2023 IMEKO TC-4 International Conference on Metrology for Archaeology and Cultural Heritage Rome, Italy, October 19-21, 2023 Protecting Art and People: Environmental Monitoring of Beata Vergine dei Miracoli Sanctuary for Health and Heritage Conservation Antonio Spagnuolo 1,2 , Andrea Bergomi 3 , Carmela Vetromile 1,2 , Antonio Masiello 2 , Noemi Mantile 1 , Mattia Borelli 3 , Chiara Andrea Lombardi 3 , Valeria Comite 3 , Paola Fermo 3 , Carmine Lubritto 1 1 Department of Environmental, Biological and Pharmaceutical Sciences and Technologies and MAReA Centre, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100, Caserta. antonio.spagnuolo@unicampania.it, carmela.vetromile@unicampania.it, noemi.mantile@unicampania.it, carmine.lubritto@unicampania.it 2 Energreenup srl; info@energreenup.it 3 Department of Chemistry, University of Milan, Via Golgi 19, 20133, Milano, Italia paola.fermo@unimi.it, valeria.comite@unimi.it, mattia.borelli@unimi.it, andrea.bergomi@unimi.it, chiara.lombardi@unimi.it, Abstract – This research article discusses the importance of environmental monitoring to ensure the health and well-being of humans and ecosystems, with a specific focus on cultural heritage sites, which are susceptible to damage by pollution and microclimatic conditions. The Beata Vergine dei Miracoli sanctuary, a notable cultural heritage site in Italy, was studied to analyse the environmental quality of the site and any changes in environmental conditions during the COVID-19 pandemic. The study monitored different environmental parameters from 20 January to 11 April 2023. The data collected were evaluated, and the results were compared with previous campaigns. This study highlights the importance of environmental monitoring in cultural heritage site conservation, particularly in response to global challenges like climate change and pandemics. I. INTRODUCTION Environmental monitoring is essential to ensure the health and well-being of human beings and the ecosystem. In recent years, the importance of environmental monitoring has increased considerably, as pollution and climate change have become major challenges to be confronted [1]. The awareness on pollution-related damages is also increasing due to the effects on the works of art. It is in fact known that air pollution and bad microclimatic conditions can cause mechanical ruptures in response to strong temperature and relative humidity variations, colour changes due to chemical reactions, soiling due to particulate matter deposition; the effects can be synergic [2][3][4][5]. For this reason, several museums around the world started to put forth measures to ensure optimal microclimatic conditions within the indoor environments hosting important works of art. However, museums are not the only sites in which artifacts of artistic and historical interest may be found. Sanctuaries can also be the home to numerous works of art such as frescoes, sculptures, and paintings. However, there is currently no legislation defining limit levels for air pollutants or microclimatic parameters to ensure proper conservation conditions, leaving these sites essentially unmonitored. In this regard, studies conducted in the sanctuary of the Beata Vergine dei Miracoli in Saronno (VA), Italy, represent one of the first attempts to evaluate environmental conditions in sites other than museums [6,7,8,9]. This sanctuary, is an important spiritual and cultural heritage site, visited by thousands of worshippers and tourists every year. It was decorated by some of the most renowned and influential artists of the time, such as Bernardino Luini and Gaudenzio Ferrari [10]. Therefore, the indoor air quality of this site needs to be closely monitored to ensure a safe and healthy environment for the people and for the works of art. Indeed, initial studies conducted in previous years highlighted non-ideal microclimatic conditions within the sanctuary [6,8,9]. Thermohygrometric parameters (temperature and relative humidity) were often outside the ranges recommended in the UNI 10829 “Goods of historical and artistic interest. Environmental conservation conditions. Measurement and analysis” technical standard [6]. Also, the large influx of people during religious ceremonies, guided tours and other activities caused air pollutant (PM and NOx) levels to rise above the suggested limits in the Ministerial Decree D.M. 10 May 2001 “Guidance document on technical-scientific criteria and museum functioning and development standards” for the 785