In order to characterize the influence of environmental factors in dust metal loadings inside homes in an urban environment and to evaluate the associated potential health risks, samples of settled indoor dust from 10 apartments in the urban area of Madrid (Spain) were collected with wet wipes. Cd, Cr, Cu, Pb, Zn, Ni, and Mn loads were determined by Atomic Absorption Spectroscopy (AAS) after a HNO₃ + H₂O₂ digestion. The environmental factors evaluated were load distribution between rooms, number of residents, presence of smokers, traffic intensity, apartment elevation, and frequency of house cleaning. Tukey’s range test and stepwise multiple linear regression analysis revealed that metal dust loadings present two prevailing origins: (1) They present higher loadings in the entry hall, which suggest that dust is tracked indoors adhered to footwear and clothing and (2) they arise from tobacco smoking. Significant correlations were also observed between metal loadings and traffic intensity (Cr), number of residents (Cr, Pb, and Cu), number of days between cleaning (Ni), and flat height (Mn). A human health risk assessment considering a mechanistic hand-to-mouth model for dust ingestion and dermal absorption revealed that urban children are not expected to develop adverse health effects from exposure to trace elements in household dust. The contribution of this exposure scenario to the overall received dose should be included when assessing the background exposure of children to trace elements. A more precise assessment should attempt to reduce the significant uncertainty of the risk model output associated with estimates of exposure variables, deposition rates, and metal bioaccessibility.

La Banya spit, located at the south of the River Ebro Delta, is a sandy formation, developed by annexation of bars forming successive beach ridges, which are oriented and modeled by the eastern and southern waves. The initial ridges run parallel to the coastline, and above them small dunes developed, the crests of which are oriented by dominant winds, forming foredune ridges and barchans. This study attempted to test a number of techniques in order to understand the dune dynamic on this coastal spit between 2004 and 2012: LiDAR data were used to reconstruct changes to the surface and volume of the barchan dunes and foredunes; ground-penetrating radar was applied to obtain an image of their internal structure, which would help to understand their recent evolution. GPS data taken on the field, together with application of GIS techniques, made possible the combination of results and their comparison. The results showed a different trend between the barchan dunes and the foredunes. While the barchan dunes increased in area and volume between 2004 and 2012, the foredunes lost thickness. This was also reflected in the radargrams: the barchan dunes showed reflectors related to the growth of the foresets while those associated with foredunes presented truncations associated with storm events. However, the global balance of dune occupation for the period 2004–2012 was positive.

A blind field test with 136 independent measurements of radon (222Rn) in soil air retrieved from a depth of 0.8 m in a decommissioned lindane (γ-hexachlorocyclohexane) production plant was undertaken to evaluate the performance of the 222Rn-deficit technique as a screening methodology for the location and delineation of subsurface accumulations of complex mixtures of organic contaminants. Maps of 222Rn iso-concentrations were drawn and interpreted before direct analytical information regarding concentrations of hexachlorocyclohexanes, chlorobenzenes and BTEX compounds in soil, groundwater and soil air were disclosed to the authors. The location and extension of pollution hot spots inferred from the 222Rn campaigns agrees remarkably well with the analytical data obtained from the intrusive sampling campaigns and with the location of contaminant source zones (chemical reactor and waste-storage area) and geological sinks of those contaminants (paleochannel). Two main limitations to the applicability of the 222Rn-deficit technique were identified and assessed: The statistically significant variation of 222Rn concentrations with diurnal changes of ground-level air temperature and the maximum depth of investigation in the absence of significant advective and co-advective transport of radon. If the influence of those two factors is accounted for and/or minimized (by averaging replicated measurements during the workday and in different days), the 222Rn-deficit technique has the potential to be an efficient technique which delivers information in quasi-real time, with a much higher spatial density than that of intrusive techniques, at a much faster rate and at a significantly lower cost. MAIN FINDINGS: The 222Rn-deficit technique is an effective tool for real-time site characterization only limited by diffusion length of radon and diurnal temperature variations.