Grain harvesting as a local source of Cladosporium spp. in Denmark

Abstract

Cladosporium spp. are omnipresent moulds that grow on multiple substrates. Their spores possess a high allergenic potential. Currently, little is known about the incidence and the sources of airborne Cladosporium spores in Denmark. Air samples were collected between 31 May and 22 September 2015 in Viborg (Jutland, western Denmark). Eighteen out of 21 days with daily average concentrations exceeding the health relevant threshold of 3,000 Spores m-3, including the day with peak daily (13,553 Spores m-3) and 3-h concentrations (35,662 Spores m-3), occurred in August. The air masses that approached Viborg during the longest episode of elevated spore concentrations originated from northern Poland, the Baltics, passing over southern Sweden and the eastern Danish island of Zealand. The Cladosporium spore concentrations from Viborg were compared with the Cladosporium spore concentrations from the operational monitoring station in Copenhagen (Zealand, eastern Denmark). During the episode concentrations in Viborg were on average 2,268 spores m-3 higher than in Copenhagen. On the peak day between 8:00-15:00 concentrations in Viborg were 4-7 times higher than in Copenhagen, which we associated with grain crop harvesting in eastern Jutland. Elevated day time concentrations in Viborg on the days with daily average concentrations exceeding the threshold also indicate the local character of the sources.

Airborne Cladosporium and Alternaria spore concentrations through 26 years in Copenhagen, Denmark

“…We found an earlier peak for Cladosporium (11:30 -14:30) than for Alternaria concentrations (17:00 -19:00). Our results confirm and add to recently reported diurnal patterns for Alternaria, based on data for ten seasons (Skjøth et al 2012), and for Cladosporium based on one season in Denmark (Olsen et al 2019a). Comparable diurnal profiles were observed in Ireland and UK (Corden and Millington 2001;O'Connor et al 2014).…”

“…A consistent change towards a certain wind direction on the high concentration days might be related to a systematic contribution from distant sources. The episodes with unusual Alternaria diurnal distributions have been associated with atmospheric transport form the main agricultural areas in central Europe and southern Sweden (Skjøth et al 2012), whereas high Cladosporium concentrations coincided with a period of air masses transport from northern Poland, the Baltics, and southern Sweden (Olsen et al 2019a). We found increasing incidence of South and South-East wind directions in parallel to increasing spore concentrations, and this was more evident for Alternaria, which may be related to patterns in long distant transport.…”

“…Data on possible Cladosporium sources are scarce in the literature. There is a commonly accepted link between agriculture and higher Cladosporium spore concentrations (Weryszko-Chmielewska et al 2018;Olsen et al 2019a). However, the ever-presence of Cladosporium in the air with spore concentrations dominating over other fungal air spora, suggests, that its sources can exist also within urban areas, such as parks or other green zones, typical for the city.…”

Annual Change in Fungal Concentrations and Allergic Sensitization Rates to Alternaria and Cladosporium in Korea During the Period 1998–2022

“… 11 Grain crops and their harvesting processes are associated with increases in atmospheric concentrations of Alternaria and Cladosporium species, which disperse over a wide area. 12 13 14 15 The threshold number of spores that can elicit allergic symptoms in sensitized patients is unknown and varies across species. 3 4 Only a few studies have assessed the long-term trends in concentrations of air spores, and they obtained inconsistent results.…”