Temporal variations in airborne Alternaria and Cladosporium spores and the effect of meteorological factors: three years study from a metropolis on the West Anatolian coast

Introduction Fungal spores constitute an important fraction of bioaerosols in the atmosphere. Objectives To analyse the content of Alternaria and Cladosporium spores in the atmosphere of Beja and the effect of meteorological conditions on their concentrations. Methodology The daily and hourly data of Alternaria and Cladosporium fungal spores concentration in the atmosphere of Beja were monitored from April 12, 2012 to July 30, 2014, based on the Portuguese Aerobiology Network methodology. The influence of meteorological conditions on the studied types of fungal spore concentrations was assessed through Spearman’s correlation analysis. Results During the study period, 20,741 Alternaria spores and 320,862 Cladosporium spores were counted. In 2013, there were 5,822 Alternaria spores and 123,864 Cladosporium spores. The absolute maximum concentrations of Alternaria and Cladosporium spores were recorded on November 8, 2013, with 211 and 1301 spores/m3, respectively. Temperature, insolation and wind direction parameters showed a positive correlation with Alternaria and Cladosporium spore levels, while relative humidity and precipitation presented a negative correlation, which is statistically significant. Wind speed only showed a statistically significant positive correlation in terms of Alternaria spore levels. Conclusion Alternaria and Cladosporium spores are present in the atmospheric air of Beja throughout the year, with the highest concentration period occurring during spring and autumn. There was a clear effect of meteorological parameters on airborne concentrations of these fungal spores.

This study examines the daily levels of Alternaria and Cladosporium spores in the atmosphere in Palencia city (Spain) for three consecutive years 1990–92. Alternaria and Cladosporium represented 55% of all the identified spores. Their annual distributional pattern reached its maximum values in summer. Multiple regression analyses show that Cladosporium spore concentrations have a positive correlation with minimum temperature, whereas Alternaria spore concentrations have a positive correlation with maximum temperature. Alternaria spore concentrations were also negatively correlated with precipitation. Duncan's multiple range test of Alternaria data show that winds blowing from a northeasterly direction were significantly related to higher levels of these spores.

In order to investigate the role of airborne Alternaria spp. in the sensitization of individuals having respiratory allergy symptoms, particularly bronchial asthma, an aerobiologic and clinical (diagnostic) study was conducted at several centers in Saudi Arabia. Airborne Alternaria spores were studied at four different centers in Riyadh, Jeddah and Al-Khobar, including three years at one site. Skin prick tests (SPT) were conducted on a total of 616 allergic individuals attending allergy clinics at six different hospitals in Abha, Qassim, Gizan, Jeddah, Hofuf and Makkah regions. Alternaria spores constituted between 1.9%-9.6% of the total fungal air spora, and the maximum concentration exceeded 5x10 2 spores per m3 of air in Jeddah, followed by 4.9x102 spores per m3 in Al-Khobar. Mean weekly and monthly concentration of Alternaria fluctuated, reaching up to 150 spores per m 3 and 60 spores per m 3, respectively. Quantitative regional variations were also recorded. IgE-mediated SPT reactivities conducted on allergic patients resulted in an overall 21.6% positive reactions, showing mild, moderate and strong wheal and erythema. The findings reveal that Alternaria spores are prevalent as a major component in the outdoor environment of the Kingdom, with peaks in April and October. The overall 21.6% positive SPT reactions indicate the sensitization level or cross-reactive sensitivity to Alternaria allergens. The study suggests that airborne Alternaria can be a potential allergic sensitizer in susceptible individuals and can be a risk factor in sensitized individuals with symptoms of bronchial asthma and allergic rhinitis in the Kingdom of Saudi Arabia.

Airborne Alternaria and Cladosporium fungal spores in Europe: Forecasting possibilities and relationships with meteorological parameters

Calculation of design drainage modulus is of great importance for the safety of farmland and reduction of waterlogging loss. We investigated the effects of main meteorological factors on design farmland drainage modulus by focusing on a closed farmland area in Ninghe District of Tianjin City. To resolve the problem of limited observation, the parameter sensitivity was analyzed according to mutual information and partial rank correlation coefficient aiming at the total runoff depth based on field observation experiment. The reasonable parameters were obtained by combining with soil water content and the relative variation of groundwater level. Then, a three-source runoff yield model coupling of excess infiltration and saturation was established to estimate runoff and design drainage modulus, and the effects of meteorological factors such as precipitation and evaporation on drainage modulus were analyzed. Results showed that summer precipitation significantly reduced and evaporation varied a little during 1960-2015. The corresponding drainage modulus decreased with the reduction of precipitation. When return period increased, the magnitude of the reduction in precipitation as well as the design drainage modulus increased. However, the effects of meteorological factors on design drainage modulus was generally inapparent. Thus, we concluded that the current drainage modulus is suitable for the study area.

Cladosporium spp. and Alternaria spp. spores are dominating the airspora of Denmark. Currently, little is known about the influence of climate change on the fungal spore abundance in the air. The aim of this study was to examine temporal changes in airborne Alternaria and Cladosporium spores over 26 years. This is the first report of long-term airborne Cladosporium spore occurrence in Denmark. Air spore concentrations were obtained with a Burkard volumetric spore sampler placed in Copenhagen, Denmark, during June–September, 1990–2015. The highest monthly Spore integrals (SIn) for Alternaria were measured in August, whereas for Cladosporium July SIn was nearly as high as August SIn. Average Alternaria seasonal spore integral (SSIn) was 8615 Spores day m−3, while average 3-month (July–September) Cladosporium SIn was 375,533 Spores day m−3. Despite increasing annual temperature and decreasing relative humidity, we found a decreasing trend for Alternaria seasonal SIn (Slope = − 277, R2 = 0.38, p < 0.05), Alternaria (Slope = − 31, R2 = 0.27, p < 0.05) and Cladosporium (Slope = − 440, R2 = 0.23, p < 0.05) annual peak concentrations. We did not find any statistically significant trends for airborne Alternaria seasonal characteristics and duration, and likewise for Cladosporium 3-month SIn and peak concentration dates. Mean temperature was the main meteorological factor affecting daily spore concentrations. However, effect of meteorological parameters on daily spore concentrations was stronger for Cladosporium (R2 = 0.41) than for Alternaria (R2 = 0.21). Both genera had diurnal peaks during the day hours, earlier for Cladosporium (11:30–14:30) and later for Alternaria (15:00–19:00). Although Alternaria and Cladosporium daily concentrations were moderately correlated (Spearman’s correlation coefficient: rs = 0.55, p < 0.05), their overall annual indices were different, which indicates different sources and different factors determining spore release. We explain temporal decreasing trends in Alternaria SSIn by growing urbanisation around Copenhagen and by changes in agricultural practices.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick‐borne zoonotic disease, which are classified by the World Health Organization as a priority disease for research and development in emergency situations due to the high mortality rate. Previous studies indicated that the complex nonlinear and delayed association was observed between meteorological factors and SFTS. However, these did not consider the short‐term effect of meteorological factors on the incidence of SFTS. In this study, we used generalized additive models (GAM) and distributed lag nonlinear models (DLNM) to investigate the short‐term correlation between meteorological factors and SFTS incidence. From 1 January 2013 to 31 December 2023 a total of 6,601 cases of SFTS were reported in Xinyang. Females constituted the majority with a male‐to‐female ratio of 0.68 and the average age of cases being approximately at around 61.52 years old. The multivariate GAM analysis revealed that mean temperature exerted the greatest influence on the incidence of SFTS compared to other meteorological factors and interacted with these factors. After accounting for lag period of 0–14 days, the DLNM analysis indicated that specific range of temperature (18–23°C), a certain range atmospheric pressure (1,006–1,017 hPa), extreme high wind speed (>11.6 m/s), and prolonged sunshine duration (>9h) were associated with SFTS, while there was no significant correlation between relative humidity and the incidence of SFTS. This study investigates the non‐linear trend and lagged exposure effect of various meteorological factors on short‐term SFTS incidence, thereby enhancing our comprehensive understanding of the effect of meteorological factors on SFTS.

Short term seasonal effects of airborne fungal spores on lung function in a panel study of schoolchildren residing in informal settlements of the Western Cape of South Africa

Varicella (chickenpox) is a serious public health problem in China, with the most reported cases among childhood vaccine-preventable infectious diseases, and its reported incidence has increased over 20-fold since 2005. Few previous studies have explored the association of multiple meteorological factors with varicella and considered the potential confounding effects of air pollutants. It is the first study to investigate and analyze the effects of multiple meteorological factors on varicella incidence, controlling for the confounding effects of various air pollutants. Daily meteorological and air pollution data and varicella cases were collected from January 1, 2015, to December 31, 2020, in Lu'an, Eastern China. A combination of the quasi-Poisson generalized additive model (GAM) and distributed lag nonlinear model (DLNM) was used to evaluate the meteorological factor-lag-varicella relationship, and the risk of varicella in extreme meteorological conditions. The maximum single-day lag effects of varicella were 1.288 (95%CI, 1.201-1.381, lag 16 day), 1.475 (95%CI, 1.152-1.889, lag 0 day), 1.307 (95%CI, 1.196-1.427, lag 16 day), 1.271 (95%CI, 0.981-1.647, lag 4 day), and 1.266 (95%CI, 1.162-1.378, lag 21 day), when mean temperature, diurnal temperature range (DTR), mean air pressure, wind speed, and sunshine hours were -5.8°C, 13.5°C, 1035.5 hPa, 6 m/s, and 0 h, respectively. At the maximum lag period, the overall effects of mean temperature and pressure on varicella showed W-shaped curves, peaked at 17.5°C (RR=2.085, 95%CI: 1.480-2.937) and 1035.5hPa (RR=5.481, 95%CI: 1.813-16.577), while DTR showed an M-shaped curve and peaked at 4.4°C (RR=6.131, 95%CI: 1.120-33.570). Sunshine hours were positively correlated with varicella cases at the lag of 0-8 days and 0-9 days when sunshine duration exceeded 10 h. Furthermore, the lag effects of extreme meteorological factors on varicella cases were statistically significant, except for the extremely high wind speed. We found that mean temperature, mean air pressure, DTR, and sunshine hours had significant nonlinear effects on varicella incidence, which may be important predictors of varicella early warning.

BackgroundThe effects of multiple meteorological factors on influenza activity remain unclear in Chongqing, the largest municipality in China. We aimed to fix this gap in this study.MethodsWeekly meteorological data and influenza surveillance data in Chongqing were collected from 2012 to 2019. Distributed lag nonlinear models (DLNMs) were conducted to estimate the effects of multiple meteorological factors on influenza activity.ResultsInverted J-shaped nonlinear associations between mean temperature, absolute humidity, wind speed, sunshine and influenza activity were found. The relative risks (RRs) of influenza activity increased as weekly average mean temperature fell below 18.18°C, average absolute humidity fell below 12.66 g/m3, average wind speed fell below 1.55 m/s and average sunshine fell below 2.36 hours. Taking the median values as the references, lower temperature, lower absolute humidity and windless could significantly increase the risks of influenza activity and last for 4 weeks. A J-shaped nonlinear association was observed between relative humidity and influenza activity; the risk of influenza activity increased with rising relative humidity with 78.26% as the break point. Taking the median value as the reference, high relative humidity could increase the risk of influenza activity and last for 3 weeks. In addition, we found the relationship between aggregate rainfall and influenza activity could be described with a U-shaped curve. Rainfall effect has significantly higher RR than rainless effect.ConclusionsOur study shows that multiple meteorological factors have strong associations with influenza activity in Chongqing, providing evidence for developing a meteorology-based early warning system for influenza to facilitate timely response to upsurge of influenza activity.

A study was made of the link between time of day, weather variables and the hourly content of certain fungal spores in the atmosphere of the city of Szczecin, Poland, in 2004-2007. Sampling was carried out with a Lanzoni 7-day-recording spore trap. The spores analysed belonged to the taxa Alternaria and Cladosporium. These spores were selected both for their allergenic capacity and for their high level presence in the atmosphere, particularly during summer. Spearman correlation coefficients between spore concentrations, meteorological parameters and time of day showed different indices depending on the taxon being analysed. Relative humidity (RH), air temperature, air pressure and clouds most strongly and significantly influenced the concentration of Alternaria spores. Cladosporium spores correlated less strongly and significantly than Alternaria. Multivariate regression tree analysis revealed that, at air pressures lower than 1,011 hPa the concentration of Alternaria spores was low. Under higher air pressure spore concentrations were higher, particularly when RH was lower than 36.5%. In the case of Cladosporium, under higher air pressure (>1,008 hPa), the spores analysed were more abundant, particularly after 0330 hours. In artificial neural networks, RH, air pressure and air temperature were the most important variables in the model for Alternaria spore concentration. For Cladosporium, clouds, time of day, air pressure, wind speed and dew point temperature were highly significant factors influencing spore concentration. The maximum abundance of Cladosporium spores in air fell between 1200 and 1700 hours.

Alternaria is the most important fungal species belonging to the class Deuteromycetes which causes allergic respiratory diseases. The fungus pattern often shows a pronounced seasonal periodicity and with fluctuations related to meteorological conditions. In this study, we aimed to investigate the effect of outdoor Alternaria spore concentrations on monthly lung function tests, symptoms, and medication scores in children sensitised only to Alternaria. Additionally, we planned to determine the Alternaria spores of the outdoor environment in Adana, with special respect to their relationships with meteorological conditions and their seasonal changes. Twenty-five patients with a clinical diagnosis of asthma and/or rhinitis sensitised only to Alternaria were enrolled in the prospective study. Meteorological data and outdoor samples of airborne fungi were obtained between November 2006 and October 2007. The outdoor Alternaria spore concentrations were significantly correlated with the monthly average temperature (r=0.626, p=0.03) and monthly average barometric pressure (r=-0.613, p=0.03). Similarly, the outdoor Alternaria spore concentrations were significantly correlated with mean monthly asthma medication score (r=0.599, p=0.04), value monthly PEF (r=-0.737, p=0.006), value monthly FEF25-75% (r=-0.914, p=0.0001) and, variation in PEF (r=0.901, p=0.0001). The atmospheric concentration of Alternaria spores are markedly affected by meteorological factors such as air temperatures and barometric pressures. In hypersensitive patients, Alternaria spores can induce decreases in respiratory functions and development of allergic symptoms between May and September, being especially more influential in August.

The effects of environmental and climatic factors on the prevalence of allergic rhinitis (AR) in Changchun, China, have not been reported. This study aimed to investigate the relationship between meteorological factors, air pollution, and the number of AR outpatient visits in Changchun, and determine whether different temperature and humidity conditions would influence the effect of air pollution on the number of AR outpatient visits. Generalized additive and distributional lag non-linear models were used to assess the relationship between meteorological factors, air pollution, and the number of AR outpatient visits. Using different temperatures and relative humidities, we determined whether the effects of air pollution on the number of AR outpatients would change under different meteorological conditions. In total, 15,338 AR outpatient records were collected during the study period. Except for O3, other pollutants were positively correlated with AR outpatient visits overall. Results found that each 10 µg/m3 increase in PM2.5, PM10 and NO2, and per 1 µg/m3 increase in the daily average concentration of SO2, the number of AR outpatient visits increased by 1.45% (95% CI: 0.23%-2.70%), 1.03% (95% CI: 0.06%-2.00%), 3.98% (95% CI: 1.25%-6.78%), and 1.68% (95% CI: 0.78%-2.59%), respectively. Air pollution has immediate and cumulative lagged effects on these visits. There was a non-linear correlation between meteorological factors and the number of AR outpatient visits. Low and high temperatures, low RH and low barometric pressure may affect the number of AR outpatient visits. Compared with the minimum risk of each respective meteorological factor, their Relative Risk (RR) values are 1.65(95%CI: 0.80–3.40), 1.05(95%CI: 1.03–1.08), 1.53(95%CI: 1.21–1.93), and 1.75(95%CI: 1.25–2.43), respectively. The impact of low temperature is more pronounced. The hazardous effect of extreme meteorological factors was stronger in the < 15 years age group. In addition, The effect of air pollution on the number of AR outpatient visits increased at low temperature (< 33.3% percentile) and low relative humidity (< 33.3% percentile). Increased air pollution and changes in meteorological factors are associated with an increased risk of AR outpatient visits. Children < 15 years old are the most vulnerable to extreme weather factors. Low temperature and low RH could positively modify the effects of air pollution on AR outpatient visits.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-16265-1.

We studied the diversity and abundance of the airborne fungal spores in the city of Thessaloniki, Greece, for two consecutive years. Air samples were collected at one rooftop station (at 30m) and six near-ground stations (at 1.5m) that differed in the size and composition of adjacent green spaces. The effects of meteorological factors on airborne fungal spore concentrations were also explored. Cladosporium spores were dominant everywhere in the air of the city. The total concentration of the airborne fungal spores at 30m was 10 times lower than near the ground. Differences in concentration and composition were far less pronounced among near-ground stations. The attributes of the fungal spore season did not change in a consistent way among stations and years. Concentrations at the near-ground stations matched the grouping of the latter into stations of high, intermediate, and low urban greenspace. Minimum air temperature was the primary meteorological factor affecting spore abundance, followed by relative humidity. Airborne fungal spores are more homogeneously distributed in the air of the city, but their concentrations decrease more rapidly with height than pollen.

Fungal spores are important bio-allergens frequently encountered in the atmosphere. Cladosporium Link and Alternaria Nees spores are generally recorded as dominant in many atmospheric fungal spore studies and have high allergic effects on susceptible individuals. The species belonging to these two genera may live as pathogens on the plants and cause low yield. This study was carried out between January 2012 to December 2013. Durham sampler, which is the device of the gravimetric method, was used in the research. A total of 10817 spores were recorded in the Büyükorhan (Bursa) atmosphere during the consecutive years. 4119 spores belonged to the first year and 6698 to the second year. The total numbers of Cladosporium spores were observed much higher than the total numbers of Alternaria spores in both years. This study aims to determine the variation of atmospheric spores in these two genera during the two years by comparing them with meteorological factors. For both spore types, the maximum spore numbers were found between the June-August term. Summer months revealed a risky period in terms of atmospheric fungal spore allergy for sensitive individuals.