Publications by authors named "Otakar Makeš"

5 Publications

  • Page 1 of 1

Single Usage of a Kitchen Degreaser Can Alter Indoor Aerosol Composition for Days.

Environ Sci Technol 2017 Jun 10;51(11):5907-5912. Epub 2017 May 10.

Institute of Chemical Process Fundamentals of the CAS , Prague CZ-165 02, Czech Republic.

To the best of our knowledge, this study represents the first observation of multiday persistence of an indoor aerosol transformation linked to a kitchen degreaser containing monoethanol amine (MEA). MEA remaining on the cleaned surfaces and on a wiping paper towel in a trash can was able to transform ammonium sulfate and ammonium nitrate into (MEA)SO and (MEA)NO. This influence persisted for at least 60 h despite a high average ventilation rate. The influence was observed using both offline (filters, impactors, and ion chromatography analysis) and online (compact time-of-flight aerosol mass spectrometer) techniques. Substitution of ammonia in ammonium salts was observed not only in aerosol but also in particles deposited on a filter before the release of MEA. The similar influence of other amines is expected based on literature data. This influence represents a new pathway for MEA exposure of people in an indoor environment. The stabilizing effect on indoor nitrate also causes higher indoor exposure to fine nitrates.
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http://dx.doi.org/10.1021/acs.est.6b06050DOI Listing
June 2017

Markers of nucleic acids and proteins oxidation among office workers exposed to air pollutants including (nano)TiO2 particles.

Neuro Endocrinol Lett 2016 Dec;37(Suppl1):13-16

Charles University and General University Hospital in Prague, 1st Faculty of Medicine, Department of Occupational Medicine, Prague, Czech Republic.

Objectives: Experimental studies using nanoscale TiO2 have documented lung injury, inflammation, oxidative stress, and genotoxicity. Human health data are extremely scarce.

Methods: In exhaled breath condensate (EBC) and urine of 22 office employees occupationally exposed to TiO2 during their visit in the production workshops for average 14±9 min/day a panel of biomarkers of nucleic acids and proteins oxidation was studied, specifically 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-hydroxymethyl uracil (5-OHMeU), o-tyrosine (o-Tyr), 3-chlorotyrosine (3-ClTyr), and 3-nitrotyrosine (3-NOTyr). Examination was performed also in 14 comparable controls.

Results: The median respirable TiO2 mass concentration in the workshops was 0.40 mg/m3, median number concentration was 2.32×104 particles/cm3 with 80% of the particles being <100 nm in diameter. All 6 markers of oxidation were elevated in EBC in factory office employees relative to controls (p<0.01). Significant association was found between their job in TiO2 production plant and 5 markers of oxidation (except 3-NOTyr) in the EBC in multivariate analysis. No elevation of markers was detected in the urine.

Conclusion: This pilot study suggests that even short nanoTiO2 exposure may lead to pulmonary oxidative stress; however this effect may be short-term and reversible. The clinical significance of these findings is unclear and more studies are needed.
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December 2016

Markers of lipid oxidative damage in the exhaled breath condensate of nano TiO production workers.

Nanotoxicology 2017 02 9;11(1):52-63. Epub 2016 Dec 9.

h UMass Lowell, Department of Public Health , College of Health Sciences , Lowell, MA , USA.

Nanoscale titanium dioxide (nanoTiO) is a commercially important nanomaterial. Animal studies have documented lung injury and inflammation, oxidative stress, cytotoxicity and genotoxicity. Yet, human health data are scarce and quantitative risk assessments and biomonitoring of exposure are lacking. NanoTiO is classified by IARC as a group 2B, possible human carcinogen. In our earlier studies we documented an increase in markers of inflammation, as well as DNA and protein oxidative damage, in exhaled breath condensate (EBC) of workers exposed nanoTiO. This study focuses on biomarkers of lipid oxidation. Several established lipid oxidative markers (malondialdehyde, 4-hydroxy-trans-hexenal, 4-hydroxy-trans-nonenal, 8-isoProstaglandin F2α and aldehydes C-C) were studied in EBC and urine of 34 workers and 45 comparable controls. The median particle number concentration in the production line ranged from 1.98 × 10 to 2.32 × 10 particles/cm with ∼80% of the particles <100 nm in diameter. Mass concentration varied between 0.40 and 0.65 mg/m. All 11 markers of lipid oxidation were elevated in production workers relative to the controls (p < 0.001). A significant dose-dependent association was found between exposure to TiO and markers of lipid oxidation in the EBC. These markers were not elevated in the urine samples. Lipid oxidation in the EBC of workers exposed to (nano)TiO complements our earlier findings on DNA and protein damage. These results are consistent with the oxidative stress hypothesis and suggest lung injury at the molecular level. Further studies should focus on clinical markers of potential disease progression. EBC has reemerged as a sensitive technique for noninvasive monitoring of workers exposed to engineered nanoparticles.
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http://dx.doi.org/10.1080/17435390.2016.1262921DOI Listing
February 2017

Markers of lipid oxidative damage among office workers exposed intermittently to air pollutants including nanoTiO2 particles.

Rev Environ Health 2017 Mar;32(1-2):193-200

Nanoscale titanium dioxide (nanoTiO2) is a commercially important nanomaterial used in numerous applications. Experimental studies with nanotitania have documented lung injury and inflammation, oxidative stress, and genotoxicity. Production workers in TiO2 manufacturing with a high proportion of nanoparticles and a mixture of other air pollutants, such as gases and organic aerosols, had increased markers of oxidative stress, including DNA and protein damage, as well as lipid peroxidation in their exhaled breath condensate (EBC) compared to unexposed controls. Office workers were observed to get intermittent exposures to nanoTiO2 during their process monitoring. The aim of this study was to investigate the impact of such short-term exposures on the markers of health effects in office workers relative to production workers from the same factory. Twenty-two office employees were examined. They were occupationally exposed to (nano)TiO2 aerosol during their daily visits of the production area for an average of 14±9 min/day. Median particle number concentration in office workers while in the production area was 2.32×104/cm3. About 80% of the particles were <100 nm in diameter. A panel of biomarkers of lipid oxidation, specifically malondialdehyde (MDA), 4-hydroxy-trans-hexenal (HHE), 4-hydroxy-trans-nonenal (HNE), 8-isoprostaglandin F2α (8-isoprostane), and aldehydes C6-C12, were studied in the EBC and urine of office workers and 14 unexposed controls. Nine markers of lipid oxidation were elevated in the EBC of office employees relative to controls (p<0.05); only 8-isoprostane and C11 were not increased. Significant association was found in the multivariate analysis between their employment in the TiO2 production plant and EBC markers of lipid oxidation. No association was seen with age, lifestyle factors, or environmental air contamination. The EBC markers in office employees reached about 50% of the levels measured in production workers, and the difference between production workers and office employees was highly significant (p<0.001). None of these biomarkers were elevated in urine. The approach presented here seems to be very sensitive and useful for non-invasive monitoring of employees exposed to air pollutants, including gases, organic aerosols, and nanoTiO2, and may prove useful for routine biomonitoring purposes. Among them, aldehydes C6, C8, C9, and C10 appear to be the most sensitive markers of lipid oxidation in similar occupational cohorts. One major challenge with sensitive biomonitoring techniques, however, is their non-specificity and difficulty in interpreting the meaning of their physiological values in the context of chronic disease development and damage-repair kinetics.
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http://dx.doi.org/10.1515/reveh-2016-0030DOI Listing
March 2017

Leukotrienes in exhaled breath condensate and fractional exhaled nitric oxide in workers exposed to TiO2 nanoparticles.

J Breath Res 2016 06 30;10(3):036004. Epub 2016 Jun 30.

Department of Occupational Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Na Bojišti 1, 128 00 Prague 2, Czech Republic.

Human health data regarding exposure to nanoparticles are extremely scarce and biomonitoring of exposure is lacking in spite of rodent pathological experimental data. Potential markers of the health-effects of engineered nanoparticles were examined in 30 workers exposed to TiO2 aerosol, 22 office employees of the same plant, and 45 unexposed controls. Leukotrienes (LT) B4, C4, E4, and D4 were analysed in the exhaled breath condensate (EBC) and urine via liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Fractional exhaled nitric oxide (FeNO) and spirometry was also measured. The median particle number concentration of the aerosol in the production ranged from 1.98  ×  10(4) to 2.32  ×  10(4) particles cm(-3); about 80% of the particles were  <100 nm in diameter. Median total mass concentration varied between 0.4 and 0.65 mg m(-3). All LT levels in workers' EBC were elevated relative to the controls (p  <  0.01). LTs in the EBC sample were correlated with titanium levels. Urinary LTs were not elevated in the workers and office employees. Office workers had higher LTB4 in EBC (p  <  0.05), and higher levels of FeNO (p  <  0.01). FeNO was higher in office employees with allergic diseases and was negatively correlated with smoking (p  <  0.01). In spirometry significant impairment in the workers was seen only for %VCIN and %PEF (both p  <  0.01). Multiple regression analysis confirmed a significant association between production of TiO2 and all cysteinyl LTs in EBC (p  <  0.01) and impaired %VCIN and %PEF (both p  <  0.01). LTB4 was also associated with smoking (p  <  0.01). LT levels complemented our earlier findings of DNA, protein, and lipid damage in the EBC of workers with nanoTiO2 exposures. Cysteinyl LTs in EBC analysis suggest inflammation and potential fibrotic changes in the lungs; they may be helpful for monitoring the biological effect of (nano)TiO2 on workers. Spirometry was not sensitive enough.
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http://dx.doi.org/10.1088/1752-7155/10/3/036004DOI Listing
June 2016