Twenty-eight ceramic workers aged between 19 and 64 years old (mean age 46,28 years old) participated in the study. All of them resided in the town of Caltagirone characterized by a humid climate. The overall duration of the ceramic working period was 27,82 years. The working setting consisted of minor industries located in homes or small factories.
Of the 28 subjects, 8 (28,57%) were allergic (3 to grasses, 1 to mites, 2 to parietaria, 1 to alternaria, 1 to grass and mites), 3 (10,71%) had previous upper airway surgery (2 adenoidectomy, 1 septoplasty), 9 (32,14%) were smokers and 5 (17,85%) were former smokers. Nasal symptoms were reported by all the participants. Nasal congestion was the main symptom, followed by sneezing and itching of the nasal mucosa. In particular, the subjects who reported sneezing referred it as immediately as they entered their workplaces or during contact with the glazes and crystalline materials.
All of them worked the refined clay by hand. 89,28% of the study population (25 subjects) reported that either the process of clay modelling, or its drying and firing, took place in the same environment, while 3 of them (10,71%) made use of an electric oven for the firing process, placed in a separate room from the workroom.
Room air extractors were present only in 5 cases (17,85%): located inside of the laboratory for 2 subjects, and for the other 3, the air extractors were placed where the electric oven was situated. Only 6 participants (21,42%) did not make use of plaster molding.
For the decoration techniques, 18 subjects (64,28%) used hand painting, while the other 10 (35,71%) made use of spray decoration. Two subjects (7,14%) made exclusive use of watery colours; otherwise, the others 26 (92,85%) used crystalline metal oxides, and enamels.
The cytological study of the nasal mucosa revealed the constant presence of abundant, thick and filamentous mucus, generally tending to be basic (Fig. 1). The mucus was detected in a lower quantity only in the samples of three subjects (10,7%), the ones with the oven in a separate room. In 10 participants (35,71%), precipitates and dust were documented (Fig. 2,3).
From a strictly cytological point of view, there was a reorganization of the nasal mucosa structure with a prevalence of muciparous metaplasia (Fig. 4) and numerous polynucleations (Fig. 3) and an almost total absence of hair cells; for rather all the subjects, 26 out of 28 or 92,85%.
Regarding the presence of inflammatory cells, 10 participants (35,71%) presented a majority of neutrophilic granulocytes (Fig. 1). Of the 8 allergic patients, nasal samples from 5 of them showed very rare neutrophils, and many lymphocytes and eosinophils were found only in a single rhinocytogram.