Investigating the effects of the greenery increase on air temperature, ventilation and cooling energy demand in Melbourne with the Weather Research and Forecasting model and Local Climate Zones.

Vegetation has a well-known potential for mitigating urban overheating. This work aims to explore the effects of enhancing urban greenery in Melbourne (Australia) through a configuration of the Weather Research and Forecasting (WRF) model including the Building Effect Parameterization and the Local Climate Zones and presents novelties in: i) covering two-months and ii) focusing on air circulation and buildings cooling energy demand through the ventilation coefficient (VC) and the cooling degree hours (CDHs). A control case and two "what-if" scenarios with a growing green coverage equal to 35 % (control case), 50 % (modest increase) and 60 % (robust increase) have been designed and then simulated for January and February 2019. Outcomes reveal a maximum drop in 2 m temperature of approximately 0.4 °C and 0.8 °C at 14:00 LT for the modest and robust green increase scenario, respectively. The urban-rural energy surplus for cooling buildings is reduced and even counterbalanced. Peak CDHs decrease from 143 °C·h of the control case to 135 °C·h (modest increase) and 126 °C·h (robust increase), while they measure 137 °C·h in the non-urban areas. Average wind speed increases by 0.8 m/s (equal to 22 % with respect to the control case). Furthermore, adding urban greenery has an unfavorable implication on VC (maximum reduction of 500 m2s-1) with a consequent deterioration of the transport and dispersion of pollutants. Middle- and high-density classes are touched more than low-density by the VC reduction. In addition, the benefits of enhancing urban greenery concern physiologically and psychologically the quality of life of the dwellers.

Assessing microclimate thresholds for heritage preventive conservation to achieve sustainable and energy efficiency goals in a changing climate.

This research addresses the issue of the heritage preventive conservation in the perspective of energy sustainability, for contributing to the achievement of the Sustainable Development Goals (SDGs) and towards the EU Green Deal. The study analyses and compares four cases associated with different microclimate thresholds as suggested by the standard EN 16893:2018 (Cases 1-3) and as derived from the outputs of three degradation models for preserving paper, wood, and canvas paintings (Case 4). Weather-based indices (degree and gram days) were calculated to estimate trends in the potential energy demand of collection facilities in three European cities belonging to different Köppen-Geiger climate zones (Cfb, Csa, and Dfb), under recent past (1981-2010) and near/far future climate scenarios (2021-2050 and 2071-2100) from two Shared Socioeconomic Pathways (SSP2-4.5 and SSP5-8.5). The findings suggest that adapting facilities' management strategies to focus on collections preservation can facilitate the achievement of 5 out of 17 SDGs, offering a viable alternative to costly energy retrofits and encouraging the development of shared solutions for similar facilities in the same climate zone. The results can contribute to inform the revision of EN 16893 and to face major challenges such as the preservation of paper collections in southern latitudes.

A review on inorganic gaseous pollutants in conservation spaces: monitoring instrumentation and indoor concentrations.

This contribution presents the results of a review of scientific literature on gaseous inorganic pollutants monitored in confined indoor spaces housing cultural heritage. A survey on standards suggesting concentration thresholds together with European projects on the topic was provided. Sixty-six scientific articles were systematically selected based on the PRISMA flow diagram over the period 1984-2021 for a total number of 80 case studies mainly located in Europe (64%). Monitoring was mainly performed in museums and galleries (61%), specifically in exhibition rooms (79%). Active devices were rarely employed, whereas passive samplers, exposed in situ and then laboratory-analysed, were mostly used for nitrogen dioxide and sulphur dioxide monitoring. Direct-reading continuous devices were widely used for ozone monitoring. It was found that average concentrations of ozone were below 5 ppb in only 50% of cases, nitrogen dioxide below 10 ppb in more than 60% of cases, nitric oxide below 5 ppb in 30% of cases, nitric and nitrous acid below 1 ppb in less than 50% of cases, sulphur dioxide below 2 ppb in more than 60% of cases, and hydrogen sulphide below 0.1 ppb in only 25% of cases. Comparisons were performed following the thresholds suggested in the literature. The lowest concentration values were usually associated to the use of mechanical ventilation systems equipped with air filters and to non-urban case studies. The low number of case studies can be due to the difficulties to perform monitoring in conservation spaces with current instruments. Further research should be conducted to uniform standards that suggest instruments' requirements and pollutant thresholds to limit degradation on cultural materials.

A Statistical Approach for A-Posteriori Deployment of Microclimate Sensors in Museums: A Case Study.

The deployment of sensors is the first issue encountered when microclimate monitoring is planned in spaces devoted to the conservation of artworks. Sometimes, the first decision regarding the position of sensors may not be suitable for characterising the microclimate close to climate-sensitive artworks or should be revised in light of new circumstances. This paper fits into this context by proposing a rational approach for a posteriori deployment of microclimate sensors in museums where long-term temperature and relative humidity observations were available (here, the Rosenborg Castle, Copenhagen, Denmark). Different statistical tools such as box-and-whisker plots, principal component analysis (PCA) and cluster analysis (CA) were used to identify microclimate patterns, i.e., similarities of indoor air conditions among rooms. Box-and-whisker plots allowed us to clearly identify one microclimate pattern in two adjoining rooms located in the basement. Multivariate methods (PCA and CA) enabled us to identify further microclimate patterns by grouping not only adjoining rooms but also rooms located on different floors. Based on these outcomes, new configurations about the deployment of sensors were proposed aimed at avoiding redundant sensors and collecting microclimate observations in other sensitive locations of this museum.

Conservation risks for paper collections induced by the microclimate in the repository of the Alessandrina Library in Rome (Italy).

The Alessandrina Library was founded in 1667 by pope Alexander VII Chigi and is nowadays housed in the Campus of Sapienza University of Rome (Italy). Within its Ancient (mostly made of rag paper) and Modern (mostly made of contemporary paper) collections, it includes more than one million books produced from the XVI to the XXI century. In 2019, six thermo-hygrometers were deployed in its multi-storey repository to monitor temperature (T) and relative humidity (RH). Hourly T and RH data collected over 2 years allowed us to evaluate spatial and temporal thermo-hygrometric distributions and to carry out a comprehensive assessment of the climate-induced risks (mechanical, chemical, and biological deterioration mechanisms). Vertical temperature gradients associated with unstable conditions occurred in winter, resulting in upraising air flows up to the ceiling. The risky short-term RH fluctuations (EN 15757:2010) were determined to avoid mechanical stress in case of loans, relocation, and consultation. The Time Weighted Expected Lifetime (TWEL) index was used to evaluate the chemical risk for different paper-based collections as a function of their acidity and degree of polymerisation, also considering the typical response time of paper books to T and RH changes. The TWEL calculation estimated that the durability of acidic paper was around 300 years and highlighted that rag paper could be subject to cellulose hydrolysis only in summer and autumn, while contemporary paper was mostly at no risk. The risk of mould germination (Sedlbauer diagram) was possible on few days in Autumn, while the production of insect eggs (Brimblecombe empirical function) was favoured during approximately 42% of time over the year. In addition, illuminance and colorimetric measurements (performed on selected book covers) showed that light-sensitive objects could be exposed to the photodeterioration risk in the east-facing side of the repository. Although the investigation focussed on a specific case study, a similar approach could be effectively adapted to most library and archival repositories conserving paper-based collections.

Analysis of two-decade meteorological and air quality trends in Rome (Italy).

This study presents a trend analysis of a two-decade (2000-2020) series of surface meteorological and air quality data measured in Rome (Italy). Data series are collected at three sites in Rome downtown and its coastal surroundings. This paper fills the gap due to missing or incomplete recent information about the meteorological and atmospheric composition tendencies in the Rome area. Datasets are subjected to in-depth quality control and to statistical analysis to verify the data homogeneity, whilst trend analysis is performed using the Seasonal Kendall test. The results show a statistically significant positive trend for average air temperature (0.07 °C year-1 in urban and coastal sites), whilst maximum and minimum temperatures increase more in urban (0.10 °C year-1) than in coastal (0.01 °C year-1) environment. The water vapour mixing ratio trend is higher in the city (0.10 g kg-1 year-1) than along the coast (0.03 g kg-1 year-1). The heat index tendency is more pronounced in the Rome centre (0.11 °C year-1) than in the coast (0.06 °C year-1). The monthly cumulative precipitations do not show statistically significant trends. On the other hand, air quality generally improved: surface pollutant concentrations show a significant decrease thanks to the reduction of local emissions (C6H6, - 0.12 µg m-3 year-1; SO2, - 0.09 µg m-3 year-1; CO, - 0.02 mg m-3 year-1; NOx, - 1.28 µg m-3 year-1; NO, - 0.38 µg m-3 year-1; NO2, - 0.60 µg m-3 year-1, PM10, - 0.35 µg m-3 year-1). Only O3 shows a statistically significant positive trend (0.15 µg m-3 year-1), in agreement with wider scale studies. The outcomes suggest that whilst local and national policies contribute to the improvement of air quality, the rising of temperature-as likely consequence of climate change-may be an emerging cause of concern for human thermal discomfort and potential effect on the conservation of tangible immovable heritage. Supplementary Information: The online version contains supplementary material available at 10.1007/s00704-022-04047-y.

Novel Model Based on Artificial Neural Networks to Predict Short-Term Temperature Evolution in Museum Environment.

The environmental microclimatic characteristics are often subject to fluctuations of considerable importance, which can cause irreparable damage to art works. We explored the applicability of Artificial Intelligence (AI) techniques to the Cultural Heritage area, with the aim of predicting short-term microclimatic values based on data collected at Rosenborg Castle (Copenhagen), housing the Royal Danish Collection. Specifically, this study applied the NAR (Nonlinear Autoregressive) and NARX (Nonlinear Autoregressive with Exogenous) models to the Rosenborg microclimate time series. Even if the two models were applied to small datasets, they have shown a good adaptive capacity predicting short-time future values. This work explores the use of AI in very short forecasting of microclimate variables in museums as a potential tool for decision-support systems to limit the climate-induced damages of artworks within the scope of their preventive conservation. The proposed model could be a useful support tool for the management of the museums.

Does solar ultraviolet radiation play a role in COVID-19 infection and deaths? An environmental ecological study in Italy.

A significantly stronger impact in mortality and morbidity by COVID-19 has been observed in the northern Italian regions compared to the southern ones. The reasons of this geographical pattern might involve several concurrent factors. The main objective of this work is to investigate whether any correlations exist between the spatial distribution of COVID-19 cases and deaths in the different Italian regions and the amount of solar ultraviolet (UV) radiation at the Earth's surface. To this purpose, in this environmental ecological study a mixed-effect exponential regression was built to explain the incidence of COVID-19 based on the environmental conditions, and demographic and pathophysiologic factors. Observations and estimates of the cumulative solar UV exposure have been included to quantify the amount of radiation available e.g., for pre-vitamin D3 synthesis or SARS-CoV-2 inactivation by sunlight. The analysis shows a significant correlation (p-value <5 × 10-2) between the response variables (death percentage, incidence of infections and positive tests) and biologically effective solar UV radiation, residents in nursing homes per inhabitant (NHR), air temperature, death percentage due to the most frequent comorbidities. Among all factors, the amount of solar UV radiation is the variable contributing the most to the observed correlation, explaining up to 83.2% of the variance of the COVID-19 affected cases per population. While the statistical outcomes of the study do not directly entail a specific cause-effect relationship, our results are consistent with the hypothesis that solar UV radiation impacted on the development of the infection and on its complications, e.g. through the effect of vitamin D on the immune system or virus inactivation by sunlight. The analytical framework used in this study, based on commonly available data, can be easily replicated in other countries and geographical domains to identify possible correlations between exposure to solar UV radiation and the spread of the pandemic.

The 2020 Arctic ozone depletion and signs of its effect on the ozone column at lower latitudes.

The present study discusses the effect of the ozone depletion that occurred over the Arctic in 2020 on the ozone column in central and southern Europe by analysing a data set obtained from ground-based measurements at six stations placed from 79 to 42°N. Over the northernmost site (Ny-Ålesund), the ozone column decreased by about 45% compared to the climatological average at the beginning of April, and its values returned to the normal levels at the end of the month. Southwards, the anomaly gradually reduced to nearly 15% at 42°N (Rome) and the ozone minimum was detected with a delay from about 6 days at 65°N to 20 days at 42°N. At the same time, the evolution of the ozone column at the considered stations placed below the polar circle corresponded to that observed at Ny-Ålesund, but at 42°-46°N, the ozone column turned back to the typical values at the end of May. This similarity in the ozone evolutional patterns at different latitudes and the gradually increasing delay of the minimum occurrences towards the south allows the assumption that the ozone columns at lower latitudes were affected by the phenomenon in the Arctic. The ozone decrease observed at Aosta (46°N) combined with predominantly cloud-free conditions resulted in about an 18% increase in the erythemally weighted solar ultraviolet irradiance reaching the Earth's surface in May.

A Comprehensive Study of the Microclimate-Induced Conservation Risks in Hypogeal Sites: The Mithraeum of the Baths of Caracalla (Rome).

The peculiar microclimate inside cultural hypogeal sites needs to be carefully investigated. This study presents a methodology that aimed at providing a user-friendly assessment of the frequently occurring hazards in such sites. A Risk Index was specifically defined as the percentage of time for which the hygrothermal values lie in ranges that are considered to be hazardous for conservation. An environmental monitoring campaign that was conducted over the past ten years inside the Mithraeum of the Baths of Caracalla (Rome) allowed for us to study the deterioration before and after a maintenance intervention. The general microclimate assessment and the specific conservation risk assessment were both carried out. The former made it possible to investigate the influence of the outdoor weather conditions on the indoor climate and estimate condensation and evaporation responsible for salts crystallisation/dissolution and bio-colonisation. The latter took hygrothermal conditions that were close to wall surfaces to analyse the data distribution on diagrams with critical curves of deliquescence salts, mould germination, and growth. The intervention mitigated the risk of efflorescence thanks to reduced evaporation, while promoting the risk of bioproliferation due to increased condensation. The Risk Index provided a quantitative measure of the individual risks and their synergism towards a more comprehensive understanding of the microclimate-induced risks.

Review on Nonoccupational Personal Solar UV Exposure Measurements.

Solar ultraviolet (UV) radiation follows people during their whole life. Exposure to UV radiation is vital but holds serious risks, too. The quantification of human UV exposure is a complex issue. UV exposure is directly related to incoming UV radiation as well as to a variety of factors such as the orientation of the exposed anatomical site with respect to the sun and the duration of exposure. The use of badge-sensors allows assessing the UV exposure of differently oriented body sites. Such UV devices have been available for over 40 years, and a variety of measuring campaigns have been undertaken since then. This study provides an overview of those studies which reported measurements of the personal UV exposure (PE) during outdoor activities of people not related to their occupation. This overview is given chronologically to show the progress of knowledge in this research and is given with respect to different activities. Special focus is put on the ratio of personal exposure to ambient UV radiation. This ratio, when given as a function of solar elevation, allows estimating PE at any other location or date if ambient UV radiation is known.

Cluster analysis of microclimate data to optimize the number of sensors for the assessment of indoor environment within museums.

For the first time, the cluster analysis (k-means) has been applied on long time series of temperature and relative humidity measurements to identify the thermo-hygrometric features in a museum. Based on ASHRAE (2011) classification, 84% of time all rooms in the Napoleonic Museum in Rome (case study) were found in the class of control B. This result was obtained by analyzing all recorded data in 10 rooms of the museum as well as using the cluster aggregation. The use of objective-oriented methodology allows to achieve an acceptable knowledge of the microclimate in case of multi-room buildings, reducing computations with large amounts of collected data and time-consuming in redundant elaborations. The cluster analysis enables to reduce the number of the sensors in microclimate monitoring programs within museums, provided that the representativeness of the instrument location is known, and professional conservators have assessed that the artifacts are well preserved.

CleAir Monitoring System for Particulate Matter: A Case in the Napoleonic Museum in Rome.

Monitoring the air particulate concentration both outdoors and indoors is becoming a more relevant issue in the past few decades. An innovative, fully automatic, monitoring system called CleAir is presented. Such a system wants to go beyond the traditional technique (gravimetric analysis), allowing for a double monitoring approach: the traditional gravimetric analysis as well as the optical spectroscopic analysis of the scattering on the same filters in steady-state conditions. The experimental data are interpreted in terms of light percolation through highly scattering matter by means of the stretched exponential evolution. CleAir has been applied to investigate the daily distribution of particulate matter within the Napoleonic Museum in Rome as a test case.

UV Index monitoring in Europe.

The UV Index was established more than 20 years ago as a tool for sun protection and health care. Shortly after its introduction, UV Index monitoring started in several countries either by newly acquired instruments or by converting measurements from existing instruments into the UV Index. The number of stations and networks has increased over the years. Currently, 160 stations in 25 European countries deliver online values to the public via the Internet. In this paper an overview of these UV Index monitoring sites in Europe is given. The overview includes instruments as well as quality assurance and quality control procedures. Furthermore, some examples are given about how UV Index values are presented to the public. Through these efforts, 57% of the European population is supplied with high quality information, enabling them to adapt behaviour. Although health care, including skin cancer prevention, is cost-effective, a proportion of the European population still doesn't have access to UV Index information.

Assessment of the Minimum Sampling Frequency to Avoid Measurement Redundancy in Microclimate Field Surveys in Museum Buildings.

Monitoring temperature and relative humidity of the environment to which artefacts are exposed is fundamental in preventive conservation studies. The common approach in setting measuring instruments is the choice of a high sampling rate to detect short fluctuations and increase the accuracy of statistical analysis. However, in recent cultural heritage standards the evaluation of variability is based on moving average and short fluctuations and therefore massive acquisition of data in slowly-changing indoor environments could end up being redundant. In this research, the sampling frequency to set a datalogger in a museum room and inside a microclimate frame is investigated by comparing the outcomes obtained from datasheets associated with different sampling conditions. Thermo-hygrometric data collected in the Sorolla room of the Pio V Museum of Valencia (Spain) were used and the widely consulted recommendations issued in UNI 10829:1999 and EN 15757:2010 standards and in the American Society of Heating, Air-Conditioning and Refrigerating Engineers (ASHRAE) guidelines were applied. Hourly sampling proved effective in obtaining highly reliable results. Furthermore, it was found that in some instances daily means of data sampled every hour can lead to the same conclusions as those of high frequency. This allows us to improve data logging design and manageability of the resulting datasheets.

Extreme UV index and solar exposures at Plateau Rosà (3500 m a.s.l.) in Valle d'Aosta Region, Italy.

The purpose of this study is to assess personal exposures of skiers at the Alpine site of Plateau Rosà (45.9°N, 7.7°E, 3500 m a.s.l.), in the Valle d'Aosta region, Italy. The campaign was carried out on July 12th, 2011 during the summer ski season. A peak UVI value of 12.3, among the highest in Europe, was recorded on that day. Personal exposures (PE) were quantified using both polysulphone (PS) and poly-dimethyl phenylene oxide (PPO) dosimeters attached vertically to the cap because it is representative of the vertically oriented face of skiers. Exposure ratio (ER) defined as the ratio between PE and the corresponding ambient dose (i.e. erythemally weighted dose received by a horizontal surface) measured by a broad-band radiometer during the same exposure time of the subjects, was used to compare the results with previous studies. Skin color was also measured on the inner upper arm and on the cheek and differences in ITA (Individual Typology Angle) and a* (redness) values before and after exposure, were statistically analyzed. During the exposure period, the median PE (with PS) was 1.47 kJ m(-2) and that obtained by PPO was 1.15 kJ m(-2). The median of the ERs was 0.65 (min: 0.50, max: 0.83) considering the cumulative PS exposure and 0.46 (min: 0.29, max: 0.95) for PPO. An increase in ITAs on the exposed site (i.e. the skin became lighter) was observed after exposure. These results indicate that: a) for some skiers, the exposures were similar to those received on the horizontal plane; and b) the targeted population showed exposures above the occupational threshold limit value (TLV) defined by ICNIRP; c) the use of physical sunscreens which tend to leave a white cast, might have reduced skin color change. Nevertheless possible visible sun-induced skin-color changes could be observed after longer time intervals after exposure.

Investigation on the capability of polysulphone for measuring biologically effective solar UV exposures.

Polysulphone (PS) dosimetry is a well-known technique broadly used to assess the erythemally effective solar UV dose received by anatomical sites (personal exposure). We investigate the capability of PS dosimetry to convert doses absorbed by PS badges into biologically effective solar UV exposures taking as examples two relevant effects for human skin: erythema induction and pre-vitamin D3 production. PS calibration curves for erythemal and pre-vitamin D3 were distinctly determined by using an empirical relationship between the biologically effective UV exposures and the PS absorbance change. This relationship is parameterized by a coefficient, distinct for each of the two considered biological effects, multiplying the same cubic polynomial function. It is shown how the multiplying coefficient is related to the ratio between the biologically effective and the PS weighted irradiances which is the prevailing factor affecting the accuracy of the calibration and, consequently, the capability of PS films for measuring biologically effective solar UV exposures. The points addressed in this paper can be extended to other biological effects of interest whose action spectra have some similarity with the PS film response.

A critical assessment of two types of personal UV dosimeters.

Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cut-off filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be over-estimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments.

Applicability of the polysulphone horizontal calibration to differently inclined dosimeters.

Polysulphone (PS) dosimetry has been a widely used technique for more than 30 years to quantify the erythemally effective UV dose received by anatomic sites (personal exposure). The calibration of PS dosimeters is an important issue as their spectral response is different from the erythemal action spectrum. It is performed exposing a set of PS dosimeters on a horizontal plane and measuring the UV doses received by dosimeters using calibrated spectroradiometers or radiometers. In this study, data collected during PS field campaigns (from 2004 to 2006), using horizontal and differently inclined dosimeters, were analyzed to provide some considerations on the transfer of the horizontal calibration to differently inclined dosimeters, as anatomic sites usually are. The role of sky conditions, of the angle of incidence between the sun and the normal to the slope, and of the type of surrounding surface on the calibration were investigated. It was concluded that PS horizontal calibrations apply to differently inclined dosimeters for incidence angles up to approximately 70° and for surfaces excluding ones with high albedo. Caution should be used in the application of horizontal calibrations for cases of high-incidence angle and/or high albedo surfaces.

Occupational exposures to solar ultraviolet radiation of vineyard workers in Tuscany (Italy).

A study to quantify the UV exposure of vineyard workers was carried out using polysulphone dosimetry. The study took place in Tuscany (Italy) involving 32 vineyard workers, covering three different stages of the vine's growth. The level of personal exposure expressed as a function on the available ambient UV radiation was determined. We also assessed skin reflectance parameters, pre and post exposure. It was found that during spring backs received between 53% and 87% of ambient exposure and arms between 30% and 60%. During summer, the workers received on the back between 36% and 77% of ambient exposure and between 19% and 43% of ambient exposure on the arm. The comparison with the occupational UV exposure limit showed that all subjects received UV exposures in excess of the limit. The exposure of back of neck exceeded 10 SED (assumed as a threshold level of sun-adapted skin for Mediterranean subjects) in spring, which means that in the case of non sun-adapted skin and without sun protection, erythema can be induced in this targeted population. The cumulative exposure was also estimated under specific assumptions of UV exposure giving values in some cases higher than previous studies.