Monitoring of firefighters exposure to smoke during fire experiments in Portugal

Forest fires represent a serious threat to public security in Europe due to the large burned area. Moreover, smoke pollution due to forest fire events is an important public health issue for the communities directly affected, and particularly for the personnel involved in firefighting operations. Aiming to contribute to the scientific knowledge concerning firefighters exposure to forest fires smoke, data of individual exposure to carbon monoxide, nitrogen dioxide, volatile organic compounds, and particulate matter were obtained during experimental field fires for a group of 10 firefighters equipped with portable “in continuum” measuring devices. Measured values are very high exceeding the Occupational Exposure Standard limits, in particular for peak limit thresholds. These are the first measurements and analysis of firefighter's individual exposure to toxic gases and particles in fire smoke experiments in Europe. However, they already indicate that urgent measures to avoid these levels of exposure are needed.     

Bias Correction Techniques to Improve Air Quality Ensemble Predictions: Focus on O3 and PM Over Portugal

Five air quality models were applied over Portugal for July 2006 and used as ensemble members. Each model was used, with its original set up in terms of meteorology, parameterizations, boundary conditions and chemical mechanisms, but with the same emission data. The validation of the individual models and the ensemble of ozone (O₃) and particulate matter (PM) is performed using monitoring data from 22 background sites. The ensemble approach, based on the mean and median of the five models, did not improve significantly the skill scores due to large deviations in each ensemble member. Different bias correction techniques, including a subtraction of the mean bias and a multiplicative ratio adjustment, were implemented and analysed. The obtained datasets were compared against the individual modelled outputs using the bias, the root mean square error (RMSE) and the correlation coefficient. The applied bias correction techniques also improved the skill of the individual models and work equally well over the entire range of observed O₃ and PM values. The obtained results revealed that the best bias correction technique was the ratio adjustment with a 4-day training period, demonstrating significant improvements for both analysed pollutants. The increase in the ensemble skill found comprehends a bias reduction of 88 % for O₃, and 92 % for PM10, and also a decrease in 23 % for O₃ and 43 % for PM10 in what concerns the RMSE. In addition, a spatial bias correction approach was also examined with successful skills comparing to the uncorrected ensemble for both pollutants.     

Heavy metals intake by cultured mushrooms growing in model system

Micro element and heavy metal contents of mushrooms were determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). It was seen an increase in the heavy metal contents (except Cu and Zn) of the mushrooms until the second dose. A decrease was seen in heavy metal intake of the mushroom in the application of the third dose. The highest accumulation occurred from the upper soils treated with the second dose. Amounts of Cd, Cr, Cu, Pb and Zn, which were accumulated in the mushroom after the application of this dose, were detected as 5.7, 23.1, 75.7, 62.8 and 99.3 ppm, respectively.     

Macro- and microelement contents of some legume seeds

Macro- and microelement contents of legume seeds were determined by ICP-AES. The potassium K contents of seeds ranged between 7,426 mg/kg (Lupinus albus L.) and 16,558 mg/kg (Phaseolus vulgaris L. ssp. sphaericus Mart). In addition, while P contents of seeds changed from 2,719 mg/kg (L. albus L.) to 5,792 mg/kg (Vigna sinensis (L.) Savi), Ca contents ranged at the levels between 1,309 mg/kg (Cicer arietinum L.) and 2,781 mg/kg (L. albus L.). The microelement contents of samples were found to be different depending on several species. The iron levels of samples were determined at the levels between 90.51 mg/kg (Phaseolus mungo L.) and 152.80 mg/kg (P. vulgaris L. ssp. sphaericus Mart). In addition, Zn contents of seeds were found between 31.32 mg/kg (C. arietinum L.) and 44.75 mg/kg (V. sinensis (L.) Savi).     

The application of a simplified method to map the aerobic acetate mineralization rates at the groundwater table of the Netherlands

A simplified method is used to assess the microbial activity of subsoils and soils across a broad geographic scale. Acetate was selected because it is a major intermediate in catabolic biochemical pathways. In order to get minimal disturbance, only a small amount of tritium labelled acetate and water is added to the subsoil material. After an incubation time, the subsoil material is separated from the water by centrifugation and the formed tritium labelled water is separated from the remaining acetate by evaporation. The data of 128 locations in the Netherlands were plotted in a soil map and were also compared with the depth, dry weight, electric conductivity, pH and nitrate concentration. The peat areas consisted of limed meadows with a high groundwater level whereas the sand areas often showed deeper groundwater levels and a lower pH. The subsoils at the groundwater table of the peat areas, which are in contact with soil air, showed a higher mineralization rate compared with the surface soils in our study. In contrast, the mineralization rate of the subsoil at the groundwater table of sandy soils showed on average a factor 30 lower rate. Nevertheless, the self purification capacity of the subsoil can be vital under weather conditions where the surface soil becomes less active.     

Correlation between physicochemical and ecotoxicological approaches to estimate landfill leachates toxicity

Leachates from municipal solid waste (MSW) landfills may contain a huge diversity of contaminants; these wastewaters should be considered as potentially hazardous complex mixtures, representing a potential environmental risk for surface and groundwater. Current MSW landfill wastes regulatory approaches deem exclusively on the physicochemical characterization and does not contemplate the ecotoxicological assessment of landfill leachates. However, the presence of highly toxic substances in consumer products requires reconsideration on the need of more specific ecotoxicological assessments. The main aim of this study was to evaluate the toxicity of different MSW landfill leachates using a battery of toxicity tests including acute toxicity tests with Daphnia magna and the anuran Xenopus laevis and the in vitro toxicity test with the fish cell line RTG-2. The additional objective was to study the possible correlation between physicochemical properties and the toxicity results obtained for untreated landfill leachates. The results showed that the proposed test battery was effective for the ecotoxicological characterization of MSW landfill leachates. A moderate to strong correlation between the measured physicochemical parameters and the calculated toxicity units was detected for all toxicity assays. Correlation factors of 0.85, 0.86 and 0.55 for Daphnia, Xenopus and RTG-2 tests, respectively, were found. The discriminant analysis showed that certain physicochemical parameters could be used for an initial categorization of the potential aquatic acute toxicity of leachates; this finding may facilitate leachates management as the physicochemical characterization is currently the most common or even only monitoring method employed in a large majority of landfills. Ammonia, alkalinity and chemical oxygen demand (COD), together with chloride, allowed a proper categorization of leachates toxicity for up to 75% of tested samples, with a small percentage of false negatives.     

Relations between PM10 composition and cell toxicity: a multivariate and graphical approach

Previous studies have used particle mass and size as metrics to link airborne particles with deleterious health effects. Recent evidence suggests that particle composition can play an important role in PM-toxicity; however, little is known about the specific participation of components (individually or acting in groups) present in such a complex mixture that accounts for toxicity. This work explores relationships among PM(10) components in order to identify their covariant structure and how they vary in three sites in Mexico City. Relationships between PM(10) with cell toxicity and geographical location were also explored. PM(10) was analyzed for elemental composition, organic and elemental carbon, endotoxins and the induction of inhibition of cell proliferation, IL-6, TNFalpha and p53. PM(10) variables were evaluated with principal component analysis and one-way ANOVA. The inhibition of cell proliferation, IL-6 and TNFalpha were evaluated with factorial ANOVA and p53 with the Welch test. The results indicate that there is heterogeneity in particle mass, composition and toxicity in samples collected at different sites. Multivariate analysis identified three major groups: (1) S/K/Ca/Ti/Mn/Fe/Zn/Pb; (2) Cl/Cr/Ni/Cu; and (3) endotoxins, organic and elemental carbon. Groups 1 and 3 showed significant differences among sites. Factorial ANOVA modeling indicated that cell proliferation was affected by PM concentration; TNFalpha and IL-6 by the interaction of concentration and site, and p53 was different by site. Radial plots suggest the existence of complex interactions between components, resulting in characteristic patterns of toxicity by site. We conclude that interactions of PM(10) components determine specific cellular outcomes.     

Indicators of physiological and immunological status of <Emphasis Type="Italic">Litopenaeus setiferus</Emphasis> wild populations (Crustacea,Penaeidae)

Constant environmental changes in oceanic and estuarine systems due to human activity in coastal zones require different tools and strategies for their study to be able to assess the health status of aquatic ecosystems. The Gulf of Mexico has a tremendous ecological importance because of its biological diversity. Baseline levels of blood metabolites and immune components were defined for wild tropical populations of Litopenaeus setiferus, an important shrimp species of the Gulf of Mexico. Osmotic pressure, oxy hemocyanin (OxyHc), glucose, proteins, cholesterol, lactate, and triacylglycerols (TAG) were used as indicators of physiological status; pro phenoloxydase (proPO) and phenoloxydase (PO) quantification of hemocytes, as well as respiratory burst, were used to assess the immunological status. Significant differences were observed in live weight of juveniles, males, and females of L. setiferus with mean values of 10.54, 35.05, and 40.33 g, respectively. A value of 460 mOsm/kg was recorded in the water where juveniles were sampled and 1,000 mOsm/kg in adult sampling zones. Consequently, the osmotic pressure of L. setiferus juveniles (718.02 mOsm/kg) was 22% lower than in adults (925 mOsm/kg); there were no differences between sexes. A significantly lower value in juvenile OxyHc was observed. This value was 24 and 16% lower than that observed in males and females, respectively. Hemolymph glucose, cholesterol, and triacylglycerol levels were not statistically different between shrimp stages, showing median values of 0.19, 0.32, and 0.39 mg/ml of glucose, cholesterol, and triacylglycerols, respectively. Hemocyanin was distributed normally in the juvenile–male population but not in females. A proportion between 52 to 81% of OxyHc of the total protein (OxyHc/Prot) was obtained for all stages. Digestive gland glycogen showed no normal distribution in juveniles and adults. Digestive gland glycogen was significantly higher in juveniles (median value of 2.64 mg/g) than in adults (median value of 1.58 mg/g). A higher value of lactate (0.11 mg/ml) was observed in juveniles than in males (0.09 mg/ml) and females (0.04 mg/ml). Granular cells (GC) corresponded to 36, 44, and 39% of the total hemocytes (TH) observed in juveniles, males, and females. ProPO showed no normal distribution in all stages. A high proPO activity was recorded in L. setiferus females that was 95% higher than in the juvenile–male group. Respiratory burst was divided into two groups, juveniles–males and females, and was distributed normally in both. Female respiratory burst values were 40 and 45% higher than those observed in the juvenile and male groups, respectively. There was an increment in OxyHc, proteins, PO, hemocytes, and respiratory burst with an increase in body weight. In contrast, the relationship of live weight to glucose, TAG, and proPO revealed no significant regressions. A significant decrease in cholesterol, glycogen, and lactate with an increase in body weight was also observed. We now have indicators of nutritional and immune status of juveniles and adults that can reveal changes in trophic relations and health at the population level. This will serve as a basis for using L. setiferus as environmental sentinels, as non-controversial and inexpensive models to evaluate the potential changes that human activities could exert on this important marine ecosystem.Communicated by P.W. Sammarco, Chauvin