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A set of 8 polycyclic aromatic hydrocarbons (PAHs) has been analysed in a traffic-limited area in Bologna downtown, both in the gas-phase and in the particulate phase (PM10), and gas-to-particle partitioning has been investigated. From Sep 2002 to May 2003, 28 high volume PM10 samplings were carried out, and in 50 % of the samplings, PMi0 concentrations exceeded the limit of 50 μg/m³ established by a 1999 EU directive. A precisely defined sampling strategy was adopted to limit artifacts (8 h sampling in the same time interval) in the 28 samplings carried out in different meteorological conditions. A linear log-log correlation was found between gas-particle partitioning coefficients KBp and the subcooled liquid vapour pressures pB0LB, with rP2P = 0.82 and slope = -0.59. This empirical correlation may be used to anticipate the total (gas + particle-bound) concentration of each PAHs in this urban site, once PM10 and the particle-bound concentration is measured. Parallel samplings of PM10 and of PM2.5 allowed us to ascertain that PM2.5 represents the gross contribution to PM10 and that most of the particle-bound PAHs reside on the finest fraction of particulate matter. [ABSTRACT FROM AUTHOR]

Seven sediment cores were collected along a transect about 20 km off from the mouth of the Po River, in the northern Adriatic Sea (Italy). Cores were characterised by different depositional sequences associated with late Pleistocene-Holocene lowstand (LST), transgressive (TST) and highstand (HST) system tracts. Sediment samples were analysed for mercury, copper, nickel, chromium, manganese and iron, as well as for total organic matter. Metal distribution generally showed vertical and spatial variability ascribed to grain size effects with no significant anthropogenic perturbation. Conversely, mercury showed vertical profiles characterised by surface enrichment, with concentrations in the upper layer (50–230 ng g-1) exceeding 3–11 times the background value of 20 ng g-1 determined in bottom cores. Surface maxima were attributed to anthropogenic mercury delivered mainly by the Po River. [ABSTRACT FROM AUTHOR]

A simple device consisting of a Petri dish containing cellulose paper soaked with paraffin oil (hereinafter defined "artificial leaf", AL) was deployed in a typical urban site and partitioning of a set of PAHs between the atmosphere and AL was investigated. Gas-phase PAHs rapidly equilibrate with AL, thus rendering it a promising cost-effective tool for spatial and temporal trends studies of air quality.