Emission factors for high-emitting vehicles based on on-road measurements of individual vehicle exhaust with a mobile measurement platform

Fuel-based emission factors for 143 light-duty gasoline vehicles (LDGVs) and 93 heavy-duty diesel trucks (HDDTs) were measured in Wilmington, CA using a zero-emission mobile measurement platform (MMP). The frequency distributions of emission factors of carbon monoxide (CO), nitrogen oxides (NO(x)), and particle mass with aerodynamic diameter below 2.5 microm (PM2.5) varied widely, whereas the average of the individual vehicle emission factors were comparable to those reported in previous tunnel and remote sensing studies as well as the predictions by Emission Factors (EMFAC) 2007 mobile source emission model for Los Angeles County. Variation in emissions due to different driving modes (idle, low- and high-speed acceleration, low- and high-speed cruise) was found to be relatively small in comparison to intervehicle variability and did not appear to interfere with the identification of high emitters, defined as the vehicles whose emissions were more than 5 times the fleet-average values. Using this definition, approximately 5% of the LDGVs and HDDTs measured were high emitters. Among the 143 LDGVs, the average emission factors of NO(x), black carbon (BC), PM2.5, and ultrafine particle (UFP) would be reduced by 34%, 39%, 44%, and 31%, respectively, by removing the highest 5% of emitting vehicles, whereas CO emission factor would be reduced by 50%. The emission distributions of the 93 HDDTs measured were even more skewed: approximately half of the NO(x) and CO fleet-average emission factors and more than 60% of PM2.5, UFP, and BC fleet-average emission factors would be reduced by eliminating the highest-emitting 5% HDDTs. Furthermore, high emissions of BC, PM2.5, and NO(x) tended to cluster among the same vehicles.     

Anoxic-aerobic treatment of the liquid fraction of cattle manure

Cattle manure from a dairy farm was treated in order to reduce its pollution potential. The manure came from a farm with 120 cows kept in stables in a free stall barn. As pretreatment, the manure is usually filtered on the farm using a screw press separator with a 0.5 mm mesh. Approximately 70% of the total filtered volume passes through the screen, thus constituting the liquid fraction. This fraction, with a composition of around 64,500 mg COD/l, 5770 mg total-N/l and 800 mg total-P/l, was subjected to centrifugation followed by a two-step biological treatment (anoxic-aerobic) to reduce organic matter (COD), nitrogen and phosphorus compounds. Centrifugation led to the following removal efficiencies: 35% total solids, 60% COD, 75% total phosphorus and 20% total nitrogen (mainly organic nitrogen). With the subsequent anoxic-aerobic treatment, average removal efficiencies of 85% for COD, 90% for total phosphorus and 75% for total nitrogen were achieved.     

Pesticide residue removal in classic domestic processing of tomato and its effects on product quality

This study was undertaken to evaluate the effectiveness of several household practices (washing with water or acidic, alkaline, and oxidizing solutions, and peeling) in minimizing pesticide residue contamination of tomatoes, as well as the impact on the quality of the treated fruit. Tests were performed using two systemic fungicides (azoxystrobin and difenoconazole) and one contact fungicide (chlorothalonil). Solid-liquid extraction with low temperature partition (SLE/LTP) and liquid-liquid extraction with low temperature partition (LLE/LTP) were used to prepare the samples for pesticides determination by gas chromatography. Washing the tomatoes with water removed approximately 44% of chlorothalonil, 26% of difenoconazole, and 17% of azoxystrobin. Sodium bicarbonate (5%) and acetic acid (5%) solutions were more efficient, removing between 32 and 83% of the residues, while peeling removed from 68 to 88% of the pesticides. The washing solutions altered some fruit quality parameters, including acidity and chroma, and also caused weight loss. Acetic acid (0.15 and 5%) and hypochlorite (1%) solutions had the greatest effect on these parameters.     

Genetic differentiation in Sargassum polyceratium (Fucales: Phaeophyceae) around the island of Curaçao (Netherlands Antilles)

The seaweed Sargassum polyceratium Montagne inhabits a broad spectrum of subtidal and intertidal habitats. Genetic diversity and spatial genetic structure were examined within and among 12 stands using random amplified polymorphic DNA (RAPD) phenotypes. Data were analyzed using analysis of molecular variance (AMOVA) and Shannon's information measure. In both analyses, 60-75% of the variation occurred within stands and 25-40% between stands. These values are consistent with out-crossing, high-dispersal species. Significant differentiation was found among bays ca. 25 km apart (Shannon's G'_st averaged 0.37 and pairwise AMOVA K_st values averaged 0.272) and among stands 150-200 m apart within bays (AMOVA K_st values averaged 0.149). Effects of shore (windward vs. leeward), depth, and bay on population structure were tested. These analyses revealed that the factor depth is confounded with shore, and that bays show significant differentiation from each other but are not completely isolated from one another. Mantel tests for differentiation-by-distance were significant along both sides of the island but stronger along the windward side. A neighbor-joining analysis of genetic distances among stands showed that the effects of currents around both tips of the island were especially important for shallow populations. For S. polyceratium, depth and bay promote population differentiation along shores, yet dispersal around the tips of the island simultaneously connects these populations to varying degrees. This study highlights the importance of investigating the relative contribution of habitat factorsin relation to island-scale population structure.     

Indoor air quality in university environments

This study evaluates the airborne microflora in research laboratories of the University of Chieti (Italy). A quali-quantitative evaluation of the index microbial air contamination was performed using the settle plate method. The microbial air contamination was evaluated during 6 months in three university buildings (A, B, and C). Nutrient agar plates were exposed, monthly, for 1 h at the morning and the afternoon to evaluate the colony forming units per plate per hour. Together with the quantitative analysis, the most frequent bacterial and fungal colonies isolated were also characterized. Moreover, in each sampling, the number of the occupants in each room was recorded to evaluate a possible relationship with the microbial pollution. The microbial concentration was always within the limit values defined for these environments. Buildings A and C displayed a seasonal fluctuation of airborne microflora with the increase in microbial concentration in the warmer season (April to June) in respect to the colder period (October to December). The most common microorganisms detected in the indoor air of the examined buildings were Gram-positive bacteria, belonged to the genera Staphylococcus, Bacillus, and Actinomyces. Data presented here underline the useful monitoring of the research university laboratories also emphasizing the effectiveness of the settle plate method.     

The role of environmental and socio-demographic indicators in the analysis of land use changes in a protected area of the Natura 2000 Network: the case study of Lake Trasimeno,Umbria, Central Italy

This article sets out to analyse how and to what degree land use is linked to the physical characteristics of the territory itself, and the way in which changes in land use are determined by agricultural and socio-demographic dynamics. The study was conducted within the territorial boundaries of five municipalities surrounding Lake Trasimeno and refers to the periods 1977–2000 for land use and 1971–2001 for socio-demography data. The use of environmental, social, economic and agricultural indicators demonstrates how a mix of various indicators are useful for monitoring the changes which took place. It also shows the powerful influence that socio-demographic factors exert upon land use and landscape change.     

Contaminants in fish tissue from US lakes and reservoirs: a national probabilistic study

An unequal probability design was used to develop national estimates for 268 persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake). Predator (fillet) and bottom-dweller (whole body) composites were collected from 500 lakes selected randomly from the target population of 147,343 lakes in the lower 48 states. Each of these composite types comprised nationally representative samples whose results were extrapolated to the sampled population of an estimated 76,559 lakes for predators and 46,190 lakes for bottom dwellers. Mercury and PCBs were detected in all fish samples. Dioxins and furans were detected in 81% and 99% of predator and bottom-dweller samples, respectively. Cumulative frequency distributions showed that mercury concentrations exceeded the EPA 300 ppb mercury fish tissue criterion at nearly half of the lakes in the sampled population. Total PCB concentrations exceeded a 12 ppb human health risk-based consumption limit at nearly 17% of lakes, and dioxins and furans exceeded a 0.15 ppt (toxic equivalent or TEQ) risk-based threshold at nearly 8% of lakes in the sampled population. In contrast, 43 target chemicals were not detected in any samples. No detections were reported for nine organophosphate pesticides, one PCB congener, 16 polycyclic aromatic hydrocarbons, or 17 other semivolatile organic chemicals.     

Risk on the ramble: The international transfer of risk and vulnerability

In this paper the purpose is to discuss a concept of technology that can explain how the transfer of technology implies the risk of new failures, misuse, accidents and unhealthy workplaces. Production technologies are often transformed through a steady stream of incremental changes appropriate to their social context, and the technology will therefore gradually acquire some contextually dependent preconditions for use. These preconditions will most probably be revealed when a technology is transferred from one context to another. Thus, a technology transfer project may trigger a long process of re-innovations just to make the technology fully operational in its new context. In a transfer process, technological risks may arise due to incomplete transfer of mastering capacity; mismatch between transferred technology and the environment; transfer of latent conditions for failure; and the transformation of latent conditions or known risks when the technology is installed in a new environment. Longitudinal data from the Norwegian petroleum industry indicates that the first phases in a transfer process will create high technological risks. It will take many years before the transferred technologies are adapted to the new context and the risk level has been normalised.     

Peroxin Puzzles and Folded Freight: Peroxisomal Protein Import in Review

Peroxisomes are organelles that perform a variety of functions, including the metabolism of hydrogen peroxide and the oxidation of fatty acids. Peroxisomes do not possess organellar DNA; all peroxisomal matrix proteins are post-translationally translocated into the organelle. The mechanism of peroxisomal protein translocation has been the subject of vigorous research in the past decade. Many of the proteins (peroxins, abbreviated Pex) that play critical roles in peroxisome biogenesis have been identified through functional complementation of yeast strains and of Chinese hamster ovary cell lines that are defective in peroxisome biogenesis. Researchers are now turning towards biochemical and genetic analyses of these peroxins to define their roles in peroxisome biogenesis and to discover interacting protein partners. Evidence suggests that some of the interacting partners include molecular chaperones. Several current models for peroxisomal protein import are presented.