SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "swepub ;lar1:(umu);srt2:(2000-2004);mspu:(article);pers:(Levin Jan Olof)"

Sökning: swepub > Umeå universitet > (2000-2004) > Tidskriftsartikel > Levin Jan Olof

  • Resultat 1-10 av 19
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Axmon, Anna, et al. (författare)
  • CYP1A1 and GSTM1 polymorphisms affect urinary 1-hydroxypyrene levels after PAH exposure
  • 2000
  • Ingår i: Carcinogenesis. - : Oxford University Press. - 0143-3334 .- 1460-2180. ; 21:4, s. 669-676
  • Tidskriftsartikel (refereegranskat)abstract
    • Certain human biotransformation enzymes have been implicated in the formation and scavenging of the ultimate reactive metabolites, the diolepoxides, from polycyclic aromatic hydrocarbons (PAHs). In the present study, performed on aluminum smelter workers, we have analyzed airborne PAH, the pyrene metabolite 1-hydroxypyrene (1-OHP) in urine, and genotypes for biotransformation enzymes involved in PAH metabolism. The aim was to evaluate the correlation between external exposure and biomarkers of exposure and to investigate to what extent genetic polymorphism in metabolic enzymes can explain interindividual variation in urinary 1-OHP levels. DNA was prepared from blood samples from 98 potroom workers and 55 controls and altogether eight polymorphisms in the CYP1A1, mEH, GSTM1, GSTP1 and GSTT1 genes were analyzed. The 1-OHP excretion was found to correlate significantly (P 100-fold) and univariate and multivariate regression analyses were used to find the variables that could determine differences in excretion. The variation could, to some degree, be explained by differences in exposure to airborne particulate-associated PAHs, the use of personal respiratory protection devices, smoking habits and genetic polymorphisms in the cytochrome P450 1A1, GSTM1 and GSTT1 enzymes. The part of the variance that could be explained by differences in biotransformation genotypes seemed to be of the same order of magnitude as the variance explained by differences in exposure. In the control group as well as in the occupationally exposed group, the highest 1-OHP levels were observed in individuals carrying the CYP1A1 Ile/Val genotype who were also of the GSTM1 null genotype. The results show that urinary 1-OHP is a sensitive indicator of recent human exposure to PAHs and that it may also to some extent reflect the interindividual variation in susceptibility to PAHs.
  •  
2.
  • Sandström, K. J. Mattias, et al. (författare)
  • Amperometric biosensor for formic acid in air
  • 2000
  • Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 70:1–3, s. 182-187
  • Tidskriftsartikel (refereegranskat)abstract
    • The possibility of developing a simple, inexpensive and specific personal passive “real-time” air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD+) as a co-factor and Meldola's blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldola's blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4–15 min and the limit of detection was calculated to be below 1 mg/m3. However, the response decreased by 50% after storage at −15°C for 1 day.
  •  
3.
  • Sandström, K. J. Mattias, et al. (författare)
  • Multivariate evaluation of factors influencing the performance of a formic acid biosensor for use in air monitoring
  • 2001
  • Ingår i: The Analyst. - : Royal Society of Chemistry. - 0003-2654 .- 1364-5528. ; 126:11, s. 2008-2014
  • Tidskriftsartikel (refereegranskat)abstract
    • A formic acid biosensor for air monitoring has been evaluated using chemometric methods. Using experimental design eleven factors that could influence the performance of the biosensor were examined. The response matrices consisted of six parameters (steady state currents at three different formic acid concentrations and response rates during changes in formic acid concentrations) describing the performance of the biosensor. The data were evaluated using a combination of principal component analysis (PCA) and multiple linear regression (MLR). To confirm the conclusions from the PCA-MLR partial least squares (PLS) was also used. The most important factor for the biosensor performance was found to be the enzyme concentration. Using the information from the chemometric analyses the optimum operation conditions for the biosensor were determined. The steady state currents were increased by 18-30% and the initial two response rates increased by 47-89% compared with a biosensor that had not been optimised.
  •  
4.
  • Claeson, Anna-Sara, 1974-, et al. (författare)
  • Volatile metabolites from microorganisms grown on humid building materials and synthetic media
  • 2002
  • Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry. - 1464-0325 .- 1464-0333. ; 4:5, s. 667-672
  • Tidskriftsartikel (refereegranskat)abstract
    • Growth of different microorganisms is often related to dampness in buildings. Both fungi and bacteria produce complicated mixtures of volatile organic compounds that include hydrocarbons, alcohols, ketones, sulfur- and nitrogen-containing compounds etc. Microbially produced substances are one possible explanation of odour problems and negative health effects in buildings affected by microbial growth. A mixture of five fungi, Aspergillus versicolor, Fusarium culmorum, Penicillium chrysogenum, Ulocladium botrytis and Wallemia sebi were grown on three different humid building materials (pinewood, particle board and gypsum board) and on one synthetic medium. Six different sampling methods were used, to be able to collect both non-reactive volatile organic compounds and reactive compounds such as volatile amines, aldehydes and carboxylic acids. Analysis was performed using gas chromatography, high-performance liquid chromatography and ion chromatography, mass spectrometry was used for identification of compounds. The main microbially produced metabolites found on pinewood were ketones (e.g. 2-heptanone) and alcohols (e.g. 2-methyl-1-propanol). Some of these compounds were also found on particle board, gypsum board and the synthetic medium, but there were more differences than similarities between the materials. For example, dimethoxymethane and 1,3,5-trioxepane and some nitrogen containing compounds were found only on particle board. The metabolite production on gypsum board was very low, although some terpenes (e.g. 3-carene) could be identified as fungal metabolites. On all materials, except gypsum board, the emission of aldehydes decreased during microbial growth. No low molecular weight carboxylic acids were identified.
  •  
5.
  • Ekman, Jenny, et al. (författare)
  • Comparison of sampling methods for 1,6-hexamethylene diisocyanate, (HDI) in a commercial spray box
  • 2002
  • Ingår i: The Analyst. - : Royal Society of Chemistry. - 0003-2654 .- 1364-5528. ; 127:1, s. 169-173
  • Tidskriftsartikel (refereegranskat)abstract
    • In this study three different types of samplers for the determination of 1,6-hexamethylene diisocyanate in air were compared. The experimental set up was a simulation of real life conditions with spray painting operations performed inside a commercial, full sized, spray box. The sampling methods were 1-(2-methoxyphenyl)-piperazine impregnated on glass fibre filter, and the same reagent in impinger, and also dibutylamine in impinger. All analyses were performed by LC-MS-MS. The determined concentrations varied between 20 and 90 microg m(-3) with relative standard deviations from 7 to 17% for each method. No significant difference was found between the three methods using ANOVA with a significance level of alpha = 0.05.
  •  
6.
  • Eriksson, Kåre, et al. (författare)
  • Dermal exposure to terpenic resin acids in Swedish carpentry workshops and sawmills
  • 2004
  • Ingår i: Annals of Occupational Hygiene. - : Oxford University Press. - 0003-4878 .- 1475-3162. ; 48:3, s. 267-275
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: The aim of this study was to evaluate dermal exposure to the resin acids abietic acid, dehydroabietic acid and 7-oxodehydroabietic acid during collecting in sawmills and during sawing in carpentry workshops, respectively. METHODS: Sampling was performed by fastening patches at 12 different areas on a sampling overall, one patch on the front of a cap, one patch on the chest inside the clothing and one patch on the inner lower right leg. Exposure of the hands was assessed by fastening patches on cotton gloves representing the dorsal sides and the palms of the left and right hands. Sampling was performed on 30 different occasions in the sawmills and in the carpentry workshops with mean sampling times of 120 and 59 min, respectively. The acids were solvent desorbed from the patches. Identification and quantification of the resin acids was performed by gas chromatography-mass spectrometry. RESULTS: The geometric means (GMs) of the potential body exposures to abietic acid, dehydroabietic acid and 7-oxodehydroabietic acid during sawing and collecting of wood from pine and spruce were 3346 and 17 247 micro g/h, respectively. The GM of the potential exposure on the hands was 3020 micro g/h in the carpentry workshops and 4365 micro g/h in the sawmills. Resin acids were detected on the inner chest and inner lower front right leg, respectively. CONCLUSIONS: There is a potential dermal exposure to terpenic resin acids in carpentry workshops as well as in sawmills. The hands have the highest exposure during sawing as well as during collecting. There is a spatial distribution of contaminants, with the outer chest, arms and legs showing the highest exposures. Resin acids also contaminated the inner chest and inner lower leg. It is necessary to take action to reduce dermal exposure to these allergenic substances.
  •  
7.
  • Eriksson, Kåre, et al. (författare)
  • Quantification of melatonin in human saliva by liquid chromatography-tandem mass spectrometry using stable isotope dilution
  • 2003
  • Ingår i: Journal of chromatography. B. - : Elsevier. - 1570-0232 .- 1873-376X. ; 794:1, s. 115-123
  • Tidskriftsartikel (refereegranskat)abstract
    • A method for the determination of melatonin in human saliva has been developed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS). Saliva was collected in plastic tubes. 7-D-Melatonin was added as internal standard and the samples were cleaned and concentrated by solid-phase extraction. The limit of detection was 1.05 pg x ml(-1) and the limit of quantification was 3.0 pg x ml(-1). The accuracy of the method was +/-14% at 5.60 pg x ml(-1) and +/-9% at 19.6 pg x ml(-1). The precision was +/-13% at 6.18 pg x ml(-1) and +/-11% at 31.2 pg x ml(-1), respectively. Our HPLC-MS-MS method shows a high sensitivity and specificity for melatonin and more reliable results compared with a radioimmunoassay. The chromatographic method has been used to determine the circadian rhythm of melatonin among three nurses working the night shift and a patient suffering from an inability to fall asleep at night.
  •  
8.
  •  
9.
  • Hagenbjörk-Gustafsson, Annika, et al. (författare)
  • Validation of the Willems badge diffusive sampler for nitrogen dioxide determinations in occupational environments
  • 2002
  • Ingår i: The Analyst. - : Royal Society of Chemistry. - 0003-2654 .- 1364-5528. ; 127:1, s. 163-168
  • Tidskriftsartikel (refereegranskat)abstract
    • The Willems badge, a diffusive sampler for nitrogen dioxide, has previously been validated for ambient air measurements. This paper describes the laboratory and field validation of the Willems badge for personal sampling under working environment conditions. The mean sampling rate in the laboratory tests was 46 ml min(-1), with an RSD of 12%. No statistically significant effects on sampling rate of the sampling time, concentration of NO2 or relative humidity were found. A slightly decreased sampling rate was observed at low wind velocity. This was also confirmed during static sampling, which makes the sampler less appropriate for static sampling indoors. No back diffusion was observed. Storage of the samplers for two weeks before or after exposure did not affect the sampling rate. Our analysis is based on a modified colorimetric method, performed by FIA (flow injection analysis). This technique was compared to ion chromatography analysis. The use of ion chromatography lowered the detection limit from 11 to 2 microg m(-3) for an 8 h sample, and furthermore enabled the detection of other anions. In conclusion, the diffusive sampler was found to perform well for personal measurements in industrial environments.
  •  
10.
  • Liljelind, Ingrid E, et al. (författare)
  • Comparison of self-assessment and expert assessment of occupational exposure to chemicals
  • 2001
  • Ingår i: Scandinavian Journal of Work, Environment and Health. - : Tyoterveyslaitos, Finnish Institute of Occupational Health. - 0355-3140 .- 1795-990X. ; 27:5, s. 311-317
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES: Occupational assessments of chemical exposure are often inadequate because of difficulties in obtaining sufficient numbers of measurements by trained professionals (experts). The objective of this study was to determine whether workers can provide unbiased data via self-assessments of exposure facilitated by the use of simple passive monitors for personal sampling.METHODS: Untrained workers obtained personal measurements of their exposures to gaseous contaminants (terpenes in sawmills and styrene in reinforced plastics factories) with passive monitors and written instructions. To study the validity of the self-assessments, an occupational hygienist performed exposure measurements on the same occupational groups after the workers had obtained two or more measurements independently. The potential bias of the self-assessments was evaluated by comparing the self-assessments with the expert assessments in mixed-effects statistical models.RESULTS: A total of 153 terpene (97 self and 56 expert) and 216 styrene (159 self and 57 expert) measurements were obtained from four sawmills and six reinforced plastics factories, respectively. No significant differences in the geometric mean exposures were observed between the self-assessments and the expert assessments in 3 of 4 sawmills and 5 of 6 reinforced plastics factories (P > 0.10). The potential bias of the self-assessments of exposure ranged from less than 0.1% to 102% and was less than 17% in 9 of the 10 groups investigated.CONCLUSIONS: The results indicate that untrained, unsupervised workers are able to collect consistently unbiased exposure data by employing currently available passive monitors.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 19

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy