Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Internet Explorer is no longer a supported browser.

This website may not display properly with Internet Explorer. For the best experience, please use a more recent browser such as the latest versions of Google Chrome, Microsoft Edge, and/or Mozilla Firefox. Thank you.

Your Environment. Your Health.

Progress Reports: University of Arizona: Detoxification of Metals: In Vitro and In Vivo Studies

Superfund Research Program

Detoxification of Metals: In Vitro and In Vivo Studies

Project Leader: H. Vasken Aposhian
Grant Number: P42ES004940
Funding Period: 1995 - 2000

Learn More About the Grantee

Visit the grantee's eNewsletter page Visit the grantee's eNewsletter page Visit the grantee's Twitter page Visit the grantee's Instagram page Visit the grantee's Video page

Progress Reports

Year:   1999  1998  1997  1996  1995 

During the past year, new evidence has been developed which shatters former beliefs about arsenic toxicity. These three equally important results are 1) mono- methylarsonous acid (MMAIII ) is more toxic to human hepatocytes than is inorganic arsenite. This is the strongest evidence that has emerged, which brings into question methylation of inorganic arsenic as a detoxication process. 2) monomethylarsonous acid (MMAIII ) occurs in the urine of some humans chronically exposed to inorganic arsenic in their drinking water. This may indicate a new more selective biomarker for arsenic exposure. 3) the rate limiting enzyme of rabbit liver arsenic biotransformation is MMA(V) reductase. This points out the most crucial step in the methylation of inorganic arsenic.

to Top