If you were a server at a worldwide restaurant – one that could seat every last man, woman and child on Earth and feed them what they usually eat – you would be dishing out rice more than any other item on your menu. By far.
You’d be serving much of it with extra arsenic, too – not because anyone asked for it, but because rice almost always brings it along and in some areas of the world the rice collects much more than in others. Many other foods on the menu would have arsenic in them, too, because rice is an ingredient in many cereals, drinks, pasta, puddings, pizza crust, pie crust, brownie mix, cookies, snack bars, even some beers and wines.
Arsenic – a chemical and known carcinogen – occurs naturally in soil and is released into groundwater and soils through both natural processes and through pesticides and fertilizers. Rice is especially susceptible to arsenic contamination because of the way it is typically grown under paddy conditions and the way its roots take in water and nutrients.
Diners in Bangladesh are believed to be at greater risk of arsenic poisoning than anyone else in the world because of high contamination levels in water supplies and rice. The United States serves up its share, too, but no government authority has yet set official arsenic-related exposure standards in food.
Now an expert from Bangladesh is collaborating with an expert at the University of Delaware’s College of Agriculture and Natural Resources (CANR) to look for ways to defend rice plants against arsenic and fortify them with other nutrients at the same time.
Mahmud Hossain Sumon is a professor at Bangladesh Agricultural University in Mymensingh and a visiting Fulbright Scholar in residence this year at UD, working with plant and soil scientist Angelia Seyfferth.
Seyfferth put rice on UD’s research map in a new way in 2015, when she installed 12 rice paddies on a small plot of UD’s Newark farmland. Six more were added this year.
That’s a quaint little plot by standards in Sumon’s country, nestled between Burma and India, about 8,000 miles from Newark. More than 75 percent of arable land there is covered in rice, about 28 million acres, he said.
The climate allows three harvests in many areas in Bangladesh, while Seyfferth gets one from her Delaware paddies.
Both scientists see great benefit in their collaboration. Seyfferth hopes to test new methods in real Bangladesh field conditions and Sumon, whose research interests include geochemistry, environmental science, rhizosphere dynamics and biogeochemical cycling, now has access to UD’s research facilities.
“We have the facilities but we are lacking field situations,” Seyfferth said of her lab at UD. “The rice paddies are our laboratory, but labs are mesocosms [carefully controlled environments], not traditional rice paddy fields.”
She became aware of Sumon’s work through another colleague and suggested he apply for the Fulbright Program. He saw it as a rare opportunity to use state-of-the-art facilities. His wife and two children, ages 8 and 6, are with him for this nine-month endeavor.
Together, Seyfferth and Sumon are working to find soil amendments that deliver two significant advances – decreased arsenic and increased nutrient levels – while remaining affordable to farmers in Bangladesh and other developing countries.
Seyfferth has been testing silicon amendments that come from crop residues, such as rice husks. Using probes that continuously monitor the soil chemistry, she shows that the higher the silicon content, the lower the arsenic uptake. That could be part of the answer for Bangladesh, where rice husks are typically discarded but could instead be a readily available and affordable source of needed silicon.
There are two forms of arsenic, organic forms and inorganic forms, and both are toxic to plants and humans. The majority of the arsenic found in U.S. rice is in organic forms, which are more phytotoxic while the majority in Bangladesh rice is in inorganic forms, which cause cancer in humans.
That raises questions about what kinds of microorganisms are in the soils and how do they differ in U.S. and Bangladeshi soils and respond to different conditions?
Under carefully controlled conditions monitored by the U.S. Department of Agriculture (USDA), Seyfferth has imported soil from Bangladesh for some of these analyses. Using DNA extraction and analysis, scientists can examine genetic material and learn what sort of organisms are – or have been – active. And that helps researchers learn how environmental conditions and amendments affect the rice plants and the essential food they produce.
“Working with Mahmud has been a pleasure,” she said. “I think one thing that I can learn from him is rice cultural practices – not just for growing rice in the field, but for how rice ties into the culture. For example, if we come up with a solution on the bench top, would farmers in Bangladesh consider using the method? How would incorporating husk into soil work in practice? Would there be a mechanism to get the material back to the farmers once it is separated from the grain?”
Having access to real field conditions is essential, too, she said.
“The connections he has to various farms in Bangladesh is going to push the science forward. While we can test our ideas in our rice paddies as a proof of concept study, we really need to test our methods in fields in Asia and other places where rice is typically grown. This collaboration will help to facilitate that future work. I also envision that we will send students to do visits in Bangladesh in the future.”
About the researchers
Angelia Seyfferth is assistant professor of plant and soil sciences in the College of Agriculture and Natural Resources. She earned her bachelor’s degree in environmental science at Towson (Maryland) University, her doctorate at the University of California, Riverside, and did postdoctoral work at Stanford University before joining UD’s faculty in 2012. She won a prestigious National Science Foundation Faculty Early Career Development Award, which provided funding for the plot of rice paddies she and her team created in 2015.
Mahmud Hossain Sumon is professor of soil science at Bangladesh Agricultural University in Mymensingh. He is a graduate of that university, earned his doctorate at the University of Aberdeen (Scotland) and did postdoctoral work at the Queen’s University in Belfast, Ireland. His research interests include geochemistry, environmental science, waste management, biogeochemical cycling, rhizosphere dynamics and plant ecophysiology.
About Fulbright at UD
The Fulbright Program annually provides 8,000 grants for research or teaching in one of over 140 countries throughout the world. Established by U.S. Sen. J. William Fulbright in 1946, the program seeks to foster international partnership and cultural exchange by funding research and teaching opportunities worldwide.
Since 1950, more than 170 faculty, staff, student and alumni members of the University of Delaware community have received Fulbright Awards.
The University welcomes Fulbrighters from around the world for research and graduate study, with students hailing from Afghanistan, Bahrain, Bangladesh, Colombia, Egypt, Indonesia, Iraq, Mexico, Pakistan, Russia, South Korea, Spain, Tunisia, Turkey, Ukraine, and Uzbekistan.
For more details on Fulbright at the University of Delaware, visit the Institute for Global Studies website or contact Lisa Chieffo, associate director for study abroad and UD’s Fulbright Program adviser.
Article and video by Beth Miller
Photo by Wenbo Fan
This article can also be viewed on UDaily.