ABSTRACT Air particulate matter (PM) is widely recognized for its potential to negatively affect human health, including changes in the upper respiratory microbiome. However, research on PM-associated microbiota remains limited and mostly focused on PM (e.g., PM 2.5 and PM 10 ). This study aims to characterize for the first time the microbiome of Total Suspended Particles (TSP) and investigate the correlations of indoor TSP with the human upper respiratory microbiome. Biological and environmental samples were collected over three collection periods lasting three weeks each, between May and July 2022 at the University of Milan and the University of Insubria Como. TSP were sampled using a filter-based technique, while respiratory samples from both anterior nares (AN) and the nasopharynx (NP) were collected using swabs. Microbiome analysis of both human (N = 145) and TSP (N = 51) samples was conducted on metagenomic sequencing data. A comparison of indoor and outdoor TSP microbiomes revealed differences in microbial diversity and taxonomic composition. The indoor samples had higher relative abundance of environmental bacteria often associated with opportunistic infections like Paracoccus sp., as well as respiratory bacteria such as Staphylococcus aureus and Klebsiella pneumoniae . Additionally, both indoor and outdoor TSP samples contained broad spectrum antibiotic resistance genes. Indoor TSP exposure was negatively associated with commensal bacteria and positively associated with Staphylococcus aureus relative abundance. Finally, a correlation between the relative abundance of respiratory bacteria identified in the indoor TSP and the upper respiratory microbiome was found, suggesting a potential interaction between TSP and the upper airways.
Abstract Introduction WFH (Working From Home) is increasingly common, necessitating a careful evaluation of WFH workers’ health. Recent studies have explored various aspects, including its impact on workers’ psychological and physical well-being, highlighting positive and negative aspects of this “new” working mode. This study aims to evaluate one of these aspects: worker exposure to atmospheric pollutants. Methods Two monitoring surveys were performed: a long-term and a short-term campaign, both focused on the measurement of personal exposure to size-fractionated PM (Particulate Matter) in WFH and WFO (Working From Office) conditions, through a paired-sample study design. Results Results of the long-term campaign show how 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 to PM. Also, in the case of short-term campaign, particular activities seem to contribute to a greater worker exposure to PM. Given the potential growth of people WFH, it’s crucial to comprehensively assess these “new domestic offices.” Organizations should evaluate indoor environmental quality (IEQ), occupational exposure to risk factors, and implement mitigation measures as needed to address and manage health risks for WFH employees. Additionally, consideration should be given to other risk factors and health issues, such as those found in traditional office settings (e.g., musculoskeletal disorders, computer vision syndrome). Conclusions Monitoring IEQ, in the framework of a comprehensive risk assessment, identifying workplace-specific risks, and implementing appropriate mitigation measures are actions organizations should consider to better understand and address potential health risks associated with WFH conditions.
Airborne particulate matter (PM) concentrations inside vehicle cabins are often extremely high compared to background levels. The present study was motivated by the fact that in the last few decades, the implementation of new emission standards has led to the reduction of vehicle particle emissions. This study addresses for the first time the relationship between leading vehicle (LV) emissions and in-cabin PM exposure levels in the immediately following vehicle (henceforth called the study vehicle - SV), with particular emphasis on the role of the LV's emission reduction technologies (e.g., diesel particulate filter-DPF) as an effective risk management measure. The study was performed using an instrumented study vehicle (always to be considered as the following vehicle) on a 26-km fixed route where 10 repeated tests were conducted during 60-minute trips. On-line monitoring of the fine 0.3-1 μm and 1-2.5 μm (PM0.3-1 and PM1-2.5) and ultra-fine particle (UFP) concentrations was performed inside the SV's car cabin with fixed ventilation settings (i.e., windows closed, air conditioning off, and recirculation fan off). Simultaneously, the license plate numbers of the LVs along the route were recorded to retrieve information pertaining to their fuel type and Euro emission standard category. The results clearly showed that the in-cabin PM levels were significantly affected by the LV's Euro emission standard. Regarding petrol-fuelled LVs, the median in-cabin particle exposure levels were statistically lower (e.g., -34% for PM0.3-1) when following vehicles with stricter emission standards (in particular, Euro 6) than when following a low-emission standard vehicle (i.e., Euro 0-2). Concerning diesel-fuelled LVs, a strong and significant decrease in the in-cabin median exposure levels (up to -62%, -44%, and -48% for UFPs, PM0.3-1, and PM1-2.5, respectively) was observed for recent-emission standards LVs (i.e., Euro 5-6) with respect to older-emission standard LVs (i.e., Euro 0-4). A specific analysis revealed that the in-cabin median exposure concentrations of PM were highly and significantly reduced by DPF-equipped LVs. For UFPs, this resulted in a 47% reduction compared to diesel-fuelled (non-DPF) LVs. For PM0.3-1, an approximate 80% reduction was observed compared to both petrol-fuelled and diesel-fuelled (non-DPF) LVs. For PM1-2.5, an approximate 38% reduction was observed compared to petrol-fuelled LVs and a 46% reduction compared to non-DPF LVs.
Studies on air quality in rural environments are fundamental to obtain first-hand data for the determination of base emissions of air pollutants, to assess the impact of rural-specific airborne pollutants, to model pollutant dispersion, and to develop proper pollution mitigation technologies. The literature lacks a systematic review based on the evaluation of the techniques and methods used for the sampling/monitoring (S/M) of atmospheric pollutants in rural and agricultural settings, which highlights the shortcomings in this field and the need for future studies. This work aims to review the study design applied for on-field monitoring campaigns of airborne pollutants in rural environments and discuss the possible needs and future developments in this field. The results of this literature review, based on the revision of 23 scientific papers, allowed us to determine (i) the basic characteristics related to the study design that should always be reported; (ii) the main techniques and analyses used in exposure assessment studies conducted in this type of setting; and (iii) contextual parameters and descriptors of the S/M site that should be considered to best support the results obtained from the different studies. Future studies carried out to monitor the airborne pollution in rural/agriculture areas should (i) include the use of multiparametric monitors for the contextual measurement of different atmospheric pollutants (as well as meteorological parameters) and (ii) consider the most important boundary information, to better characterize the S/M site.
During rush hours, commuters are exposed to high concentrations and peaks of traffic-related air pollutants. The aims of this study were therefore to extend the inhaled dose estimation outcomes from a previous work investigating the inhaled dose of a typical commuter in the city of Milan, Italy, and to extend these results to a wider population. The estimation of the dose of pollutants inhaled by commuters and deposited within the respiratory tract could be useful to help commuters in choosing the modes of transport with the lowest exposure and to increase their awareness regarding this topic. In addition, these results could provide useful information to policy makers, for the creation/improvement of a mobility that takes these results into account. The principal result outcomes from the first part of the project (case study on a typical commuter in the city of Milan) show that during the winter period, the maximum deposited mass values were estimated in the “Other” environments and in “Underground”. During the summer period, the maximum values were estimated in the “Other” and “Walking (high-traffic conditions)” environments. For both summer and winter, the lowest values were estimated in the “Car” and “Walking (low-traffic conditions)” environments. Regarding the second part of the study (the extension of the results to the general population of commuters in the city of Milan), the main results show that the period of permanence in a given micro-environment (ME) has an important influence on the inhaled dose, as well as the pulmonary ventilation rate. In addition to these results, it is of primary importance to report how the inhaled dose of pollutants can be strongly influenced by the time spent in a particular environment, as well as the subject’s pulmonary ventilation rate and pollutant exposure levels. For these reasons, the evaluation of these parameters (pulmonary ventilation rate and permanence time, in addition to the exposure concentration levels) for estimating the inhaled dose is of particular relevance.
