INDUSTRIAL MINERALOGY OF PARTICULATE GENERATED FROM IGNITION SOURCES AND POTENTIAL HUMAN HEALTH CONCERNS

To date, the mineralogy of particulate emitted from ignition sources has been poorly studied. Improved understanding of the mineralogy of this particulate may potentially identify health hazards associated with ignition.

The two ignition sources studied include matches and cigarette lighters. In matches, the particulate varied in size from ~25µm to 100µm in diameter. These particulate consisted primarily of calcium, sodium, silica, and potassium and were a mixture of elongate and spherical particles. In lighters, the particulate came in several morphologies. The larger population contained particles that were around 100µm in size, whereas the smaller set had particles that varied from 2-20µm in size. These had either a spherical or platy texture and have a high rare earth element (REE) content dominated by lanthanum and cerium.

From previous studies, it has been conclusively determined that the particulate emitted from matches, which includes potassium and calcium, is far less dangerous than the particulate emitted from lighters, which includes rare earth elements such as cerium, lanthanum, and potentially thorium. In comparison to other metals, the toxicity of rare earth elements is poorly understood, though a review of the literature indicates that there are toxic effects to other forms of life. Some of these effects include negatively affecting mitochondrial functions and blood coagulation, as well as altering the renal and pulmonary body systems. In addition, the accumulations of certain REEs have been known to produce free radicals and other reactive oxygen species in the body. Reactive oxygen species are harmful because they are known to damage vital cellular processes such as lipid, protein, and DNA function. Damage to these processes can ultimately lead to serious illnesses such as cancer. Although matches seem to be less detrimental to health than lighters, further toxicological studies are needed to better understand the effects. This study provides constraints on the industrial mineralogy for future work for human health studies.