Sampling and Analysis of Volatile Organic Compounds Emitted from Leaded and Unleaded Gasoline Powered Motor Vehicles

Forecasts of air quality provide information to the general public during periods with high levels of air pollution. Criteria for testing the validity and reliability of forecast systems are discussed. As the objectives of a forecast may widely differ (providing information to the public or triggering short-term emission reduction measures) there is not a single evaluation procedure. It is recommended to use a set of performance indicators. The strong year-to-year variability in occurrence of smog episodes makes it necessarily to use several years of data in the evaluation.     

Food sources of arsenic in pregnant Mediterranean women with high urine concentrations of this metalloid

Seafood consumption provides a significant amount of arsenic, although in its organic, nontoxic forms. Mediterranean populations may incorporate high levels of this metalloid as a consequence of seafood consumption. In the present study, the significance of this input among pregnant women from a Mediterranean city (Sabadell, Catalonia, Spain) is assessed. Total urinary arsenic was analyzed in 489 pairs of urine samples, corresponding to the 12th and 32th weeks of pregnancy. Association of arsenic content with seafood and other dietary items were studied. Geometric mean concentrations were 34 and 37 μg/g creatinine during the first and third trimesters, respectively. The observed concentrations were similar to those reported in studies from other Mediterranean countries. The differences between both periods were not statistically significant. The only dietary factor significantly and positively associated with total urinary arsenic in both series of samples was seafood, particularly lean fish. Moreover, lean fish consumption during both periods was found to be the main determinant for differences in levels of arsenic between the first and third trimesters, which confirms the association between high levels of total urinary arsenic and seafood consumption.     

Polycyclic aromatic hydrocarbons in lake sediments from the High Tatras

European alpine lake systems are used as indicators of air quality over the continent. Preliminary data showed high polycyclic aromatic hydrocarbons (PAH) loads in the High Tatras (Eastern Europe) in comparison to other mountain regions. Here, insight on the spatial distribution of PAH is provided from analysis of top-core sediments of 27 alpine lakes distributed along the High Tatras.Top-core sediment concentrations were higher than those in deep-cores, and they were higher than those observed in other European high mountain regions. The PAH profiles were uniform and comparable to those observed in aerosols and snow, indicating that atmospheric deposition was the predominant PAH input pathway to the lakes. Good agreement between estimated atmospheric deposition and sedimentation fluxes was observed. However, in several lakes in the western range higher sediment fluxes may correspond to higher PAH depositions levels. The higher concentrations may also reflect inputs from potential emission source areas.     

Mercury and Organochlorine Contamination in Brown Trout (Salmo Trutta) and Arctic Charr (Salvelinus Alpinus) from High Mountain Lakes in Europe and the Svalbard Archipelago

High concentration of Hg, less volatile PCB congeners and p,p-DDE in Arctic charr from an arctic lake was mainly causedby biomagnification in the food chain where cannibalism was thedriving force. We suggest that low sediment fluxes of Hg, low net production of methyl mercury, and short food chains excludingpiscivory explain the low levels of Hg in the invertebrate feeding fish population in five European high mountain lakes.Concentrations of less volatile PCB congeners in insectivorous fish populations from the European high mountain lakes were mainly influenced by fish age and atmospheric deposition, indicated by the sediment inventory. Atmospheric deposition influenced by local sources may explain the higher concentrationsof pesticides (p,p-DDT, p,p-DDE and -HCH) observedin fish from the Pyrenees compared to the other sites. Theconcentrations of Hg and organochlorines did not exceedthe guidelines for fish consumption, except for Hg levelsin the oldest fish from the arctic lake.     

Assessment of prenatal exposure to persistent organohalogen compounds from cord blood serum analysis in two Mediterranean populations (Valencia and Menorca)

Prenatal levels of organohalogen compounds (OHCs), including polybromodiphenyl ethers (PBDEs), polychlorobiphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes and DDTs, have been investigated in two different cohorts from the Spanish Mediterranean area, Valencia and Menorca, by analysis of cord blood serum. Comparison of the observed median concentrations to other cohorts shows low PBDE levels (2.8-6.5 ng g(-1) lipid) but high values of HCB (0.68 ng ml(-1), 260 ng g(-1) lipid) and PCBs (0.65 ng ml(-1), 240 ng g(-1) lipid) in the cohort of Menorca indicating that Mediterranean areas, and not only high latitude regions, may contain population groups highly exposed to some of these pollutants. Significant differences in the concentrations of these compounds have been found between the two cohorts. Differences in maternal population such as age or body mass index cannot explain this variation. One possible cause of variability is the seven year time period elapsed between the two cohort recruitments but the strong differences observed do not allow exclusion of local diet differences. Thus, the different average PCB congener distributions between the two cohorts suggest an influence from materials containing diverse PCB mixtures. The congener mixtures found in Menorca could reflect a diet contribution from some western Mediterranean fish species. These results provide baseline information on prenatal OHC background levels in the Mediterranean area.     

Polycyclic aromatic hydrocarbon composition in soils and sediments of high altitude lakes

Polycyclic aromatic hydrocarbons (PAH) in lake sediments and nearby soils of two European high mountain regions, Pyrenees and Tatra, have been studied. Similar mixtures of parent PAH were observed in all cases, indicating predominance of airborne transported combustion products. Nevertheless, the composition of these atmospherically long-range transported PAH was better preserved in the superficial layers of soils than sediments. This difference points to significant PAH degradation process, e.g. during lake water column transport, before accumulation in the latter. Post-depositional transformation was also different in both types of environmental compartments. Thus, lake sediments exhibit higher preservation of the more labile PAH involving lower degree of post-depositional oxidation. However, they also show the formation of major amounts of perylene by diagenetic transformation in the deep sections. This compound is not formed in soils where downcore enrichments of phenanthrene are observed, probably as a consequence of diagenetic aromatization of diterpenoids.