Characterization of atmospheric aerosols by SEM in a rural area in the western part of México and its relation with different pollution sources

Samples of particulate matter were collected during the period from October 2006 through September 2007 in a rural station located 12 km from the city of Colima. A total of 3600 particles were analyzed by SEM-EDS and then classified by their chemical composition and morphology in order of abundance: those rich in C, Fe, Si–Al, Cl–Na, Ca, Ba; and to a lesser abundance, particles rich in heavy metals such as Pb and V–Ni were observed. A factorial analysis was carried out to determine the main elements related with the emission sources such as crustal/farming; fuel-oil; marine; volcanic activity and industry. Trough the seasons, the dominant winds causes the presence of anthropogenic particles in the rural site. The information presented in this study aims to give insight and detailed of the analysis of the morphological characteristics and chemical composition of atmospheric particles at individual level in a rural site from Colima State, Mexico.     

An Evaluation of Microscopic Emission Models for Traffic Pollution Simulation Using On-board Measurement

As a result of the continuously increasing numbers of motor vehicles in metropolitan areas worldwide, road traffic emission levels have been recognized as a challenge during the planning and management of transportation. Experiments were conducted to collect on-road emission data using portable emission measurement systems in two Chinese cities in order to estimate real traffic emissions and energy consumption levels and to build computational models for operational transport environment projects. In total, dynamic pollutant emissions and fuel consumption levels from dozens of light duty vehicles, primarily from four different vehicle classes, were measured at a second-by-second level. Using the collected data, several microscopic emission models including CMEM, VT-Micro, EMIT, and POLY were evaluated and compared through calibration and validation procedures. Non-linear optimization methods are applied for the calibration of the CMEM and EMIT models. Numerical results show that the models can realize performance levels close to the CMEM model in most cases. The VT-Micro model shows advantages in its unanimous performance and ability to describe low emission profiles while the EMIT model has a clear physics basis and a simple model structure. Both of them can be applied when extensive emission computation is required in estimating environmental impacts resulting from dynamic road traffic.     

Atmospheric trace element concentrations in total suspended particles near Paris,France

To evaluate today’s trace element atmospheric concentrations in large urban areas, an atmospheric survey was carried out for 18 months, from March 2002 to September 2003, in Saclay, nearby Paris. The total suspended particulate matter (TSP) was collected continuously on quartz fibre filters. The TSP contents were determined for 36 elements (including Ag, Bi, Mo and Sb) using two analytical methods: Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The measured concentrations were in agreement within the uncertainties with the certified values for the polycarbonate reference material filter SRM-2783 (National Institute for Standard Technology NIST, USA). The measured concentrations were significantly lower than the recommended atmospheric concentrations. In 2003, the Pb atmospheric level at Saclay was 15 ng/m³, compared to the 500 ng/m³ guideline level and to the 200 ng/m³ observed value in 1994. The typical urban background TSP values of 1–2, 0.2–1, 4–6, 10–30 and 3–5 ng/m³ for As, Co, Cr, Cu and Sb, respectively, were inferred from this study and were compared with the literature data. The typical urban background TSP concentrations could not be realised for Cd, Pb and Zn, since these air concentrations are highly influenced by local features. The Zn concentrations and Zn/Pb ratio observed in Saclay represented a characteristic fingerprint of the exceptionally large extent of zinc-made roofs in Paris and its suburbs. The traffic-related origin of Ba, Cr, Cu, Pb and Sb was demonstrated, while the atmospheric source(s) of Ag was not identified.     

Background levels of heavy metals in surficial sediments of the Gulf of Lions (NW Mediterranean): an approach based on 133Cs normalization and lead isotope measurements

This paper presents an attempt to reach natural background levels of heavy metals in surficial sediments of the Gulf of Lions (NW Mediterranean). To correct for the grain-size effect, normalization procedures based on a clay mineral indicator element are commonly used, after a first grain size separation by sieving. In our study, we tested the applicability of this method with respect to commonly used normalizer elements, and found that stable Cs shows the best ability to reflect the fine sediment fraction. Background levels were successfully reached for Co, Cr, Cu, Ni and Pb, compared to various literature references. Nevertheless, in the case of lead, the normalized data depicted a general enrichment in all samples, and the natural levels could only be reached when concentrations were corrected for the atmospheric contribution by analysing lead isotope ratios. Also for Zn, a general enrichment was found in our samples, although less important.     

Temporal changes in giant panda habitat connectivity across boundaries of Wolong Nature Reserve, China.

Global biodiversity loss is largely driven by human activities such as the conversion of natural to human-dominated landscapes. A popular approach to mitigating land cover change is the designation of protected areas (e.g., nature reserves). Nature reserves are traditionally perceived as strongholds of biodiversity conservation. However, many reserves are affected by land cover changes not only within their boundaries, but also in their surrounding areas. This study analyzed the changes in habitat for the giant panda (Ailuropoda melanoleuca) inside Wolong Nature Reserve, Sichuan, China, and in a 3-km buffer area outside its boundaries, through a time series of classified satellite imagery and field observations. Habitat connectivity between the inside and the outside of the reserve diminished between 1965 and 2001 because panda habitat was steadily lost both inside and outside the reserve. However, habitat connectivity slightly increased between 1997 and 2001 due to the stabilization of some panda habitat inside and outside the reserve. This stabilization most likely occurred as a response to changes in socioeconomic activities (e.g., shifts from agricultural to nonagricultural economies). Recently implemented government policies could further mitigate the impacts of land cover change on panda habitat. The results suggest that Wolong Nature Reserve, and perhaps other nature reserves in other parts of the world, cannot be managed as an isolated entity because habitat connectivity declines with land cover changes outside the reserve even if the area inside the reserve is well protected. The findings and approaches presented in this paper may also have important implications for the management of other nature reserves across the world.     

Environmental and Ecological Aspects in the Overall Assessment of Bioeconomy

Bioeconomy solutions potentially reduce the utilization demand of natural resources, and therefore, represent steps towards circular economy, but are not per se equivalent to sustainability. Thus, production may remain to be achieved against losses in natural resources or at other environmental costs, and materials produced by bioeconomy are not necessarily biodegradable. As a consequence, the assumption that emerging bioeconomy by itself provides an environmentally sustainable economy is not justified, as technologies do not necessarily become sustainable merely through their conversion to using renewable resources for their production. A source of the above assumption is that the utility of bioeconomy is mostly assessed in interaction between technology developers and economists, resulting in biased assessment with private commercial technology benefits being included, but environmental costs, especially longer term ones, not being sufficiently considered in the economic models. A possible solution to this conceptual contradiction may come from bioethics, as a strong concept in environmental ethics is that no technological intervention can be imposed on nature beyond its receptive capacity. To achieve a better balanced analysis of bioeconomy, environmental and ecological, as well as non-economic social aspects, need to be included in the overall assessment.     

Controls on hourly variations in urban background air pollutant concentrations

Average 21st century concentrations of urban air pollutants linked to cardiorespiratory disease are not declining, and commonly exceed legal limits. Even below such limits, health effects are being observed and may be related to transient daytime peaks in pollutant concentrations. With this in mind, we analyse >52,000 hourly urban background readings of PM₁₀ and pollutant gases throughout 2007 at a European town with legal annual average concentrations of common pollutants, but with a documented air pollution-related cardiorespiratory health problem, and demonstrate the hourly variations in PM₁₀, SO₂, NO_x, CO and O₃. Back-trajectory analysis was applied to track the arrival of exotic PM₁₀ intrusions, the main controls on air pollutants were identified, and the typical hourly pattern on ambient concentrations during 2007 was profiled. Emphasis was placed on “worst case” data (>90th percentile), when health effects are likely to be greatest. The data show marked daytime variations in pollutants result from rush-hour traffic-related pollution spikes, midday industrial SO₂ maxima, and afternoon O₃ peaks. African dust intrusions enhance PM₁₀ levels at whatever hour, whereas European PM incursions produce pronounced evening peaks due to their transport direction (across an industrial traffic corridor). Transient peak profiling moves us closer to the reality of personal outdoor exposure to inhalable pollutants in a given urban area. We argue that such an approach to monitoring data potentially offers more to air pollution health effect studies than using only 24 h or annual averages.     

Metabolic responses of Eisenia fetida after sub-lethal exposure to organic contaminants with different toxic modes of action

Nuclear magnetic resonance (NMR) - based metabolomics has the potential to identify toxic responses of contaminants within a mixture in contaminated soil. This study evaluated the metabolic response of Eisenia fetida after exposure to an array of organic compounds to determine whether contaminant-specific responses could be identified. The compounds investigated in contact tests included: two pesticides (carbaryl and chlorpyrifos), three pharmaceuticals (carbamazephine, estrone and caffeine), two persistent organohalogens (Aroclor 1254 and PBDE 209) and two industrial compounds (nonylphenol and dimethyl phthalate). Control and contaminant-exposed metabolic profiles were distinguished using principal component analysis and potential contaminant-specific biomarkers of exposure were found for several contaminants. These results suggest that NMR-based metabolomics offers considerable promise for differentiating between the different toxic modes of action (MOA) associated with sub-lethal toxicity to earthworms.     

Organic matter compounds as source indicators and tracers for marine pollution in a western Mediterranean coastal zone

Introduction  

Complex organic compounds found in oil and sediments linked with a particular source (such as algae, bacteria or vascular plants) are defined as biomarkers and are useful dating indicators in organic geochemistry.