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Throughout the Youngz River Delta, a region in southern China, farmers, famous for their extensive rice production, grow thin green stem belts. Before they reach a few feet tall and turn golden brown, the grassy plants soak in muddy, flooded fields for several months. Along a row of submerged plants, the embankments store and distribute stable water that farmers supply from nearby canals.
This traditional practice of flooding paddy fields to grow infamous thirsty crops is almost as old as ancient grain livestock. Thousands of years later, agricultural methods continue to dominate rice farming practices from lowlands in Arkansas to vast terraces in Vietnam.
As the planet gets hotter, this popular process of growing rice is becoming increasingly dangerous to millions of people around the world who regularly eat grains. the study It was featured in the Journal Lancet Planetary Health on Wednesday. After drinking water, researchers say that rice is the world’s second largest dietary source of inorganic arsenic, and climate change appears to be increasing the amount of highly toxic chemicals in it. If nothing is done to change how much rice in the world is produced, how much people consume, or alleviate warming, the authors conclude that in 2050, communities with high rice-heavy diets could begin to face.
“Our results are very scary,” said Donming Wang, a doctoral student of the Ecosystems from the Institute of Soil Science at the Chinese Academy of Sciences, who led the paper. “It’s a disaster…and a wake-up call.”
In 2014, Wang and a team of international climate, plant and public health scientists began collaborating on a research project that would be completed in nearly a year. Walking across Yangtze Delta through rice paddies, the predicted temperature and levels of atmospheric CO2 in 2050 was to find ways to interact with arsenic in the soil and rice crops planted there. They knew from past research that carcinogens are the problem of rice cultivation, but wanted to know how much of this is a problem in the world of global warming. The team didn’t just look at rice, but some of the most produced and consumed grain varieties in the world.
There is but An estimated 40,000 types of rice On planets, they tend to be grouped into three categories based on grain length. Short grain rice, or a sticky type commonly used in sushi. Long grains containing aromatic types such as basmati and jasmine. and medium grains, or rice that tends to be It was served as a main dish. Of these, the short japonica and long grain indica are Two major subspecies of cultivated rice Eats all over Asia. Wang’s study modeled the growth of 28 japonica, indica and hybrid rice strains at the heart of seven culinary 7 of the continent’s seven US consumption and producer countries. India, Vietnam and China are one of the groups Eight countries That will guide the rest of the world with rice exports.
After nearly a decade of observing and analyzing plant growth, researchers found that a combination of higher temperatures and CO2 promotes root growth and increases the ability of rice plants to absorb arsenic from the soil. They believe this is because climate-related changes in arsenic-like soil chemistry can be more easily absorbed by grains. Carbon dioxide concentrate crops have been found to capture more atmospheric carbon and pump some of it into the soil, stimulating the microorganisms that produce arsenic.
The more roots grow, the more carbon in the soil. This is a food source for soil bacteria that grow at warm temperatures. When the soil in rice paddies is flooded, oxygen is depleted and soil bacteria rely more on arsenic to produce energy. The final result is that arsenic accumulates in rice paddies and there is more roots to bring it to the developing grain.
These arsenic accumulation effects associated with increased root growth and carbon capture are paradoxical surprises for Corey Lesk, a postdoctoral climate at Dartmouth University. The paradox is that both of these results are spoken as potential benefits to rice yield under climate change. “More roots can tolerate rice more drought, and cheaper carbon generally can increase yields,” he said. “However, the accumulation of excess arsenic can make it difficult to realize the health benefits from its yield.”
Arsenic comes in a variety of forms. What is the infamous toxic, inorganic arsenic – a compound of carbon-free elements – the World Health Organization I’ll classify it As “confirmed carcinogens” and “the most important chemical contaminants in drinking water around the world.” Such a form of arsenic is Usually more toxic Because for humans, they are less stable than organic matter, and may allow arsenic to interact with molecules that enhance exposure. Chronic exposure is associated with lung, bladder, skin cancer, heart disease, diabetes, the negative effects of pregnancy, neurodevelopmental problems, and weakening of the immune system.
Scientists and public health experts have long known that the presence of arsenic in food is a threat to the increased presence of food, but dietary exposure has long been considered less risky compared to contaminated groundwater. Therefore, policy measures to mitigate risk have been delayed. For example, some existing standards established by the European Union and China are considered inconsistent and largely reinforced. No country has formally established regulations regarding organic arsenic exposure in foods. (In the US, the Food and Drug Administration has established it Action level of 100 parts per inorganic arsenic in infant grainshowever, its recommendation to manufacturers is not a compulsory regulation regarding arsenic in rice and other foods. )
The King wants to see this change. For example, although the levels of inorganic arsenic, which are common in the rice today, belong to China’s recommended standards, her paper shows that the incidence of lifetime bladder and lung cancer is likely to increase “proportionally” with exposure by 2050. 200 copies per 200 copiesThe level of inorganic arsenic in the studied rice varieties is projected to rise at a whopping 44%. In other words, more than half of the rice samples exceed China’s current proposed limits, limiting 20 billion portions of inorganic arsenic in paddy fields, and an estimated 13.4 million cancers are associated with rice-based arsenic exposure.
These health risks are calculated in part based on weight, so toddlers and young children will face the greatest health burden. Researchers say babies in particular can face different risks through rice grain consumption.
“You’re talking about a crop staple that feeds billions of people. When you think that more carbon dioxide and warm temperatures can have a big impact on the amount of arsenic in its staple food, and the associated health effects, it’s a better word, a huge one.
But as a result, not everyone should suddenly stop eating, he added. The team found that the amount of inorganic arsenic in rice is higher than many other plants, but overall it is still very low. The key variable is how much rice a person eats. If you are in the majority of the world where you consume rice multiple times a week, this looming health burden may apply to you, but if you sporadically do it more, Zizca says the inorganic arsenic you expose may not be a “big deal.”
In that way, research predictions are also likely to deepen existing global and social inequality, as they are a major reason that they long governed as one of the planet’s most greedy grains.
Simply mitigate global greenhouse gas emissions – what Ziska calls “waving rainbows, unicorns, and sprinkle canes” – adaptation efforts to avoid the future with toxic rice include rice paddy farmers planted early in the season to breed to minimize growth, avoid warmer temperature development, improve soil management, avoiding plant growth.
Water-saving irrigation techniques such as alternative wetting and drying, where paddy fields are first allowed to flood and then dry in cycles, can also be used to reduce these increasing health risks and Huge methane footprint of grain. On a global scale, rice production is roughly explained 8% of all methane emissions from human activities – Inundated rice fields are ideal conditions Methane-releasing bacteria.
“This is the realm I know I’m not sexy and I don’t have the same atmosphere, sea level rise, Category 10 storm as the end of the world,” says Ziska. “But since we are all eating, we’ll be very honest that it will have the greatest effect on humanity.”
This article was originally published Grist in https://grist.org/food-and-agriculture/the-king-of-poisons-Arsenic-is-building-up-in-rice/. Grist is a non-profit, independent media organization dedicated to telling climate solutions and stories of just the future. See more details at Grist.org
