dy and tested it against various cancers. It was found to have worked extremely well against APL and in one case, 14 out of 15 terminal APL victims realized complete remissions when treated with arsenic trioxide. (Mervis 1996)The way arsenic trioxide works is still under scrutiny, but it appears to act very differently from ATRA. ATRA does not kill APL cells. Instead, ATRA keeps the cell from dividing unchecked. Arsenic trioxide, according to the journal Blood, stimulates cell death in an APL cell line. Arsenic trioxide, though it does not get rid of all leukemic cells, does allow patients to benefit from remissions lasting for 18 months or more. Some have been cancer free for 20 years. Complete remission from APL has been accomplished for about 70% of the patients. (Mervis 1996)Despite its virtues, arsenic is a deadly element. As of now, the chief problem with arsenic is its contamination of groundwater throughout the world because it is present throughout the earth's crust. (Turkington 1994) The slightest amount of this tainted water can lead to cancer and as of now, over 700 hazardous-waste sites in the U.S. are contaminated with arsenic. Health officials wish to remove the arsenic from the soil and water, but are unable to do it until they understand how the element reacts with environment and how its compounds alter over time. (Brown 1997)Professor Hemond and students at the Massachusetts Institute of Technology have been studying how arsenic moves within the Aberjona Watershed ecosystem north of Boston. They use an instrument that quickly identifies various layers of soils and sediments. (see Figure 4-A) This allows the researchers to predict possible paths for water laced with arsenic. They have found that arsenic there frequently alternate between two compounds: arsenate and arsenite. Arsenite is extremely toxic and highly soluble in water, thus making it easier for humans to ingest it. Arsenate, on the other hand...
