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Dr. Maria P. Plaza

Group Leader Human Exposure Science
+49 821 598 6415Email meBuilding/Room: UK Augsburg, administrative building 3 / 036

Research Areas

Maria P. Plaza has studied Forestry Engineering (BSc), Natural Environment and Forestry (MSc), Bioinformatics and Biostatistics (MSc) and her PhD is in Biology. She has been engaged in research since 2012, always in the inter-disciplinary field of Environmental Exposure and Health Impacts. In particular, her expertise is in Aerobiology, aeroallergen detection and quantification, impacts on human health and forecasting all-level spatiotemporal interactions towards the aim to provide accurate and timely risk alerts.

As a young researcher, Maria has published more than 15 international scientific publications in transnational scientific journals with peer review, thanks also to the collaboration and experiences in research group of international recognition in Spain, Denmark, Portugal and Germany. Maria participates in the COST networks ADOPT ( as active Working Group member on New approaches in detection of pathogens and aeroallergens.

Today, Maria leads the group Human Exposure Science at the Institute of Environmental Medicine, Augsburg together with Dac-Loc Nguyen. Research within that group focuses on atmospheric science and health, which includes both monitoring and development of new methods for the research on bioaerosols and their influence on human health. The task also includes the development of a computational facility that can be used in atmospheric science and related disciplines such as remote sensing, aerobiology and symptomatology. Moreover, Maria is the junior leader in the group IMPACCT (Improved decision-support for Managing the risk from Environmental disease to Public Health in a Climate Change perspective) funded by BMBF, whose main objective goes beyond the mere understanding of the highly complex feedback loops in the atmosphere and the multiple influencing factors and beyond identifying key atmospheric processes that affect public health in a climate change context. IMPACCT integrates observations, remote sensing, past and future environmental data, patient data, new technologies in big data management and modelling. It works as an innovative group within a network of international and national partners.

Fields of Work and Expertise

Big DataAir QualityEnvironmental SciencePublic HealthClimate ChangeAir QualityAerobiologyPollen MonitoringApplied BiostatisticsEcologyForecasting

Professional Career

2022 - Now

Group Leader Human Exposure Science

2021 - Now

Member at Helmholtz Zentrum München

2018 - 2021

Member at UNIKA-T, University of Augsburg



2017 -2019

Thesis dissertation "Airborne pollen and major allergens of olive trees and grasses in the atmosphere of Córdoba, Spain"

Honors and Awards

  • 2022
    BMBF Grant

  • 2019
    Best Thesis Award
    Association of Spanish Language Palynologists


See all

2021 PNAS

Athanasios Damialis, Stefanie Gilles, Mikhail Sofiev, Viktoria Sofieva, Franziska Kolek , Daniela Bayr, Maria P Plaza, Vivien Leier-Wirtz, Sigrid Kaschuba, Lewis H Ziska, Leonard Bielory, László Makra, Maria Del Mar Trigo; COVID-19/POLLEN study group; Claudia Traidl-Hoffmann

Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown-no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen-virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.

2021 International Journal of Environmental Research and Public Health

Franziska Kolek, Maria Del Pilar Plaza, Vivien Leier-Wirtz, Arne Friedmann, Claudia Traidl-Hoffmann, Athanasios Damialis

Earlier Flowering of Betula pendula Roth in Augsburg, Germany, Due to Higher Temperature, NO2 and Urbanity, and Relationship with Betula spp. Pollen Season

Flowering and pollen seasons are sensitive to environmental variability and are considered climate change indicators. However, it has not been concluded to what extent flowering phenology is indeed reflected in airborne pollen season locally. The aim of this study was to investigate, for the commonly represented in temperate climates and with highly allergenic pollen Betula pendula Roth, the responsiveness of flowering to different environmental regimes and also to check for commensurate changes in the respective pollen seasons. The region of Augsburg, Bavaria, Germany, was initially screened for birch trees, which were geolocated at a radius of 25 km. Random trees across the city were then investigated during three full flowering years, 2015–2017. Flowering observations were made 3–7 times a week, from flower differentiation to flower desiccation, in a total of 43 plant individuals. Data were regressed against meteorological parameters and air pollutant levels in an attempt to identify the driving factors of flowering onset and offset. Flowering dates were compared with dates of the related airborne pollen seasons per taxon; airborne pollen monitoring took place daily using a Hirst-type volumetric sampler. The salient finding was that flowering occurred earlier during warmer years; it also started earlier at locations with higher urbanity, and peaked and ended earlier at sites with higher NO2 concentrations. Airborne pollen season of Betula spp. frequently did not coincide locally with the flowering period of Betula pendula: while flowering and pollen season were synchronized particularly in their onset, local flowering phenology alone could explain only 57.3% of the pollen season variability. This raises questions about the relationship between flowering times and airborne pollen seasons and on the rather underestimated role of the long-distance transport of pollen.

2022 International Journal of Environmental Research and Public Health

Maria Pilar Plaza, Franziska Kolek, Vivien Leier-Wirtz, Jens Otto Brunner, Claudia Traidl-Hoffmann, Athanasios Damialis

Detecting airborne pollen using an automatic, real-time monitoring system: evidence from two sites

Airborne pollen monitoring has been an arduous task, making ecological applications and allergy management virtually disconnected from everyday practice. Over the last decade, intensive research has been conducted worldwide to automate this task and to obtain real-time measurements. The aim of this study was to evaluate such an automated biomonitoring system vs. the conventional 'gold-standard' Hirst-type technique, attempting to assess which may more accurately provide the genuine exposure to airborne pollen. Airborne pollen was monitored in Augsburg since 2015 with two different methods, a novel automatic Bio-Aerosol Analyser, and with the conventional 7-day recording Hirst-type volumetric trap, in two different sites. The reliability, performance, accuracy, and comparability of the BAA500 Pollen Monitor (PoMo) vs. the conventional device were investigated, by use of approximately 2.5 million particles sampled during the study period. The observations made by the automated PoMo showed an average accuracy of approximately 85%. However, it also exhibited reliability problems, with information gaps within the main pollen season of between 17 to 19 days. The PoMo automated algorithm had identification issues, mainly confusing the taxa of Populus, Salix and Tilia. Hirst-type measurements consistently exhibited lower pollen abundances (median of annual pollen integral: 2080), however, seasonal traits were more comparable, with the PoMo pollen season starting slightly later (median: 3 days), peaking later (median: 5 days) but also ending later (median: 14 days). Daily pollen concentrations reported by Hirst-type traps vs. PoMo were significantly, but not closely, correlated (r = 0.53-0.55), even after manual classification. Automatic pollen monitoring has already shown signs of efficiency and accuracy, despite its young age; here it is suggested that automatic pollen monitoring systems may be more effective in capturing a larger proportion of the airborne pollen diversity. Even though reliability issues still exist, we expect that this new generation of automated bioaerosol monitoring will eventually change the aerobiological era, as known for almost 70 years now.

2023 Science of The Total Environment

Daniela Bayr, Maria P Plaza, Stefanie Gilles, Franziska Kolek, Vivien Leier-Wirtz, Claudia Traidl-Hoffmann, Athanasios Damialis

Pollen long-distance transport associated with symptoms in pollen allergics on the German Alps: An old story with a new ending?

Pollen grains are among the main causes of respiratory allergies worldwide and hence they are routinely monitored in urban environments. However, their sources can be located farther, outside cities' borders. So, the fundamental question remains as to how frequent longer-range pollen transport incidents are and if they may actually comprise high-risk allergy cases. The aim was to study the pollen exposure on a high-altitude location where only scarce vegetation exists, by biomonitoring airborne pollen and symptoms of grass pollen allergic individuals, locally. The research was carried out in 2016 in the alpine research station UFS, located at 2650 m height, on the Zugspitze Mountain in Bavaria, Germany. Airborne pollen was monitored by use of portable Hirst-type volumetric traps. As a case study, grass pollen-allergic human volunteers were registering their symptoms daily during the peak of the grass pollen season in 2016, during a 2-week stay on Zugspitze, 13-24 June. The possible origin of some pollen types was identified using back trajectory model HYSPLIT for 27 air mass backward trajectories up to 24 h. We found that episodes of high aeroallergen concentrations may occur even at such a high-altitude location. More than 1000 pollen grains m-3 of air were measured on the UFS within only 4 days. It was confirmed that the locally detected bioaerosols originated from at least Switzerland, and up to northwest France, even eastern American Continent, because of frequent long-distance transport. Such far-transported pollen may explain the observed allergic symptoms in sensitized individuals at a remarkable rate of 87 % during the study period. Long-distance transport of aeroallergens can cause allergic symptoms in sensitized individuals, as evidenced in a sparse-vegetation, low-exposure, 'low-risk' alpine environment. We strongly suggest that we need cross-border pollen monitoring to investigate long-distance pollen transport, as its occurrence seems both frequent and clinically relevant.