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Kolossa-Gehring, Marike

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Kolossa-Gehring
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Marike
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  • Veröffentlichung
    Risk assessment for irritating chemicals - derivation of extrapolation factors
    (2021) Mangelsdorf, Inge; Schröder, Katrin; Escher, Sylvia E.; Kolossa-Gehring, Marike; Debiak, Malgorzata
    Irritation of the eyes and the upper respiratory tract are important endpoints for setting guide values for chemicals. To optimize the use of the often-limited data, we analysed controlled human exposure studies (CHS) with 1-4 h inhalation of the test substance, repeated dose inhalation studies in rodents, and Alarie-Tests and derived extrapolation factors (EF) for exposure duration, inter- and intraspecies differences. For the endpoint irritating effects in the respiratory tract in rodents, geometric mean (GM) values of 1.9 were obtained for the EF for subacute ->subchronic (n = 16), 2.1 for subchronic -> chronic (n = 40), and 2.9 for subacute -> chronic (n = 10) extrapolation. Based on these data we suggest an EF of 2 for subchronic -> chronic and of 4 for subacute -> chronic extrapolation. In CHS, exposure concentration determines the effects rather than exposure duration. Slight reversible effects during 4 h exposure indicate that an EF of 1 can be considered for assessing chronic exposures. To assess species extrapolation, 10 chemicals were identified with both, reliable rat inhalation studies and CHS. The GM of the ratio between the No Observed Adverse Effect Concentration (NOAEC) in rats and humans was 2.3 and increased to 3.6 when expanding the dataset to all available EF (n = 25). Based on these analyses, an EF of 3 is suggested to extrapolate from a NOAEC in a chronic rat study to a NOAEC in a CHS. The analysis of EFs for the extrapolation from a 50% decrease in respiratory frequency in the Alarie test in mice (RD50) to a NOAEC in a CHS resulted in a GM of 40, for both, the reliable (n = 11) and the overall dataset (n = 19). We propose to use the RD50 from the Alarie test for setting guide values and to use 40 as EF. Efs for intraspecies differences in the human population must account for susceptible persons, most importantly for persons with chemical intolerance (CI), who show subjective signs of irritation at low concentrations. The limited data available do not justify to deviate from an EF of 10 - 20 as currently used in different regulatory settings. © 2020 The Authors.
  • Veröffentlichung
    Formaldehyde, aliphatic aldehydes (C2-C11), furfural, and benzaldehyde in the residential indoor air of children and adolescents during the German Environmental Survey 2014-2017
    (2022) Bethke, Robert; Birmili, Wolfram; Brasse, Gregor; Conrad, André; Daniels, Anja; Debiak, Malgorzata; Kolossa-Gehring, Marike; Hurraß, Julia; Schechner, Nadine
    Indoor air concentrations of formaldehyde, furfural, benzaldehyde, and 11 aliphatic aldehydes (C2-C11) were measured in residences of 639 participants in the German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Sampling was conducted using passive samplers over periods of approximately seven days for each participant. The most abundant compounds were formaldehyde and hexanal with median concentrations of 24.9 (micro)g m-3 and 10.9 (micro)g m-3, respectively. Formaldehyde concentrations exceeded the Guide Value I recommended by the German Committee on Indoor Guide Values (Ausschuss für Innenraumrichtwerte - AIR) (0.10 mg m-3) for 0.3% of the participating residences. The sum of aliphatic n-aldehydes between C4 (butanal) and C11 (undecanal) exceeded their Guide Value (0.10 mg m-3) for 2.0% of the residences. The geometric mean concentrations of most aldehydes were lower than in the earlier GerES IV (2003-2006) study. Formaldehyde and hexanal concentrations, however, were comparable in both studies and showed no significant difference. Indoor aldehyde concentrations did not exhibit significant correlations with factors collected in questionnaires, such as the age of the participants, their socio-economic status, the location of the residence (former East/West Germany), migration background, tobacco exposure, and the type of furniture used. The validity of the passive sampler measurements was verified against active sampling techniques in a test chamber experiment. © 2021 The Authors