Monitoring of urban particulate using an electret-based passive sampler

Site sampling trials have been carried out in the urban environment in order to assess the usefulness of a passive sampling device, originally developed for personal monitoring of airborne dust levels in industry. The sampling element is a small disc of electret material (polymer carrying a permanent electric charge) within a metal frame weighing approximately 15 g. The sampler is designed to capture particles by electrostatic attraction, in which case the capture rate depends on their electrical mobility but is independent of the rate at which air flows past the device. Passive samplers, along with miniaturized cascade impactors, have been exposed to urban particulate for periods of up to 28 days in locations with significantly different levels of airborne pollution. The cascade impactor data enabled good estimates to be made of PM10 and PM2.5 levels, and data from the passive sampler correlated with the total dust sampled by the impactor and with both the size fractions, that with the PM10 being better. Too few data have yet been obtained for its accuracy to be established, but it is unlikely that it will approach that of pumped samplers. It has been shown to be potentially useful for multiple, simultaneous site sampling and for monitoring personal environmental exposure situations in which dispensing with a power source is particularly useful. Being small, the sampler is easy to hide or camouflage, and because it is cheap, its loss or damage is not a serious matter.     

Field evaluation of a passive sampler for assessing 2-ethoxyethyl acetate exposures

This paper presents a field evaluation of a passive badge for measuring 2-ethoxyethyl acetate (2-EEAc) in a humid working environment. Forty-eight pairs of side-by-side active/passive 8-h full-shift personal samples were collected to evaluate the performance of a passive badge for monitoring 2-EEAc with the co-exposure of toluene and methyl iso-butyl ketone (MIBK) in a warm and humid workplace. Sixteen pairs of side-by-side passive badges, active charcoal tubes, and active charcoal tube with drying tube samples were also compared to evaluate the humidity effect in sampling. No statistical difference was found between the passive and active samples in assessing 2-EEAc. Linear regression showed the correlation to be high (r=0.987, slope=1.018, n=48) over the range 0.42-41.5 ppm. The mean concentration difference was 0.53 ppm and the mean relative error was 5.39%. Close correlation was also found between passive and active samples for assessing both toluene (r=0.949, slope=0.918, n=16), and MIBK (r=0.943, slope=1.098, n=16). Similar high correlation (r>0.962, n=16) was found among passive badges, active charcoal tubes, and active charcoal tube with drying tube samples. The humidity effect and the interference of co-exposure of polar and non-polar solvents were insignificant at a low sampling rate (26.6 ml/min) in assessing 2-EEAc exposures. The use of the passive samplers produces comparable findings to that of active sampling.     

Field evaluation of a passive sampler for the exposure assessment of 2-methoxyethanol

Objective: This paper presents a field evaluation of 3 M 3500 passive badges for measuring 2-methoxyethanol (ME) in a humid working environment. Methods: A total of 93 pairs of side-by-side active/passive samples, 48 pairs of duplicate active samples, 52 pairs of duplicate passive samples, and three groups of six replicate active/passive samples were compared. Three groups of six replicate active charcoal/active charcoal tube with drying tube samples were also compared to evaluate the humidity effect. Results: No statistical difference was found between the passive badges and active samplers. Linear regression showed the correlation to be high (r = 0.992, slope  =  0.973, n = 93) over the range of 0.17–163 ppm. The mean concentration difference was −0.34 ppm and the mean relative error was 3.50%. The intraclass correlation coefficients of 48 duplicate active samples and 52 duplicate passive samples were 0.994 and 0.989, respectively. The precision of replicate passive, active, and active/drying tube samples (n = 6) were 3.84%, 7.14%, and 5.12%, respectively. Conclusions: The humidity effect for active samples was insignificant at the low sampling rate (36.3 ml/min). It is therefore concluded that the use of the passive samplers to assess ME exposure produces comparable findings to that of active sampling. Received: 5 March 1999 / Accepted: 9 September 1999     

Performance assessment of a passive sampler in industrial atmospheres

In this work we investigate the performances of a passive sampler (GABIE badge) in industrial atmospheres, in accordance with the general specifications of the EN 838 standard. The field experiment was carried out in a paint-manufacturing factory producing a large number of pollutants at the workplaces. A comparison was performed between the results obtained by passive sampling and the conventional tube/pump method (reference method) on nine solvents usually encountered in the different workshops: n-butanol, isobutanol, toluene, ethylbenzene, m-xylene, methylisobutylketone, methylethylketone (MEK), ethyl acetate, butyl acetate. Results were compared by use of the distribution of the relative difference between badge "passive sampling" and tube "active sampling" results (with the latter considered as the reference method). In general, results revealed good agreement between passive and active sampling (except in the case of MEK) and confirmed the accuracy of sampling rates determined for the GABIE sampler. Bias was generally low and variability could be considered to be satisfactory (generally < 20% with a maximum of 30% for ethylbenzene). For MEK, strong bias was noted together with probable underestimation of the tube results. Additional results lead us to suggest that this phenomenon could be due to poor desorption of the SKC tubes by carbon disulphide (CS2); (quantitative recovery for MEK is in fact possible using other desorption solvents).     

Performance assessment of a passive sampler in industrial atmospheres

In this work we investigate the performances of a passive sampler (GABIE badge) in industrial atmospheres, in accordance with the general specifications of the EN 838 standard. The field experiment was carried out in a paint-manufacturing factory producing a large number of pollutants at the workplaces. A comparison was performed between the results obtained by passive sampling and the conventional tube/pump method (reference method) on nine solvents usually encountered in the different workshops: n-butanol, isobutanol, toluene, ethylbenzene, m-xylene, methylisobutylketone, methylethylketone (MEK), ethyl acetate, butyl acetate. Results were compared by use of the distribution of the relative difference between badge “passive sampling” and tube “active sampling” results (with the latter considered as the reference method). In general, results revealed good agreement between passive and active sampling (except in the case of MEK) and confirmed the accuracy of sampling rates determined for the GABIE sampler. Bias was generally low and variability could be considered to be satisfactory (generally <20% with a maximum of 30% for ethylbenzene). For MEK, strong bias was noted together with probable underestimation of the tube results. Additional results lead us to suggest that this phenomenon could be due to poor desorption of the SKC tubes by carbon disulphide (CS₂); (quantitative recovery for MEK is in fact possible using other desorption solvents). Received: 23 December 1999 / Accepted: 26 July 2000     

管式个体采样器测定空气中甲醛的研究

目的:研制测定空气中甲醛的被动式个体采样器。方法:根据费克第一扩散定律设计新型被动式个体采样器,并对采样器的性能指标进行评价。结果:在温度10℃~40℃,湿度20%~40%,风速50~600 cm/s的范围内,被动式采样器测定空气中甲醛采样流量:104.05 ml/min,最大吸附容量0.2751 mg,最短采样时间为30 min,用前稳定性≥30 d,样品稳定性≥14 d,精密度RSD为5.34%。结论:研制的个体采样器可以作为一种测定空气中甲醛的新型采样仪器。     

Laboratory evaluation of the CIP 10 personal dust sampler

The "capteur individuel de poussiere" CIP 10 personal dust sampler--developed by the Centre d'Etudes et Recherches de Charbonnages de France (CERCHAR) research organization--is a small, quiet, lightweight unit which samples at a flow rate of 10 L/min. It is a three-stage sampler, using two stages to remove nonrespirable dust particles and one stage to collect the respirable fraction. Airflow through the sampler is induced by the third stage, which is a rotating collector cup that contains a fine grade sponge. Laboratory tests were conducted in a dust chamber using aerosols of Arizona road dust, coal dust and silica dust. Aerosol concentrations measured with the CIP 10 were compared to those measured with the coal mine dust personal sampler unit used in the United States. The results of this study showed that aerosol concentrations measured with the CIP 10 were linearly related to those obtained with the coal mine dust personal sampler. The relationship, however, was dependent on preselector configuration and aerosol characteristics. The collection medium allows some small particles (less than 3 microns) to pass through the sampler without being collected. As much as 13% (by weight) of the aerosol that penetrated through the preseparating stages was exhausted from the sampler.     

扩散法被动式甲醛个体监测器（Ⅱ型）的研制

介绍了一种基于气体分子扩散原理的被动式甲醛个体采样器，它是在Ⅰ型采样器的基础上完成的。采用甘油（２０％）／偏重亚硫酸钠（０．２５％）浸渍的定量滤纸（φ４２ｍｍ）作为吸收层，空气中甲醛扩散到吸收层上，形成稳定的化合物。采样一定时间后，取出吸收层，洗脱后，用ＡＨＭＴ化学比色法测定所采集到的甲醛。这种采样器的平均采样速率为８３ｍｌ／ｍｉｎ，标准偏差为７．２ｍｌ／ｍｉｎ，与有动力吸收管采样的方法相比较，总不确定度小于±２５％。     

A new static sampler for airborne total dust in workplaces

This paper describes the development and laboratory testing of a new static dust sampler for airborne total dust in workplaces. Particular attention is paid to designing the sampling head and entry consistent with the concept of inspirability which in turn defines a biologically-relevant aspiration efficiency. The sampling head has a small cylindrical body and a transverse entry slot with thin protruding lips forming an integral part of a weighable capsule containing a 37 mm filter which collects all of the sampled dust (without introducing errors due to external particle blow-off or internal wall losses). A battery-powered sampling pump provides both air suction at 3 L/min and rigid mounting for the sampling head. The sampling head is rotated continuously through 360 degrees at approximately 1.5 rpm by a simple electric drive, connected to the stationary pump through a rotating seal. Wind tunnel testing of the instrument showed it to display an entry efficiency very close to the inspirability curve of Vincent and Armbruster (now recommended by the ACGIH Technical Committee on Air Sampling Procedures for defining inspirable particulate matter (IPM] for particles of aerodynamic diameter up to 90 micron and for windspeeds in the range of one to three m/sec.     

工作场所空气中苯系物的被动采样仪测定法

目的建立被动采样仪测定工作场所空气中苯系物的方法,并对活化后采样仪进行评价。方法在自制实验舱中模拟工作场所空气中苯系物浓度,采用3M 3500被动采样仪进行采样,苯系物经被动采样器采集,二硫化碳解吸,解吸液采用气相色谱仪分析。结果经热解吸活化的3M 3500被动采样仪对苯系物的采样速率为30.5～38.4 ml/min,解吸效率为90%～110%,采样效率为100%,风速在1～3 m/s范围内对被动采样仪的采样速率影响不明显。被动采样法和主动采样法现场实际样品测定结果的相对偏差小于10%。结论 3M 3500被动采样仪经过250℃活化后可再次用于工作场所空气中苯系物的采集分析,解吸效率、采样效率等满足GBZ/T 210.4—2008《职业卫生标准制定指南第4部分:工作场所空气中化学物质的测定方法》,可用于工作场所空气中苯系物的测定。     

多组分气体污染物被动式监测方法的研究

研究了一种同时对甲醛、二氧化氮以及二氧化硫三种气体污染物进行监测的扩散法被动式监测方法。用经过处理的活性炭纤维作为吸收材料。采样后 ,将在吸收层上的HCHO、NO2 、SO2 经加入 0 0 5mol LNaOH溶液洗脱、0 3 %H2 O2 溶液氧化等步骤分别转化为HCOO-、NO-2 和SO2 -4 ,用离子色谱法进行定量测定。被动式采样器适合在风速 0 2～ 1 5m s,相对湿度 2 0 %～ 90 %以及温度 - 1 0～ 35℃的范围内使用。采样速率(ml min) :甲醛 67、二氧化氮 80、二氧化硫 64 ,相应的相对标准偏差为 7 3 %、3 6 %、6 8%。本方法 2 4小时采样的最小可测浓度是 (mg m3 ) :甲醛 0 0 2 6 ,二氧化氮 0 0 0 8,二氧化硫 0 0 69。在现场与有动力的采样方法比较 ,总不确定度甲醛 2 3 %、二氧化氮 2 3 %、二氧化硫 1 8%。本方法实现了用一个采样器采集三种气体污染物 ,同时测定出各个污染物的浓度。本项研究拓展了扩散法被动式采样方法在室内外环境空气监测中的使用前景。     

Effect of altitude on personal respirable dust sampler calibration.

Air sampling instruments often are used at altitudes other than the altitude at which they were calibrated. This investigation quantitates the effect of personal samplers and provides empirical relationships for adjusting the calibration mark for use at any altitude.     

Performance of prototype high-flow inhalable dust sampler in a livestock production facility

A high-flow inhalable sampler, designed for operational flow rates up to 10 L/min using computer simulations and examined in wind tunnel experiments, was evaluated in the field. This prototype sampler was deployed in collocation with an IOM (the benchmark standard sampler) in a swine farrowing building to examine the sampling performance for assessing concentrations of inhalable particulate mass and endotoxin. Paired samplers were deployed for 24 hr on 19 days over a 3-month period. On each sampling day, the paired samplers were deployed at three fixed locations and data were analyzed to identify agreement and to examine systematic biases between concentrations measured by these samplers. Thirty-six paired gravimetric samples were analyzed; insignificant, unsubstantial differences between concentrations were identified between the two samplers (p = 0.16; mean difference 0.03 mg/m³). Forty-four paired samples were available for endotoxin analysis, and a significant (p = 0.001) difference in endotoxin concentration was identified: the prototype sampler, on average, had 120 EU/m³ more endotoxin than did the IOM samples. Since the same gravimetric samples were analyzed for endotoxin content, the endotoxin difference is likely attributable to differences in endotoxin extraction. The prototype's disposable thin-film polycarbonate capsule was included with the filter in the 1-hr extraction procedure while the internal plastic cassette of the IOM required a rinse procedure that is susceptible to dust losses. Endotoxin concentrations measured with standard plastic IOM inserts that follow this rinsing procedure may underestimate the true endotoxin exposure concentrations. The maximum concentrations in the study (1.55 mg/m³ gravimetric, 2328 EU/m³ endotoxin) were lower than other agricultural or industrial environments. Future work should explore the performance of the prototype sampler in dustier environments, where concentrations approach particulates not otherwise specified (PNOS) limits of 10 mg/m³, including using the prototype as a personal sampler.     

环境监测用大气、粉尘采样器的简易维护

简述定期对环境监测用大气、粉尘采样器的流量计、蓄电池等部件进和合理有效的维护方法。     

Comparison of a passive aerosol sampler to size-selective pump samplers in indoor environments

The objective of this work was to investigate the ability of the Wagner-Leith passive aerosol sampler to measure indoor exposures over periods of 24 hours to 2 weeks. An automated analysis technique was developed so that lower aerosol concentrations could be sampled over shorter time periods. A test of the new analytical method against a manual method showed good agreement. The passive sampler was tested alongside three pump-operated, size-selective samplers in indoor environments. Generally, good correlation with the active samplers was observed. Correlation with a personal impactor with uncoated substrates was not statistically significant, but the cyclone, MS&T impactor, and overall correlations had R(2) values of 0.73-0.88. Combining these data with a previous study produced an R(2) of 0.96 between passive and active results. Large discrepancies (up to 147%) between passive and personal impactor results were observed and were attributed to particle bounce in the impactor, passive sampler imprecision due to few collected fine particles, and problems with detection of organic particles in the passive sampler. The Wagner-Leith sampler has now been tested over five orders of magnitude in mass concentration, in which it has proved useful for obtaining aerosol size distributions, mass fractions, qualitative elemental analysis, and morphology of individual particles. The sampler has several limitations, including increased sensitivity to contamination when fewer particles are collected, uncertainties in sampling semi-volatile particles, and the need for some expertise and expense to analyze the passive samples.     

5家煤炭企业粉尘管理现状调查

目的 了解我国煤炭企业粉尘的管理现状及粉尘管理中存在的问题,为制定尘肺防治工作计划、修订煤炭企业粉尘管理政策提供参考依据.方法 根据企业生产粉尘的性质、生产水平、生产方式、地域分布等特点选择具有粉尘危害的5家煤炭企业作为现场研究及示范基地;以接尘人员为调查对象进行面对面问卷调查,对职业病防治人员、工程技术人员及粉尘监测人员进行个人深入访谈.用EpiData 3.0建立数据库,使用SAS软件进行统计分析.结果 所调查的5家煤炭企业对粉尘危害及预防知识的宣传力度不够,职业健康体检工作不到位,防尘措施不完善,粉尘浓度监测可能存在漏洞;接尘人员自我防护意识差,对国家相关法规认识程度低.结论 5家煤矿企业粉尘管理工作不完善,仍需采取相应措施.针对此问题提出了相关建议,为国家修订粉尘危害管理政策提供参考依据.     

Comparison of measured respirable dust sampler penetration curves with sampling conventions.

Measured sampler penetration curves are presented for British personal cyclone samplers and the MRE 113A static horizontal elutriator in calm air. These curves are compared with previous results for these instruments, and with theoretical models of sampler behaviour. The sampling efficiency of the elutriator when facing a moderate wind is discussed. The penetration curves are assessed by comparison with standard sampling conventions for respirable dust.