For the outcome of the summit, see:
Stanton BA, et al. MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic. Curr Environ Health Rep. 2015 Sep;2(3):329-37. PMID: 26231509. DOI:10.1007/s40572-015-0057-9.
The 2014 Summit will focus on reducing the human health consequences of arsenic in the environment. The summit will open with a public lecture by Deborah Blum, best-selling author of The Poisoner’s Handbook and 2014 Kinter Lecturer, on Wednesday, August 13 at 5 p.m. A reception, sponsored by Nature’s One, will follow the lecture. The summit is modeled on the Future Search method that brings together diverse stakeholders in order to create and deliver upon concrete action plans. Participation in the stakeholder portion of the summit is by invitation only. Arsenic’s presence in the environment, from both natural and human sources, has massive human health consequences for billions of people. Worldwide, approximately 3 billion people are exposed to arsenic in food and 500 million ingest arsenic in drinking water. People are exposed to elevated levels of inorganic arsenic through drinking contaminated water, using contaminated water in food preparation and crop irrigation, industrial processes, eating contaminated food, and smoking tobacco.
Numerous studies associate arsenic with adverse health effects. Drinking water with arsenic for many years can lead to cancer of the bladder, lung, liver, prostate, and skin; diabetes; heart disease; reproductive and developmental problems; and cardiovascular, pulmonary, immunological, neurological, and endocrine problems. Fetuses and babies exposed to arsenic face an increased potential for cancer and other diseases in adulthood. Exposure has also been associated with increased infant mortality, reduced birth weight, and reduced ability to fight other diseases.
Expected actions from this summit include:
- eliminating arsenic to undetectable levels in food and drinking water
- developing novel and cost effective approaches to reduce arsenic exposure in rice, while encouraging the consumption of rice, the major food staple in the world
- developing science curricula to educate students and consumers about arsenic exposure and engage teachers and students and their families in well water testing
- creating new or leveraging existing citizen science programs to encourage and facilitate well water testing
- developing cost-effective technology for identification and reduction of arsenic in water and food
- developing a global standard for arsenic in water and food
Arsenic in Drinking Water
Arsenic is found in groundwater supplies across the globe. It is a major public health issue in several countries, including Argentina, Chile, China, India, Mexico, Taiwan, Thailand, Bangladesh, and the United States. Long-term human exposure is associated with many adverse health effects. Approximately 500 million people worldwide are exposed to arsenic in drinking water, and more than 25 million Americans drink well water contaminated with arsenic.
The enforceable standard for arsenic in U.S. public drinking water is a maximum contaminant level (MCL) of 10 parts per billion (ppb), though the U.S. Environmental Protection Agency (EPA) originally suggested 5 ppb. 10 ppb of arsenic in water means that there are 10 parts of arsenic for every 999,999,990 molecules of water. That is equivalent to a few drops of ink in an Olympic-sized swimming pool. 10 ppb is also the standard in many other countries.
Arsenic is one of World Health Organization’s (WHO) 10 chemicals of major public health concern. The WHO publishes a guideline value for arsenic in its Guidelines for drinking-water Quality. The current WHO-recommended limit of arsenic in drinking water is 10 ppb.
Arsenic in Private Wells
Homeowners with wells in the U.S. and many other countries are responsible for testing and treating their own water. In the U.S., the Safe Drinking Water Act (SDWA) of 1974 directs the EPA to issue enforceable drinking water regulations for public water systems for contaminants that may cause health problems. However, these standards do not apply to private wells.
Concentrations of 100 ppb and higher are commonly found in private well water in regions where arsenic is geologically abundant, including New England, Texas, Florida, California, and large parts of the Upper Midwest, the Southwest, and the Rocky Mountains.
Arsenic in Food
Exposure to arsenic via water has long been a priority of public health agencies and scientists, but more recent studies and investigations have led to concerns about exposure to arsenic through food. Grains, fruits, and vegetables that are grown in or near contaminated soil and groundwater accumulate arsenic. Rice, fruits, vegetables, food and beverage products, chicken, fruit juices, and juice concentrates often have measurable levels of arsenic. Approximately 3 billion people in the world are exposed to arsenic in rice and rice products.
Few regulations exist to limit the amount of arsenic in food, though several countries are currently considering standards. One issue centers on whether exposure to arsenic via food raises the same health concerns as exposure to arsenic through drinking water. Another issue is whether total daily exposure should be considered in setting regulations for arsenic in food and water. The U.S. limit for the amount of arsenic in public drinking water, which is set by the U.S. Environmental Protection Agency (EPA), is 10 parts per billion (ppb). In 2013, the U.S. Food and Drug Administration lowered the action limit for the allowable amount of arsenic in juice to 10 ppb, but no limit exists for the amount of arsenic in rice, rice-products, or other foods.
Human data on exposure to arsenic in food are scarce, and further studies are needed to understand the extent of arsenic exposure through food. Assessing exposure to arsenic in rice is particularly difficult because the concentration and speciation of arsenic in different rice cultivars vary widely, and because consumption of rice and its byproducts also vary by ethnic group and culture.
- Bruce A. Stanton, Ph.D.Andrew C. Vail Memorial Professor of PhysiologyDartmouth Medical School