Submicron and Ultrafine Particles in Downtown Rome: How the Different Euro Engines Have Influenced Their Behavior for Two Decades

Occurrence of organic contaminants bonded to the particulate matter from outdoor air influenced by industrial activities

This paper discusses the occurrence of organic contaminants bonded to particulate matter (PM) in ambient air. We describe the presence and concentration levels of contaminants mainly reported in atmospheres close to factories or at locations influenced by them, and the relationship between factory emissions and the type of organic contaminants found in PM samples from the surrounding air. Many organic contaminants have been found in these types of samples, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). Their sources, fates and distributions in the ambient atmosphere are therefore well known. However, in addition to these most studied compounds, others are also of concern nowadays due to their detection and toxic effects on the environment. The continuous updating of regulations on these contaminants and the appearance of new air pollutants make it important to be aware of their occurrence. This will help to either establish new guidelines for the newer contaminants or reassess existing limitations for known ones. Moreover, if we know their occurrence, we can analyse their sources, destinations and distributions in the outdoor air.

Relationship between Indoor High Frequency Size Distribution of Ultrafine Particles and Their Metrics in a University Site

Exposure to ultrafine particles (UFPs size < 100 nm) in life and work environments can contribute to adverse health effects also in terms of health burden of related diseases over time. The choice of parameters which better characterize UFPs is challenging, due to their physical-chemical properties and their variable size. It is also strictly related to the availability of different instrumental techniques. In the present study we focus on real time high frequency (1 Hz) UFPs particle size distribution (PSD) and their relationship with total particle number concentration (TPNC) and mean particle diameter (Davg) as a contribution characterizing by size the human exposure to UFPs in an indoor site of the University of Rome “Sapienza” (Italy). Further considerations about UFPs contribution to nucleation mode (NM) and accumulation mode (AM) have been highlighted, also in order to investigate the contribution of polycyclic aromatic hydrocarbons (PAHs) surface-adsorbed on indoor air particles (pPAHs). High indoor TPNC values were registered during the rush hours (early morning and mid/late afternoon) according to the outdoor influences originated from anthropogenic activities. AM mainly contribute to the indoor TPNC during working days showing high correlation with pPAHs. These findings may provide useful indications in terms of occupational exposure to UFPs since there are many evidences that indoor exposures to such pollutants may be associated with adverse health effects also in working environments.

Indoor Air Quality Levels in Schools: Role of Student Activities and No Activities

This work describes a methodology for the definition of indoor air quality monitoring plans in schools and above all to improve the knowledge and evaluation of the indoor concentration levels of some chemical pollutants. The aim is to guide interventions to improve the health of students and exposed staff connected with the activities carried out there. The proposed methodology is based on the simultaneous study of chemical (indoor/outdoor PM_2.5, NO₂, CO₂) and physical (temperature, humidity) parameters by means of automatic analyzers coupled with gaseous compounds (benzene, toluene, ethylbenzene, xylenes, formaldehyde and NO₂) sampled by denuders. The important novelty is that all the data were collected daily in two different situations, i.e., during school activities and no-school activities, allowing us to evaluate the exposure of each student or person. The different behaviors of all the measured pollutants during the two different situations are reported and commented on. Finally, a statistical approach will show how the investigated compounds are distributed around the two components of combustion processes and photochemical reactions.