Biomonitoring of the air inside the Florence Cathedral begins
Atmospheric particulate matter will be analysed, using lichens, and the microorganisms present in the air and on surfaces. The lichens, the plates with nutrient media for fungi and bacteria and the microbiological filters were positioned in various points of the Cathedral, Brunelleschi's Dome and in Santa Reparata
For the first time the air inside the Cathedral of Florence will be biomonitored thanks to a project by Opera di Santa Maria del Fiore with Istituto Nazionale di Geofisica e Vulcanologia, Università degli Studi di Firenze, Università degli Studi di Siena and Accademia Nazionale dei Lincei.
The air we breathe indoors carries atmospheric particulates, known as PM or fine dust, and microorganisms from the outside. For this reason, the investigations will take place, in parallel, on two fronts: on the one hand the biomonitoring of atmospheric particulates will be carried out and on the other the identification and quantification of the microorganisms present in the air but also on the surfaces of different materials such as marble, stone, brick, plaster, wood, etc.
The analyzes on the atmospheric particulate bioaccumulated by lichens will allow us to qualitatively and quantitatively determine the possible presence of polluting metals inside the Cathedral of Florence, using chemical and magnetic methods, discerning their emission sources. The data obtained from the microbiological analysis will provide useful information for identifying potentially harmful species for the artistic heritage and human health.
The biomonitoring of atmospheric particulates - which below 10 µm has harmful effects on human health and together with airborne biological agents acts on stone and frescoed surfaces, accelerating their deterioration - will be carried out using lichen bags positioned in various points of the Cathedral, of Brunelleschi's Dome and in Santa Reparata, for a duration of approximately three months.
In the Dome the lichens were placed on the three levels of the galleries, at 32 m and 50 m high, and at the base of the frescoes, hypothesizing that the air flow can transport the particulate matter and microorganisms from the outside, through the doors, towards the the pinnacle of the same. Other lichens were placed inside Santa Reparata, to outline the characteristics of the particulate matter emitted in correspondence with the air exchange systems, natural or forced. Still others outside the façade of the Cathedral and the Cricket Cage, to identify the characteristics of the atmospheric particulate entering the monument.
For the microbiological part, the microorganisms will be collected by the University of Florence, in the same places where the lichens are positioned, directly on plates with nutrient media for fungi and bacteria, for the purposes of their cultivation, and on microbiological filters (diameter 0.2 µm) for the purpose of extracting total DNA for metagenomic analysis.
“We are constantly working with universities and other institutes,” explains Luca Bagnoli, president of Opera di Santa Maria del Fiore, "on research and experiments aimed at understanding and conserving our heritage. This research, in particular, could constitute an indispensable complement to the monitoring and maintenance activities that we constantly carry out, paying attention to the most modern technologies and the most recent discoveries".
“The use of lichens has a long tradition in biomonitoring and is linked to their effectiveness in retaining airborne components” he explains Aldo Winkler, physicist of Istituto Nazionale di Geofisica e Vulcanologia. In the field of Cultural Heritage we have used this multidisciplinary method, to date, at the Peggy Guggenheim Collection in Venice, in the loggias frescoed by Raphael of the Villa Farnesina and on the Palatine Hill of the Colosseum Archaeological Park in Rome, and in the Museums of National History and Fine Arts of Buenos Aires, with the aim of controlling, with non-invasive and biological methods, the spread of polluting dust within cultural assets located in highly anthropized contexts".
The following are part of the research group:
- Istituto Nazionale di Geofisica e Vulcanologia, Aldo Winkler
- Dipartimento di Biologia dell’Università degli Studi di Firenze, Brunella Perito e Domenico Celi
- Dipartimento di Scienze della Terra dell’Università degli Studi di Firenze, Alba Santo
- Dipartimento di Scienze della Vita dell'Università degli Studi Siena, Stefano Loppi e Lisa Grifoni
- Opera di Santa Maria del Fiore, Samuele Caciagli
- Accademia Nazionale dei Lincei, Antonio Sgamellotti