Screening of dioxin-like compounds by complementary evaluation strategy utilising ELISA, micro-EROD, and HRGC-HRMS in soil and sediments from Montevideo, Uruguay.

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) are persistent, toxic, and bioaccumulate in the environment. Due to their high analytical costs, these compounds are hardly regulated and mostly not monitored in the Third World. To overcome this, bioassays have been proposed as low-cost alternative methods. Two of the most established bioanalytical tools, the dioxin antibody-based enzyme-linked immunosorbent assay ELISA and the micro-EROD bioassay are evaluated and compared to high resolution gas chromatography and high resolution mass spectrometry (HRGC/HRMS) analytical methodology. The methods were tested using thirteen soils and sediment samples selected from diverse sites in Montevideo, Uruguay. The WHO2005 total toxic equivalent (WHO2005-TEQ) of soils ranged from 2.4 to 2212 (ng WHO2005-TEQ/kg dry sample) and from 0.14 to 9.4 (ng WHO2005-TEQ/kg dry sample) in sediments. This study shows significant contamination related to dioxin-like compounds, particularly in sites where uncontrolled burnings were carried out. ELISA and micro-EROD bioassay correlated well with HRGC/HRMS, R Spearman 0.773 and 0.913, respectively and were highly correlated to each other, R Spearman 0.879. Preliminary threshold values of bioassay toxic equivalents of 330 (ng/kg dry sample) for the micro-EROD bioassay and 220 (ng/kg dry sample) for ELISA are proposed.

Vertical distribution of organochlorine pesticides in humus along Alpine altitudinal profiles in relation to ambiental parameters.

In forest soils along vertical profiles located in different parts of the Alps, concentrations of persistent organic pollutants (POPs), namely organochlorine pesticides (OCPs) like dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), heptachlor, aldrin, dieldrin and mirex, were measured. Though local characteristics of the sites are influenced by numerous factors like orographic and meteorological parameters, forest stand characteristics and humus parameters, we ascertained a marked vertical increase of concentrations of some organochlorine compounds in the soil. On the basis of climatological values of each site, we found that the contamination increase with altitude can be ascribed to a certain 'cold condensation effect'. In addition, the perennial atmospheric deposition of POPs is controlled by precipitation. Other key parameters explaining the accumulation of POPs are the soil organic carbon stocks, the turnover times, the re-volatilisation and degradation processes, which vary with altitude.

Long-term air monitoring of organochlorine pesticides using Semi Permeable Membrane Devices (SPMDs) in the Alps.

Atmospheric sampling of organochlorine pesticides (OCPs) was conducted using Semi Permeable Membrane Devices (SPMDs) deployed in the Alps at different altitudinal transects for two consecutive exposure periods of half a year and a third simultaneous year-long period. Along all the altitude profiles, the sequestered amounts of OCPs increased in general with altitude. SPMDs were still working as kinetic samplers after half a year for the majority of the OCPs. However, compounds with the lowest octanol-air partition coefficient (K(oa)), reached equilibrium within six months. This change in the SPMD uptake was determined for the temperature gradient along the altitude profile influencing K(oa), OCPs availability in the gaseous phase, and SPMD performance. In sum, it seems two effects are working in parallel along the altitude profiles: the change in SPMD performance and the different availability of OCPs along the altitudinal transects determined by their compound properties and concentrations in air.

PCB and PCDD/F in sediments and mussels of the Istanbul strait (Turkey).

Sediment and mussel samples collected along the coasts of the Istanbul strait and an island in Marmara Sea (Turkey) were analyzed for six indicator polychlorinated biphenyl (PCB), 12 dioxin-like PCB (dl-PCB) and 17 polychlorinated dibenzo-p-dioxin/furan (PCDD/F) congeners. Samples contained different concentrations of PCBs and among these, congeners 153, 75, 105 and 118 in sediments and congeners 153, 138 and 118 in mussels were most abundant. The concentration levels of total PCBs and PCDD/Fs in sediments ranged from 17.9 to 539746 pg g(-1)dm and 2.04 to 60.5 pg g(-1)dm, respectively. The total WHO-TEQ values ranged between 0.01 and 17.8 pg g(-1)dm in sediments, and 0.98 and 1.01 pg g(-1)ww in mussels. None of the sediment and mussel samples analyzed exceeded the limits suggested in the sediment quality guideline and safe values set by the European Community for seafood intended for human consumption, respectively.

Polycyclic aromatic hydrocarbons and effects on marine organisms in the Istanbul Strait.

Surficial sediments and mussels (Mytilus galloprovincialis) from the Istanbul Strait and Marmara Sea were analysed for sixteen parent polycyclic aromatic hydrocarbon (PAH) contents by gas chromatography-mass spectrometry (GC-MS) employing isotope dilution technique. Microalgae toxicity testing was applied to sediment elutriates and biological responses in terms of filtration rate and lysosomal stability were measured in mussels. Total PAH concentrations ranged from 2.1 to 3152 ng g(-1) dry wt in sediments and from 43-601 ng g(-1) wet weight in mussels. Molecular indices of phenanthrene/ anthracene, fluoranthene/pyrene and benzo(a)anthracene/chrysene were used to differentiate between pyrolytic and petroleum origin. Results showed that most of the contamination originates from high temperature pyrolytic inputs with some slight contribution of petrogenic PAH. PAH in sediments were frequently lower than the National Oceanic and Atmospheric Administration (NOAA)-ERM (Effects Range Medium) index. Results of sediment elutriate toxicity testing and biomarkers indicate that the cause of negative effects in sediments may result from different classes of pollutants and does not only relate with PAH contamination. Mussels from most of the stations showed both reduced lysosomal membrane stability and filtration rate indicating disturbed health although the two biomarker results did not always complement each other. The effect studies showed that the pollutants in the strait ecosystem have more pronounced effects in the middle parts than those at the Black Sea entrance.

Monitoring of PCDD/Fs in a mountain forest by means of active and passive sampling.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) are sampled and investigated in a forested area in Middle-Europe. The campaigns, consisting in active and passive samplings, were conducted in the Bavarian and Bohemian Forest at four sites chosen for their similar soil and forest stand characteristics. Passive sampling was conducted using both semi-permeable membrane devices (SPMDs) and needles of well-exposed dominant spruce trees. Active air sampling was also performed at one site with a low volume air sampler. Correlations were performed to identify relationships and trends of PCDD/F. Lower chlorinated PCDD/F are accumulated in SPMDs, needles collected all compounds among homologues and their PCDD/F pattern is close to that of active sampling. Results of the analysed compounds obtained with the different sampling methods served as a basis for the establishment of advantages and disadvantages of the sampling tools applied and their possible optimisation.