Student Research: Gail Gislason

Assessment of Arsenic Exposure in a Highly Exposed Population in Chile
Faculty Advisor: 


As a result of its history of use and toxicity, arsenic and its health effects have been extensively studied. Arsenic is an element present naturally in the environment, is used in idustry and agriculture, and is extremely stable. Exposures to arsenical compounds may be common and represent a health concern. By analyzing environmental and biological samples, this thesis will characterize the arsenic exposures of two Chilean populations who are exposed to different amounts of inorganic arsenic through their drinking water supplies. It will be determined whether the exposures contribute to increased levels of arsenic in the hair and urine of these individuals. A comparison of the hair and urinary arsenic levels will determine if there is a correlation between these values, and if so, if hair may be used as a dependable biomonitor of exposure. Replacement water with a lower arsenic content was provided to the Chilean population with high arsenic content in their drinking water. The reduction in urinary arsenic levels following this intervention in drinking water source for these individuals will be described.

An understanding of the chemistry of arsenic and knowledge of its distribution in the environment can lead to prevention of arsenic exposure in many situations. If exposure cannot be avoided, it may be measured through the use of analytical techniques including atomic absorption. Analytical techniques are able to masure nanogram amounts of arsenic present in environmental and biological materials. Becuase of arsenic's unique characteristics and chemistry, the use of urine, hair, fingernails and other tissues are able to be used for estimating dose more effectively than measurement of arsenic in air, soil, and water. Measurement of arsenic metabolites in urine is useful for short-term biomonitoring of acute and chronic exposures while there is strong evidence that hair is a useful method for measuring long-term chronic exposures.

Taken from the beginning of thesis.