Description:
Food may surpass drinking water as the major source of ingestion of total elemental arsenic for the general population. For this reason, accurate assessments of inorganic arsenic intake via food are needed to provide estimates for dietary exposure within future epidemiology studies. Currently, the available food databases only report total arsenic (ng/g arsenic) and do not provide guidance as to the percentage of toxic versus nontoxic arsenic species (i.e, arsenicals) present. Thus, the toxicity of diets composed of various food groups, and food commodities, containing arsenic is not well characterized. The analytical capability to speciate arsenic in a number of target foods (prioritized based on FDA market basket analysis) has been developed and should allow for the development of a preliminary speciation based database for these target foods. To provide a scientifically defensible estimate of the arsenicals present in these target foods, it will be necessary to analyze a number of samples which represent a cross section of the target food groups. This extramural task is intended to utilize the FDA's knowledge with respect to sources (regional crop production, import, export, etc.) to estimate reasonable cross sectional sampling. The development of a preliminary speciation based database is the ultimate product and is called for in ORD's Arsenic Research Plan as Exposure Issue 6 and is considered a high priority. This database will allow the inorganic arsenic exposure from target foods to be estimated and aid in replacing default assumptions in relative source contribution estimates which are used in establishing Safe Drinking Water Regulations.
A second aspect of this task is the continuation of research efforts in compositing similar types of target foods in order to minimize the number of samples which need to be collected and analyzed. However, this may lead to additional analytical shortcomings which may compromise the analysis if not resolved. Thus, this task will initially focus on compositing only starches (e.g., rice, wheat, potatoes, yams, etc) and fruits. This effort compliments a separate in-house task entitled "Speciation of Arsenic in Dietary and Dietary Composite Samples to Provide a More Complete Assessment of Arsenic Exposure from Dietary Sources" which focuses on compositing only proteins such as seafood. The ultimate goal is a complete composite of proteins, starches etc. to minimize the number of samples needed to develop the database while preserving analytical reliability.
Keywords:
ARSENIC, DATABASE,
Project Information:
Progress
:The research within this task is being conducted through an Interagency Agreement (IAG) with the U.S. FDA. In this IAG, emphasis has shifted to preliminary database generation from the methods development conducted under a previous IAG with the U.S. FDA entitled "Speciation of Arsenic in Target Foods and Composite Diet Samples".
In FY03, 6 presentations and 2 publications have been delivered:
1. 2003 Almunecar, Spain, "Investigation of Arsenic Speciation in Poultry Samples." Poster presented at the International Symposium on Speciation of Elements in Biological, Environmental, and Toxicological Sciences.
2. 2003 Almunecar, Spain, "A Comparison of Hydride Generation Atomic Fluorescence and Inductively Coupled Plasma Mass Spectrometry Detectors for the Liquid Chromatographic Determination of Arsenic Species in Foods." Poster presented at the International Symposium on Speciation of Elements in Biological, Environmental, and Toxicological Sciences.
3. 2003 Orlando, FL, "Method Development for Arsenic Speciation in Rice Using Microwave Assisted Extraction Ion Chromatography Inductively Coupled Plasma Mass Spectrometry." Oral presentation at the Pittsburgh Conference and Exposition on Analytical Chemistry and Applied Spectroscopy.
4. 2003 Garmisch-Partenkirchen, Germany, "A Mass Balance Approach to Determine Arsenic Absorption Rates from Contaminated Water by Rice During the Food Preparation Process." Poster presented at the Winter Conference on Plasma Spectrochemistry.
5. 2003 Garmisch-Partenkirchen, Germany, "Speciation of Arsenic in Crop, Vegetable and Soil Samples from an Area Irrigated with Arsenic Contaminated Groundwater in West Bengal, India" Poster presented at the Winter Conference on Plasma Spectrochemistry.
6. 2003 Garmisch-Partenkirchen, Germany, "Using HPLC-ICP-MS to Study the Non-Enzymatic Methylation of Arsenite by Methycobalamin." Poster presented at the Winter Conference on Plasma Spectrochemistry.
Publications:
1. Vela, N.P., Heitkemper, D.T., "Total Arsenic Determination and Speciation in Infant Food Products by IC-ICP-MS," accepted Journal of AOAC International Special Section, Aug, 2003
2. Pergantis, S.A., Miguens-Rodriguez, M., Vela, N.P., and Heitkemper, D.T., "Investigating the Non-enzymatic Methylation of Arsenite by Methylcobalamin B12 Using High-performance Liquid Chromatography On-line with Inductively Coupled Plasma - Mass Spectrometry," accepted J. Anal. At. Spectrom., Sept. 2003
The development of the trifluoroacetic acid (TFA) extraction for starch based foods has produced the capability to evaluate the uptake of arsenic in water by rice during the cooking process. This data was presented in Jan of FY03 and has been drafted for publication. It has been through internal review and was sent to Environmental Science & Technology in November 2003. A pre-print of this publication was sent to contacts in EPA's OGWDW and Office of Pesticide Program's as part of the Strategic Customer Value Analysis (SCVA) process. Future SCVA activities include briefing on arsenic speciation results in infant foods and arsenic speciation results for rice grown in contaminated and non-contaminated waters.
Relevance
:The Office of Research and Development (ORD) has designated the study of arsenic as a high priority research area because of the health risk associated from exposure to this element. This task is relevant to the Agency's mission in that it addresses research needs identified in ORD's Arsenic Research Plan (Exposure issues 6 - generation of a preliminary database of arsenicals in food) which ultimately will improve drinking water regulations and minimize exposure to arsenic from drinking water ingestion. This research is considered a high priority area within the plan. The ability to estimate arsenic dietary exposure has also been identified by research groups such as the American Water Works Association Research Foundation and the National Research Council as a critical need in establishing accurate exposure estimates in future epidemiology studies. The data in this preliminary database should provide a more toxicity based risk estimate for arsenic in target foods. In addition, the analysis of regional composites in FY04-06 will provide a more realistic estimate of the dietary exposures because the sample collection will be based on a larger cross section of the US population. These estimates could then be used to make exposure comparisons between the Taiwanese (the population the current risk assessment is based on) and US populations and, in turn, impact the Maximum Contaminant Level (MCL) reassessment. Significance/Impact: This database should improve relative source contributions (water vs. diet) estimates which are used in establishing Safe Drinking Water Regulations. This data could be used by the FDA to support exposure estimates under the Food Quality Protection Act and the analytical capability refined under this task can be used in improving dietary exposure estimates in future epidemiology studies. Finally, the US dietary exposure estimates could be compared to the Taiwanese in a more quantitative manner; thereby, influencing the calculated risk to US populations and ultimately influencing the MCL in water. Collaboration and Customer Interaction: The research within this task is being conducted through an Interagency Agreement (IAG) with the U.S. FDA. The FDA provided guidance to NHEERL on the tribal sampling and has a limited collaboration with scientists in Bangladesh. Communication is maintained with the Office of Ground Water and Drinking Water (OGWDW) in order to determine research needs and provide information which could impact future arsenic drinking water regulations. This exchange is accomplished through teleconferences, through communication with NERL's Assistant Laboratory Director for Drinking Water or through exchange of research results. OGWDW was briefed on the progress in this task during a 10/01 conference call. An additional arsenic conference call was held in OCT 2002 between ORD and OGWDW. During this call individual projects were discussed and their relevance to a re-evaluation of the arsenic drinking water standard. This input, may redirect some of the research effort within this task FY04.
Clients
:Office of Ground Water and Drinking Water (Irene Dooley), NERL Human Exposure Research Program.
Research Component
:ARSENIC
Risk Paradigm
:EXPOSURE
Project IDs:
ID Code
:none
Project type
:ORD-DW Plan
ID Code
:5882
Project type
:OMIS