Holger Martin Koch

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An individual (male, 36 years, 87 kg) ingested two separate doses of di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP) at a rate of ~60 μg/kg. Key monoester and oxidized metabolites were identified and quantified in urine continuously collected until 48 h post-dose. For both DnBP and DiBP, the majority of the dose was excreted in the first 24 h(More)
BACKGROUND Prenatal exposure to bisphenol A (BPA) has been associated with adverse birth outcomes, but findings of previous studies have been inconsistent. OBJECTIVE We investigated the relation of prenatal BPA exposure with intrauterine growth and evaluated the effect of the number of measurements per subject on observed associations. METHODS This(More)
Hexamoll® DINCH® (diisononyl-cyclohexane-1,2-dicarboxylate) is a new high-molecular-weight plasticizer and a phthalate substitute. In this study, the metabolism of DINCH® was investigated by oral dosage of three male volunteers with approximately 50 mg Hexamoll® DINCH® (resulting in individual doses between 0.552 and 0.606 mg/kg body weight). Their urine(More)
BACKGROUND For Europe as a whole, data on internal exposure to environmental chemicals do not yet exist. Characterization of the internal individual chemical environment is expected to enhance understanding of the environmental threats to health. OBJECTIVES We developed and applied a harmonized protocol to collect comparable human biomonitoring data all(More)
We noted serious methodologic issues in the measurement of bisphenol A (BPA), phthalate diesters, and their metabolites in blood serum and other tissues, as reported in the recent Breast Cancer Research article by Sprague and colleagues [1]. Such measurements are analytically possible. However, for the reasons that follow, it is seldom possible to verify(More)
BACKGROUND Fundamental considerations indicate that, for certain phthalate esters, dermal absorption from air is an uptake pathway that is comparable to or greater than inhalation. Yet this pathway has not been experimentally evaluated and has been largely overlooked when assessing uptake of phthalate esters. OBJECTIVES This study investigated transdermal(More)
We discuss considerations that are essential when evaluating exposure to nonpersistent, semivolatile environmental chemicals such as phthalates and phenols (e.g., bisphenol A). A biomarker should be chosen to best represent usual personal exposures and not recent, adventitious, or extraneous exposures. Biomarkers should be selected to minimize contamination(More)
The International Agency for Research on Cancer considers the carcinogenicity of welding fume of priority for re-evaluation. Genotoxic effects in experimental animals are still inconclusive. Here, we investigated the association of personal exposure to metals in respirable welding fumes during a working shift with oxidatively damaged guanosine in DNA of(More)