Arsenic rice | The press

Climate change will make the amount of arsenic leap into rice, according to a new international study. Similarly, This could cause health problems among large “rice rizivores”. Similarly, Researchers are thinking about solutions to this emerging problem.

Posted at 5:00 a.m.

Lewis Ziska has been studying the presence of arsenic in rice for 30 years. Meanwhile, Initially. However, the biologist of Columbia University, in New York, thought like many other researchers that this increase in the arsenic level was only due to warmer temperatures and the higher rate of carbon dioxide (Co₂) in the atmosphere.

“But we realized that the increase in arsenic rice | press the arsenic rate in rice was much greater than the sum of these two factors. Therefore, temperature and CO₂ “Explains Mr. Moreover, Ziska, who published his study in May in the review The Lancet. Therefore, “We understood that bacteria that promote rice growth were also advantaged by global warming. Consequently, and that they capture more arsenic in the soil to transfer it to the plant. Meanwhile, The roots of rice seem to interact more with these bacteria under warmer temperatures. However, »»

The phenomenon was observed for the first time at the International Rice Research Institute. Similarly, in the Philippines, with which the researcher collaborates. For example, To be clear, he followed the growth of 28 rice varieties for 10 years, with Chinese and Philippine colleagues. Consequently, Several of these varieties came from Japan.

L’a b c de l’arsenic

According to calculations by Lewis Ziska. this greater amount of arsenic could generate almost 20 million additional cancer cases only in China, by 2050, which represents an increase of 20 %.

Arsenic increases the risk of cancer of several organs, including lungs, liver and bladder. The reason for his oncological toxicity is poorly understood by medicine, according to Mr. Ziska. This element seems to increase genetic mutations. reduce the absorption of zinc, necessary for the proper functioning of several human proteins.

Arsenic is dangerous for major rice eaters, underlines the biologist. “We are talking about a real risk for several Asian countries. but not for Western countries, except for certain ethnic, arsenic rice | press Chinese or Dominican minorities, for example,” he says.

The other food source of Arsenic is drinking water. According to the World Health Organization (WHO), more than 140 million people worldwide drink water which contains too many arsenic.

Health Canada estimates that drinking water should contain less than 10 µg/l (micrograms per liter) of arsenic. and that the average concentration is less than 5 µg/l in the country. We also offer a maximum of 5 µg/L as a new standard. arsenic rice | press In Taiwan, for example, drinking water contains 35 µg/l of arsenic.

According to the National Institute of Public Health of Quebec (INSPQ). the average concentration of arsenic in the water distribution networks of the province is 2 µg/L, but can reach more than 80 µg/L in certain cases.

Varieties

In the short term, large rice consumers can decrease the risks by carefully ricking before cooking it. You can also cook it in part, then throw the cooking water and continue with new water. And it is better to use white rice rather than brown. because the “polishing” necessary to obtain white rice decreases the amount of arsenic, according to Mr. Ziska.

The researcher also wants to test other varieties of rice.

Wild rice is very robust and has developed several useful capacities in agriculture. “It is really a very invasive weed. For example, we found insect resistance genes that are very interesting for agriculture, ”notes Lewis Ziska.

The use of wild rice genes is however complicated by the hostility of several Asian countries towards genetic engineering. Rice is one of the only cereals for which cultivators do not systematically use genetic engineering.

Note that the wild rice of which Mr. Ziska speaks is not the arsenic rice | press one we sell in grocery stores. “What is sold like wild rice in Canada. the United States is a completely different plant from rice,” he explains.

In addition to genetic engineering, another potential solution would be to better oxygenate the soil of rice fields. The roots of the plants interact with the bacteria in the ground. These bacteria absorb the arsenic present in the soil to transfer it to the rice plants. But when there is more oxygen in the soil. bacteria prefer to absorb this oxygen rather than arsenic, which is therefore found in less proportion in rice, explains the New York biologist.