Browsing by Author "Kačer, Petr"

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    Deep Airway Inflammation and Respiratory Disorders in Nanocomposite Workers
    (MDPI, 2019-09-16) Pelclová, Daniela; Ždímal, Vladimír; Komarc, Martin; Vlčková, Štěpánka; Fenclová, Zdenka; Ondráček, Jakub; Schwarz, Jaroslav; Koštejn, Martin; Kačer, Petr; Dvořáčková, Štěpánka; Popov, Alexey; Klusáčková, Pavlína; Zakharov, Sergey; Bello, Dhimiter
    Thousands of researchers and workers worldwide are employed in nanocomposites manufacturing, yet little is known about their respiratory health. Aerosol exposures were characterized using real time and integrated instruments. Aerosol mass concentration ranged from 0.120 mg/m3 to 1.840 mg/m3 during nanocomposite machining processes; median particle number concentration ranged from 4.8 × 104 to 5.4 × 105 particles/cm3 . The proportion of nanoparticles varied by process from 40 to 95%. Twenty employees, working in nanocomposite materials research were examined pre-shift and post-shift using spirometry and fractional exhaled nitric oxide (FeNO) in parallel with 21 controls. Pro-inflammatory leukotrienes (LT) type B4, C4, D4, and E4; tumor necrosis factor (TNF); interleukins; and anti-inflammatory lipoxins (LXA4 and LXB4) were analyzed in their exhaled breath condensate (EBC). Chronic bronchitis was present in 20% of researchers, but not in controls. A significant decrease in forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) was found in researchers post-shift (p < 0.05). Post-shift EBC samples were higher for TNF (p < 0.001), LTB4 (p < 0.001), and LTE4 (p < 0.01) compared with controls. Nanocomposites production was associated with LTB4 (p < 0.001), LTE4 (p < 0.05), and TNF (p < 0.001), in addition to pre-shift LTD4 and LXB4 (both p < 0.05). Spirometry documented minor, but significant, post-shift lung impairment. TNF and LTB4 were the most robust markers of biological effects. Proper ventilation and respiratory protection are required during nanocomposites processing.
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    Markers of Oxidative Stress in the Exhaled Breath Condensate of Workers Handling Nanocomposites
    (MDPI, 2019-08-10) Pelclová, Daniela; Ždímal, Vladimír; Schwarz, Jaroslav; Dvořáčková, Štěpánka; Komarc, Martin; Ondráček, Jakub; Koštejn, Martin; Kačer, Petr; Vlčková, Štěpánka; Fenclová, Zdenka; Popov, Alexey; Lischková, Lucie; Zakharov, Sergey; Bello, Dhimiter
    Researchers in nanocomposite processing may inhale a variety of chemical agents, including nanoparticles. This study investigated airway oxidative stress status in the exhaled breath condensate (EBC). Nineteen employees (42.4 ± 11.4 y/o), working in nanocomposites research for 18.0 ± 10.3 years were examined pre-shift and post-shift on a random workday, together with nineteen controls (45.5 ± 11.7 y/o). Panels of oxidative stress biomarkers derived from lipids, nucleic acids, and proteins were analyzed in the EBC. Aerosol exposures were monitored during three major nanoparticle generation operations: smelting and welding (workshop 1) and nanocomposite machining (workshop 2) using a suite of real-time and integrated instruments. Mass concentrations during these operations were 0.120, 1.840, and 0.804 mg/m3 , respectively. Median particle number concentrations were 4.8 × 104 , 1.3 × 105 , and 5.4 × 105 particles/cm3 , respectively. Nanoparticles accounted for 95, 40, and 61%, respectively, with prevailing Fe and Mn. All markers of nucleic acid and protein oxidation, malondialdehyde, and aldehydes C6–C13 were elevated, already in the pre-shift samples relative to controls in both workshops. Significant post-shift elevations were documented in lipid oxidation markers. Significant associations were found between working in nanocomposite synthesis and EBC biomarkers. More research is needed to understand the contribution of nanoparticles from nanocomposite processing in inducing oxidative stress, relative to other co-exposures generated during welding, smelting, and secondary oxidation processes, in these workshops.