The application of dustiness tests to the prediction of worker dust exposure.
ABSTRACT Laboratory bench tests, known as dustiness tests, have been used to evaluate and compare the potential of various powders to cause occupational dust exposure. Dustiness tests are used to develop products with reduced dust emissions. The correlation between dustiness test results and dust exposures was evaluated at two bag dumping and bag filling operations. At one bag dumping and one bag filling operation, there was evidence of a relationship between dustiness test results and dust exposures. In one case, regression analysis showed that dust exposures could be predicted to within nearly one order of magnitude. The variability in this prediction was caused by the inherent variability in the occupational dust exposures. In the other case, there was evidence of a correlation after the data had been adjusted for the effect of varying drop height. At the remaining two operations, no correlation between dust exposures and dustiness test results were observed. These results indicate that the relevance of dustiness tests to occupational dust exposure needs to be evaluated at each site. Because a better option does not exist, manufacturers should continue to use empirical dustiness tests to develop better products in the laboratory. The conclusions reached in the laboratory need to be validated by dust exposure measurements in the field, however.
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ABSTRACT: The objective of the present study was to assess the effect of different waste storage systems on the potential of the waste to emit airborne dust, micro-organisms and endotoxin. Batches of 8.8 kg of compostable waste were incubated at 20°C for periods of 1–2 weeks in three different storage systems: a system with relatively free access of air (FA) to the waste (paper bags in the kitchen, paper sacks outside the house), a system with low access (LA) of air (plastic bags in the kitchen, a container outside the house), and an intermediate (IA) system (trash can in the kitchen, a container outside the house). The compostable waste was prepared in the laboratory using a standard recipe simulating average kitchen waste in Denmark. Weight loss and temperature of the waste were recorded during the storage period. After incubation, the volume of percolate was determined and the dustiness of the waste was measured in terms of the potential of the waste to emit bio-aerosols in a rotating drum. Storage in the FA system resulted in high weight loss of the waste (15–25% per week), a maximum temperature of 45°C and no percolate was observed. The LA system resulted in low weight loss (<3% per week), a temperature at ambient level and a volume of percolate less than 0.1 litre. Waste stored in the IA system was intermediate with a weight loss of 5–8% per week, a maximum temperature of 36°C and a volume of percolate less than 1 litre. Dustiness in terms of dust, endotoxin and micro-organisms was highly correlated to weight loss of the waste. Storage of the waste in the FA system resulted in extremely high concentrations of airborne micro-organisms in the rotating drum compared to that seen after storage in the LA system. The dustiness with respect to airborneAspergillus fumigatuswas at least a factor of 400 000 higher for FA waste compared to LA waste. The present method of testing dustiness of waste is considered important for the design of waste collection equipment and may therefore, over time, contribute to an improved air quality for the workers engaged in waste handling.Waste Management & Research 04/1997; 15(2):169–187. · 1.05 Impact Factor
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ABSTRACT: A standard rotating drum with a modified sampling train (RD), a vortex shaker (VS), and a SSPD (small-scale powder disperser) were used to investigate the emission characteristics of nano-powders, including nano-titanium dioxide (nano-TiO2, primary diameter: 21 nm), nano-zinc oxide (nano-ZnO, primary diameter: 30–50 nm), and nano-silicon dioxide (nano-SiO2, primary diameter: 10–30 nm). A TSI SMPS (scanning mobility particle sizer), a TSI APS (aerodynamic particle sizer), and a MSP MOUDI (micro-orifice uniform deposit impactor) were used to measure the number and mass distributions of generated particles. Significant differences in specific number and mass concentration or distributions were found among different methods and nano-powders with the most specific number and mass concentration and the smallest particles being generated by the most energetic SSPD, followed by VS and RD. Near uni-modal number or mass distributions were observed for the SSPD while bi-modal number or mass distributions existed for nano-powders except nano-SiO2 which also exhibited bimodal mass distributions. The 30-min average results showed that the mass median aerodynamic diameter (MMAD) and number median diameter (NMD) of the SSPD ranged 1.1–2.1 μm and 166–261 nm, respectively, for all three nano-powders, which were smaller than those of the VS (MMAD: 3.3–6.0 μm and NMD: 156–462 nm), and the RD (MMAD: 5.2–11.2 μm and NMD: 198–479 nm). For nano-particles (electric mobility diameter < 100 nm), specific mass concentrations were nearly negligible for all three nano-powders and test methods. Specific number concentrations of nano-particles were low for the RD tester but were elevated when more energetic VS and SSPD testers were used. The quantitative size and concentration data obtained in this study is useful to elucidate the field emission and personal exposure data in the future provided that particle loss in the generation system is carefully assessed.Journal of Nanoparticle Research 03/2012; 14(4). · 2.28 Impact Factor
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ABSTRACT: Dust exposures are observed in some production departments of pharmaceutical industries, especially in tablet manufacturing processes. This dust generally includes a portion of therapeutic material. The development of an adequate industrial hygiene monitoring strategy is therefore required to evaluate these specific exposures. The first step for a proper health risk assessment consists of establishing adequate exposure limits for each drug of interest. Second, the dust must be sampled to quantify the drug exposure. This monitoring often requires the development of analytical methods for each pharmaceutical active of concern. However, the development of analytical methods for some drugs is a procedure too expensive for many industries, especially where industrial hygiene resources are limited. These difficulties would be avoided if the proportion of drug in the total dust could be estimated without direct chemical analysis of the drug. Over a three-year period, two types of granulation processes were monitored in one pharmaceutical industry. Total dust exposure levels and drug ratios in the recipe were compared with drug exposures obtained with direct drug analysis. The data suggest that a direct comparison was possible between total dust air sampling results and drug concentrations, depending on the manufacturing process used. Tartre, A.: An Industrial Hygiene Monitoring Strategy for Dust in the Pharmaceutical Industry. Appl. Occup. Environ. Hyg. 7(11):764–771; 1992.Applied Occupational and Enviromental Hygiene 11/1992; 7(11):764-771.