Characterization of particle exposure in ferrochromium and stainless steel production.

This study describes workers' exposure to fine and ultrafine particles in the production chain of ferrochromium and stainless steel during sintering, ferrochromium smelting, stainless steel melting, and hot and cold rolling operations. Workers' personal exposure to inhalable dust was assessed using IOM sampler with a cellulose acetate filter (AAWP, diameter 25 mm; Millipore, Bedford, MA). Filter sampling methods were used to measure particle mass concentrations in fixed locations. Particle number concentrations and size distributions were examined using an SMPS+C sequential mobile particle sizer and counter (series 5.400, Grimm Aerosol Technik, Ainring, Germany), and a hand-held condensation particle counter (CPC, model 3007, TSI Incorporated, MN). The structure and elemental composition of particles were analyzed using TEM-EDXA (TEM: JEM-1220, JEOL, Tokyo, Japan; EDXA: Noran System Six, Thermo Fisher Scientific Inc., Madison,WI). Workers' personal exposure to inhalable dust averaged 1.87, 1.40, 2.34, 0.30, and 0.17 mg m(-3) in sintering plant, ferrochromium smelter, stainless steel melting shop, hot rolling mill, and the cold rolling mill, respectively. Particle number concentrations measured using SMPS+C varied from 58 × 10(3) to 662 × 10(3) cm(-3) in the production areas, whereas concentrations measured using SMPS+C and CPC3007 in control rooms ranged from 24 × 10(3) to 243 × 10(3) cm(-3) and 5.1 × 10(3) to 97 × 10(3) cm(-3), respectively. The elemental composition and the structure of particles in different production phases varied. In the cold-rolling mill non-process particles were abundant. In other sites, chromium and iron originating from ore and recycled steel scrap were the most common elements in the particles studied. Particle mass concentrations were at the same level as that reported earlier. However, particle number measurements showed a high amount of ultrafine particles, especially in sintering, alloy smelting and melting, and tapping operations. Particle number concentration and size distribution measurements provide important information regarding exposure to ultrafine particles, which cannot be seen in particle mass measurements.

Systemic inflammatory responses following welding inhalation challenge test.

AIM: The aim of this study was to investigate inflammatory and respiratory responses to welding fume exposure in patients with suspected occupational asthma. METHODS: Sixteen patients referred to the Finnish Institute of Occupational Health underwent mild steel (MS) and stainless steel (SS) welding challenge tests, due to suspicion of OA. Platelet count, leucocytes and their differential count, hemoglobin, sensitive CRP, lipids, glucose and fibrinogen were analyzed in addition to interleukin (IL)-1ß, IL-6, IL-8, TNF-α, endothelin-1, and E-selectin in plasma samples. Peak expiratory flow (PEF), forced expiratory volume in 1 min (FEV1) and exhaled nitric oxide (NO) measurements were performed before and after the challenge test. Personal particle exposure was assessed using IOM and a mini sampler. Particle size distribution was measured by an Electric Low Pressure Impactor (ELPI). RESULTS: The number of leukocytes, neutrophils, and platelets increased significantly, and the hemoglobin level and number of erythrocytes decreased significantly after both the MS and SS exposure tests. Five of the patients were diagnosed with OA, and their maximum fall in FEV1 values was 0.70 l (±0.32) 4 h after SS exposure. MS welding generated an average inhalable particle mass concentration of 31.6, and SS welding of 40.2 mg/m3. The mean particle concentration measured inside the welding face shields by the mini sampler was 30.2 mg/m3 and 41.7 mg/m3, respectively. CONCLUSIONS: Exposure to MS and SS welding fume resulted in a mild systemic inflammatory response. The particle concentration from the breathing zones correlated with the measurements inside the welding face shields.

Inflammatory response to acute exposure to welding fumes during the working day.

OBJECTIVES: To investigate cardiorespiratory and inflammatory responses in male workers following exposure to welding fumes and airborne particles in actual workplace conditions. MATERIALS AND METHODS: We measured blood leukocytes and their differential counts, platelet count, hemoglobin, sensitive C-reactive protein, fibrinogen, E-selectin, IL-(interleukin)1ß, IL-6, IL-8, tumor necrosis factor alpha (TNF-α) and endothelin-1 in blood samples of twenty workers before and after their working day. We also studied peak expiratory flow (PEF), forced expiratory volume in one second (FEV1), and exhaled nitric oxide (NO). We assessed heart rate variability (HRV) by obtaining 24-hour ambulatory electrocardiograms. RESULTS: The total blood leukocytes and neutrophils increased after the work shift, whereas IL-1ß and E-selectin decreased significantly. There were no statistically significant changes in exhaled NO, FEV1, PEF or HRV. CONCLUSION: Occupational exposure to welding fumes and particles caused a slight, acute inflammatory effect estimated based on the increased values of leukocytes and neutrophils in blood and a decrease in the interleukin 1ß and E-selectin values, but no changes in the pulmonary function (exhaled NO, FEV1, PEF) or HRV during the working day were observed.

Occupational respiratory and skin diseases among Finnish machinists: findings of a large clinical study.

PURPOSE: Machinists are exposed to many sensitizing and irritant substances, but no previous study has assessed the occurrence of clinically verified occupational diseases in an unselected large workforce of machinists. Our aim was to study the occurrence of clinically verified occupational respiratory and skin diseases cross-sectionally in a large sample of machinists in southern Finland. METHODS: A computer-assisted telephone interview on occupational exposures and health was carried out in a sample of 961 machining workers from 64 metalworking companies. Of these, 757 (79%) answered the interview. A total of 245 subjects reported work-related respiratory or skin symptoms and were invited to clinical examinations; 138 of these underwent a clinical interview and examination by an occupational health physician. On the basis of this examination, 32 subjects were further examined at the Finnish Institute of Occupational Health (FIOH) for occupational skin or respiratory diseases. RESULTS: One case of occupational asthma (OA) and seven cases of occupational dermatoses (OD) were diagnosed, giving a prevalence of 0.13% (95% CI 0-0.39) for OA, and 0.92% (95% CI 0.24-1.16) for OD. The OA was induced by the patient's own MWF. Additional five cases of newly diagnosed non-occupational asthma (0.79%, 95% CI = 0.16-1.42) were detected. No cases of occupational rhinitis or COPD were diagnosed. The dermatoses diagnoses consisted of four cases of allergic contact dermatitis and three cases of irritant contact dermatitis. The most common causes of the ODs were MWFs. CONCLUSION: This large clinical study of machinists representing metalworking in South Finland showed a prevalence of 0.13% of OA and 0.92% of OD. This relatively low occurrence of occupational diseases may reflect the strict Finnish criteria for the diagnosis of these occupational diseases and the relatively good level of occupational hygiene in machining workshops in Finland. Reported respiratory and skin symptoms were common, and these milder conditions may be linked to irritant rather than sensitizing exposures.

Exposure to CeO(2) nanoparticles during flame spray process.

The use of nanotechnology in different fields is increasing rapidly. Engineered nanoparticles (ENPs) may have adverse effect on human health, but little is known about the exposure levels of ENPs at occupational settings. In this study, exposure levels of cerium oxide (CeO(2)) ENPs were measured during enclosed flame spray process used for coating and surface modification of materials. Particle number concentration, mass concentration, and morphology and composition of the ENPs were studied. The average particle number concentration varied from 4.7·10(3) to 2.1·10(5) 1/cm(3) inside the enclosure, and from 4.6·10(3) to 1.4·10(4) 1/cm(3) outside the enclosure. The average mass concentrations inside and outside the enclosure were 320 and 66 µg/m(3), respectively. A batch-type process caused significant variation in the concentrations, especially inside the enclosure. CeO(2) ENPs were mainly chainlike aggregates, consisting of spherical 20-40 nm primary particles having crystalline structure. In conclusion, enclosure of the process with efficient ventilation seemed to be an effective means to reduce the exposure to CeO(2) ENPs as expected.

Micronuclei, hemoglobin adducts and respiratory tract irritation in mice after inhalation of toluene diisocyanate (TDI) and 4,4'-methylenediphenyl diisocyanate (MDI).

Toluene diisocyanate (TDI) and 4,4'-methylenediphenyl diisocyanate (MDI), used in the production of polyurethane foam, are well known for their irritating and sensitizing properties. Contradictory results have been obtained on their genotoxicity. We investigated the genotoxicity and protein binding of inhaled TDI and MDI in mice by examining micronucleated polychromatic erythrocytes (PCEs) in bone marrow and peripheral blood and TDI- and MDI-derived adducts in hemoglobin. Male C57Bl/6J mice (8 per group) were exposed head-only to TDI vapour (mean concentrations 1.1, 1.5, and 2.4mg/m(3); the mixture of isomers contained, on the average, 63% 2,4-TDI and 37% 2,6-TDI) or MDI aerosol (mean concentrations 10.7, 20.9 and 23.3mg/m(3)), during 1h/day for 5 consecutive days. Bone marrow and peripheral blood were collected 24h after the last exposure. Inhalation of TDI caused sensory irritation (SI) in the upper respiratory tract, and cumulative effects were observed at the highest exposure level. Inhalation of MDI produced SI and airflow limitation, and influx of inflammatory cells into the lungs. Hemoglobin adducts detected in the exposed mice resulted from direct binding to globin of 2,4- and 2,6-TDI and MDI, and dose-dependent increases were observed especially for 2,4-TDI-derived adducts. Adducts originating from the diamines of TDI (toluene diamine) or MDI (methylene dianiline) were not observed. No significant increase in the frequency of micronucleated PCEs was detected in the bone marrow or peripheral blood of the mice exposed to TDI or MDI. The ratio of PCEs and normochromatic erythrocytes (NCEs) was reduced at the highest concentration of MDI, and a slight reduction of the PCE/NCE ratio, dependent on cumulative inhaled dose, was also seen with TDI. Our results indicate that inhalation of TDI or MDI (1h/day for 5 days), at levels that induce toxic effects and formation of TDI- or MDI-specific adducts in hemoglobin, does not have detectable genotoxic effects in mice, as studied with the micronucleus assay.

Cytotoxicity and genotoxicity in vitro and irritation potency in vivo of two red phosphorus-based pyrotechnic smokes.

Two red phosphorus (RP)-based smokes (P60 and RPB), differing from each other mainly in RP content and in type of additive, were evaluated for in vitro cytotoxicity (cell viability by the trypan-blue exclusion method) and genotoxicity (comet assay) by exposing BEAS 2B human bronchial epithelial cells to the smokes in a laboratory-scale chamber for 5 min. The irritation potency of RPB smoke was studied in mice. A hexachloroethane-based smoke (HC/Zn/TNT) was used as a reference in the studies. A 5-min exposure of BEAS 2B cells to P60 smoke (1.1, 2.2 and 4.4 g/m(3), measured as H(3)PO(4)) did not induce any cytotoxic effects, while RPB smoke (1.3, 2.6 and 5.1g/m(3), measured as H(3)PO(4)) caused a mild decrease in cell viability at higher concentrations, without a clear dose-dependent effect. Neither of the RP smokes showed a genotoxic response in the comet assay with BEAS 2B cells, while HC/Zn/TNT was clearly genotoxic (0.9-3.5 g/m(3) as ZnCl(2)). In the mouse bioassay, head-only exposure to RPB smoke (20-450 mg/m(3) for 30 min as a single exposure, or 65-90 and 25-110 mg/m(3) - measured as H(3)PO(4) - for 30 min/day during 5 days) caused a concentration-dependent sensory irritation, which was evident as a decrease in respiratory rate and an increase in time-of-pause after inspiration, in a similar manner as with HC/Zn/TNT smoke. The concentration that caused a 50% decrease in respiratory frequency (RD(max)50) was calculated to be 1140 mg/m(3) for the RPB smoke and 145 mg/m(3) for the HC/Zn/TNT smoke. No pulmonary irritation was observed.

Respiratory symptoms and conditions related to occupational exposures in machine shops.

OBJECTIVES: Since there are few data on the effects of metalworking in populations representing a variety of metal companies or on dose-response relationships concerning metalworking, this study investigated the relationship between occupational exposures in machine shops and the occurrence of upper and lower respiratory symptoms, asthma, and chronic bronchitis. METHODS: A cross-sectional study of 726 male machine workers and 84 male office workers from 64 companies was conducted in southern Finland. All of the participants filled out a questionnaire, and aerosol measurements were performed in 57 companies. RESULTS: Exposure to metalworking fluids (MWF) showed a greater risk [odds ratio (OR)>or=2) for upper-airway symptoms, cough, breathlessness, and current asthma than exposures in office work did. Exposure to aerosol levels above the median (>or=0.17 mg/m3 in the general workshop air) was related to an increased risk (OR>or=2) of nasal and throat symptoms, cough, wheezing, breathlessness, chronic bronchitis, and current asthma. Machine workers with a job history of >or=15 years experienced increased throat symptoms, cough, and chronic bronchitis. CONCLUSIONS: This large study representing machine shops in southern Finland showed that machine workers experience increased nasal and throat symptoms, cough, wheezing, breathlessness, and asthma even in environments with exposure levels below the current occupational exposure limit for oil mists. The study suggests that improving machine shop environments could benefit the health of this workforce. It also suggests that it is time to consider reducing the current Finnish occupational exposure limit for oil mist or introducing the use of other health-relevant indicators of exposure.