Biomonitoring data on young adults from the Environmental Specimen Bank suggest a decrease in the exposure to the fragrance chemical 7-hydroxycitronellal in Germany from 2000 to 2018.

7-Hydroxy-3,7-dimethyl-1-octanal, also known as 7-hydroxycitronellal (7-HC, CAS No. 107-75-5) is a synthetic fragrance widely used in cosmetic and hygiene products. Because of its wide spread use and its known sensitizing properties, 7-HC was selected as one of 50 chemicals within the frame of the cooperation project between the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) and the German Chemical Industry Association (VCI) to develop a suitable human biomonitoring (HBM) method in order to assess the exposure of the general population in Germany. Within this scope, the recently published analytical method for urinary 7-hydroxycitronellylic acid (7-HCA), the major metabolite of 7-HC, was applied to 329 24h-urine samples of young adults (20 to 29 years) collected between 2000 and 2018 and stored in the Environmental Specimen Bank (ESB). The widespread exposure to 7-HC as already observed in a pilot study with 40 volunteers could be confirmed with quantifiable concentrations of 7-HCA in all 329 study samples (mean: 14.9 ng/mL; median: 8.1 ng/mL). A significant, chronological decrease in 7-HCA levels was found for the monitored years (2000, 2004, 2008, 2012, 2015, 2018). The most pronounced decline occurred between 2000 and 2004 (means: 34.37 versus 23.31, medians: 20.97 versus 12.49 µg/24h; p < 0.01). On average, females exhibited higher levels of urinary 7-HCA compared to males (29.34 versus 17.21 µg/24h, p < 0.05). Based on the urinary 7-HCA excretion, the daily intake (DI) of 7-HC normalized for body weight (bw) was estimated. Over all sampling years, average DI in females was significantly higher compared to males (0.99 versus 0.46 µg/kg bw/d). Assuming dermal exposure as the main route of 7-HC intake, the mean DIs correspond to <0.1% of the derived no effect level (DNEL) of 1,100 µg/kg bw/d defined by the European Chemical Agency (ECHA). The presented results for the exposure to the widely used fragrance 7-HC in Germany can be substantiated by applying the described methodology to the representative cohort of the launched German Environmental Survey in adults (GerES VI).

Discovering time-trends of the German populations exposure to contaminants by analysis of human samples of the German Environmental Specimen Bank (ESB).

The German Environmental Specimen Bank (ESB) is a monitoring instrument of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. The permanent biobank facility is run since 1981 containing environmental and human samples from Germany. All samples are collected according to standard operating procedures (SOP). An standardized annual collection of human samples at four different regional sites of the country has been established since 1997. Routine sampling is done once a year, recruiting healthy non occupationally exposed students aged 20-29 years, in an equal gender distribution. The number of participants recruited is approximately 120 students per site and year. Directly after the annual sampling process, the human samples are analyzed for selected environmental chemicals. The time-trends of lead in blood, mercury and pentachlorophenol in 24 h-urine and polychlorinated biphenyls in plasma demonstrated a decrease of exposure during the last two decades by about 40-90 percent. In parallel retrospective studies using cryo-archived samples revealed increasing time trends of emerging chemicals used as substitutes for regulated toxicants. The data demonstrates the great relevance of the ESB for the health related environmental monitoring and shows the importance of human biomonitoring as a tool in information based policy making.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the human biomonitoring of non-occupational exposure to the fragrance 2-(4-tert-butylbenzyl)propionaldehyde (lysmeral).

2-(4-tert-Butylbenzyl)propionaldehyde also known as lysmeral, lilial, or lily aldehyde (CAS No. 80-54-6) is a synthetic odorant mainly used as a fragrance in a variety of consumer products like cleaning agents, fine fragrances, cosmetics, and air fresheners. Due to its broad application in various fields, lysmeral was selected for the development of a biomonitoring method for the quantitative exposure assessment within the frame of the cooperation project of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) and the German Chemical Industry Association (VCI). A method based on ultra-high pressure liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of potential biomarkers of lysmeral in human urine samples. Sample cleanup was performed by liquid-liquid extraction (LLE). Quantification was achieved by standard addition using stable isotope-labeled, authentic reference standards. The method is characterized by its robustness, reliability, and excellent sensitivity as proven during method validation according to approved standard guidelines. The following five lysmeral metabolites were identified as potential biomarkers of exposure for lysmeral in human urine samples: lysmerol, lysmerylic acid, hydroxylated lysmerylic acid, tert-butylbenzoic acid (TBBA), and tert-butylhippuric acid (TBHA). The determination of lysmerol required derivatization with 3-nitrophthalic acid anhydride and showed the lowest limit of detection (LOD) and limit of quantification (LOQ) in urine (0.035 and 0.10 µg/L, respectively). LOD and LOQ for the other metabolites were in the range of 0.12-0.15 and 0.36-0.45 µg/L, respectively. Accuracy for all analytes was in the range of 90-110 %. Intra- and inter-day precision was in the range of 5-10 %, except for TBHA, for which the coefficient of variation was unacceptably high (>20 %) and therefore excluded from the method. The method was applied to urine samples of 40 adult volunteers. The four remaining lysmeral metabolites were detectable in most of the 40 urine samples in the following order according to quantity excreted: TBBA >> lysmerol ≈ lysmerylic acid > hydroxy-lysmerylic acid. In conclusion, we successfully developed a biomonitoring method for the assessment of the exposure to lysmeral in the general population. The method is characterized by its precision, robustness, and accuracy. The metabolites lysmerol, lysmerylic acid, hydroxylated lysmerylic acid, and TBBA turned out to be suitable biomarkers of exposure to lysmeral, either alone or in combination with one or more of the other metabolites. Sensitivity was found to be sufficient for assessing the background exposure to this chemical in the general population.