Abstract
Outdoor air quality guidelines have been constantly implemented during the last decades. Nonetheless, no international regulations have been put into action in terms of indoor air quality standards and standardized procedures for indoor pollution measurements. In this study, we investigated the chemical composition of PM2.5 collected outdoors and indoors at six dwellings located in two Italian areas. The selected sites concerned inland/central and southern Italy, including urban, peri-urban, rural and coastal settings. The seasonal and site-specific particulate matter (PM) variations were analyzed outdoors and indoors, by estimating the impact of the main macro-sources and the contribution of the macro- and micro-components. Outdoors, organic matter represented the main contribution at inland and coastal sites, respectively during winter and summer. A clear, seasonal variation was also observed for secondary inorganic species. A site-specific dependence was exhibited by traffic-related components. Indoors, organic and soil-related species were influenced by the presence of the inhabitants. Some specific tracers allowed to identify additional local source contributions and indoor activities. Although the sampling season and site location defined the outdoor air quality, the higher PM concentrations and the chemical composition indoors were influenced by the infiltration of outdoor air and by the indoor activities carried out by its inhabitants.
Highlights
During the last decades, outdoor air pollution regulations have been extensively improved both in North America and Europe
Urban Winter (Urban-W), Coastal Summer (Coast-S) and Coastal Winter (Coast-W) data are provided as the average value calculated between multiple campaigns
The average particulate matter (PM) concentrations measured outdoors during the winter campaigns were higher at inland locations in comparison to coastal sites, resulting in the range 26–34 μg/m3 and 16 μg/m3
Summary
Outdoor air pollution regulations have been extensively improved both in North America and Europe. These enhancements were aimed at establishing new health-based concentration standards and at improving the pre-existing legislations, providing new air quality objectives. The WHO published the document Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide (Global update 2005, Summary of risk assessment) to inform about the health risks related to environmental exposure and to guide policy-makers towards the implementation of appropriate air quality targets [3]. In 2013, the specialized cancer agency of WHO, the International Agency for Research on Cancer (IARC), classified outdoor air pollution and particulate matter (PM) as carcinogenic of Group 1 [4]. The REVIHAAP report (Review of Evidence on Health Aspects of Air Pollution) was published, with a full review and Atmosphere 2020, 11, 368; doi:10.3390/atmos11040368 www.mdpi.com/journal/atmosphere
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