Saturday, April 13, 2013

Arsenic Contamination In Food And Water Supplies

After virtually eliminating arsenic as a useful tool for homicide, science now faces challenges in doing the same for natural sources of this fabled old "inheritance powder" that contaminates water supplies and food, threatening more than 35 million people worldwide. 

"Because of its sinister, homicidal uses, arsenic - a naturally occurring element found in the Earth's crust - became world-renowned as the 'inheritance powder,'" explained Deborah Blum, the plenary speaker for the symposium. "What made arsenic such a good homicidal poison is the same thing that makes it dangerous in environmental exposures - it gives no warning," said Blum, who is at the University of Wisconsin-Madison. "It's mostly tasteless, it's odorless, and it's colorless. The symptoms of arsenic poisoning, especially if given in small doses over a long time, mimic those of natural diseases, so for a long time, people got away with it. Arsenic became one of the great historical poisons in human history." 

Blum described how arsenic remained largely the poisoner's first choice until the 19th century, when manufacturers started using it in pesticides, candies, jewelry and even in wallpaper to give it a deep green color. It even found uses in patent remedies and as an additive in certain foods. It was all over the place and easy for anyone to get. 

"At the start of the 19th century, scientists started realizing that they had to put a stop to this free-wheeling, murderous situation," she explained. "That's when the big revolution happened - scientists finally figured out how to detect arsenic in the body. Slowly, people realized they couldn't easily get away with it anymore, and arsenic became more difficult to obtain - manufacturers stopped adding it to common household products." 

Other speakers in the symposium focused on the ongoing problem of arsenic contamination in the 21st century. Arsenic occurs naturally in elevated concentrations in the soil in certain areas of the world. It sometimes leaches into drinking water supplies and food. Recent reports in the news media have drawn attention to its presence in apple juice and rice, and in groundwater in Bangladesh and Chile. 

"The goal of the symposium was to bring together experts on many aspects of arsenic, including general insights about arsenic contamination in food and water, regulatory issues, ways to analyze the element and ways to clean up contamination," said Jennifer Maclachlan of PID Analyzers, LLC, who was a co-organizer of the symposium. The other co-organizers were Britt Burton-Freeman, Ph.D., of the Illinois Institute of Technology; Lauren Jackson, Ph.D., of the U.S. Food and Drug Administration (FDA); John Johnston, Ph.D., of the U.S. Department of Agriculture; and Bill Mindak of FDA. 

The Pulitzer Prize-winning author of a popular book documenting arsenic's horrific history as a poison highlighted that situation at a far-ranging symposium on arsenic here today during the 245th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society. The following topics were among the two dozen presentations at the "Arsenic Contamination in Food and Water" symposium:
  • Poisoner's cupboard: The long (and sometimes homicidal) history of arsenic in everyday life.

    Deborah Blum1, University of Wisconsin, Madison, WI, United States

    The story of the element arsenic is a story of human history through a uniquely poisonous lens. One of the earliest realized poisonous elements, homicidal uses of arsenic can easily be traced back to the Middle Ages. But these were notably murders at the upper levels of society. It wasn't until the 19th century -- and the rise of industrial use of elements such as arsenic -- that it became the poison of the everyday citizen, the weapon of choice for serial poisoners. This relates to the fact that arsenic was widely available -- in medicine, in cosmetics, as a pesticide and even as a coloring agent in food. My talk will explore the rise of arsenic for both commercial and homicidal use, the rise of forensic toxicology that grew up as a result and the consequences, even today, of our long and close relationship with history's most important poison.
  • Arsenic in rice and rice products

    Brian P Jackson1, Dartmouth College, Department of Earth Sciences, HB 6105 Fairchild Bldg, Hanover, NH, 03755, United States

    Rice can be a source of both inorganic and organic arsenic to diet. In areas where water exposure is low, food may be the major exposure route for arsenic and rice can be a major source. This talk discusses why rice contains higher levels of arsenic than other grains, the concentration range of arsenic found in rice and rice products, the bioavailability of arsenic from rice and rice products and implications for dietary exposure. The talk also describes the analytical approaches to total and speciated arsenic analysis in rice and rice products.
  • Remediation of arsenic contamination of groundwater in Asia and USA

    Satinder Ahuja1, Dr., Ph.D., Ahuja Consulting, Research and Development, 1061 Rutledge Ct, Calabash, NC, 28467, United States

    Arsenic contamination of groundwater has been reported worldwide, including Asia and the United States. This problem is most pronounced in Bangladesh, where naturally occurring arsenic contaminates millions of wells that were installed to solve the problem of microbial contamination. Arsenicosis, resulting from drinking arsenic-contaminated water, is affecting around 200 million people in Asia; it can lead to a slow and painful death. To seek viable solutions, workshops were held in Bangladesh and India, and several symposia were organized at ACS and UNESCO meetings. Discussion of the problem will focus on how groundwater is contaminated with arsenic, desirable methods for monitoring arsenic contamination at ultratrace levels, and the best options for remediation. Solutions that offer significant improvements in water purification technologies, at reasonable costs, will be highlighted. The talk will encompass how the lessons learned from Asia can help solve the problem in other parts of the world.
  • Development of a method for assessing perinatal exposures to heavy metals using residual dried blood spots from newborn screening programs

    William E. Funk1, Dr., Ph.D., 1810 Hinman Avenue, Evanston, IL, United States

    Exposures to heavy metals during fetal and perinatal development are of particular concern. Yet, the health impacts of exposures to toxic metals during these early stages of human development are not well understood due to the paucity of in vivo human data. Dried blood spots, collected by public health departments to screen for inherited metabolic errors and other disorders, are routinely archived and can be used for exposure assessment. Here we report a method for quantifying arsenic in newborn DBS to facilitate epidemiologic research on the health effects of early exposures. Forty-nine randomly selected DBS were obtained from the North Carolina State Laboratory of Public Health with collection dates ranging from 2003-2009, and arsenic was quantified using one-half of a DBS for each sample. The median concentration of arsenic was 1.4 ppb, and the 90th percentile was 6.5 ppb. Arsenic was detectable in 80% of the samples.
  • Low, slow, and Next Gen impact: Arsenic, human health, and cancer risks

    Janet M Hock1, Sr. Investigator, Ph.D., Maine Institute for Human Genetics and Health, 8215 River Bay Dr East, Indianapolis, IN, 46240, United States

    Arsenic exposure contributes to human health risks of cardiovascular disease, diabetes, and cancer. Arsenic's mechanisms of action and threshold for disease risk remain controversial. While arsenic exposure via water has been more studied, relatively little is known about arsenic in food. This review discusses current concepts of low dose and time responses to arsenic and consequences of exposure on the next generation. While short-term effects of arsenic in immortalized human lung cells appear reversible, longer-term in vitro exposure promoted malignant transformation, essential for lung carcinogenesis. Drosophila, mouse and zebrafish studies suggest that early-life exposure to arsenic exacerbate health risks. Detrimental health effects in offspring occur when pregnant mice are exposed to arsenic during gestation. The underlying mechanisms were linked to epigenetic effects. Cell and animal models link in vitro and epidemiology studies, and will likely translate as human health risks, with pregnant mothers and their children being especially susceptible.

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