Particle Databases

The interpretation of qualitative and quantitative results of the analysis of particulate material in environmental and biomedical samples often requires or is enhanced by a matching of sample particle data with information in an appropriate reference database. For common mineral grains this may be as simple as matching the particle shape and composition to data in a mineralogy textbook.

In many instances however, database information which would allow the identification of unknown particles in environmental and biomedical samples does not exist. Furthermore, database information on the concentrations of particle types which are typical for these types of sample is generally unavailable.

Comparative findings reported by our facility draw on information archived in several "in-house" databases. We also have the experience to develop new databases for specific analytic projects.

Data on various potentially hazardous particle types, including microscopic images and X-ray spectral data, has been archived in order to facilitate particle morphology and composition comparisons.

In many instances variations in form, surface morphology and/or elemental composition are sufficient to make specific particle identifications.

For example, lead particle sources can often be recognized on the basis of individual particle shape and chemistry.

In many cases, as with iron oxide-bearing coal fly ash particles, surface morphology can be characteristic of the particle's source.

In other instances, especially in biopsy or autopsy samples of lung tissues in which occupational or environmental exposures are being investigated, determination of the concentration of particles by specific type (e.g., silica, asbestos, talc, tungsten, etc.) is essential. Such data enhances the comparison of individual case results with those from unexposed populations, and the investigation of dose-response relationships between exposure and disease severity. The extent of our reference pneumoconiosis database provides a unique resource for such comparisons. This database contains information on particle concentration, type, and size from over 1000 analyses of non-fibrous as well as fibrous inorganic particulates in lung tissues from persons with a wide variety of environmental and occupational exposures and diseases. Pathologic diagnoses included in the database range from normal 'background' cases to cases of asbestosis, silicosis, hard metal disease, beryllium disease, arc welder's pneumoconiosis, talcosis, lung cancer, mesothelioma, interstitial fibrosis, hypersensitivity pneumonitis, and many others.