Determination of aerosol yields from 3-methylcatechol and 4-methylcatechol ozonolysis in a simulation chamber

Secondary Organic Aerosol (SOA) formation during the ozonolysis of 3-methylcatechol (3-methyl-1,2-dihydroxybenzene) and 4-methylcatechol (3-methyl-1,2-dihydroxybenzene) was investigated using a simulation chamber (8 m³) at atmospheric pressure, room temperature (294 ± 2 K) and low relative humidity (5–10%). The initial mixing ratios were as follows (in ppb): 3-methylcatechol (194–1059), 4-methylcatechol (204–1188) and ozone (93–531). The ozone and methylcatechol concentrations were followed by UV photometry and GC–FID (Gas chromatography–Flame ionization detector), respectively and the aerosol production was monitored using a SMPS (Scanning Mobility Particle Sizer). The SOA yields (Y) were determined as the ratio of the suspended aerosol mass corrected for wall losses (M_o) to the total reacted methylcatechol concentrations assuming a particle density of 1.4 g cm^?3. The aerosol formation yield increases as the initial methylcatechol concentration increases, and leads to aerosol yields ranging from 32% to 67% and from 30% to 64% for 3-methylcatechol and 4-methylcatechol, respectively. Y is a strong function of M_o and the organic aerosol formation can be expressed by a one-product gas/particle partitioning absorption model. These data are comparable to those published in a recent study on secondary organic aerosol formation from catechol ozonolysis. To our knowledge, this work represents the first investigation of SOA formation from the ozone reaction with methylcatechols.     

Insecticide residues in cotton soils of Burkina Faso and effects of insecticides on fluctuating asymmetry in honey bees (Apis mellifera Linnaeus)

Four insecticides (acetamiprid, cypermethrin, endosulfan and profenofos) are used quarterly in the cotton-growing areas of Burkina Faso, West Africa. These insecticides were investigated in soils collected from traditionally cultivated and new cotton areas. Also, the effects of insecticide exposure on the developmental instability of honey bees, Apis mellifera, were explored. In soil samples collected three months after insecticide treatments, endosulfan and profenofos concentrations varied in the range of 10-30 μg kg(-1) in the traditionally cultivated zones and 10-80 μg kg(-1) in the new cotton zones, indicating a pollution of agricultural lands. However, only profenofos concentrations were significantly higher in the new cotton zone than the traditionally cultivated zones. In addition, the index of fluctuating asymmetry, FA1, in the length of second tarsus (L(HW)) was increased for bees when exposed to pesticide treated cotton fields for 82d, and their FA levels were significantly higher than those in the control colony in an orchard. The other studied traits of bees exposed to insecticides were not significantly different from controls. Our results indicate that FA may be considered as a biomarker reflecting the stress induced by insecticide treatments. However, the relationship between FA and stressors needs further investigations.     

Enzymatic basis for fungicide removal by <Emphasis Type="Italic">Elodea canadensis</Emphasis>

Purpose  

Plants can absorb a diversity of natural and man-made toxic compounds for which they have developed diverse detoxification mechanisms. Plants are able to metabolize and detoxify a wide array of xenobiotics by oxidation, sugar conjugation, glutathione conjugation, and more complex reactions. In this study, detoxification mechanisms of dimethomorph, a fungicide currently found in aquatic media were investigated in Elodea canadensis.     

PBDEs in serum and blubber of harbor, grey and harp seal pups from Eastern Canada

Serum and blubber of pup harbor (Phoca vitulina), grey (Halichoerus grypus) and harp (Phoca groenlandica) seals from the Estuary and the Gulf of St. Lawrence were analyzed for polybrominated diphenyl ethers (PBDEs). Concentrations of ∑PBDEs (on lipid weight basis) in tissues of harbor seal pups inhabiting the St. Lawrence Estuary were about five times higher than in those from a colony located in the northern Gulf. Harp seal pups have the lowest levels of ∑PBDEs among the seal species born in the Gulf of St. Lawrence. Lipid normalized concentrations of ∑PBDEs in serum and blubber were strongly correlated, suggesting that the blood collection as a less invasive method could be used to monitor ∑PBDEs in pups. This study shows that fluvial inputs of PBDEs are important to the St. Lawrence marine ecosystem and that inhabiting harbor seal pups have a substantial exposure to PBDEs at a critical developmental stage. In addition, the observed difference in PBDE levels between harp and grey or harbor seal pups from the Gulf of St. Lawrence is explained by the difference in diets of their mothers which is linked with their residency time in the Gulf and their seasonal migration pattern.     

Genotoxicity of organic extracts of urban airborne particulate matter: an assessment within a personal exposure study

Airborne particulate matter, PM(10) and PM(2.5), are associated with a range of health effects including lung cancer. Their complex organic fraction contains genotoxic and carcinogenic compounds such as polycyclic aromatic hydrocarbons (PAHs) and their derivatives. This study evaluates the genotoxicity of the PM(10) and PM(2.5) organic extracts that were sampled in the framework of a personal exposure study in three French metropolitan areas (Paris, Rouen and Strasbourg), using the comet assay, performed on HeLa S3 cells. In each city, 60-90 non-smoking volunteers composed of two groups of equal size (adults and children) carried the personal Harvard Chempass multi-pollutant sampler during 48h along two different seasons ('hot' and 'cold'). Volunteers were selected so as to live (home and work/school) in 3 different urban sectors contrasted in terms of air pollution within each city (one highly exposed to traffic emissions, one influenced by local industrial sources, and a background urban environment). Genotoxic effects are stronger for PM(2.5) extracts than for PM(10), and greater in winter than in summer. Fine particles collected by subjects living within the traffic proximity sector present the strongest genotoxic responses, especially in the Paris metropolitan area. This work confirms the genotoxic potency of particulate matter (PM(10) and PM(2.5)) organic extracts to which urban populations are exposed.     

Bioaccumulation of trace elements in pelagic fish from the Western Indian Ocean

Trace elements were analyzed in fish of commercial interest to determine their importance in marine systems of the Western Indian Ocean and their bioaccumulation patterns. The results are equivalent or lower than levels reported in ichthyofauna worldwide. Certain values of muscular Cd, Hg, Pb and Zn were, however, above thresholds for human consumption. Levels varied among tissues, species and fish length, but were seldom influenced by the nutritional condition of the fish, its gender and its reproductive status. Correlations between hepatic Hg and Se levels in Swordfish (r2=0.747) and Yellowfin Tunas (r2=0.226), and among metallothionein linking metals imply the existence of detoxification processes in these species. Level differences between fish from the Mozambique Channel and Reunion Island reflect differences of diets rather than differences of elemental availability in both environments.     

A vehicle emissions system using a car simulator and a geographical information system: Part 1--System description and testing

A methodology for estimating vehicular emissions comprising a car simulator, a basic traffic model, and a geographical information system is capable of estimating vehicle emissions with high time and space resolution. Because of the extent of the work conducted, this article comprises two sections: In Part 1 of this work, we describe the system and its components and use examples for testing it. In Part 2 we will study in more detail the emissions of the sample fleet using the system and will make comparisons with another emission model. The experimental data for the car simulator is obtained using on-board measuring equipment and laboratory Fourier transform IR (FTIR) measurements with a dynamometer following typical driving cycles. The car simulator uses this data to generate emission factors every second. These emission factors, together with information on car activity and velocity profiles of highways and residential and arterial roads in Mexico City in conjunction with a basic traffic model, provide emissions per second of a sample fleet. A geographical information system is used to localize these road emissions.     

Ecological assessment of French Atlantic lakes based on phytoplankton, phytobenthos and macrophytes

Biological elements, including phytoplankton, phytobenthos, macrophytes, benthic invertebrates and fish, are employed by the EU Water Framework Directive (WFD) 2000/60/EC as ecological indicators for the assessment of surface waters. The use of primary producers (phytoplankton, phytobenthos and macrophytes) for water quality assessment has a long history, and several methods have been developed worldwide. In this study, we used these three communities to assess the ecological status of five natural lakes located in the Aquitaine region (southwest France). Several biological indices used in lakes from other European countries or in French rivers were employed and compared among the three communities. Each primary producer provided complementary information about the ecological status of the lakes, including the invasiveness of exotic taxa. Regardless of the producer community used, the response to the environment, as reflected by the indices (adequate for each community), was similar: Lakes Cazaux, Lacanau and Hourtin showed the best ecological status and Parentis and Soustons the worst. Phytoplankton diagnosis reflected and integrated unambiguously the water quality of the lakes, as demonstrated by the strong relationships between the phytoplankton index and the trophic status criteria. This community appeared as the best indicator, especially when macrophytes were absent. The methods applied here represent a potential tool for the assessment of the ecological status in the context of WFD, but they need to be refined. We propose modifications for phytobenthos index initially tailored for running waters for adequate use in lentic ecosystems. Indices for the three primary producers should be modified to incorporate exotic species which may provide information on potential biodiversity losses.     

Allium cepa L. as a bioindicator to measure cytotoxicity of surface water of the Quatorze River,located in Francisco Beltrão,Paraná, Brazil

Due to an increase in water consumption in the industrial sector and within the Brazilian population, surface water that receives wastewater from industries, domestic sewage, agricultural industries, and sewage treatment stations can pollute water bodies when not properly treated. The water quality has been linked to catchment characteristics and intensity of agricultural activities. Thus, the aim of this study was to monitor the cytotoxic potential of the water of the Quatorze River, located in the town of Francisco Beltrão, Paraná, Brazil, along its route in the rural area, using the root meristematic cells of Allium cepa L. as a bioindicator. The results showed that the water at points 2, 3, and 4 were not cytotoxic because the rates of A. cepa cell division were unaltered. Point 1 had presented a mitotic index that was statistically larger than the negative control, indicating that this water contained substances with mitogenic capacity, as demonstrated by elevated values in chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, the mitotic index values decreased along the route of the river (point 1 to point 4), possibly indicating a mechanism of self-purification, despite having received other sources of pollution. Thus, the results of this study show that the water of the Quatorze River should undergo periodic environmental monitoring at different times of the year, including cytotoxicity analysis, to evaluate the principal sources of contamination to maintain the quality of the river water and, consequently, to maintain human health and equilibrium of the entire ecosystem.     

Time-Frequency Analysis of the Relationship Between EUA and CER Carbon Markets

In this paper, interactions or co-movement between the CER and EUA futures prices are examined in order to shed light on the dependency between the European Union Emissions Trading Scheme (EU ETS) and the clean development mechanism (MDP). Our analysis uses the wavelet method to model the correlation between CER and EUA in the time-frequency domain. It highlights the impact of different investors (according to their investment horizons) on the co-movement between the CER and EUA prices, and therefore, the behavior of individual investors as speculators, arbitrageurs, and hedgers on European allowance and CDM credits cumulatively. In this vein, we analyze according to the frequency intervals, price convergence, identification of potential factors that could explain a difference in futures prices, and structural changes in the EUA and CER prices. The application is made using daily EUA’s and CER’s prices data.