Work Category Affects the Exposure to Allergens and Endotoxins in an Animal Facility Laboratory in Italy: A Personal Air Monitoring Study

Simona Di Renzi,Renata Sisto,Maria Concetta D’Ovidio,Paola Melis,Stefania Massari,Annarita Wirz,Alessandra Chiominto,Maria Cristina Riviello,Emilia Paba,Anna Maria Marcelloni

doi:10.3390/app11167220

Abstract

Scientists and technicians who work in contact with laboratory animals are exposed to complex biological mixtures from animals, bedding and feed. The main objective of this study was to characterize the exposures to endotoxins and animal allergens in a biomedical research institution located in Central Italy by means of air sampling in the breathing zone of the staff during daily work activities. Forty-two inhalable dust samples were collected for endotoxins and allergens analysis. Filter extracts were analyzed using a Kinetic-QCL LAL kit for endotoxins; ELISA assays were performed for Mus m 1, Rat n 1, Can f 1, Fel d 1 and Equ c 4 detection. Laboratory animal attendants (LAAs) showed endotoxin concentrations significantly higher (4.59 ng/m3) than researchers (0.57 ng/m3), researchers working only in an office (0.56 ng/m3) and technicians (0.37 ng/m3). Endotoxin concentrations exceeding the recommended occupational exposure limit proposed by the Dutch Expert Committee on Occupational Safety were found in the case of two subjects in the animal attendants category. With regards to rat and mouse allergens, a higher average dose was found for mouse than rat allergens. Also for these bio-contaminants, the LAAs are confirmed as the work category at higher risk of exposure (15.85 ng/m3), followed by technicians (10.67 ng/m3), researchers (2.73 ng/m3) and researchers in an office (0.08 ng/m3). Fel d 1 was also detected (average: 0.11 ng/m3) highlighting a passive transport between living and occupational settings. Our data could be useful to improve the control and preventive measures, ensuring lower levels of allergens and endotoxins in animal facilities.

Highlights

Research scientists and technicians who work with laboratory animals are exposed to complex mixtures containing both allergens and bacterial endotoxins from animals, bedding and feed [1,2]
Laboratory animal attendants worked for about 167 min of their shift in animal rooms, where they were mostly changing cages; the remaining time they spent in the wash and storage areas
Personal exposure to airborne animal allergens and endotoxins was studied in a conventional animal facility

Summary

Introduction

Research scientists and technicians who work with laboratory animals are exposed to complex mixtures containing both allergens and bacterial endotoxins from animals, bedding and feed [1,2]. Animals constantly shed proteins via the urine, secretions and desquamation of skin, and these allergens can be released in the air or deposited on surfaces and equipment, so making the animal facility a risky environment for the development of allergies [3]. Endotoxins, lipopolysaccharide components of the cell-wall of Gramnegative bacteria with high biological potency in respiratory systems, may exist in the air of animal units due to the presence of organic material, causing an additional risk for personnel working there. Fecal bacteria in soiled bedding may produce increased concentration of endotoxins, compared to other settings, and this may be an occupational health concern [4]

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