Publications by authors named "Ramona Brejcha"

The health effects of exposure to secondary organic aerosols (SOAs) are still limited. Here, we investigated and compared the toxicities of soot particles (SP) coated with β-pinene SOA (SOA-SP) and SP coated with naphthalene SOA (SOA-SP) in a human bronchial epithelial cell line (BEAS-2B) residing at the air-liquid interface. SOA-SP mostly contained oxygenated aliphatic compounds from β-pinene photooxidation, whereas SOA-SP contained a significant fraction of oxygenated aromatic products under similar conditions.

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Background: Secondary organic aerosols (SOAs) formed from anthropogenic or biogenic gaseous precursors in the atmosphere substantially contribute to the ambient fine particulate matter [PM in aerodynamic diameter ()] burden, which has been associated with adverse human health effects. However, there is only limited evidence on their differential toxicological impact.

Objectives: We aimed to discriminate toxicological effects of aerosols generated by atmospheric aging on combustion soot particles (SPs) of gaseous biogenic () or anthropogenic (naphthalene) precursors in two different lung cell models exposed at the air-liquid interface (ALI).

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Toxic boron (B) concentrations cause impairments in several plant metabolic and physiological processes. Recently we reported that B toxicity led to a decrease in the transpiration rate of Arabidopsis plants in an ABA-dependent process within 24 h, which could indicate the occurrence of an adjustment of whole-plant water relations in response to this stress. Since plasma membrane intrinsic protein (PIP) aquaporins are key components influencing the water balance of plants because of their involvement in root water uptake and tissue hydraulic conductance, the aim of the present work was to study the effects of B toxicity on these important parameters affecting plant water status over a longer period of time.

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We examined the potential of stable-isotope Raman microspectroscopy (SIRM) for the evaluation of differently enriched C-labeled humic acids as model substances for soil organic matter (SOM). The SOM itself can be linked to the soil water holding capacity. Therefore, artificial humic acids (HA) with known isotopic compositions were synthesized and analyzed by means of SIRM.

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Compound-specific isotope analysis (CSIA) receives increasing interest for its ability to detect natural degradation of pesticides and pharmaceuticals. Despite recent laboratory studies, CSIA investigations of such micropollutants in the environment are still rare. To explore the certainty of information obtainable by CSIA in a near-environmental setting, a pulse of the pesticide bentazone, the pesticide metabolite 2,6-dichlorobenzamide (BAM), and the pharmaceuticals diclofenac and ibuprofen was released into a mesoscale aquifer with quasi-two-dimensional flow.

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An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.

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