values were below 1, indicating insignificant non-cancer risk of exposure to the dust-bound PAHs. Even though incremental lifetime cancer risk total was estimated at 6.25 × 10−6 –1.6 × 10−5 for adult that seems at tolerable levels for lifetime cancer risk, the highest attained of 1.6 × 10−5 is above the critical value of 10−5 , which suggest that workplace dusts may pose in cancer risk. The correlation results (0.12 ≤ r ≤ 0.74) and one way ANOVA analysis showed that the amounts of analytes were significantly different, suggesting that the contaminants share same origin. In general, it is recommended to improve the working conditions of workshop workers, and inform residents to limit their stay in electronic maintenance workshops