You are here:
Biomarkers for assessing potential carcinogenic effects of chronic arsenic exposure in Inner Mongolia, CHINA
Citation:
MUMFORD, J. S. Biomarkers for assessing potential carcinogenic effects of chronic arsenic exposure in Inner Mongolia, CHINA. Presented at 8th International Conference of Anticancer Research, KOS, GREECE, October 17 - 22, 2008.
Impact/Purpose:
research results
Description:
Arsenic is ubiquitous in the environment. Chronic arsenic exposure via drinking water has been associated. with carcinogenic, cardiovascular, neurological and diabetic effects in humans and has been of great public health concern worldwide. In 2001, U.S. Environmental Protection Agency adopted an arsenic standard of 10 ug/L from 50 ug/L in drinking water. However, there are still great uncertainties on the health effects of arsenic at low doses. Due to the lack of appropriate animal models for extrapolation to human risk, research needs are better understanding of the mechanisms of arsenic carcinogenesis. and assessing health effects of arsenic in humans at low dose. The major modes of action (MOA) proposed for arsenic effects in humans are increasing oxidative stress, altering signal transduction pathways, inducing DNA and chromosomal damage, affecting DNA repair, promoting cell proliferation, and DNA methylation. The objectives of this research were to apply biomarkers to assess arsenic exposure and cancer risks and identify biomarkers useful for assessing arsenic effects in humans. The residents of Ba Men in Inner Mongolia have been exposed to a wide range of arsenic concentrations via well water and showed adverse health effects. This population provides us an opportunity to assess the relationships between arsenic exposure and health effects. Based on the proposed MOA, we selected biomarkers to assess potential carcinogenic effects of arsenic in the Inner Mongolia population. A total of 324 Ba Men residents, exposed to arsenic via well water ranging from non-detectable levels to 826jlg/L of arsenic participated in this study. Samples of well water, urine and toe nail were collected to assess arsenic exposure and investigate metabolic profiles in urine. Human buccal cells and blood samples were collected and the health effects investigated are arsenic-related dermal effects, DNA fragmentation, micronucleus frequency for chromosomal damage, and mRNA expression of the genes (OGG1 and ERCCl) responsible for DNA repair of oxidative damage and human telomerase reverse transcriptase (hTER1) for cell proliferation. The results showed significant associations between arsenic exposure and increase in DNA damage, micronucleus frequency and gene expression of OGGl and ERCCl and hTERT. This paper will report the results of these studies and provide some insights on arsenic MOA and human dose-response data. (This is an abstract of a presentation and does not necessarily reflect U.S. EPA policy.)