VOA标准英语2010年-Thousands Blind for Want of GM Rice?

Excessive regulation of genetically² modified crops has delayed release of a variety of rice that could help reduce the leading cause of preventable blindness in children, according to an editorial published in the British journal Nature.

Vitamin A is essential for vision and a healthy immune system. The World Health Organization estimates that at least 250,000 children go blind each year from vitamin A deficiency, and half of them die within a year of losing their sight.

Rice doesn't naturally contain this essential nutrient⁴. That's why vitamin A deficiency is so common in parts of Africa and Southeast Asia, where rice is the mainstay of the diet.

Making rice golden

To tackle the problem, researchers took genes⁵ involved in producing beta carotene, a vitamin A precursor⁶, from other plant species and inserted them into rice. It gives the rice grains a yellow-orange color, and their name: Golden Rice.

When the project began in 1990, it was considered unlikely to succeed, says Golden Rice's co-inventor, Ingo Potrykus, a retired⁷ professor of plant sciences at the Swiss Federal Institute of Technology.

International Rice Research Institute
Flowers of a rice plant producing beta carotene

"It was considered far too ambitious because you had to transfer an unknown number of genes — at least six different genes — into rice. At that time people were happy to transfer a single gene³."

Potrykus says they had succeeded by 1999, but it will be 2012 at the earliest before Golden Rice is available to people who need it. He blames the delay on excessive regulation. He says an unreasonable⁸ amount of testing has been required, without scientific justificiation.

'Death and blindness'

"I therefore hold the regulation of genetic¹ engineering responsible for the death and blindness of thousands of children and young mothers," he writes in the Nature editorial.

Potrykus wants the regulations changed because research institutes around the world are working on other important GM crops besides Golden Rice that could also help feed people in the developing world. However, he says, because bringing them to market takes 10 years longer and costs 10 times as much as a conventional crop, these crops are languishing⁹ on the shelves. He says now that some GM crops have been grown successfully for more than a decade, it's time to loosen the restrictions¹⁰.

"Despite claims of high risk of this material," he says, "there is not a single documented case of harm to any environment or any consumer."

'Scientific garbage'

Doug Gurian-Sherman, with the environmental group the Union of Concerned Scientists, calls that argument "scientific garbage." He says you can't say GM crops are safe because no one's really done a large-scale epidemiological study to see how people's bodies respond to them. He says they may very well be safe. But that won't be clear until they are tested.

"Potrykus' argument is like saying, 'Well, we've got these wonder drugs that could cure AIDS or cure malaria¹¹ or cure whatever," says Gurian-Sherman, "but let's not do any testing on them because there's people suffering in the meantime.'"

Gurian-Sherman says one reason Golden Rice needs to be tested for safety is because vitamin A and its chemical relatives can be toxic¹² at high levels.

Carrot poisoning

Others don't see that as a convincing argument.

"It's like saying if you ate too many carrots you could get vitamin A poisoning. It just doesn't happen," says Howarth Bouis, director of a project called Harvest Plus, which is working to breed more nutritious¹³ crops for the developing world.

Bouis is on the board of the Golden Rice project. But he says Harvest Plus decided¹⁴ to stay away from using GM technology because regulations would slow progress.

"I think we're going to make some good progress with conventional breeding that we couldn't have made with transgenics simply because of the regulatory systems in place."

For example, researchers are developing vitamin A-rich maize¹⁵ using conventional breeding. While regulators require extensive testing on GM Golden Rice, the new fortified¹⁶ maize varieties won't raise an eyebrow¹⁷.

Doug Gurian-Sherman of the Union of Concerned Scientists says GM technology is inherently more costly¹⁸ and time-consuming than conventional breeding. He would prefer to see more of the limited resources available for agriculture research spent on conventional means of tackling malnutrition¹⁹.  But if tests show Golden Rice is safe and effective, he says it should be considered.

The question will be, how much testing is enough?
 

1 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

2 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

3 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

4 nutrient   

adj.营养的，滋养的；n.营养物，营养品

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。

5 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

6 precursor   

n.先驱者；前辈；前任；预兆；先兆

参考例句：

• Error is often the precursor of what is correct.错误常常是正确的先导。
• He said that the deal should not be seen as a precursor to a merger.他说该笔交易不应该被看作是合并的前兆。

7 retired   

adj.隐退的，退休的，退役的

参考例句：

• The old man retired to the country for rest.这位老人下乡休息去了。
• Many retired people take up gardening as a hobby.许多退休的人都以从事园艺为嗜好。

8 unreasonable   

adj.不讲道理的，不合情理的，过度的

参考例句：

• I know that they made the most unreasonable demands on you.我知道他们对你提出了最不合理的要求。
• They spend an unreasonable amount of money on clothes.他们花在衣服上的钱太多了。

9 languishing   

a. 衰弱下去的

参考例句：

• He is languishing for home. 他苦思家乡。
• How long will she go on languishing for her red-haired boy? 为想见到她的红头发的儿子，她还将为此烦恼多久呢？

10 restrictions   

约束( restriction的名词复数 )； 管制； 制约因素； 带限制性的条件（或规则）

参考例句：

• I found the restrictions irksome. 我对那些限制感到很烦。
• a snaggle of restrictions 杂乱无章的种种限制

11 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

12 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

13 nutritious   

adj.有营养的，营养价值高的

参考例句：

• Fresh vegetables are very nutritious.新鲜蔬菜富于营养。
• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。

14 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

15 maize   

n.玉米

参考例句：

• There's a field planted with maize behind the house.房子后面有一块玉米地。
• We can grow sorghum or maize on this plot.这块地可以种高粱或玉米。

16 fortified   

adj. 加强的

参考例句：

• He fortified himself against the cold with a hot drink. 他喝了一杯热饮御寒。
• The enemy drew back into a few fortified points. 敌人收缩到几个据点里。

17 eyebrow   

n.眉毛，眉

参考例句：

• Her eyebrow is well penciled.她的眉毛画得很好。
• With an eyebrow raised,he seemed divided between surprise and amusement.他一只眉毛扬了扬，似乎既感到吃惊，又觉有趣。

18 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

19 malnutrition   

n.营养不良

参考例句：

• In Africa, there are a lot of children suffering from severe malnutrition.在非洲有大批严重营养不良的孩子。
• It is a classic case of malnutrition. 这是营养不良的典型病例。