Transfer of pesticides to the brew during mate drinking process and their relationship with physicochemical properties

In order to evaluate the extraction of pesticide residues that are transferred to the brew during mate drinking process of P.U.1 yerba mate leaves (Ilex paraguariensis), a special device to simulate the way in which mate is drunk in Uruguay was developed. The transfer to the brew of 12 organophosphates, 5 synthethic pyrethroids and one organochlorine pesticide from spiked samples was studied. The relationship between the transfer data thus obtained and physicochemical properties like water solubility (Ws), octanol-water coefficient (Kow) and Henry's constant (H) was evaluated. The extractability of the pesticide residues from yerba mate can be correlated with log Ws and log Kow. These transfer values allowed the calculation of ARLs (acceptable residue level) for the pesticides following Food and Agriculture Organization (FAO), World Health Organizaion (WHO) guidelines. These results can help the future establishment of maximum residue levels (MRLs).     

Ecotoxicity assessment of lipid regulators in water and biologically treated wastewater using three aquatic organisms

Background, aim, and scope  

The high consumption of blood lipid regulators is leading to frequent reports of the occurrence of fibrates in natural streams and wastewater effluents. This paper describes a study undertaken to evaluate the acute toxicity of bezafibrate, clofibric acid, gemfibrozil, and fenofibric acid, a metabolite of fenofibrate whose ecotoxicity has not been previously reported.     

South Pole Antarctica observations and modeling results: New insights on HOx radical and sulfur chemistry

Measurements of OH, H₂SO₄, and MSA at South Pole (SP) Antarctica were recorded as a part of the 2003 Antarctic Chemistry Investigation (ANTCI 2003). The time period 22 November, 2003–2 January, 2004 provided a unique opportunity to observe atmospheric chemistry at SP under both natural conditions as well as those uniquely defined by a solar eclipse event. Results under natural solar conditions generally confirmed those reported previously in the year 2000. In both years the major chemical driver leading to large scale fluctuations in OH was shifts in the concentration levels of NO. Like in 2000, however, the 2003 observational data were systematically lower than model predictions. This can be interpreted as indicating that the model mechanism is still missing a significant HO_x sink reaction(s); or, alternatively, that the OH calibration source may have problems. Still a final possibility could involve the integrity of the OH sampling scheme which involved a fixed building site. As expected, during the peak in the solar eclipse both NO and OH showed large decreases in their respective concentrations. Interestingly, the observational OH profile could only be approximated by the model mechanism upon adding an additional HO_x radical source in the form of snow emissions of CH₂O and/or H₂O₂. This would lead one to think that either CH₂O and/or H₂O₂ snow emissions represent a significant HO_x radical source under summertime conditions at SP. Observations of H₂SO₄ and MSA revealed both species to be present at very low concentrations (e.g., 5 × 10⁵ and 1 × 10⁵ molec cm^?3, respectively), but similar to those reported in 2000. The first measurements of SO₂ at SP demonstrated a close coupling with the oxidation product H₂SO₄. The observed low concentrations of MSA appear to be counter to the most recent thinking by glacio-chemists who have suggested that the plateau's lower atmosphere should have elevated levels of MSA. We speculate here that the absence of MSA may reflect efficient atmospheric removal mechanisms for this species involving either dynamical and/or chemical processes.     

Contribution of atmospheric emissions to the contamination of leaf vegetables by persistent organic pollutants (POPs): Application to Southeastern France

A modeling approach has been developed to estimate the contribution of atmospheric emissions to the contamination of leaf vegetables by persistent organic pollutants (POPs). It combines an Eulerian chemical transport model for atmospheric processes (Polair3D/Polyphemus) with a fate and transport model for soil and vegetation (Ourson). These two models were specifically adapted for POPs. Results are presented for benzo(a)pyrene (BaP). As expected no accumulation of BaP in leaf vegetables appears during the growth period for each harvest over the 10 years simulated. For BaP and leaf vegetables, this contamination depends primarily on direct atmospheric deposition without chemical transfer from the soil to the plant. These modeling results are compared to available data.     

Evaluation of airborne particulate matter and metals data in personal,indoor and outdoor environments using ED-XRF and ICP-MS and co-located duplicate samples

Factors and sources affecting measurement uncertainty associated with monitoring metals in airborne particulate matter (PM) were investigated as part of the Windsor, Ontario Exposure Assessment Study (WOEAS). The assessment was made using co-located duplicate samples and a comparison of two analytical approaches: ED-XRF and ICP-MS. Sampling variability was estimated using relative percent difference (RPD) of co-located duplicate samples. The comparison of ICP-MS and ED-XRF results yields very good correlations (R² ≥ 0.7) for elements present at concentrations that pass both ICP-MS and ED-XRF detection limits (e.g. Fe, Mn, Zn, Pb and Cu). PM concentration ranges (median, sample number) of 24-h indoor PM₁₀ and personal PM₁₀ filters, and outdoor PM_2.5 filters were determined to be 2.2–40.7 (11.0, n = 48) μg m^?3, 8.0–48.3 (11.9, n = 48) μg m^?3, and 17.1–42.3 (21.6, n = 18) μg m^?3, respectively. The gravimetric analytical results reveal that the variations in PM mass measurements for same-day sampling are insignificant compared to temporal or spatial variations: 92%, 100% and 96% of indoor, outdoor and personal duplicate samples, respectively, pass the quality criteria (RPD ≤ 20%). Uncertainties associated with ED-XRF elemental measurements of S, Ca, Mn, Fe and Zn for 24-h filter samples are low: 78%–100% of the duplicate samples passed the quality criteria. In the case of 24-h filter samples using ICP-MS, more elements passed the quality criteria due to the lower detection limits. These were: Li, Na, K, Ca, Si, Al, V, Fe, Mn, Co, Cu, Mo, Ag, Zn, Pb, As, Mg, Sb, Sn, Sr, Th, Ti, Tl, and U. Low air concentrations of metals (near or below instrumental detection limits) and/or inadvertent introduction of metal contamination are the main causes for excluding elements based on the pass/fail criteria. Uncertainty associated with elemental measurements must be assessed on an element-by-element basis.     

Characterisation of particulate exposure during fireworks displays

Little is known about the level and content of exposure to fine particles (PM_2.5) among persons who attend fireworks displays and those who live nearby. An evaluation of the levels of PM_2.5 and their elemental content was carried out during the nine launches of the 2007 Montréal International Fireworks Competition. For each event, a prediction of the location of the firework plume was obtained from the Canadian Meteorological Centre (CMC) of the Meteorological Service of Canada. PM_2.5 was measured continuously with a photometer (Sidepak?, TSI) within the predicted plume location (“predicted sites”), and integrated samples were collected using portable personal samplers. An additional sampler was located on a nearby roof (“fixed site”). The elemental composition of the collected PM_2.5 samples from the “predicted sites” was determined using both a non-destructive energy dispersive ED-XRF method and an ICP-MS method with a near-total microwave-assisted acid digestion. The elemental composition of the “fixed site” samples was determined by the ICP-MS with the near-total digestion method. The highest PM_2.5 levels reached nearly 10 000 μg m^?3, roughly 1000 times background levels. Elements such as K, Cl, Al, Mg and Ti were markedly higher in plume-exposed filters. This study shows that 1) persons in the plume and in close proximity to the launch site may be exposed to extremely high levels of PM_2.5 for the duration of the display and, 2) that the plume contains specific elements for which little is known of their acute cardio-respiratory toxicity.     

Airborne molds and mycotoxins associated with handling of corn silage and oilseed cakes in agricultural environment

In agricultural areas, the contamination of feedstuffs with molds and mycotoxins presents major environmental and health concerns. During cattle feeding, fungi and mycotoxins were monitored in corn silage, oilseed cakes and bioaerosols collected in Normandy. Most of the corn silages were found to be contaminated by deoxynivalenol (mean concentration: 1883 μg kg^?1) while a few of oilseed cakes were contaminated by alternariol, fumonisin B₁ or gliotoxin. In ambient bioaerosols, the values for fungi per cubic meter of air varied from 4.3 × 10² to 6.2 × 10⁵ cfu m^?3. Seasonal variations were observed with some species like Aspergillus fumigatus which significantly decreased between the 2 seasons (P = 0.0186) while the Penicillium roqueforti group significantly increased during the second season (P = 0.0156). In the personal bioaerosols, the values for fungi per cubic meter of air varied from 3.3 10³ to 1.7 10⁶ cfu m^?3 and the number of A. fumigatus spores significantly decreased between the 2 seasons (P = 0.0488). Gliotoxin, an immunosuppressive mycotoxin, was quantified in 3 personal filters at 3.73 μg m^?3, 1.09 μg m^?3 and 2.97 μg m^?3.     

Discriminating the regional and urban contributions in the North-Western Mediterranean: PM levels and composition

Simultaneous measurements of the PM concentration levels and chemical composition of atmospheric aerosols at a regional background (RB) and an urban background (UB) site, located in the same geographic region, allowed for the determination of their urban and regional contributions. In the specific case of the North-Western region of the Mediterranean the RB amount has been quantified in 18, 13 and 12 μg m^?3 for PM₁₀, PM_2.5 and PM₁, respectively, whereas the UB contribution reached 22, 13 and 8 μg m^?3, respectively. The UB contributions in the Western Mediterranean are much higher than those observed in other European regions; especially concerning the coarse fraction. The high loads of road dust in the urban areas across the Mediterranean may account for these large differences.The urban contributions are extremely enriched in Ca, Fe, Sb, Sn, Cu, Zn, being the main tracers of the road dust, with concentrations up to 6–8 times higher than those at the RB. Elemental carbon and nitrate are mainly derived from direct vehicular emissions. Some industrial tracers (Mn, Pb, Bi) are also enriched in the urban area. The evaluation of the Cu/Sb, Cu/Zn, Cu/Cd and Cu/Pb ratios and the high enrichment of these trace elements versus the Upper Crustal Composition average values corroborates the importance of the road-traffic emissions in the study area, also influencing the RB.The supplementary results from a suburban site in the Balearic Islands and the evaluation of the V/Ni ratios evidence the strong signature of fuel-oil combustion processes, which is a general characteristic of the Mediterranean aerosols.     

Characterisation of PM10 emissions from woodstove combustion of common woods grown in Portugal

A series of source tests was performed to evaluate the chemical composition of particle emissions from the woodstove combustion of four prevalent Portuguese species of woods: Pinus pinaster (maritime pine), Eucalyptus globulus (eucalyptus), Quercus suber (cork oak) and Acacia longifolia (golden wattle). Analyses included water-soluble ions, metals, radionuclides, organic and elemental carbon (OC and EC), humic-like substances (HULIS), cellulose and approximately l80 organic compounds. Particle (PM₁₀) emission factors from eucalyptus and oak were higher than those from pine and acacia. The carbonaceous matter represented 44–63% of the particulate mass emitted during the combustion process, regardless of species burned. The major organic components of smoke particles, for all the wood species studied, with the exception of the golden wattle (0.07–1.9% w/w), were anhydrosugars (0.2–17% w/w). Conflicting with what was expected, only small amounts of cellulose were found in wood smoke. As for HULIS, average particle mass concentrations ranged from 1.5% to 3.0%. The golden wattle wood smoke presented much higher concentrations of ions and metal species than the emissions from the other wood types. The results of the analysis of radionuclides revealed that the ²²⁶Ra was the naturally occurring radionuclide more enriched in PM₁₀. The chromatographically resolved organics included n-alkanes, n-alkenes, PAH, oxygenated PAH, n-alkanals, ketones, n-alkanols, terpenoids, triterpenoids, phenolic compounds, phytosterols, alcohols, n-alkanoic acids, n-di-acids, unsaturated acids and alkyl ester acids.