Systemic availability of lipophilic organic UV filters through dermal sunscreen exposure.

Background: Chemical UV filters are common components in sunscreens and cosmetic products and used to protect the skin against harmful effects of sunlight like sunburn. However, the effectiveness of sunscreens in the prevention of skin cancer is in some parts still controversial. Meanwhile, questions about negative effects of the chemical UV filters on human health arise and request an effective risk assessment.

Toxicokinetics of urinary 2-ethylhexyl salicylate and its metabolite 2-ethyl-hydroxyhexyl salicylate in humans after simulating real-life dermal sunscreen exposure.

Chemical UV filters are common components in sunscreens and cosmetic products. The question of adverse health risks is not completely resolved, partly owing to lacking human data from dermal exposure, which are essential for sound risk assessment. Therefore, we investigated the urinary toxicokinetics of 2-ethylhexyl salicylate (EHS) after a 1-day dermal real-life sunscreen application scenario.

Quantification of prominent organic UV filters and their metabolites in human urine and plasma samples.

Monitoring human exposure to chemical UV filters is essential for an accurate assessment of the health risk caused by the resorbed compounds. We developed different procedures for the determination of the prominent UV filters octocrylene (OC), avobenzone (AVO) and 2-ethylhexyl salicylate (EHS) as well as for two OC and EHS metabolites in human urine and OC, AVO and 2-cyano-3,3-diphenylacrylic acid (CDAA) in plasma samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Since the development of a multi-method for all analytes proved to be difficult, three different procedures were established for the determination of AVO, OC and its metabolite CDAA in urine and plasma as well as for EHS and its metabolite 5-hydroxy-EHS in urine.

Validity of different biomonitoring parameters in human urine for the assessment of occupational exposure to naphthalene.

Up to date, information on the validity of human biomonitoring (HBM) parameters of naphthalene exposure is poor. This study was performed to reveal the relation between occupational exposure to naphthalene and biological exposure markers. Therefore, ten lowly and highly exposed workers from the abrasives industry were selected to characterise a broad exposure range.

Suitability of several naphthalene metabolites for their application in biomonitoring studies.

Naphthalene occurs together with polycyclic aromatic hydrocarbons (PAHs) at industrial workplaces and is ubiquitous in the environment. For biological monitoring of naphthalene exposures, up to now mainly 1- and 2-naphthol in urine have been used. Recently, we proposed 1,2-dihydroxynaphthalene (1,2-DHN) and the 1- and 2-naphthylmercapturic acid (1- and 2-NMA) as new urinary biomarkers to characterise a naphthalene exposure.

LC-MS/MS procedure for the simultaneous determination of N-acetyl-S-(1-naphthyl)cysteine and N-acetyl-S-(2-napthyl)cysteine in human urine.

A two-dimensional liquid chromatographic electrospray-ionization tandem mass spectrometric (LC/LC-ESI-MS/MS) procedure for the simultaneous determination of the expected mercapturic acids of naphthalene (1- and 2-naphthylmercapturic acids; 1- and 2-NpMA) and of the well-established parameter for benzene biomonitoring (S-phenylmercapturic acid; PhMA) in human urine was developed, validated and applied to human urine samples. Apart from sample acidification, the enrichment of analytes and sample clean-up as well as the separation of all analytes were completely automated using both a restricted access material column (RAM C18) and a core-shell biphenyl material. Sensitive, specific and reliable detection of all target substances, with limits of detection ranging from 0.

The Health Effects of Aluminum Exposure.

Background: Aluminum is regularly taken up with the daily diet. It is also used in antiperspirants, as an adjuvant for vaccination, and in desensitization procedures. In this review, we present the scientifically documented harmful effects of aluminum on health and the threshold values associated with them.

Reliable quantification of 1,2-dihydroxynaphthalene in urine using a conjugated reference compound for calibration.

After environmental and occupational exposure to naphthalene, 1,2-dihydroxynaphthalene (1,2-DHN) was shown to be one major metabolite in human naphthalene metabolism. However, the instability of free 1,2-DHN complicates the reliable determination of this promising biomarker in urine. To solve this stability problem, glucuronide conjugates of 1,2-DHN and the corresponding isotopically labelled D-1,2-dihydroxynaphthalene (D-1,2-DHN) were synthesised and applied as reference material and internal standard in a gas chromatographic-tandem mass spectrometric (GC-MS/MS) method.

Human Biomonitoring of Lead Exposure.

After a chronic exposure, lead accumulates in the human body, especially in bones and teeth. Critical effects of lead affect the nervous system, reproduction, fertility as well as genotoxicity and carcinogenicity [1]. Analyses of lead concentrations in human biological material are performed using inductively coupled plasma mass spectrometry and atomic absorption spectrometry, but also electrochemical methods and X-ray fluorescence spectroscopy.

Quantification of naphthoquinone mercapturic acids in urine as biomarkers of naphthalene exposure.

Naphthalene shows carcinogenic properties in animal experiments. As the substance is ubiquitary present in the environment and has a possibly high exposure at industrial workplaces, the determination of naphthalene metabolites in humans is of environmental-medical as well as occupational-medical importance. Here, biomarkers of 1,2- and 1,4-naphthoquinone, as possibly carcinogenic metabolites in the naphthalene metabolism, are of outstanding significance.

[Tracing for arsenic exposure--a differentiation of arsenic compounds is essential for the health assessment].

Arsenic is ubiquitous and harmful to health in occupation and environment. Arsenic exposure is measured through analysis of arsenic compounds in urine. The identification of several arsenic species is necessary to understand the hazardous potential of the arsenic compounds which differ highly in their toxicity.

Determination of cadmium in biological samples.

Analyses of cadmium concentrations in biological material are performed using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS), but also electrochemical methods, neutron activation analysis (NAA), and X-ray fluorescence spectrometry (XRF). The predominant sample matrices include blood, plasma, serum, and urine, as well as hair, saliva, and tissue of kidney cortex, lung, and liver. While cadmium in blood reveals rather the recent exposure situation, cadmium in urine reflects the body burden and is an indicator for the cumulative long term exposure.

1,2-Dihydroxynaphthalene as biomarker for a naphthalene exposure in humans.

Objectives: The possibly carcinogenic properties of naphthalene are, regarding to its ubiquitary presence, of environmental-medical and occupational-medical importance. Seven isomeric dihydroxynaphthalenes (DHN) were examined for their suitability as biomarkers in human biomonitoring and to get insights in human naphthalene metabolism.

Methods: We developed a GC-MS-method for the quantification of 1,2-, 1,4-, 1,5-, 1,6-, 1,7-, 2,6- and 2,7-DHN after solid phase extraction and derivatization with BSA/TMCS.