and Mass Spectrometry

Upcoming Speakers

Water water everywhere but what do we drink - - the chemistry that makes water drinkable

presented by

Susan Richardson
U.S. Environmental Protection Agency

January 15, 2003

The Scripps Research Institute, The Committee Lecture Hall


Dr. Richardson received her doctorate in Chemistry from Emory University in 1989 and has been employed with the U.S. Environmental Protection Agency for the past 13 years. She has been conducting research at the U.S. Environmental Protection Agency in an effort to "clear up" the water issue. Working with a team of spectroscopists at the EPA in Athens, Georgia, Dr. Richardson has devoted the last ten years to the identification of drinking water disinfection by-products (DBPs) from different disinfectants. She has also been active in pursuading toxicologists to study the new DBPs that have been identified. DBPs are formed when disinfectants, such as chlorine or ozone, react with natural organic matter and bromide present in the water. Despite the many reports of DBPs in the literature, very few have been studied toxicologically, and very little quantitative occurrence data exists for most. In addition, only a fraction of the DBPs that are formed have been identified. The concern over DBPs comes from human epidemiology studies that indicate a possible association between disinfected drinking water and cancer, cancer results from animal toxicology studies of DBPs, and more recently, human epidemiology studies that suggest greater risks of reproductive and developmental effects from DBPs.


Susan will present an overview of drinking water disinfection, as well as two recent major efforts--a Nationwide DBP Occurrence Study and a chemical-toxicological study (called the "Four Lab Study"). The Nationwide DBP Occurrence Study involves the quantification of approximately 50 high priority DBPs in drinking waters across the U.S. (including California) and identification of new DBPs that have not been previously reported. The high priority DBPs were chosen by experts from 500 DBPs reported in the literature as being most likely to cause an adverse health effect. Quantitative occurrence information, as well as their fate & transport in drinking water distribution systems was studied. The "Four Lab Study" involves the study of concentrated drinking water (treated with different disinfectants) in a battery of in vivo and in vitro toxicological assays, along with a complete chemical characterization of the water, to link effects observed with chemicals in the water. The ultimate goal of Susan's research is to identify the chemical DBPs that are formed in drinking water treatment, determine how they are formed, determine whether any pose an adverse human health risk, and work to minimize the ones that do--to improve the safety of our drinking water.

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