Metallic corrosion in the polluted urban atmosphere of Hong Kong.

This study aimed to explore the relationship between air pollutants, particularly acidic particles, and metallic material corrosion. An atmospheric corrosion test was carried out in spring-summer 2012 at a polluted urban site, i.e.

Trends of ambient fine particles and major chemical components in the Pearl River Delta region: observation at a regional background site in fall and winter.

Unlabelled: In the fall and winter of 2007 to 2011, 167 24-h quartz filter-based fine particle (PM2.5) samples were collected at a regional background site in the central Pearl River Delta. The PM2.

Historical trends in the mass and chemical species concentrations of coarse particulate matter in the Los Angeles Basin and relation to sources and air quality regulations.

Unlabelled: To assess the impact of past, current and proposed air quality regulations on coarse particulate matter (CPM), the concentrations of CPM mass and its chemical constituents were examined in the Los Angeles Basin from 1986 to 2009 using PM data acquired from peer-reviewed journals and regulatory agency database. PM10 mass levels decreased by approximately half from 1988 to 2009 at the three sampling sites examined- located in downtown Los Angeles, Long Beach and Riverside. Annual CPM mass concentrations were calculated from the difference between daily PM10 and PM2.

Diurnal trends in oxidative potential of coarse particulate matter in the Los Angeles Basin and their relation to sources and chemical composition.

To investigate the relationship among sources, chemical composition, and redox activity of coarse particulate matter (CPM), three sampling sites were set up up in the Los Angeles Basin to collect ambient coarse particles at four time periods (morning, midday, afternoon, and overnight) in summer 2009 and winter 2010. The generation of reactive oxygen species (ROS) was used to assess the redox activity of these particles. Our results present distinct diurnal profiles of CPM-induced ROS formation in the two seasons, with much higher levels in summer than winter.

Diurnal trends in coarse particulate matter composition in the Los Angeles Basin.

To investigate the diurnal profile of the concentration and composition of ambient coarse particles, three sampling sites were set up in the Los Angeles Basin to collect coarse particulate matter (CPM) in four different time periods of the day (morning, midday, afternoon and overnight) in summer and winter. The samples were analyzed for total and water-soluble elements, inorganic ions and water-soluble organic carbon (WSOC). In summer, highest concentrations of CPM gravimetric mass, mineral and road dust, and WSOC were observed in midday and afternoon, when the prevailing onshore wind was stronger.

Monitoring the inflammatory potential of exhaust particles from passenger cars in mice.

This study presents different research techniques linked together to improve our understanding of the particulate matter (PM) impacts on health. PM samples from the exhaust of different vehicles were collected by a versatile aerosol concentration enrichment system (VACES). Waterborne PM samples were collected with this technique, thus retaining the original physicochemical characteristics of aerosol particles.