Morley J C, Clark C S, Deddens J A, Ashley K, Roda S
Department of Environmental Health, University of Cincinnati, College of Medicine, Ohio, USA.
Appl Occup Environ Hyg. 1999 May;14(5):306-16. doi: 10.1080/104732299302891.
Occupational Safety and Health Administration (OSHA) regulations for worker exposure to lead specify worker protection levels based upon airborne concentrations of lead dust. The rapid, on-site determination of lead in air filter samples using a portable x-ray fluorescence (XRF) instrument with an attachment to hold the filter would expedite the exposure assessment process and facilitate compliance with the OSHA standards. A total of 65 lead in air filter samples were collected at bridge blasting lead-abatement projects using closed-faced, 37-mm cassettes with pre-loaded 0.8 micron pore size mixed cellulose ester membrane filters. The lead loading range of the data set was 0.1-1514.6 micrograms (micrograms) of lead/sample. Samples were initially analyzed with a field portable XRF (NITON 700) using an experimental non-destructive XRF method. Samples were subsequently analyzed using National Institute for Occupational Safety and Health (NIOSH) Method 7105 (Graphite Furnace AA) as a reference analytical method. The paired data were not normally distributed; therefore, the non-parametric Wilcoxon signed rank test was used for statistical analysis. There was no statistically significant difference between data from the field portable XRF method and the NIOSH method (p-value = 0.72). Linear regression of the data resulted in a slope of 0.959, a y-intercept of 5.20 micrograms, and an r2 of 0.985. The XRF limit of detection and limit of quantitation were determined to be 6.2 and 17 micrograms of lead/sample, respectively. The XRF method accuracy was +/- 16.4% (7.1%-27%, 90% confidence interval). The data presented in this study indicate that field-portable XRF can be used for the analysis of lead air filter samples over the range of 17 to 1500 micrograms of lead/sample. The practicing industrial hygienist can use field-portable XRF to produce a rapid, on-site determination of lead exposure that can immediately be communicated to workers and help identify appropriate levels of personal protection. As the method is non-destructive, samples can subsequently be sent to a laboratory for confirmation. Confirmation would be recommended when greater than 16.4 percent accuracy from an analytical method is required. This study provided data of suitable quality for the development of NIOSH Method 7702, "Lead by Field Portable XRF."
美国职业安全与健康管理局（OSHA）关于工人接触铅的规定，根据空气中铅尘的浓度规定了工人的保护水平。使用带有固定过滤器装置的便携式X射线荧光（XRF）仪器对空气过滤器样本中的铅进行快速现场测定，将加快暴露评估过程，并有助于遵守OSHA标准。在桥梁爆破铅清除项目中，使用封闭面的37毫米盒式采样器和预先装载的孔径为0.8微米的混合纤维素酯膜过滤器，共采集了65个空气过滤器样本中的铅。数据集的铅负载范围为0.1 - 1514.6微克（μg）铅/样本。样本最初使用现场便携式XRF（NITON 700）采用实验性无损XRF方法进行分析。随后使用美国国家职业安全与健康研究所（NIOSH）方法7105（石墨炉原子吸收光谱法）作为参考分析方法对样本进行分析。配对数据不呈正态分布；因此，使用非参数威尔科克森符号秩检验进行统计分析。现场便携式XRF方法和NIOSH方法的数据之间没有统计学上的显著差异（p值 = 0.72）。数据的线性回归得出斜率为0.959，y轴截距为5.20微克，r²为0.985。XRF的检测限和定量限分别确定为6.2和17微克铅/样本。XRF方法的准确度为±16.4%（7.1% - 27%，90%置信区间）。本研究中呈现的数据表明，现场便携式XRF可用于分析铅负载范围在17至1500微克铅/样本的空气过滤器样本。执业工业卫生学家可以使用现场便携式XRF对铅暴露进行快速现场测定，测定结果可立即传达给工人，并有助于确定适当的个人防护水平。由于该方法是无损的，随后可以将样本送到实验室进行确认。当需要分析方法的准确度高于16.4%时，建议进行确认。本研究为NIOSH方法7702“现场便携式XRF法测定铅”的制定提供了质量合适的数据。
