Evaluation of occupational exposure to xylene in petroleum workers by assessing urinary methyl hippuric acid and cellular changes of exfoliated epithelial cells in buccal mucosa smears

Abstract

Xylene is an important component of petrol and a widely distributed environmental contaminant. About 98% of Xylene is derived from the petrochemical and petroleum refining industries. When human get expose to xylene, which is one of the major Geno toxicants, may be associated with a range of acute/chronic diseases and cancer still literature is not available. Taking into our mind that occupational exposure to such derivatives may possess genotoxic risk or not. Hence our study aims to investigate and correlate the cellular changes in exfoliated oral epithelial cells oral smears with urinary methyl hippuric acid level estimation in petrol pump workers and to identify the significant role of xylene on oral mucosa. Materials and Methods: Urine samples and oral buccal mucosa smears were collected from 30 healthy individual (control) and 30 petroleum pump workers (case) working in petroleum station who are above 18 years of age. The urine was collected before exposure/work shift and after completion of work shift. The urinary methyl hippuric acid (MHA) level was analyzed by using Shimadzu UV-Visible Spectrophotometer procedure. The smeared slides were stained with PAP stain and analyses the cytomorphometric changes of exfoliated epithelial cells by using Axio Vision SE64 Rel 4.9.1. Ink Software. Results: The urinary Methyl hippuric acid level was substantially higher in cases than in controls (p<0.001). The Micronuclei (MN) frequency was drastically increased in cases than in controls and was statistically highly significant (P<0.0001). The frequency of MN gradually increased along with increased urinary MHA level in petroleum pump workers (case). Conclusion: The urinary MHA level and MN frequency is a useful index to recognize the occupational exposure to the petroleum product. Thus, our study emphasizes that appropriate precaution and regular biomonitoring must be taken among petrol pump workers which shall help to reduce their potential levels of risk associated with the occupation.