Toxigenic fungi and mycotoxins in outdoor, recreational environments

Some epidemiological studies of damp buildings have focused on health risks from indoor exposure to toxigenic fungi and mycotoxins. Most of these studies have not considered assessment of these hazards in outdoor environments. The purpose of this investigation was to assess for toxigenic fungal species in outdoor recreational environments through the microbial analysis of locations representing opportunities for human exposure. A screening assessment was also conducted using commercially available ELISA kits to assess for trichothecene mycotoxins in outdoor samples.

Ten swab and tape-lift samples were obtained from a city park. Swabs were cultured and identified by a trained mycologist. Bulk samples of grasses were screened for deoxynivalenol using a commercial ELISA assay. A pilot study of 6 bulk samples was screened for macrocyclic trichothecenes using a commercial ELISA assay.

Tape-lift samples contained trace to moderate spores. Penicillium and Aspergillus-like spores were identified in 50% of tape-lift samples. 50% of swab samples contained potentially toxigenic species of Penicillium (P. citrinum, P. brevicompactum, P. chrysogenum). None of the bulk samples tested positive for deoxynivalenol. 3 of 6 (50%) bulk samples were positive for macrocyclic trichothecenes (> 0.2 ppb), however both negative control samples also tested positive.

Potentially toxigenic fungi were commonly encountered in an outdoor, recreational environment. Future epidemiological studies need to consider outdoor activities in hazard and exposure assessment. Further work is needed to define the accuracy of commercially developed ELISA kits that are being used for the detection of mycotoxins in environmental samples.