1,720,969 research outputs found
S-(acetamidomethyl)mercapturic acid (AMMA): A new biomarker for occupational exposure to N,N-dimethylacetamide
No full textN,N-dimethylacetamide (DMA) is used in the textile and plastics industry as a solvent alternative to more toxic N,N-dimethylformamide. Here we studied toxicokinetics of two major urinary metabolites of DMA, namely, S-(acetamidomethyl)mercapturic acid (AMMA) and N-methylacetamide (NMA). Urine samples were collected from workers exposed to DMA in a factory manufacturing acrylic fibers. AMMA and NMA were determined by HPLC/MS and GC/MS, respectively. The working scheme in the factory consisted of periods of three consecutive working shifts alternated regularly with two days off work. In the first stage of the study, NMA and AMMA were determined in urine samples collected before, in the middle, and at the end of one working shift. In the second stage, urine was collected five times during three consecutive days after a two-day rest: before and at the end of the first and second working shifts and before the third shift. It was found that the end-of-shift NMA levels were several folds higher than the pre-shift levels of the same day and dropped significantly until the next shift. On the other hand, there were no significant differences in AMMA levels before and at the end of the same shift but a continuous rise during the three-day working period was observed. Median values of NMA concentrations at the end of working shifts were between 10.1 and 17.3 mg/g creatinine, median AMMA concentrations in the second or third day of the working period varied between 12.4 and 38.1 mg/g creatinine. The approximate half-lives of NMA and AMMA (means) in the exposed workers were about 9 and 29 h, respectively. Thus, while NMA in the end-of-shift urine samples remains a preferential biomarker of DMA exposure during that shift, AMMA determined at the end of a work-week reflects cumulative exposure over the last few days. Further studies are needed to determine AMMA concentrations corresponding to the threshold limit value of DMA
Nuove acquisizioni per il monitoraggio biologico delle esposizioni professionali a N,N-dimetilacetammide.
No full textLo scopo del presente lavoro è quello di riportare i
primi dati sull’acido S-acetamido-metilmercapturico (AMMA), che abbiamo recentemente identificato come un importante metabolita urinario della N,N-dimetilacetammide (DMA). Tale solvente è ampiamente utilizzato nell’industria per la preparazione di fibre sintetiche di tipo acrilico. Per il monitoraggio biologico delle esposizioni a DMA si ricorre comunemente all’analisi della N-metilacetammide in campioni di urine raccolti al termine del turno di lavoro. In un gruppo di lavoratori sono stati raccolti campioni biologici all’inizio e alla fine di vari giorni di lavoro per valutare la cinetica di escrezione del nuovo metabolita. Nelle condizioni studiate l’AMMA ha presentato una emivita urinaria di circa 35 ore che è molto più lunga di quella della N-metilacetammide e potrebbe permettere di valutare esposizioni a DMA di più giorni consecutivi (forse settimanali)
Biological monitoring of occupational exposure to N,N-dimethylacetamide with identification of a new metabolite.
No full textInterethnic differences at the thermometric response to cold test: functional disorders of blood circulation in hand fingers and exposure to hand-arm vibration.
No full textOBJECTIVES:
To report some notable aspects regarding thermometric response to cold test in black African subjects compared with Caucasians: both groups comprised persons exposed to hand-arm vibration and controls.
METHODS:
An overall sample of 48 workers was examined in order to study their blood circulation in hand fingers: a control group of 12 healthy Caucasian workers never exposed before to hand-arm vibration; 12 Caucasian workers exposed for several years to vibrating tools and affected by occupational Raynaud's phenomenon; 12 healthy black African workers exposed to hand-arm vibration for almost 3 years; and 12 healthy black African workers never exposed to hand-arm vibration. Computerized skin thermometry was performed and thermometric curves were analyzed according to thermometric interpretation criteria such as the area-over-curve (AOC), the fifth minute of recovery/baseline temperature ratio (5REC/BT) and the temperature at the tenth minute of recovery (10REC) after cold tes
Biological monitoring of occupational exposure to acrylonitrile
No full textAcrylonitrile (ACN) is a solvent widely used in industry especially as raw material in the manufacturing of acrylic fibres, clothes and domestic furniture. It is also used in manufacturing of resins (ACN-butadiene-styrene...) and for production of nitrilic elastomers. Some researchers proposed the biological monitoring of occupational exposure to ACN by measuring the solvent in the urine, but results were widely spread especially in relation to the analytical method used. This article reports the main aspects that can reduce the variability of results. We checked several ACN solutions in water and urine after heating at 90 degrees C for 1, 3, 5, 8 and 16 hours. Water solutions maintained their ACN concentration in all the checked conditions, while urine concentrations of ACN in urine deceased during the conditioning time until 80% of their initial concentration. The analysis of ACN in urine provided by workers potentially exposed to ACN and by control subjects gave median results of 1.9 and 2.0 micrograms/g creat, without any statistical difference. The results split in relation to the smoking habit showed a statistic difference: the median values of ACN were 1.7 and 4.7 micrograms/g creat, respectively among the 175 non-smokers and 57 smokers
Analysis of benzene, toluene, ethylbenzene and m-xylene in biological samples from the general population
No full textComparison of breath, blood and urine concentrations in the biomonitoring of environmental exposure to 1,3-butadiene, 2,5-dimethylfuran, and benzene
No full textOBJECTIVES: To investigate and compare alveolar, blood, and urine concentrations of 1,3-butadiene, 2,5 dimethylfuran, and benzene, in non-occupational exposure to these products.
METHODS: Benzene, 2,5-dimethylfuran and 1,3-butadiene were measured in the breath, blood, and urine samples of 61 subjects living in small mountain villages. All 61 were regularly employed as forestry workers. Sampling was done during the long winter-season non-working period. Samples were collected after overnight rest and analysed by headspace and GC-mass spectrometry methods
Comparison of breath, blood and urine in biomonitoring of environmental exposure to 1,3-butadiene, 2,5-dimethylfuran and benzene.
No full textIl monitoraggio biologico del cobalto quale metodo di misura per esposizioni professionali ed ambientali dicirca 4 mesi
No full textDati sulla cinetica del Co nel sangue in un gruppo di 32 lavoratori esposti attraverso il monitoraggio per 16 settimane consecutive degli addotti del cobalto alla globin
- …
