Comparison of Filter and Wall Deposits From Samplers Used to Collect Airborne Lead-Containing Dusts at Field Sites

Figures & data

TABLE 1 Results of comparisons between particle mass-weighted size distributions of filter and wall deposit pairs and IOM and CFC filter pairs

Site	Number of job locations	Number of particles analyzed	Wall vs. filter differences, (IOM & CFC)	IOM vs. CFC Filter differences
Bronze foundry	4	41,527	1 / 14	0 / 7
Solder manufacturer	3	21,601	1 / 10	1 / 5
Lead ore concentrator	3	36,951	0 / 18	1 / 8
Lead-acid battery recycler	5	24,295	1 / 15	1 / 6
Copper ore smelter	5	19,050	0 / 15	1 / 7

FIG. 1 Comparison of individual particle masses of 988 particles from the lead ore processing facility calculated by the IMIX Quant and the Cliff–Lorimer methods. The vast majority of particles have a mass less than 1000 pg.

FIG. 2 Example of normalized mass distributions of an IOM and CFC filter pair that were not significantly different (according to Mann–Whitney statistical analysis.)

FIG. 3 Example of normalized mass distributions of a CFC wall and filter pair that were significantly different (according to Mann–Whitney statistical analysis.)

FIG. 4 Typical field of particles on a polycarbonate filter, imaged by backscattered electrons at a magnification of 1500 X. The circled particle has an “estimated aerodynamic equivalent diameter” of 2.1 μm and is composed of a mixture of mostly calcium, tin, silicon, and lead, with traces of iron, potassium, and chlorine.

FIG. 5 X-ray spectrum of particle shown in Figure 4. Five seconds of data acquisition excited by 20 keV electrons at 2.1 nA current. Two weaker lines not labeled in this spectrum are from potassium and chlorine.