Cytomorphological Pattern of Respiratory Epithelium among those Exposed to Cement Dust Pollution in Amran City – Yemen

Abstract

This is descriptive case control study, from July 2010 to July 2013, aimed to detect the respiratory epithelium changes in regards to occupational exposure to cement dust pollution. Sputum samples were collected from 531 individuals; of who 433 were exposed to cement dust pollution (cases) and 98 were non exposed (controls), their ages ranging from 11 to 70 years and genders participated 376/431 male and 155/531 female in the cases. Cytological one smear was prepared from each sample and demonstrated by Papanicolaou stain for detection of cytological changes and AgNOR method for evaluation of the mean count of AgNOR dots per nucleus. A significant correlation between exposure to cement dust pollution and respiratory epithelium changes was found among cases compared to controls. Cytological atypia (dysplasia) was detected in 21(4.8%) of the cases and was not detected in controls (P=0.013). Notably, squamous metaplasia was detected in 236(54.5%) of the cases compared to 43(43.9%) of controls (P=0.037). Acute inflammatory cells infiltrates were observed in 252(58.2%) of the cases compared to 43(43.9%) of controls (P=0.007). Chronic inflammatory cells infiltrates were observed in 45(10.4%) of the cases compared to 4(4.1%) of controls (P=0.032). Asbestos bodies were detected in 59(13.6%) of the cases and non of the controls (P=0.000). The fungal infection by Actinomyces israelii and Monilia were detected in 54(13%) and 9(2%) of the cases compared to 1(1%) of controls (p=0.001). Also were found a significant relationship between respiratory epithelium changes and duration, closeness, female than male, surrounding population than workers, and with Alhagz residence. The mean AgNORs dots counts were elevated in cases (3±.043) compared to (1.8±.07) in controls (P=0.000), in addition elevated with long term of duration, 3km to 5km of distance, male, workers, and with Alhagz village residence. Also it were elevated in cytological atypia (3.89±0.9) (P=0.000), squamous metaplasia (3.09±0.8) (P=0.035) and asbestosis (3.32±0.9) (P=0.004). This study concluded that exposure to cement dust is a risk factor for occurrence of respiratory epithelium atypical changes, Squamous metaplasia, susceptibility of infections, inflammatory changes and asbestosis. The cytological changes increase with duration, closeness, female than male, surrounding populations than workers and with Alhagz than other residence. Cytology is a useful technique in evaluation of environmental and pollution induced changes in respiratory tract. The mean AgNORs count is a useful indicator for cellular proliferation activity in respiratory epithelium and for prediction of the risk of exposure to certain carcinogenic elements that may induce lung cancer.