A multi-component data assimilation experiment directed to sulphur dioxide and sulphate over Europe

Fine particulate matter (PM) is relevant for human health and its components are associated with climate effects. The performance of chemistry transport models for PM, its components and precursor gases is relatively poor. The use of these models to assess the state of the atmosphere can be strengthened using data assimilation. This study focuses on simultaneous assimilation of sulphate and its precursor gas sulphur dioxide into the regional chemistry transport model LOTOS–EUROS using an ensemble Kalman filter. The process of going from a single component setup for SO₂ or SO₄ to an experiment in which both components are assimilated simultaneously is illustrated. In these experiments, solely emissions, or a combination of emissions and the conversion rates between SO₂ and SO₄ were considered uncertain. In general, the use of sequential data assimilation for the estimation of the sulphur dioxide and sulphate distribution over Europe is shown to be beneficial. However, the single component experiments gave contradicting results in direction in which the emissions are adjusted by the filter showing the limitations of such applications. The estimates of the pollutant concentrations in a multi-component assimilation have found to be more realistic. We discuss the behavior of the assimilation system for this application. The model uncertainty definition is shown to be a critical parameter. The increased complexity associated with the simultaneous assimilation of strongly related species requires a very careful specification of the experiment, which will be the main challenge in the future data assimilation applications.     

Cold Atmospheric Plasma as a Novel Method for Inactivation of Potato Virus Y in Water Samples

Food and Environmental Virology - While one of the biggest problems we are facing today is water scarcity, enormous quantities of water are still being used in irrigation. If contaminated, this...     

Comparison of various sensitive and selective spectrophotometric assays of environmental cyanide

A simple approach was carried out to study the effects of various parameters on high performance liquid chromatography (HPLC) performance of microcystin-LR (MC-LR) analysis in samples from some reservoirs and rivers in Taiwan under simulation conditions. Nature of column and its packing affected the instrument sensitivity. Varied column length indicated the longer column enhanced (C18, 5 μm, 4.6 × 150 mm) HPLC performance. Studies on mobile phase found that ratio and concentration of the mobile phase gradient greatly influenced the peak shape, retention time, and optimal conditions of mobile phase were set at acetonitrile and 0.01M ammonium acetate (30:70). Different compounds were added to mobile phase and their contribution to HPLC spectra was reported. Detection limits were carefully measured and reported. These investigations provide simple and important information that may be applied to HPLC performance for microcystin analysis from natural water systems.     

Changes over time in persistent organic pollutants (POP) concentrations in human milk in the Republic of Moldova

Persistent organic pollutants (POP) in human milk originating from various sources are used as environmental exposure markers. Further, mothersmilk is a predominant pathway for human exposure for suckling infants to POP. The aim of present study was to provide baseline and time trend information on human milk POP concentrations in the Republic of Moldova. A pooled sample of breast milk was analyzed in 2009 and 2015 and health risk evaluated by comparing reference values of humans' daily intake with estimated daily intake (EDI). Results showed decreases for concentrations of dichlorodiphenyltrichloroethane, hexachlorobenzene, dieldrin, heptachlor, α and β-hexachlorocyclohexane, polychlorinated biphenyls, dioxin-like polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans between sampling periods. Regardless of the decrease, EDI was higher than reference values for dioxins toxic equivalents, polychlorinated biphenyls and β-hexachlorocyclohexane in both phases. However, increased levels were detected for polybrominated diphenyl ethers (twofold) and hexabromocyclododecane (threefold) from 2009 to 2015, but the EDI in both phases is much lower than the reference. The decline in certain POP levels may be attributed to coordinated efforts undertaken by national and international entities to regulate these compounds. The basis for the elevated levels of polybrominated diphenyl ethers and hexabromocyclododecane remains unknown but raises concerns regarding lactational exposure.     

Driving difficulties as reported by older drivers with mild cognitive impairment and without neurological impairment

Objective: Considerable evidence indicates that medical conditions prevalent among older individuals lead to impairments in visual, cognitive, or psychomotor functions needed to drive safely. The purpose of this study was to explore the factors determining driving difficulties as seen from the viewpoint of 30 older drivers with mild cognitive impairment (MCI) and 30 age-matched controls without cognitive impairment.

Methods: Perceptions of driving difficulties from both groups were examined using data from an extensive questionnaire. Samples of drivers diagnosed with MCI and age-matched controls were asked to report the frequency with which they experienced driving difficulties due to functional deficits and knowledge of new traffic rules and traffic signs.

Results: The analysis revealed that 2 factors underlie MCI perceptions of driving difficulties, representing (1) difficulties associated with late detection combined with slowed response to relevant targets in the peripheral field of view and (2) difficulties associated with divided attention between tasks requiring switching from automatic to conscious processing particularly of long duration. The analysis for healthy controls revealed 3 factors representing (1) difficulties in estimating speed and distance of approaching vehicles in complex (attention-dividing) high-information-load conditions; (2) difficulties in moving head, neck, and feet; and (3) difficulties in switching from automatic responses to needing to use cognitive processing in new or unexpected situations.

Conclusions: Though both group analyses show difficulties with switching from automatic to decision making, the difficulties are different. For the control group, the difficulty in switching involves switching in new or unexpected situations associated with high-information-load conditions, whereas this switching difficulty for the MCI group is associated with divided attention between easier tasks requiring switching. These findings underline the ability of older drivers (with MCI and without cognitive impairment) to indicate probable impairments in various driving skills. The patterns of difficulties perceived by the MCI group and the age-matched healthy control group are indicative of demanding driving situations that may merit special attention for road designers and road safety engineers. They may also be considered in the design of older drivers’ fitness to drive evaluations, training programs, and/or vehicle technologies that provide for older driver assistance.     

Air pollution, precipitation chemistry and forest health in the Retezat Mountains, Southern Carpathians, Romania

In the Retezat Mountains concentrations of O3, NO2 and SO2 in summer season 2000-2002 were low and below toxicity levels for forest trees. While NH3 concentrations were low in 2000, the 2001 and 2002 concentrations were elevated indicating possibility for increased N deposition to forest stands. More than 90% of the rain events were acidic with pH values <5.5, contributing to increased acidity of soils. Crown condition of Norway spruce (Picea abies) and European beech (Fagus sylvatica) was good, however, defoliation described as >25% of foliage injured increased from 9.1% in 2000 to 16.1% in 2002. Drought that occurred in the southern Carpathians between fall 2000 and summer 2002 and frequent acidic rainfalls could cause the observed decline of forest condition. Both Norway spruce and European beech with higher defoliation had lower annual radial increments compared to the trees with low defoliation. Ambient O3 levels found in the Retezat did not affect crown condition of Norway spruce or European beech.     

Spatially valid data of atmospheric deposition of heavy metals and nitrogen derived by moss surveys for pollution risk assessments of ecosystems

For analysing element input into ecosystems and associated risks due to atmospheric deposition, element concentrations in moss provide complementary and time-integrated data at high spatial resolution every 5 years since 1990. The paper reviews (1) minimum sample sizes needed for reliable, statistical estimation of mean values at four different spatial scales (European and national level as well as landscape-specific level covering Europe and single countries); (2) trends of heavy metal (HM) and nitrogen (N) concentrations in moss in Europe (1990–2010); (3) correlations between concentrations of HM in moss and soil specimens collected across Norway (1990–2010); and (4) canopy drip-induced site-specific variation of N concentration in moss sampled in seven European countries (1990–2013). While the minimum sample sizes on the European and national level were achieved without exception, for some ecological land classes and elements, the coverage with sampling sites should be improved. The decline in emission and subsequent atmospheric deposition of HM across Europe has resulted in decreasing HM concentrations in moss between 1990 and 2010. In contrast, hardly any changes were observed for N in moss between 2005, when N was included into the survey for the first time, and 2010. In Norway, both, the moss and the soil survey data sets, were correlated, indicating a decrease of HM concentrations in moss and soil. At the site level, the average N deposition inside of forests was almost three times higher than the average N deposition outside of forests.     

Chemical and micromorphological properties of TSP and PM10 particles: case study in Bucharest urban area

The purpose of this work was to determine some aspects of micromorphology of total suspended particles (TSP) and particulate matter with aerodynamic diameter ≤10 μm (PM(10)) and their major elemental components in order to highlight the main characteristics of the atmospheric particles from an urban environment, having a case study in the urban area of Bucharest. The sampling of PM(10) and TSP were conducted in the close vicinity of a high traffic road for 72 h per sample and also priority pollutants in air: Pb and Cd were quantified and correlations between their concentrations and local wind directions were also found. The parameters characterizing the micromorphology of particle-roughness of the particle surface and area of particle-were correlated with wind direction.