Renee Bittoun1, Euan Tovey, PhD2, Leanne Lai, BSc, Hons3, and Dee Carter, PhD3. (1) Brain and Mind Reseach Institute, University of Sydney, 100 Mallett Street, MO2F, University of Sydney, Sydney, Australia, (2) Woolcock Institute of Medical Research, University of Sydney, 88 Mallett Street, Sydney, Australia, (3) Disipline of Microbiology, School of Molecular and Microbial Biosciences,, University of Sydney, University of Sydney, Sydney, Australia
Background: As biological material, tobacco leaf is susceptible to growth of fungi, particularly during processing and storage. Inhaled fungi potentially present two hazards; from inflammatory respiratory diseases directly associated with exposure to the inhaled spores, and secondly, from cancer-inducing mycotoxins associated with some fungal species. Our experience is that commercial tobacco is treated to prevent fungal growth, but this is not the case with ‘home grown' tobacco, which is preferred by some as it is cheap and believed to be ‘safe'. This study aimed to identify the types of fungi present in a variety of ‘homegrown' tobacco samples.
Method: 43 samples of home-grown tobacco were obtained via smoker's clinics; samples of were plated onto DRBC agar and further subcultured for identification of mycotoxin-producing species. Samples were analysed for aflatoxins.
Results: 81% contained fungii (56% >100 fungal colonies/g). The predominant genera were Aspergillus, Penicillium and Alternaria. 51% of samples contained A. flavus and 31% of A. flavus produced aflatoxins by culture.
Conclusions: Most ‘home-grown' tobacco samples contained significant quantities of fungi.
Implications: Many of these were associated with causing recognised respiratory health risks, such as extrinsic allergic alveolitis and also with the production of potentially carcinogenic mycotoxins. Such fungi would add to the existing hazards associated with tobacco use and this study refutes folk-wisdom that home-grown tobacco may be intrinsically ‘safer' than commercial tobacco.
