Comparison of two dust collection methods for reservoir indoor allergens and endotoxin on carpets and mattresses

Variable methods of dust collection may lead to uncertainty in the measurement of biomarkers. The purpose of this study was to examine the effect of two different dust collection devices on dust weight, Der p 1, Fel d 1, and endotoxin levels. We compared: (1) a nylon mesh sock inserted between the furniture attachment and the vacuum hose (the reference method) and (2) the ALK device. Duplicate dust samples were collected for 2 min from 2 m(2) of 37 living room floors and from each longitudinal half of 37 mattresses. Measurement of Der p 1 and Fel d 1 were by double monoclonal antibody enzyme-linked immunosorbent assay (ELISA) and endotoxin by a Limulus Amobocyte Lysate assay. Geometric mean ratios (95% confidence intervals) were calculated to show the differences between sampling devices for each measurement. Compared with the ALK device, the reference method collected significantly more dust from floors (sevenfold) and mattresses (threefold) and more total Der p 1, Fel d 1, and endotoxin in both sites. Floor, but not mattress, Der p 1 concentrations were also significantly higher (threefold) using our reference method. We recommend that, in order to minimize sampling device bias, allergen and endotoxin are expressed as a concentration, and that the bed is considered the major source of allergen exposure. Practical Implications Dust sampling equipment can influence the dust yield. In order to have confidence in comparisons of allergen and endotoxin reservoir levels between centers, standardization in the use of sampling equipment is important.     

ATMOSPHERIC DRYING MODEL FOR PARTICULATE MATERIAL

This paper evaluates the atmospheric drying of particulate material, such as coir dust or milled peat. in flat beds ( spreads). A mathematical model is presented that defines the relationship between the optimum yield of product and the prevailing weather conditions. A method is presented that enables the production manager to establish the optimum crop yield for a given drying cycle. When applied to milled peat. this method has shown a yield increase in excess of 10%.     

Sensory Pollution and Microbial Contamination of Ventilation Filters

Abstract The sensory pollution load and microbial contamination of glass-fibre filters at high and low relative humidity were investigated in an experimental set-up in the laboratory. Dust and particles from the outdoor air were collected in two EU7 glass-fibre filters for a pre-conditioning period of 16–18 weeks during which there was a constant airflow with a velocity of 1.9 m/s through the filters. One of the filters was exposed to outdoor air of approximately 40% relative humidity and 10°C, the other to outdoor air of approximately 80% relative humidity and 5°C. The dust in ventilation filters can constitute a serious pollution source in the indoor environment, causing deterioration in the quality of the supply air even before it enters the ventilated spaces. The sensory pollution load from the used filters after the continuous operating time of 16–18 weeks was significantly higher than the sensory pollution load from new filters but the sensory load at 40% and 80% relative humidity did not differ. The microbial contamination of the supply air downstream of the filters, which on average had been exposed to outdoor air of 40% and 80% relative humidity, was negligible.     

Environmental Problems Related to Refractories——Some Discussions Based on Historical Surveys mainly in Japan

1IntroductionThe significance of refractory-related environmen-tal problems are drawing a serious attention in the re-fractories industry and their markets worldwide.Thoserefractory-related problems,however,have been han-dled so far separately on a case-by-case basis.It willbe,therefore,of great help for future progress to havea bird’s-eye viewover these issues from historical andtechnological viewpoints.It has been the author’s attitude toward environ-mental problems that they should be dis…     

纺织空调滤料的性能与应用

探讨纺织空调系统滤料应用现状与性能要求.分析了在纺织空调系统滤料应用中存在的问题.针对除尘滤料的开发,认为滤料应具备除尘效率高、永久阻燃性强、耐用性能好、尘体在滤料表面的静电吸附性低、滤料表面的疏水性能好等性能要求,方能满足纺织空调除尘对滤料性能的要求.