James R. Millette

The Need to Control Asbestos Fibers in Potable Water Supply Systems

Occupational studies have shown that asbestos is a human carcinogen. Because many inhaled asbestos fibers deposited in the lung are cleared and swallowed, workers are also exposed through ingestion. Of the millions of current and former workers who have been heavily exposed to asbestos, one in ten will die from cancer of the gastrointestinal tract. A number on the order of 1 in 1,000 ingested asbestos fibers penetrate the digestive tract and ingested fibers have been recovered in such tissues as kidney, intestine, liver, and urine. One animal study showed tumor production related to ingestion of asbestos-containing material but, in general, the results of seven animal feeding studies have been inconclusive. A statistically significant relationship between male lung and stomach cancer and female peritoneal, gall bladder, and esophageal cancer and asbestos counts in drinking water was determined in one epidemiology study. Increased rates for male stomach and lung, and female pancreatic cancer related to asbestos in drinking water were reported in another study but possible occupational exposure made it difficult to draw conclusions. Data on excess gastrointestinal cancer among occupational groups has been used to estimate that drinking water containing 300,000 asbestos fibers per liter over a lifetime will result in one additional cancer among 100,000 people.

Measurement of Subcellular Ions by X-ray Microanalysis for Evidence of Hepatotoxicity

This chapter is largely an elaboration of a paper which was presented at the Forensic, Occupational and Environmental Health Symposium at the 1985 joint national meetings of the Electron Microscopy Society of America and the Microbeam Analysis Society in Louisville, Kentucky. An extended abstract of that presentation has been published by San Francisco Press.

Liver Tissue Preparation Using a Modified Cryoultramicrotomy Kit

The great potential of cryoultramicrotomy is that it is possible to observe the morphology of a sample in the electron microscope while at the same time analyze for its elemental composition using x-ray microanalysis. There are other methods using indirect means of studying the chemical composition of cell organelles, such as digestion and centrifugation, but cryoultramicrotomy is the only direct method. This unique ability will make cryoultramicrotomy a vital tool in the field of cell biology and pathology in the near future. Our interest is the quantitative analyses of diffusible elements in the mitochondria of rat liver before and after exposure to toxins both singularly and in mixtures. To obtain reliable and reproducible data it is critical that each step in the technique be carried out correctly. Any deviation in any of the steps will leave the final results in doubt.