A comparison of real-time monitoring of select metal concentrations in a copper smelter workplace compared to standard pump air sampling monitoring methods

摘要

This research was conducted to determine if a direct-reading instrument can be used as a guidance tool to estimate the concentrations of arsenic, cadmium, copper and lead in air within a copper smelter workplace based on comparison to standard pump-filter air sampling monitoring methods for these agents. Both respirable and total dust samples were collected using precision flow air sampling pumps and mixed cellulose ester (MCE) filters in sampling cassettes to determine the concentration for each of these metals in air in a smelter workplace. Particulate matter with a diameter of 10 μm or less (PM_(10)) was also sampled by using air sampling pumps and PM_(10) impactors. Samples collected in the smelter workplace were submitted to an American Industrial Hygiene Association (AIHA) accredited analytical laboratory, where gravimetric analyses for the total weight of particulates were measured and the concentration of each of the four metals of interest was determined. During the collection of the MCE filters-cassette and PM_(10) impactor samples, a Haz-Dust real-time, direct-reading instrument was simultaneously used to measure particulate concentrations in air. A Pearson's Correlation was calculated to determine the strength or degree of association between the direct-reading instrument results and metal concentration for the respirable, total dust and PM_(10) concentrations reported by the laboratory. Linear regression was then performed between the direct-reading results and each specific metal concentration reported by the laboratory for total, respirable and PM_(10) samples. This comparison of the data from the different monitoring methods provided a correction factor, which was then used to predict the metal concentrations in air based on the direct-reading instrument readings. Pearson's Correlation results showed correlation coefficients from -0.14 for respirable lead to 0.49 for copper PM_(10) compared to direct-reading instrument results. Linear regression results found R2 values ranging from 0.581 for lead PM_(10) compared to the direct-reading instrument to 0.821 for copper total dust as compared to the direct-reading instrument aerosol measurements. The direct-reading instrument appears valid and reliable for obtaining general estimates of some metals in a copper smelter workplace, however the method is not sufficiently accurate to replace current accepted, and in some cases required, pump-filter air monitoring methods and should therefore only be used as a guidance tool.