[The effect of sex factors on cytologic changes in the sputum of young adults exposed to urban air pollution].
The harmful effect of occupational and urban air pollution on the function and structure of the respiratory tract has been proved. The severity and incidence of epithelial changes are in direct relation to duration of exposure and age of the examined population groups [1]. Squamous metaplasia of bronchial epithelium is an indicator of predisposition to chronic obstructive pulmonary disease and lung cancer [1-5]. Due to its topography and the development of industry and traffic, Sarajevo used to be the city with an extremely high level of air pollution [10-12]. Some studies in adults showed that the respiratory tract exposed to air pollution responded with more severe changes in men than in women [7-9]. The aim of this study was to compare cytological changes in sputa, depending on the sex of young adults exposed to a high level of urban air pollution, and to examine whether a big difference in duration of exposure has an effect on these relations.


METHODS
The subjects in the study were young adults, university students (21 to 25 years of age), all non-smokers. At the time of sputa collection (March-April 1991) they were clinically healthy with no history of chronic and serious acute respiratory diseases. They were divided into two groups according to the duration of air pollution exposure. The first group included those who had been living in Sarajevo since birth. The second group included those who used to live in pollution-free areas, but for the last two to three years had been living in Sarajevo where they came to attend the University (Table 1). Specimens were early morning spontaneously produced sputa, expectorated directly into Saccomanno's fixative and after centrifugation immersed in paraffin. Nine sections from each block were cut and stained with haematoxylin and eosin. The differences between cytological findings were tested with Hi2 test and Fisher's exact test, regarding sex and duration of exposure to air pollution.


RESULTS
The findings are summarized in Table 1. As many as 63% and 64% of the subjects from the first and the second group, respectively, were able to produce sputum, while the others produced saliva only. All sputa contained abnormal bronchial columnar cells and half of them contained respiratory spirals (Figures 1 and 2). Squamous metaplastic cells were found in 7% and 9% of subjects in the first and second group, respectively. These cells showed no evidence of atypia. Statistical tests failed to identify significant differences in the incidence of cytological findings between the groups regarding both the sex of the subjects and duration of their exposure to air pollution (Table 2).


CONCLUSIONS
The ability to produce sputum with the frequent presence of respiratory spirals in both groups of our subjects indicate an extremely harmful effect of smog. However, the incidence of squamous metaplastic cell findings was less severe comparing to adults and the elderly urban population. In the elderly (65 to 105 years of age) severe epithelial changes developed spontaneously in the absence of any other known aetiological factor [8, 9]. The increase in severity of changes in the course of aging, in our opinion, due to a gradual decline in efficiency of the defence mechanisms and regenerative potential of the respiratory system. The experimental study showed a decline of the efficiency of mucociliary clearance [14] as well as the damage of the function and decrease in number of alveolar macrophages in lung parenchyma and bronchoalveolar lavage [15, 16]. Trying to answer the question why the sex-related differences in the severity and incidence of epithelial changes appear in the groups of adults and the elderly, it is presumed that in aging the defence and regenerative potentials decline more rapidly in men than in women. (ABSTRACT TRUNCATED)
Djuricić
S
S
Department of Clinical Pathology, Mother and Child Health Institute of Serbia, Belgrade.
Plamenac
P
P
D000328:Adult; D000397:Air Pollution / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D012737:Sex Factors; D013183:Sputum / Q000166:cytology*; D014504:Urban Health; D015022:Yugoslavia
Uticaj pola na citoloske promene u sputumu kod mladih odraslih ljudi islozenih gradskom aerozagadjenju.