Impact/Purpose:

The goal of this task is to perform a survey of industrial and foodgrade chemicals to determine perchlorate concentration. The results from the survey of industrial chemicals will be compiled in a database that provides regulators with information on the chemicals containing perchlorate, perchlorate concentration, the major industrial uses of the chemicals, and information from the National Pollutant Discharge Elimination System (NPDES) permit program. This database will make it possible to assess the impact that perchlorate-containing industrial wastewater has on raw drinking water sources. The results from the survey of foodgrade chemicals will be compiled in a similar database of chemicals containing perchlorate, food processing usage, and concentration of perchlorate. This will allow EPA regulators to assess the relative source contribution of perchlorate-containing foodgrade chemicals to the human diet.

Description:

Perchlorate anion has been found in numerous drinking water supplies at concentrations that recent studies indicate may adversely affect human health. In collaboration with the Office of Ground Water and Drinking Water (OGWDW) and Dionex Corporation, the National Exposure Research Laboratory has developed an ion chromatography mass spectrometric (IC-MS) detection method (EPA Method 330.0) that is capable of detecting perchlorate in drinking waters down to 0.1 parts per billion (ppb). The use of mass spectrometry provides quantitative and qualitative confirmation of the presence of perchlorate based on the mass-to-charge ratio of the perchlorate anion and the relative abundances of the chlorine isotopes. With the development of such a sensitive and specific method, it is possible to measure and confirm perchlorate in a variety of chemicals that are used by industries not typically identified as perchlorate users. For example, perchlorate has been found at high concentrations in chemicals such as chlorate, hypochlorite, chlorite, pyrophosphates, polyphosphates and phosphoric acid. Phosphoric acid, which is added to give a tart taste, is the third or fourth ingredient in cola drinks. Using IC-MS, perchlorate was found in a cola at 0.5 ppb; whereas, it was not found in a soft drink that did not use phosphoric acid. In addition, the highly sensitive IC-MS methodology has allowed the discovery that perchlorate is in many drinking waters with no known proximity to industries that are known perchlorate users. This task will undertake an initial screening of industrial and foodgrade chemicals that contain perchlorate as a contaminant or residual from production to describe the range of potential sources of perchlorate exposure. These data will enable the EPA to assess the relative source contributions of perchlorate to waterways from industries using and discharging these chemicals, and to processed foods containing these chemicals.

Record Details:

Record Type:PROJECT

Start Date:01/01/2005

Projected Completion Date:09/01/2006

OMB Category:Other

Record ID: 114555

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Project Information:

Progress :None. This project is in the planning phase. A research and quality assurance project plan will be prepared and peer-reviewed prior to starting this work. If approved, an IC-MS on loan from the Office of Ground Water and Drinking Water will be used until the necessary instrumentation is acquired.

Relevance :Relevance: Perchlorate, an oxidant in solid propellant and known thyroid hormone inhibitor, has been monitored under the Unregulated Contaminant Monitoring Rule (UCMR) since 1999 using an ion chromatography conductivity detection method (EPA Method 314.0). Since that time, perchlorate has been found in drinking waters in 34 states. In 2005, NERL will deliver an IC-MS method to OGWDW for measuring perchlorate down to 0.1 ppb in drinking waters. The EPA is in the process of making a regulatory determination for perchlorate in drinking water pending the results of a National Academy of Sciences review, the occurrence results from the UCMR, the development of more sensitive and specific analytical methods, and the evaluation of treatment options. This research builds on a body of knowledge acquired during the development of the IC-MS method for the determination of perchlorate and will fill an important information gap in understanding the sources of perchlorate in the environment. Significance: An important consideration in setting a regulatory level for a contaminant in drinking water is the relative source contribution of the contaminant from diet. Perchlorate has been found in milk, leafy vegetables and some fruits grown in perchlorate-contaminated irrigation waters. The Food and Drug Administration (FDA) has assessed perchlorate from these sources; however, no one has reported on the occurrence of perchlorate in foodgrade industrial chemicals. Perchlorate may be present in processed foods as a result of contamination of the chemicals used to give taste, preserve freshness, or prevent caking. Industrial chemicals not associated with the defense or pyrotechnics industry may also contain perchlorate as a contaminant. These chemicals may be discharged into U.S. waterways under the NPDES program. Conventional wastewater treatment may not remove or destroy perchlorate before it ends up in a drinking water source. Impact: This research project will fill an important gap in understanding the sources of perchlorate in the environment and in the human diet.

Clients :Office of Ground Water and Drinking Water (Hiba Shukairy, Valerie Blank, Kesha Forrest), National Center for Environmental Assessment (Annie Jarabek)

Project IDs:

ID Code :20520

Project type :OMIS