Exposure to airborne particulate matter in working from office and working from home employees.

The main aim of this study is to quantitatively evaluate the differences, in terms of exposure to PM (particulate matter), between WFO (working-from-office) and WFH (working-from-home) conditions. Two measurement surveys were performed: a long-term and a short-term campaign, focused on the monitoring of personal exposure to size-fractionated PM in these different working conditions. Results of the long-term campaign show that the WFH subject is exposed to higher (up to 4 times) PM concentration, compared to the WFO subject. Specific activities performed by the subjects impacted their exposure concentrations, even if the most relevant contribution to total exposure was made by desk work. Results of the short-term campaign indicate that the subjects can be divided into two groups: subjects most exposed during the WFH mode (HE_H - Higher_Exposure_Home) and subjects most exposed during the WFO mode (HE_O - Higher_Exposure_Office). HE_H group is exposed to levels of pollutants up to 4 times higher in the domestic than in the office environment, during the moment of desk work. The HE_O group is exposed to higher (double) concentration levels during desk work during the WFO day. Considering the possible growing trend towards remote work it is important to evaluate these "new domestic offices" comprehensively.

Exposure Assessment and Monitoring of Antiblastic Drugs Preparation in Health Care Settings: A Systematic Review.

Several antiblastic drugs (ADs) are classified as carcinogenic, mutagenic, and/or toxic for reproduction. Despite established guidelines and safe handling technologies, ADs contamination of the work environments could occur in healthcare settings, leading to potential exposure of healthcare staff. This systematic review aims to investigate the main techniques and practices for assessing ADs occupational exposure in healthcare settings. The reviewed studies unveil that workplace contamination by ADs appears to be a still-topical problem in healthcare settings. These issues are linked to difficulties in guaranteeing: (i) the adherence to standardized protocols when dealing with ADs, (ii) the effective use of personal protective equipment by operators involved in the administration or management of ADs, (iii) a comprehensive training of the healthcare personnel, and (iv) a thorough health surveillance of exposed workers. A "multi-parametric" approach emerges as a desirable strategy for exposure assessment. In parallel, exposure assessment should coincide with the introduction of novel technologies aimed at minimizing exposure (i.e., risk management). Assessment must consider various departments and health operators susceptible to ADs contamination, with a focus extended beyond worst-case scenarios, also considering activities like surface cleaning and logistical tasks related to ADs management. A comprehensive approach in ADs risk assessment enables the evaluation of distinct substance behaviors and subsequent exposure routes, affording a more holistic understanding of potential risks.

Human biomonitoring and personal air monitoring. An integrated approach to assess exposure of stainless-steel welders to metal-oxide nanoparticles.

In welding, there is a potential risk due to metal-oxide nanoparticles (MONPs) exposure of workers. To investigate this possibility, the diameter and number particles concentration of MONPs were evaluated in different biological matrices and in personal air samples collected from 18 stainless-steel welders and 15 unexposed administrative employees engaged in two Italian mechanical engineering Companies. Exhaled breath condensate (EBC) and urine were sampled at pre-shift on 1st day and post-shift on 5th day of the workweek, while plasma and inhalable particulate matter (IPM) at post-shift on 5th day and analysed using the Single Particle Mass Spectrometry (SP-ICP-MS) technique to assess possible exposure to Cr2O3, Mn3O4 and NiO nanoparticles (NPs) in welders. The NPs in IPM at both Companies presented a multi-oxide composition consisting of Cr2O3 (median, 871,574 particles/m3; 70 nm), Mn3O4 (median, 713,481 particles/m3; 92 nm) and NiO (median, 369,324 particles/m3; 55 nm). The EBC of welders at both Companies showed Cr2O3 NPs median concentration significantly higher at post-shift (64,645 particles/mL; 55 nm) than at pre-shift (15,836 particles/mL; 58 nm). Significantly lower Cr2O3 NPs median concentration and size (7762 particles/mL; 44 nm) were observed in plasma compared to EBC of welders. At one Company, NiO NPs median concentration in EBC (22,000 particles/mL; 65 nm) and plasma (8248 particles/mL; 37 nm) were detected only at post-shift. No particles of Cr2O3, Mn3O4 and NiO were detected in urine of welders at both Companies. The combined analyses of biological matrices and air samples were a valid approach to investigate both internal and external exposure of welding workers to MONPs. Overall, results may inform suitable risk assessment and management procedures in welding operations.

Evolution and Applications of Recent Sensing Technology for Occupational Risk Assessment: A Rapid Review of the Literature.

Over the last decade, technological advancements have been made available and applied in a wide range of applications in several work fields, ranging from personal to industrial enforcements. One of the emerging issues concerns occupational safety and health in the Fourth Industrial Revolution and, in more detail, it deals with how industrial hygienists could improve the risk-assessment process. A possible way to achieve these aims is the adoption of new exposure-monitoring tools. In this study, a systematic review of the up-to-date scientific literature has been performed to identify and discuss the most-used sensors that could be useful for occupational risk assessment, with the intent of highlighting their pros and cons. A total of 40 papers have been included in this manuscript. The results show that sensors able to investigate airborne pollutants (i.e., gaseous pollutants and particulate matter), environmental conditions, physical agents, and workers' postures could be usefully adopted in the risk-assessment process, since they could report significant data without significantly interfering with the job activities of the investigated subjects. To date, there are only few "next-generation" monitors and sensors (NGMSs) that could be effectively used on the workplace to preserve human health. Due to this fact, the development and the validation of new NGMSs will be crucial in the upcoming years, to adopt these technologies in occupational-risk assessment.

Toxicological assessment method for evaluating the occupational risk of dynamic olfactometry assessors.

The paper aims to propose a new method to evaluate the occupational exposure risk for examiners involved in dynamic olfactometry. Indeed, examiners are possibly exposed to hazardous pollutants potentially present in odorous samples. A standardized method to evaluate the examiners' occupational safety is not yet available and the existing models present some critical aspect if applied to real odorous samples (no uniform reference concentrations applied and presence of compounds for which no toxicity threshold is available). A deepening of assessment procedure to evaluate the occupation exposure risk for olfactometric assessors is necessary. This paper proposes a standardized approach for risk assessment in dynamic olfactometry. The proposed approach allows the quantification synthetic and conservative risk indices. In this model, the use of the hazard index for the odorous mixture was proposed to assess the non-carcinogenic risk; the calculation of the inhalation risk was applied to estimate the carcinogenic risk. Different databases can be used to retrieve proper occupational exposure limits, according to the proposed hierarchical basis. These implementations allow obtaining the complete characterization of real samples which can be used to calculate the minimum dilution factor for protecting the panellists' health.

Features and Practicability of the Next-Generation Sensors and Monitors for Exposure Assessment to Airborne Pollutants: A Systematic Review.

In the last years, the issue of exposure assessment of airborne pollutants has been on the rise, both in the environmental and occupational fields. Increasingly severe national and international air quality standards, indoor air guidance values, and exposure limit values have been developed to protect the health of the general population and workers; this issue required a significant and continuous improvement in monitoring technologies to allow the execution of proper exposure assessment studies. One of the most interesting aspects in this field is the development of the "next-generation" of airborne pollutants monitors and sensors (NGMS). The principal aim of this review is to analyze and characterize the state of the art and of NGMS and their practical applications in exposure assessment studies. A systematic review of the literature was performed analyzing outcomes from three different databases (Scopus, PubMed, Isi Web of Knowledge); a total of 67 scientific papers were analyzed. The reviewing process was conducting systematically with the aim to extrapolate information about the specifications, technologies, and applicability of NGMSs in both environmental and occupational exposure assessment. The principal results of this review show that the use of NGMSs is becoming increasingly common in the scientific community for both environmental and occupational exposure assessment. The available studies outlined that NGMSs cannot be used as reference instrumentation in air monitoring for regulatory purposes, but at the same time, they can be easily adapted to more specific applications, improving exposure assessment studies in terms of spatiotemporal resolution, wearability, and adaptability to different types of projects and applications. Nevertheless, improvements needed to further enhance NGMSs performances and allow their wider use in the field of exposure assessment are also discussed.

Indoor gaseous air pollutants determinants in office buildings-The OFFICAIR project.

The aim of this study was to identify determinants of aldehyde and volatile organic compound (VOC) indoor air concentrations in a sample of more than 140 office rooms, in the framework of the European OFFICAIR research project. A large field campaign was performed, which included (a) the air sampling of aldehydes and VOCs in 37 newly built or recently retrofitted office buildings across 8 European countries in summer and winter and (b) the collection of information on building and offices' characteristics using checklists. Linear mixed models for repeated measurements were applied to identify the main factors affecting the measured concentrations of selected indoor air pollutants (IAPs). Several associations between aldehydes and VOCs concentrations and buildings' structural characteristic or occupants' activity patterns were identified. The aldehyde and VOC determinants in office buildings include building and furnishing materials, indoor climate characteristics (room temperature and relative humidity), the use of consumer products (eg, cleaning and personal care products, office equipment), as well as the presence of outdoor sources in the proximity of the buildings (ie, vehicular traffic). Results also showed that determinants of indoor air concentrations varied considerably among different type of pollutants.

[Chemical risks in research laboratories]. / I rischi nei laboratori di ricerca: i rischi di tipo chimico.

SUMMARY: Research laboratories represent peculiar employment realities, generally characterized by the use of reduced volumes of several chemicals, often used in mixture, thus defining a potential exposure to multiple chemical agents. Methods. The aim of the study is to provide a brief review of the most widely used methods for assessing chemical risk in laboratories, with particular emphasis on their limits and advantages. Results. The approach most often used for assessing chemical risk in research laboratories involves the use of a qualitative modeling approach for risk assessment or quantitative exposure assessment tools. Conclusions. Chemical risk assessment algorithms represent a useful solution for the purposes of the initial screening for the assessment of chemical risk in research laboratories: their ease of use makes them easily accessible, but on the other hand does not allow to take into proper consideration the particularities of the assessed exposure scenarios. Regarding the exposure estimation models, although these instruments have a wide range of applicability, there is no solid and complete validation, which evaluates the accuracy and reliability for this peculiar type of exposure scenarios.

A History of Industrial Hygiene: the Clinica del Lavoro in Milan and the Italian Association of Industrial Hygienists.

In 1969, the Italian Association of Industrial Hygienists (AIDII) was founded in Milan by Academics working at the Clinica del Lavoro, one of the oldest institutions for work prevention in the world and within the most prolific institutes in the world on Occupational Medicine and Industrial Hygiene. AIDII was founded as a scientific association with the primary purpose of promoting the development, deepening and dissemination of Industrial Hygiene, the scientific discipline aimed at identifying, assessing and controlling chemical, physical and biological risk factors (as well as transversal risks) either inside or outside the workplace, which can alter the health and wellbeing status of workers and/or the general population, for the purpose of effective prevention and protection of human health. Over the decades, the activities of AIDII have evolved to meet some of the current needs and challenges, while remaining consistent with the basics set by the founders.

Short-term particulate matter exposure influences nasal microbiota in a population of healthy subjects.

BACKGROUND: Exposure to air pollutants, such as particulate matter (PM), represents a growing health problem. The aim of our study was to investigate whether PM could induce a dysbiosis in the nasal microbiota in terms of α-diversity and taxonomic composition. METHODS: We investigated structure and characteristics of the microbiota of 40 healthy subjects through metabarcoding analysis of the V3-V4 regions of the 16s rRNA gene. Exposure to PM10 and PM2.5 was assessed with a personal sampler worn for 24h before sample collection (Day -1) and with measurements from monitoring stations (from Day -2 to Day -7). RESULTS: We found an inverse association between PM10 and PM2.5 levels of the 3rd day preceding sampling (Day -3) and α-diversity indices (Chao1, Shannon and PD_whole_tree). Day -3 PM was inversely associated also with the majority of analyzed taxa, except for Moraxella, which showed a positive association. In addition, subjects showed different structural profiles identifying two groups: one characterized by an even community and another widely dominated by the Moraxella genus. CONCLUSIONS: Our findings support the role of PM exposure in influencing microbiota and altering the normal homeostasis within the bacterial community. Whether these alterations could have a role in disease development and/or exacerbation needs further research.

Precision and Accuracy of a Direct-Reading Miniaturized Monitor in PM2.5 Exposure Assessment.

The aim of this study was to evaluate the precision, accuracy, practicality, and potential uses of a PM2.5 miniaturized monitor (MM) in exposure assessment. These monitors (AirBeam, HabitatMap) were compared with the widely used direct-reading particulate matter monitors and a gravimetric reference method for PM2.5. Instruments were tested during 20 monitoring sessions that were subdivided in two different seasons to evaluate the performance of sensors across various environmental and meteorological conditions. Measurements were performed at an urban background site in Como, Italy. To evaluate the performance of the instruments, different analyses were conducted on 8-h averaged PM2.5 concentrations for comparison between direct-reading monitors and the gravimetric method, and minute-averaged data for comparison between the direct-reading instruments. A linear regression analysis was performed to evaluate whether the two measurement methods, when compared, could be considered comparable and/or mutually predictive. Further, Bland-Altman plots were used to determine whether the methods were characterized by specific biases. Finally, the correlations between the error associated with the direct-reading instruments and the meteorological parameters acquired at the sampling point were investigated. Principal results show a moderate degree of agreement between MMs and the reference method and a bias that increased with an increase in PM2.5 concentrations.

Exposure to airborne particles associated with the handling of graphene nanoplatelets.

BACKGROUND: It is recognized that engineering control measures are needed to reduce occupational exposure to engineered nanomaterials (NMs): of these, fume hoods are among the most widespread collective protection equipment used while handling NMs in occupational settings.  It is known that in some circumstances, handling NMs in fume hoods can result in a significant release of NMs. OBJECTIVE: To assess the effectiveness of fume hoods in reducing exposure while handling graphene nanoplatelets and to define the conditions that result in a lower dispersion of particles and thus less operator exposure. METHODS: An experimental protocol was established to monitor the variations of airborne particle concentrations while handling graphene in fume hoods (transferring and pouring). The measurement locations were at the laboratory, inside the hood and at operator's breathing zone. Handling tasks were performed under different operating conditions: the variable factors included hood face velocity and sash height. RESULTS: Results of this study indicate that the handling of graphene nanoplatelets may pose a potential risk of contamination of the work environment and hence exposure of the involved operators, if adequate control measures are not taken. In fact, when inadequate or not sufficiently cautionary operational conditions were utilized, non-negligible increases in airborne graphene particle concentrations during the nanomaterial manipulation phases were observed. CONCLUSIONS: Some operating conditions (e.g., face velocity, sash height) can be adjusted to avoid relevant personal exposure conditions and contamination of the work environment by NMs, thus ensuring safer conditions.

SYN-JEM: A Quantitative Job-Exposure Matrix for Five Lung Carcinogens.

OBJECTIVE: The use of measurement data in occupational exposure assessment allows more quantitative analyses of possible exposure-response relations. We describe a quantitative exposure assessment approach for five lung carcinogens (i.e. asbestos, chromium-VI, nickel, polycyclic aromatic hydrocarbons (by its proxy benzo(a)pyrene (BaP)) and respirable crystalline silica). A quantitative job-exposure matrix (JEM) was developed based on statistical modeling of large quantities of personal measurements. METHODS: Empirical linear models were developed using personal occupational exposure measurements (n = 102306) from Europe and Canada, as well as auxiliary information like job (industry), year of sampling, region, an a priori exposure rating of each job (none, low, and high exposed), sampling and analytical methods, and sampling duration. The model outcomes were used to create a JEM with a quantitative estimate of the level of exposure by job, year, and region. RESULTS: Decreasing time trends were observed for all agents between the 1970s and 2009, ranging from -1.2% per year for personal BaP and nickel exposures to -10.7% for asbestos (in the time period before an asbestos ban was implemented). Regional differences in exposure concentrations (adjusted for measured jobs, years of measurement, and sampling method and duration) varied by agent, ranging from a factor 3.3 for chromium-VI up to a factor 10.5 for asbestos. CONCLUSION: We estimated time-, job-, and region-specific exposure levels for four (asbestos, chromium-VI, nickel, and RCS) out of five considered lung carcinogens. Through statistical modeling of large amounts of personal occupational exposure measurement data we were able to derive a quantitative JEM to be used in community-based studies.

Occupational exposure to arsenic and cadmium in thin-film solar cell production.

INTRODUCTION: Workers involved in the production of Cd/As-based photovoltaic modules may be routinely or accidentally exposed to As- or Cd-containing inorganic compounds. METHODS: Workers' exposure to As and Cd was investigated by environmental monitoring following a worst-case approach and biological monitoring from the preparation of the working facility to its decommissioning. Workplace surface contamination was also evaluated through wipe-test sampling. RESULTS: The highest mean airborne concentrations were found during maintenance activities (As = 0.0068 µg m(-3); Cd = 7.66 µg m(-3)) and laboratory simulations (As = 0.0075 µg m(-3); Cd = 11.2 µg m(-3)). These types of operations were conducted for a limited time during a typical work shift and only in specifically suited containment areas, where the highest surface concentrations were also found (laboratory: As = 2.94 µg m(-2), Cd = 167 µg m(-2); powder containment booth: As = 4.35 µg m(-2), Cd = 1500 µg m(-2)). The As and Cd urinary levels (As_u; Cd_u) were not significantly different for exposed (As_u = 6.11±1.74 µg l(-1); Cd_u = 0.24±2.36 µg g(-1) creatinine) and unexposed workers (As_u = 6.11±1.75 µg l(-1); Cd_u = 0.22±2.08 µg g(-1) creatinine). CONCLUSION: Despite airborne arsenic and cadmium exposure well below the threshold limit value (TLV) when the operation is appropriately maintained in line, workers who are involved in various operations (maintenance, laboratory test) could potentially be at risk of significant exposure, well in excess of the TLV. Nevertheless, the biological monitoring data did not show significant occupationally related arsenic and cadmium intake in workers and no significant changes or differences in arsenic and cadmium urinary level among the exposed and unexposed workers were found.

Asbestos Lung Burden in Necroscopic Samples from the General Population of Milan, Italy.

The present study analysed the asbestos lung burden in necroscopic samples from 55 subjects free from asbestos-related diseases, collected between 2009 and 2011 in Milan, Italy. Multiple lung samples were analysed by light microscopy (asbestos bodies, AB) and EDXA-scanning electron microscopy (asbestos fibres and other inorganic fibres). Asbestos fibres were detected in 35 (63.6%) subjects, with a higher frequency for amphiboles than for chrysotile. Commercial (CA) and non-commercial amphiboles (NCA) were found in roughly similar frequencies. The estimated median value was 0.11 million fibres per gram of dry lung tissue (mf g(-1)) for all asbestos, 0.09 mf g(-1) for amphiboles. In 44 (80.0%) subjects no chrysotile fibres were detected. A negative relationship between asbestos mass-weighted fibre count and year of birth (and a corresponding positive increase with age) was observed for amphiboles [-4.15%, 95% confidence interval (CI) = -5.89 to -2.37], talc (-2.12%, 95% CI = -3.94 to -0.28), and Ti-rich fibres (-3.10%, 95% CI = -5.54 to -0.60), but not for chrysotile (-2.84%, 95% CI = -7.69 to 2.27). Residential district, birthplace, and smoking habit did not affect the lung burden of asbestos or inorganic fibres. Females showed higher burden only for amphiboles (0.12 versus 0.03 mf g(-1) in males, P = 0.07) and talc fibres (0.14 versus 0 mf g(-1) in males, P = 0.03). Chrysotile fibres were shorter and thinner than amphibole fibres and NCA fibres were thicker than CA ones. The AB prevalence was 16.4% (nine subjects) with concentrations ranging from 10 to 110 AB g(-1) dry, well below the 1000 AB g(-1) threshold for establishing occupational exposure. No AB were found in subjects younger than 30 years. Our study demonstrated detectable levels of asbestos fibres in a sample taken from the general population. The significant increase with age confirmed that amphibole fibres are the most representative of cumulative exposure.

An In-Field Assessment of the P.ALP Device in Four Different Real Working Conditions: A Performance Evaluation in Particulate Matter Monitoring.

This study aimed to assess the performance, in terms of precision and accuracy, of a prototype (called "P.ALP"-Ph.D. Air Quality Low-cost Project) developed for monitoring PM2.5 concentration levels. Four prototypes were co-located with reference instrumentation in four different microenvironments simulating real-world and working conditions, namely (i) office, (ii) home, (iii) outdoor, and (iv) occupational environments. The devices were evaluated for a total of 20 monitoring days (approximately 168 h) under a wide range of PM2.5 concentrations. The performances of the prototypes (based on the light-scattering working principle) were tested through different statistical methods. After the data acquisition and data cleaning processes, a linear regression analysis was performed to assess the precision (by comparing all possible pairs of devices) and the accuracy (by comparing the prototypes against the reference instrumentation) of the P.ALP. Moreover, the United States Environmental Protection Agency (US EPA) criteria were applied to assess the possible usage of this instrumentation, and to evaluate the eventual error trends of the P.ALP in the data storage process, Bland-Altman plots were also adopted. The outcomes of this study underlined that the P.ALP performed differently depending on the microenvironment in which it was tested and, consequently, on the PM2.5 concentrations. The device can monitor PM2.5 variations with acceptable results, but the performance cannot be considered satisfactory at extremely low and remarkably high PM2.5 concentrations. Thanks to modular components and open-source software, the tested device has the potential to be customized and adapted to better fit specific study design needs, but it must be implemented with ad hoc calibration factors depending on the application before being used in field.

Respirable crystalline silica and lung cancer in community-based studies: impact of job-exposure matrix specifications on exposure-response relationships.

OBJECTIVES: The quantitative job-exposure matrix SYN-JEM consists of various dimensions: job-specific estimates, region-specific estimates, and prior expert ratings of jobs by the semi-quantitative DOM-JEM. We analyzed the effect of different JEM dimensions on the exposure-response relationships between occupational silica exposure and lung cancer risk to investigate how these variations influence estimates of exposure by a quantitative JEM and associated health endpoints. METHODS: Using SYN-JEM, and alternative SYN-JEM specifications with varying dimensions included, cumulative silica exposure estimates were assigned to 16 901 lung cancer cases and 20 965 controls pooled from 14 international community-based case-control studies. Exposure-response relationships based on SYN-JEM and alternative SYN-JEM specifications were analyzed using regression analyses (by quartiles and log-transformed continuous silica exposure) and generalized additive models (GAM), adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. RESULTS: SYN-JEM and alternative specifications generated overall elevated and similar lung cancer odds ratios ranging from 1.13 (1st quartile) to 1.50 (4th quartile). In the categorical and log-linear analyses SYN-JEM with all dimensions included yielded the best model fit, and exclusion of job-specific estimates from SYN-JEM yielded the poorest model fit. Additionally, GAM showed the poorest model fit when excluding job-specific estimates. CONCLUSION: The established exposure-response relationship between occupational silica exposure and lung cancer was marginally influenced by varying the dimensions of SYN-JEM. Optimized modelling of exposure-response relationships will be obtained when incorporating all relevant dimensions, namely prior rating, job, time, and region. Quantitative job-specific estimates appeared to be the most prominent dimension for this general population JEM.

Sensitivity analyses of exposure estimates from a quantitative job-exposure matrix (SYN-JEM) for use in community-based studies.

OBJECTIVES: We describe the elaboration and sensitivity analyses of a quantitative job-exposure matrix (SYN-JEM) for respirable crystalline silica (RCS). The aim was to gain insight into the robustness of the SYN-JEM RCS estimates based on critical decisions taken in the elaboration process. METHODS: SYN-JEM for RCS exposure consists of three axes (job, region, and year) based on estimates derived from a previously developed statistical model. To elaborate SYN-JEM, several decisions were taken: i.e. the application of (i) a single time trend; (ii) region-specific adjustments in RCS exposure; and (iii) a prior job-specific exposure level (by the semi-quantitative DOM-JEM), with an override of 0 mg/m(3) for jobs a priori defined as non-exposed. Furthermore, we assumed that exposure levels reached a ceiling in 1960 and remained constant prior to this date. We applied SYN-JEM to the occupational histories of subjects from a large international pooled community-based case-control study. Cumulative exposure levels derived with SYN-JEM were compared with those from alternative models, described by Pearson correlation ((Rp)) and differences in unit of exposure (mg/m(3)-year). Alternative models concerned changes in application of job- and region-specific estimates and exposure ceiling, and omitting the a priori exposure ranking. RESULTS: Cumulative exposure levels for the study subjects ranged from 0.01 to 60 mg/m(3)-years, with a median of 1.76 mg/m(3)-years. Exposure levels derived from SYN-JEM and alternative models were overall highly correlated (R(p) > 0.90), although somewhat lower when omitting the region estimate ((Rp) = 0.80) or not taking into account the assigned semi-quantitative exposure level (R(p) = 0.65). Modification of the time trend (i.e. exposure ceiling at 1950 or 1970, or assuming a decline before 1960) caused the largest changes in absolute exposure levels (26-33% difference), but without changing the relative ranking ((Rp) = 0.99). CONCLUSIONS: Exposure estimates derived from SYN-JEM appeared to be plausible compared with (historical) levels described in the literature. Decisions taken in the development of SYN-JEM did not critically change the cumulative exposure levels. The influence of region-specific estimates needs to be explored in future risk analyses.

Early-phase pandemic in Italy: Covid-19 spread determinant factors.

Although the Covid-19 pandemic is still ongoing, the environmental factors beyond virus transmission are only partially known. This statistical study has the aim to identify the key factors that have affected the virus spread during the early phase of pandemic in Italy, among a wide set of potential determinants concerning demographics, environmental pollution and climate. Because of its heterogeneity in pollution levels and climate conditions, Italy provides an ideal scenario for an ecological study. Moreover, the selected period excludes important confounding factors, as different virus variants, restriction policies or vaccines. The short-term relationship between the infection maximum increase and demographic, pollution and meteo-climatic parameters was investigated, including both winter-spring and summer 2020 data, also focusing separately on the two seasonal periods and on North vs Centre-South. Among main results, the importance of population size confirmed social distancing as a key management option. The pollution hazardous role undoubtedly emerged, as NO2 affected infection increase in all the studied scenarios, PM2.5 manifested its impact in North of Italy, while O3 always showed a protective action. Whereas higher temperatures were beneficial, especially in the cold season with also wind and relative humidity, solar irradiance was always relevant, revealing several significant interactions with other co-factors. Presented findings address the importance of the environment in Sars-CoV-2 spread and indicated that special carefulness should be taken in crowded areas, especially if they are highly polluted and weakly exposed to sun. The results suggest that containment of future epidemics similar to Covid-19 could be supported by reducing environmental pollution, achieving safer social habits and promoting preventive health care for better immune system response, as an only comprehensive strategy.