1.Dynamic analysis of dusts in Rush-mat industries.
Guo-bing XIAO ; Jian-yi CAI ; Cheng-lai ZHOU ; Yao-zhang CAI ; Fan JIANG ; Bei-bei LU
Chinese Journal of Industrial Hygiene and Occupational Diseases 2006;24(9):552-553
Dust
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analysis
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Humans
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Magnoliopsida
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Pneumoconiosis
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epidemiology
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Prevalence
2.Physico-chemical Nature and Mutagenic Activity of Ambient Dust in Seoul.
Yonsei Medical Journal 1987;28(1):52-59
This study deals with the serious pollution of Seoul's ambient air and extends a warning regarding its adverse effects on human health. The collected dust samples exceeded the legal standard (15O microgram/m3 of total suspended particulates) of ambient air quality. Fine particles, with an aerodynamic diameter of less than 2.5 micrometer comprised on the average 75.4 percent of the total suspended particulates (TSP). The amount of ether extractable organic matter (EEOM) of the fine particles was found to range from 3.6 to 7.1 percent. Neutral, acidic and basic organics were fractionated. In the neutral fraction, aliphatic compounds (ALP), polyaromatic hydrocarbons0 (PAH), and polar neutral organic compounds (POCN) comprised 23.1, 37.8 and 39.1 percent, respectively. Mutagenic activities of the organic fractions were determined by Ames bioassay. PAH showed the most mutagenicity using Salmonella typhimurium TA98 strain and TA98NR(nitro-reductase activity deficient stain) in the presence of S-9 fractions.
Dust/analysis*
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Human
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Korea
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Mutagenicity Tests*
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Polycyclic Hydrocarbons/analysis*
4.Relationship between dust mass concentration and fiber number concentration of refractory ceramic fibers.
Xiaojun ZHU ; Tao LI ; Hongfei WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2015;33(4):309-312
OBJECTIVETo explore the quantitative relationship between the dust mass concentration and fiber number concentration of refractory ceramic fibres.
METHODSA typical refractory ceramic fiber plant was selected as the study site. Fifty-three paired samples of total dust mass concentration and fiber number concentration were collected using the long-time fixed site mode. The total dust mass concentration was measured according to the GBZ/T 192.1-2007 (Measurement of dust in the air of workplace, part 1: Total dust concentration). Membrane filter method/phase-contrast optical microscopy was used to determine the fiber number concentration. Univariate analysis was used to describe the distribution of the two concentrations and their ratio. Spearman rank correlation, as well as linear regression, logarithmic curve, polynomial, power function, and exponential curve model, were used to explore the relationship between the two concentrations. Results The range of the total dust mass concentration (x) was 0.45-13.82 mg/m3. The range of the fiber number concentration (y) was 0.01-1.04 f/ml. The range of the ratio (x/y) was 4-158. All of the three parameters did not follow normal distribution (P<0.000 1). The two concentrations showed a positive correlation (r,=0.705 22, P< 0.000 1). All the coefficients of determination (R2) of linear regression, logarithmic curve, polynomial, power function, and exponential curve model were relatively low. The trinomial curve model had the highest R2 (0.6848) and the fitted equation was y=-0.001, 1x+0.010 4x2+0.101 4x-0.055 1.
CONCLUSIONThere is a positive correlation between the total dust mass concentration and fiber number concentration of refractory ceramic fibers. However, there is no fixed regression relationship between the two concentrations, and neither is a definite coefficient which can be used to convert each other. The two concentrations cannot be replaced by each other.
Air Pollutants, Occupational ; analysis ; Ceramics ; Dust ; analysis ; Occupational Exposure
9.Re-analysis of occupational hazards in foundry.
Min ZHANG ; Cheng QI ; Wei-Hong CHEN ; Yang LU ; Xie-Yi DU ; Wen-Jie LI ; Chuan-San MENG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2010;28(4):280-285
OBJECTIVETo analyze systematically the characteristics of occupational hazards in the foundry, and provide precise data for epidemiology studies and control of occupational hazards in the foundry.
METHODSData of airborne dust, chemical occupational hazards and physical occupational agents in environment in the foundry from 1978 to 2008 were dynamically collected. Mean concentration and intensity (geometric mean) of occupational hazards were calculated by job in different years.
RESULTSMain occupational hazards in the foundry were silica, metal fume, noise and heat stress. Silica existed in all of main jobs. The mean concentration of silica before 1986 was an extremely high level of 8.6 mg/m(3), and then remarkably dropped after 1986, with the level of 2.4 mg/m(3) from 1986 to 1989, 2.7 mg/m(3) from 1990 to 2002 and 2.7 mg/m(3) from 2003 to 2008. The trend of silica concentrations by job was consistent with that in general. Silica concentrations among jobs were significantly different, with highest level in melting (4.4 mg/m(3)), followed by cast shakeout and finishing (3.4 mg/m(3)), pouring (3.4 mg/m(3)), sand preparation (2.4 mg/m(3)), moulding (2.1 mg/m(3)) and core-making (1.7 mg/m(3)). Concentration of respirable dust in pouring was highest (2.76 mg/m(3)), followed by cast shakeout and finishing (1.14 mg/m(3)). Mean concentration of asbestos dust in melting was a relative high level of 2.0 mg/m(3). In core-making and sand preparation, there existed emission production of adhesive, with mean concentrations as followed, ammonia (5.84 mg/m(3)), formaldehyde (0.60 mg/m(3)), phenol (1.73 mg/m(3)) and phenol formaldehyde resin (1.3 mg/m(3)) also existed. Benzene and its homologues existed in cast shakeout and finishing, and the level of benzene, toluene, xylene was 0.2 mg/m(3), 0.1 mg/m(3) and 1.3 mg/m(3), respectively. In pouring and melting, there existed chemical occupational hazards, including benzo(a) pyrene, metal fume (lead, cadmium, manganese, nickel, chromium) and gas(hydrogen sulfide, phosphine, sulfur dioxide, carbon monoxide). Mean concentration of benzo(a) pyrene was a low level of 1.80 x 10(-4) microg/m(3). Physical occupational agents in the foundry were noise, heat stress and vibration. Intensity of heat stress was high in melting, pouring and cast shakeout and finishing, with the level of 30 degrees C, 29 degrees C and 26 degrees C, respectively. Noise was high in cast shakeout and finishing and core-making, with the level of 93.1 dB(A) and 89.5 dB(A), respectively. Vibration existed in core-making and cast shakeout and finishing. Compulsory postures included long standing, seating and bowing.
CONCLUSIONOccupational hazards in environment of the foundry are diversified and their concentrations exceed permissible exposure limits stipulated by the national occupational hygienic standards. High-concentrations of dust, metal fume, low-concentrations of variety of chemicals, high-intensity of noise and vibration, heat stress, and harmful compulsory posture, and so on all co-exist in the foundry. Control and protective measures should be strengthened.
Dust ; analysis ; Hazardous Substances ; analysis ; Metallurgy ; Occupational Exposure