Polycyclic aromatic hydrocarbons in lake sediments from the High Tatras

European alpine lake systems are used as indicators of air quality over the continent. Preliminary data showed high polycyclic aromatic hydrocarbons (PAH) loads in the High Tatras (Eastern Europe) in comparison to other mountain regions. Here, insight on the spatial distribution of PAH is provided from analysis of top-core sediments of 27 alpine lakes distributed along the High Tatras.Top-core sediment concentrations were higher than those in deep-cores, and they were higher than those observed in other European high mountain regions. The PAH profiles were uniform and comparable to those observed in aerosols and snow, indicating that atmospheric deposition was the predominant PAH input pathway to the lakes. Good agreement between estimated atmospheric deposition and sedimentation fluxes was observed. However, in several lakes in the western range higher sediment fluxes may correspond to higher PAH depositions levels. The higher concentrations may also reflect inputs from potential emission source areas.     

Carbon Monoxide Trend,Meteorology, and Three-Way Catalysts in Mexico City

ABSTRACT

From the analysis of data of the Inspection/Maintenance (I/M) program, and of the long-term trend of ambient CO concentrations in Mexico City, it is inferred that three-way catalysts (TWCs) have a 45% efficiency, well below the expected 90% value. The most probable causes are sulfur poisoning, lead contamination, and ceramic breakage due to bumps and potholes on the streets. Also, we have found a ratio between the average daily peak value of atmospheric CO and gasoline consumption: (11 ± 1) ppbCO/MLm (million liters of gasoline per month) in 1988 decaying to (10 ±1) in 1991 for Mexico City before the introduction of TWCs. In addition, we found a correlation between the monthly averages of CO daily peak and meteorological variables, explaining most of the seasonal changes using only the intensity of the inversion layer and surface wind speed.     

The Effect of Extraction Conditions on the Chemical Characteristics of Pectin from Opuntia ficus indica Cladode Flour

Pectin from the cladode flour of Opuntia ficus indica was extracted at different ethylenediaminetetraacetate concentrations (10 or 20 %), temperatures (40 or 80 °C), pH values (2 or 11), and times (10, 20, 30 40, 50 or 60 min). The effects of the extraction conditions on the yield, purity, and chemical composition of pectin were assessed. The highest pectin yield was observed for pectin obtained under alkaline conditions and 20 % of EDTA. However, pectin produced from alkaline extractions had a lower content of GalA than pectin produced from acid extractions. Higher temperatures favored the extraction of pectin under acid conditions, but these conditions diminished the arabinose content of pectins in a time-dependent manner. The tested extraction conditions caused only slight changes in the molecular weight of the extracted pectin as a function of time.     

Adaptive Capacity of Fishing Communities at Marine Protected Areas: A Case Study from the Colombian Pacific

Departing from a theoretical methodology, we estimate empirically an index of adaptive capacity (IAC) of a fishing community to the establishment of marine protected areas (MPAs). We carried out household surveys, designed to obtain information for indicators and sub-indicators, and calculated the IAC. Moreover, we performed a sensitivity analysis to check for robustness of the results. Our findings show that, despite being located between two MPAs, the fishing community of Bazán in the Colombian Pacific is highly vulnerable and that the socioeconomic dimension of the IAC constitutes the most binding dimension for building adaptive capacity. Bazán is characterized by extreme poverty, high dependence on resources, and lack of basic public infrastructure. Notwithstanding, social capital and local awareness about ecological conditions may act as enhancers of adaptive capacity. The establishment of MPAs should consider the development of strategies to confer adaptive capacity to local communities highly dependent on resource extraction.     

Evaluating pollution-related damage and restoration success in urban forests with participatory monitoring and digital tools

Peri-urban forest monitoring requires indicators of vegetation damage. An example is the sacred fir (Abies religiosa) forests surrounding Mexico City, which have been heavily exposed to tropospheric ozone, a harmful pollutant, for over 4 decades. We developed a participatory monitoring system with which local community members and scientists generated data on ozone tree damage. Santa Rosa Xochiac rangers (13) used the digital tool KoboToolBox to record ozone damage to trees, tree height, tree ages, tree condition, tree position, and whether the tree had been planted. Thirty-five percent of the trees (n = 1765) had ozone damage. Younger trees had a lower percentage of foliage damaged by ozone than older trees (p < 0.0001), and asymptomatic trees tended to be younger (p < 0.0001). Symptomatic trees were taller than asymptomatic trees of the same age (R²_c = 0.43, R²_m = 0.27). Involving local communities facilitated forest monitoring and using digital technology improved data quality. This participatory system can be used to monitor forest condition change over time and thus aids restoration efforts driven by government or local communities’ interests, facilitating local decision-making.     

A systems approach to modeling Community-Based Environmental Monitoring: a case of participatory water quality monitoring in rural Mexico

Community-Based Environmental Monitoring (CBM) is a social practice that makes a valuable contribution to environmental management and construction of active societies for sustainable future. However, its documentation and analysis show deficiencies that hinder contrast and comparison of processes and effects. Based on systems approach, this article presents a model of CBM to orient assessment of programs, with heuristic or practical goals. In a focal level, the model comprises three components, the social subject, the object of monitoring, and the means of action, and five processes, data management, social learning, assimilation/decision making, direct action, and linking. Emergent properties were also identified in the focal and suprafocal levels considering community self-organization, response capacity, and autonomy for environmental management. The model was applied to the assessment of a CBM program of water quality implemented in rural areas in Mexico. Attributes and variables (indicators) for components, processes, and emergent properties were selected to measure changes that emerged since the program implementation. The assessment of the first 3 years (2010–2012) detected changes that indicated movement towards the expected results, but it revealed also the need to adjust the intervention strategy and procedures. Components and processes of the model reflected relevant aspects of the CBM in real world. The component called means of action as a key element to transit “from the data to the action.” The CBM model offered a conceptual framework with advantages to understand CBM as a socioecological event and to strengthen its implementation under different conditions and contexts.     

Evaluation of GC-ion trap-MS/MS methodology for monitoring PCDD/Fs in infant formulas

The application of high resolution gas chromatography in combination with low resolution mass spectrometry with electron ionization and MS/MS detection (HRGC-MS/MS) is tested for its use in the analysis of PCDD/Fs in infant formulas. Development of the analytical method was based upon EPA directrices and international recommendations. Calibration linearity was tested and average relative response for any native and labelled compound over the five-point calibration range below 14% was found. The precision and accuracy of the proposed analytical procedure are also presented. Results obtained are in agreement with EPA criteria. The method is applied to the analysis of a number of initial and follow-on milk based infant formulas. In general, HRGC-MS/MS constitutes an interesting method for the analysis of dioxins in such matrices.