Research shows that adding rice husk to soil reduces arsenic uptake by half

Monday, June 27, 2016 by: Daniel Barker
Tags: rice, arsenic contamination, plant uptake

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(NaturalNews) Scientists have discovered an eco-friendly method of reducing arsenic uptake in rice by as much 50 percent, without diminishing yield.

A team of researchers at the University of Delaware found that by simply mixing rice husk into the planting soil, levels of arsenic in rice grain were reduced by 25 to 50 percent.

The findings could have positive implications for rice cultivation in developing countries, where rice is a staple, and where arsenic contamination is a significant health issue.

Although arsenic contamination in soil can be caused by arsenic-based pesticide residues, most inorganic arsenic found in soil is naturally occurring, and varies in concentration from place to place due to geological factors.

High levels of naturally occurring inorganic arsenic can be found in the United States, South America and Asia.

Why arsenic is a problem in rice cultivation

Problems with arsenic levels in rice arise mainly because the rice plant is particularly efficient at drawing arsenic and other metals from the soil.

As reported by UnDark:

"It turns out that the rice plant is a very efficient vacuum for pulling metallic elements out of the soil. The most troubling of these include two well-known trouble-making elements: mercury, cadmium, and arsenic, which is considered a metalloid element. Researchers say the plant is at least ten times as effective as other grains at siphoning up arsenic from soil and water. Further, it has a particular affinity for inorganic arsenic (an arsenic compound that lacks the organic element carbon). Inorganic arsenic compounds are known to be far more poisonous to humans than organic, carbon-based arsenic compounds."

The issue of arsenic contamination in rice has received more attention recently, since the FDA announced earlier in 2016 that it is considering new regulatory guidelines for maximum allowable arsenic content in baby rice cereal. The agency also issued recommendations calling for a reduction in rice consumption for babies and pregnant women.

The new research could lead to the implementation of an inexpensive and natural solution to the problem in arsenic-contaminated rice growing regions.

The implications of previous studies led the researchers to the idea of experimenting with various soil incubations incorporating rice straw, rice husk and rice ash. Rice husk proved to enrich the soil, producing healthier rice plants – along with the beneficial effect of reducing arsenic content in the rice grains.

Lead researcher Angelia Seyfferth said:

"The big finding is that when we grow these plants in the fresh husk amended soil, we see a 25-50 percent decrease in the inorganic arsenic in the grains which is the most toxic form of arsenic. So right away, just by putting this material into soil, we can make the plants healthier and alter the toxic form of arsenic that's in the grain which has direct implications for human health."

Human health risks of arsenic

Scientists have only recently begun to recognize the health implications of arsenic found in our soil, water and food. Even minute concentrations have been shown to cause health problems:

"It was only in the late 20th century that scientists began to detect arsenic in soil, water and food — not at levels high enough to kill people outright, but at the part-per-billion level. The question was whether even these levels were cause for concern, and in the 1970s and 80s, researchers did begin making links between even tiny levels of arsenic in ground water and a surprising range of illnesses, from cancer to cardiovascular disease. Much of our modern awareness of the issue is tied to studies in Bangladesh, where so many people are exposed to arsenic-contaminated ground water that the World Health Organization describes it as the greatest mass poisoning in human history."

It's encouraging to see mainstream scientists researching natural, eco-friendly solutions to such a serious global problem.

But for those of us who already believe in and practice organic farming principles, it's not a big surprise to find that Mother Nature held the answer all along. ...

Sources:

ScienceDaily.com

Undark.org

Science.NaturalNews.com