House dust mites (Der p 1, Der f 1), cat (Fel d 1) and cockroach (Bla g 2) allergens in indoor work-places (offices and archives)

BACKGROUND: Exposure to indoor allergens has already been shown to occur in many public places, including workplaces, in several countries. Aim of this study was to measure the levels of house dust mites, cat and cockroach allergens in indoor workplaces (offices and archives) in Italy and to evaluate the possible relationships between allergen levels and building characteristics, type of ventilation, indoor relative humidity and temperature. METHODS: Der f 1 and Der p 1, Fel d 1, Bla g 2 were measured by ELISA in dust samples collected from floors or upholstered seats of 160 workplaces. RESULTS: Detectable Der p 1 levels were found in 86 (54%) workplaces Der f 1 in 87 (55%), Fel d 1 in 86 (54%) and Bla g 2 in 3 (1.9%). Der p 1 allergen concentrations expressed per weight were higher than the proposed sensitization thresholds in 7 samples, Der f 1 in 5, Fel d 1 in 6 and Bla g 2 in 3. The highest allergen levels were detected in samples from upholstered seats. A significant correlation was found between Der f 1 level on floors, expressed per surface, and indoor temperature (r = 0.39; P < 0.01). CONCLUSIONS: In our study we found that upholstered seats in workplaces in Italy may constitute a significant reservoir both of house dust mites and cat allergens. Exposure to these allergens in workplaces may represent a risk factor for elicitation of symptoms and/or induction/maintenance of inflammation in allergic individuals and might also constitute a risk factor for sensitization.