Dust ; analysis ; prevention & control ; Inhalation Exposure ; prevention & control ; Nanoparticles ; Occupational Exposure ; prevention & control ; Workplace

OBJECTIVETo evaluate the protective performance of N95 filtering-facepiece respirators (FFRs) used widely in China and to investigate participants' subjective evaluation about them.

METHODSFour models (A1, A2, B1, B2) of N95 FFRs from two manufactures were chosen to measure the filter penetration and inhalation resistance. Inward leakage was measured by Condensation Nuclei Counting method (CNC) in 50 participants selected using the Chinese respirator fit test panel. Each participant was asked subjective feelings after wearing a respirator by questionnaire survey.

RESULTSThe filter penetration and inhalation resistance of four FFRs complied with national standard (GB 2626-2006). The geometric mean fit factors (GMFFs) for four models were 20.9, 14.6, 74.0, 49.1 and there passing rates were 4%, 4%, 42%, 10%. All of four models had bad seal performance, especially the passing rate of A1 and A2 were lower than 10%. The self-feelings about the resistance for FFRs had no significant difference (P > 0.05). The results indicated that B (B1 and B2) has a better fit than A (A1 and A2) according to participants' subject evaluation (P < 0.05). The folding style respirator (B2) was significant more comfortable than the cup style respirator (B1). The subjective feeling of respirators leakage by participant was poor consistent with objective inward leakage test. The kappa index was 0.067 (95%CI: -0.029∼0.163, P = 0.18) and the consistent rate was 50%.

CONCLUSIONThe poor seal performance was the biggest problem of N95 FFRs in Chinese market. Respirators should be resigned or improved rely on Chinese facial features. Dust workers should choice a fit respirator according to the result of objective leakage test rather than subjective feeling of leakage.

Adult ; Female ; Humans ; Inhalation Exposure ; prevention & control ; Male ; Materials Testing ; methods ; Occupational Exposure ; prevention & control ; Respiratory Protective Devices ; Young Adult

OBJECTIVETo investigate the fit of self-inhalation air-purifying dust respirator for Chinese workers, to improve the respirators according to Chinese facial features and to evaluate the protective effects of improved respirators.

METHODSTwo types of self-inhalation air-purifying dust respirators (cup respirators A1 and folding respirators B1) were tested by Condensation Nuclei Counting method (CNC) in 25 representative subjects (15 males and 10 females). According to the Chinese facial features and fit factors, A1 and B1 respirators were improved. The fit tests were performed for the improved A1 and B1 respirators.

RESULTSThe fit factors ≥ 100 served as the qualified standard of self-inhalation air-purifying dust respirators. The qualified rate for cup respirator A1 was 0.0%. Its geometric mean fit factor was 20.7 (6.9 ∼ 46.9). The qualified rate for cup respirator B1 was 4.0%. Its geometric mean fit factor was 26.0 (6.8 ∼ 154.9). After improvement, the qualified rates and fit factors significantly increased. The qualified rate for cup respirator A2 was 72.0% and geometric mean fit factor was 223.5 (2.2 ∼ 5932.7). There were significantly differences between respirator A1 and A2 (χ(2) = 25.09, P < 0.05). The qualified rate for cup respirator B2 was 88.0 % and geometric mean fit factor was 429.8 (41.5 ∼ 3692.9). The significant differences (χ(2) = 32.21, P < 0.05) between B1 and B2 were found.

CONCLUSIONTo ensure the protective effects, the self-inhalation air-purifying dust respirators were designed according to Chinese facial features. The respirator fit test must be conducted when workers choose respirators.

Equipment Design ; Female ; Humans ; Inhalation Exposure ; prevention & control ; Male ; Materials Testing ; Occupational Exposure ; prevention & control ; Respiratory Protective Devices

OBJECTIVETo investigate the fitness characteristics of self-inhalation air-purifying dust respirators for representative subjects and to explore the influencing factors on fitness characteristics of respirators.

METHODSAccording to the Chinese new bivariate fit test panel, 50 representative subjects were studied for using 2 kinds of self-inhalation air-purifying dust respirators. The N95 Companion from TSI was used to test the Fit factor (FF), and five representative facial dimensions (face width, bigonial breadth, nasal root breadth, face length and nose protrusion) were measured. Then chi-square test was used to compare the qualified rates of 2 kinds of respirators. The t-test was utilized to analyze the differences of facial dimensions between qualified samples and unqualified samples. Multiple linear regression models were also established to analyze the effects of facial dimensions on FF.

RESULTSThe qualified rate (86%) of folding respirators was significantly higher than that (68%) of cup respirators (P < 0.05). There were no significant differences of facial dimensions between qualified subjects and unqualified subjects for folding respirators. However, the face width, bigonial breadth and face length of qualified subjects were significantly larger than those of unqualified subjects for cup respirators (P < 0.01). The regression coefficient (0.31846) demonstrated that the positive effects of face length on mean log-transformed fit factor (MLFF) for all subjects with cup respirators (P < 0.05).

CONCLUSIONThere were significant effects of respirator styles and head-face dimensions on the respirator fitness. There was a significant correlation between the respirator fitness and the facial dimensions for cup respirators.

Adult ; Equipment Design ; Face ; anatomy & histology ; Female ; Head ; anatomy & histology ; Humans ; Inhalation Exposure ; prevention & control ; Male ; Materials Testing ; Occupational Exposure ; prevention & control ; Respiratory Protective Devices

Recently, the special characteristics of work with SARS require particular attention to the facilities, equipment, policies and procedures involved. In fact, an autopsy also subject prosectors and others to a wide variety of hazards, including bloodborne, aerosolized pathogens and others (for example SARS). Forensic pathologists and other persons in close proximity to an autopsy need personal protective equipment, fourthemore, laboratory procedure and facility design principles of biosafety should be established for the protection of all personnal involved in the work.
Autopsy ; Forensic Pathology ; Humans ; Infection Control/methods* ; Inhalation Exposure/prevention & control* ; Masks/standards* ; Occupational Exposure/prevention & control* ; Protective Clothing/standards* ; Protective Devices/standards* ; Risk Factors ; Severe Acute Respiratory Syndrome/transmission*

OBJECTIVETo investigate the pharmacological effect of Nyctanthes arbortristis (NAT) leaf extract in the prevention of lung injury induced by silica particles.

METHODLung injury was induced in Swiss mice through inhalation exposure to silica particles (< 5 mu) using a Flow Past Nose Only Inhalation Chamber at the rate of -10 mg/m3 respirable mass for 5 h. Lung bronchoalveolar lavage (BAL) fluid collected between 48 and 72 h was subjected to protein profiling by electrophoresis and cytokine evaluation by solid phase sandwich ELISA. Lung histopathology was performed to evaluate lung injury.

RESULTSInhalation of silica increased the level of tumor necrosis factor-alpha (TNF-alpha), and of the 66 and 63 kDa peptides in the BAL fluid in comparison to sham-treated control. Pre-treatment of silica exposed mice with NAT leaf extract significantly prevented the accumulation of TNF-alpha in the BAL fluid, but the 66 and 63 kDa peptides remained unchanged. The extract was also effective in the prevention of silica-induced early fibrogenic reactions like congestion, edema and infiltration of nucleated cells in the interstitial alveolar spaces, and thickening of alveolar septa in mouse lung.

CONCLUSIONNAT leaf extract helps in bypassing silica induced initial lung injury in mice.

Administration, Oral ; Animals ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Inhalation Exposure ; Male ; Mice ; Oleaceae ; chemistry ; Phytotherapy ; Plant Extracts ; pharmacology ; Pulmonary Fibrosis ; etiology ; prevention & control ; veterinary ; Silicon Dioxide ; adverse effects ; Silicosis ; prevention & control ; veterinary

BACKGROUND/AIMS: Ozone is an environmentally reactive oxidant, and pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have antioxidant activity. We investigated the effects of pycnogenol on reactive nitrogen species, antioxidant responses, and airway responsiveness in BALB/c mice exposed to ozone. METHODS: Antioxidant levels were determined using high performance liquid chromatography with electrochemical detection. Nitric oxide (NO) metabolites in bronchoalveolar lavage (BAL) fluid from BALB/c mice in filtered air and 2 ppm ozone with pycnogenol pretreatment before ozone exposure (n = 6) were quantified colorimetrically using the Griess reaction. RESULTS: Uric acid and ascorbic acid concentrations were significantly higher in BAL fluid following pretreatment with pycnogenol, whereas gamma-tocopherol concentrations were higher in the ozone exposed group but were similar in the ozone and pycnogenol pretreatment groups. Retinol and gamma-tocopherol concentrations tended to increase in the ozone exposure group but were similar in the ozone and pycnogenol pretreatment groups following ozone exposure. Malonylaldehyde concentrations increased in the ozone exposure group but were similar in the ozone and pycnogenol plus ozone groups. The nitrite and total NO metabolite concentrations in BAL fluid, which parallel the in vivo generation of NO in the airways, were significantly greater in the ozone exposed group than the group exposed to filtered air, but decreased with pycnogenol pretreatment. CONCLUSIONS: Pycnogenol may increase levels of antioxidant enzymes and decrease levels of nitrogen species, suggesting that antioxidants minimize the effects of acute ozone exposure via a protective mechanism.
Animals ; Antioxidants/*pharmacology ; Ascorbic Acid/metabolism ; Bronchial Hyperreactivity/chemically induced/metabolism/*prevention & control ; Bronchoalveolar Lavage Fluid/chemistry ; Bronchoconstriction/drug effects ; Disease Models, Animal ; Female ; Flavonoids/*pharmacology ; Inhalation Exposure ; Lung/*drug effects/enzymology/physiopathology ; Malondialdehyde/metabolism ; Mice ; Mice, Inbred BALB C ; Nitric Oxide/metabolism ; Oxidative Stress/*drug effects ; *Ozone ; Uric Acid/metabolism ; Vitamin A/metabolism ; alpha-Tocopherol/metabolism