The Indoor Environmental Quality (IEQ) combines thermal, visual, acoustic, and air-quality conditions in indoor environments and affects occupants’ health, well-being, and comfort. Performing continuous monitoring to assess IEQ is increasingly proving to be important, also due to the large amount of time that people spend in closed spaces. In the present study, the design, development, and metrological characterization of a low-cost multi-sensor device is presented. The device is part of a wider system, hereafter referred to as PROMET&O (PROactive Monitoring for indoor EnvironmenTal quality & cOmfort), that also includes a questionnaire for the collection of occupants’ feedback on comfort perception and a dashboard to show end users all monitored data. The PROMET&O multi-sensor monitors the quality conditions of indoor environments thanks to a set of low-cost sensors that measure air temperature, relative humidity, illuminance, sound pressure level, carbon monoxide, carbon dioxide, nitrogen dioxide, particulate matter, volatile organic compounds, and formaldehyde. The device architecture is described, and the design criteria related to measurement requirements are highlighted. Particular attention is paid to the calibration of the device to ensure the metrological traceability of the measurements. Calibration procedures, based on the comparison to reference standards and following commonly employed or ad hoc developed technical procedures, were defined and applied to the bare sensors of air temperature and relative humidity, carbon dioxide, illuminance, sound pressure level, particulate matter, and formaldehyde. The next calibration phase in the laboratory will be aimed at analyzing the mutual influences of the assembled multi-sensor hardware components and refining the calibration functions.

As the population of urban areas is increasing continually, analysis of the particulate concentration dynamics in these areas is crucial. Therefore, this study investigated the temporal and spatial variabilities of PM₁, PM_2.5, and PM₁₀ over the urban area of Turin in the Po Valley, Italy, based on high-resolution data from a monitoring campaign conducted between 2018 and 2021 (including COVID-19 lockdown period). The study also performed a source direction analysis of the urban observation using the conditional bivariate probability function (CBPF). The results showed substantial differences in PM₁₀ concentration at background (28–30 µg/m³), and traffic stations (36 µg/m³). PM_2.5 concentration was highest at traffic stations (24 µg/m³). During the day, the highest values occurred at 9:00–11:00 AM, and the lowest concentrations occurred at 4:00–6:00 PM. The concentration peak position changed in a daily bimodal trend with the season. According to the CBPF, the relevant external particulate contributions to the Turin area are from the direction of the Po Valley (N–NE) and the typical direction of Saharan dust transport (S–SW). The present study contributes to scientific understanding by providing information on one of the main European pollutant hot spots and discussing the trends of emerging pollutants, like PM₁.

The Volume 13 published for IJEPR Journal.

Three measurement campaigns were conducted on the island of Culuccia (Sardinia, Italy) to evaluate particulate matter (PM) concentrations and the contribution of sea spray aerosol (SSA) across different seasons in a largely uncontaminated coastal environment. The goal is not only to analyze PM concentration in relation to meteorological parameters such as temperature, relative humidity (rH), and wind speed but also to provide a chemical analysis of SSA. The chemical composition of PM was determined using Raman spectroscopy and SEM-EDX, allowing for precise identification of individual particles. Results showed seasonal variations in PM composition, with sodium nitrate and sodium chloride prevalent in March and June and sulfates dominating in October. A correlation between the PM composition and meteorological parameters was observed according to the value of the deliquescence relative humidity (DRH), highlighting the reciprocal influence of rH and coarse and fine PM trends. This multi-technique approach offers valuable insights into the relative abundance of different PM compound classes based on the varying conditions for SSA formation. This enhances our understanding of the behavior of sea spray aerosol and other PM in natural coastal environments.