Experimental estimation of migration and transfer of organic substances from consumer articles to cotton wipes: Evaluation of underlying mechanisms.

The aim of this work was to identify the key mechanisms governing transport of organic chemical substances from consumer articles to cotton wipes. The results were used to establish a mechanistic model to improve assessment of dermal contact exposure. Four types of PVC flooring, 10 types of textiles and one type of inkjet printed paper were used to establish the mechanisms and model. Kinetic extraction studies in methanol demonstrated existence of matrix diffusion and indicated the presence of a substance surface layer on some articles. Consequently, the proposed substance transfer model considers mechanical transport from a surface film and matrix diffusion in an article with a known initial total substance concentration. The estimated chemical substance transfer values to cotton wipes were comparable to the literature data (relative transfer ∼ 2%), whereas relative transfer efficiencies from spiked substrates were high (∼ 50%). For consumer articles, high correlation (r(2)=0.92) was observed between predicted and measured transfer efficiencies, but concentrations were overpredicted by a factor of 10. Adjusting the relative transfer from about 50% used in the model to about 2.5% removed overprediction. Further studies are required to confirm the model for generic use.

The determination of exogenous formaldehyde in blood of rats during and after inhalation exposure.

Formaldehyde (FA) is suspected of being associated with the development of leukemia. An inhalation experiment with FA was performed in rats to study whether FA can enter the blood and could thus cause systemic toxicity in remote tissues such as the bone marrow. Therefore, a sophisticated analytical method was developed to detect blood concentrations of FA during and after single 6-h exposure by inhalation. In order to differentiate between exogenous and endogenous FA the rats were exposed to stable isotope ((13)C) labeled FA by inhalation. During and after exposure of the rats to (13)C-FA their blood was analyzed to determine the ratio between labeled and natural FA in blood and the total blood concentration of FA. With respect to sensitivity, with the applied method exogenous (13)C-FA could have been detected in blood at a concentration approximately 1.5% of the endogenous FA blood concentration. Exogenous (13)C-FA was not detectable in the blood of rats either during or up to 30 min after the exposure. It was concluded that the inhalation of (13)C-FA at 10 ppm for 6h did not result in an increase of the total FA concentration in blood.

Consumer inhalation exposure to formaldehyde from the use of personal care products/cosmetics.

We measured consumer exposure to formaldehyde (FA) from personal care products (PCP) containing FA-releasing preservatives. Six study subjects applied facial moisturiser, foundation, shower gel, shampoo, deodorant, hair conditioner, hair styling gel or body lotion at the 90th percentile amount of EU PCP consumer use. FA air concentrations were measured in the empty room, in the presence of study subjects prior to PCP use, and for one hour (breathing zone, area monitoring) after PCP use. The mean FA air concentration in the empty bathroom was 1.32 ± 0.67 µg/m³, in the presence of subjects it was 2.33 ± 0.86 µg/m³). Except for body lotion and hair conditioner (6.2 ± 0.1.9 or 4.5 ± 0.1.5 µg/m³, respectively), mean 1-h FA air concentrations after PCP use were similar to background. Peak FA air concentrations, ranging from baseline values (2.2 µg/m³; shower gel) to 11.5 µg/m³ (body lotion), occurred during 0-5 to 5-10 min after PCP use. Despite of exaggerated exposure conditions, FA air levels were a fraction of those considered to be safe (120 µg/m³), occurring in indoor air (22-124 µg/m³) or expired human breath (1.4-87 µg/m³). Overall, our data yielded evidence that inhalation of FA from the use of PCP containing FA-releasers poses no risk to human health.

Perioperative instillation therapy in superficial bladder cancer: is it effective regarding outcome and costs?

PURPOSE OF REVIEW: This article reviews the current knowledge concerning immediate intravesical instillation therapy in nonmuscle-invasive bladder cancer after transurethral resection of the bladder tumour, with emphasis on the literature of the last few years. RECENT FINDINGS: A review was conducted on the recent literature available by PubMed database on the subject of immediate bladder chemotherapy after transurethral resection of the bladder tumour and its recent developments. SUMMARY: A single immediate bladder instillation with chemotherapy will give 39% reduction of recurrence. Numbers needed to treat to prevent one recurrence are estimated at 8.5. In intermediate and high-risk bladder cancer, the immediate postoperative instillation does not give sufficient reduction in recurrence rate to leave out subsequent bladder instillations. The significant reduction of recurrences, the mild side-effects of the treatment and the clear cost-effectiveness make one immediate instillation a valuable addition to transurethral resection of the bladder tumour in the treatment of nonmuscle-invasive bladder cancer. Points of controversy are the true numbers needed to treat to prevent a recurrence and the type of recurrences that will be prevented. No new types of instillation are added recently to the ones available, but promising types are under investigation of which pharmacokinetic studies have shown acceptable rates of side-effects.