A systematic review of outdoor airborne fungal spore seasonality across Europe and the implications for health

Samuel Anees-Hill; Philippa Douglas; Catherine H Pashley; Anna Hansell; Emma L Marczylo

doi:10.1016/j.scitotenv.2021.151716

A systematic review of outdoor airborne fungal spore seasonality across Europe and the implications for health

Sci Total Environ. 2022 Apr 20:818:151716. doi: 10.1016/j.scitotenv.2021.151716. Epub 2021 Nov 17.

Authors

Samuel Anees-Hill¹, Philippa Douglas², Catherine H Pashley³, Anna Hansell⁴, Emma L Marczylo⁵

Affiliations

¹ Centre for Environmental Health and Sustainability, University of Leicester, Leicester LE1 7LW, UK; The National Institute of Health Research Health Protection Research Unit in Environmental Exposures and Health, University of Leicester, Leicester LE1 7LW, UK. Electronic address: sph22@leicester.ac.uk.
² The National Institute of Health Research Health Protection Research Unit in Environmental Exposures and Health, University of Leicester, Leicester LE1 7LW, UK; Environmental Hazards and Emergencies Department, UK Health Security Agency, Harwell Campus, Chilton, Oxfordshire OX11 0RQ, UK. Electronic address: philippa.douglas@phe.gov.uk.
³ The National Institute of Health Research Health Protection Research Unit in Environmental Exposures and Health, University of Leicester, Leicester LE1 7LW, UK; Department of Respiratory Sciences, Institute for Lung Health, University of Leicester, Leicester LE1 7RH, UK. Electronic address: chp5@leicester.ac.uk.
⁴ Centre for Environmental Health and Sustainability, University of Leicester, Leicester LE1 7LW, UK; The National Institute of Health Research Health Protection Research Unit in Environmental Exposures and Health, University of Leicester, Leicester LE1 7LW, UK. Electronic address: ah618@leicester.ac.uk.
⁵ The National Institute of Health Research Health Protection Research Unit in Environmental Exposures and Health, University of Leicester, Leicester LE1 7LW, UK; Toxicology Department, UK Health Security Agency, Harwell Campus, Chilton, Oxfordshire OX11 0RQ, UK. Electronic address: emma.marczylo@phe.gov.uk.

Abstract

Fungal spores make up a significant proportion of organic matter within the air. Allergic sensitisation to fungi is associated with conditions including allergic fungal airway disease. This systematic review analyses outdoor fungal spore seasonality across Europe and considers the implications for health. Seventy-four studies met the inclusion criteria, the majority of which (n = 64) were observational sampling studies published between 1978 and 2020. The most commonly reported genera were the known allergens Alternaria and Cladosporium, measured in 52 and 49 studies, respectively. Both displayed statistically significant increased season length in south-westerly (Mediterranean) versus north-easterly (Atlantic and Continental) regions. Although there was a trend for reduced peak or annual Alternaria and Cladosporium spore concentrations in more northernly locations, this was not statistically significant. Peak spore concentrations of Alternaria and Cladosporium exceeded clinical thresholds in nearly all locations, with median peak concentrations of 665 and 18,827 per m³, respectively. Meteorological variables, predominantly temperature, precipitation and relative humidity, were the main factors associated with fungal seasonality. Land-use was identified as another important factor, particularly proximity to agricultural and coastal areas. While correlations of increased season length or decreased annual spore concentrations with increasing average temperatures were reported in multi-decade sampling studies, the number of such studies was too small to make any definitive conclusions. Further, up-to-date studies covering underrepresented geographical regions and fungal taxa (including the use of modern molecular techniques), and the impact of land-use and climate change will help address remaining knowledge gaps. Such knowledge will help to better understand fungal allergy, develop improved fungal spore calendars and forecasts with greater geographical coverage, and promote increased awareness and management strategies for those with allergic fungal disease.

Keywords: Aerobiology; Alternaria; Cladosporium; Fungi; Outdoor air; Season.

Publication types

Review
Systematic Review

MeSH terms

Air Microbiology*
Alternaria
Environmental Monitoring*
Europe
Seasons
Spores, Fungal

Grants and funding

MR/P023673/2/MRC_/Medical Research Council/United Kingdom