VOA慢速英语：专家解读：灌溉后不要立刻收割农作物

American researchers say farmers should wait one dayafter a rain storm or watering their fields to harvest fresh fruits and vegetables.They say gathering the crops at least 24 hours after rainfall increases foodsafety. They say it also may be enough to protect those eating from freshproduce from food borne illnesses.美国研究人员指出，农民应该在暴风雨或者灌溉一天之后丰收新鲜的水果和蔬菜。他们称降水过后一天收获谷物才安全。同时这样也能避免食用这些果蔬后带来的一些疾病。

Listeria is a food borne bacteria. It grows best in wet conditions. Poisoningwith Listeria monocytogenes can cause muscle pain. The person can alsofeel sick to the stomach and even experience diarrhea – the uncontrolledexpulsion of wastes from the body.

李斯特菌是一种食物病毒。这种病毒在潮湿状态下繁殖很快。感染单核细胞增生李斯特氏菌会引起肌肉疼痛。受到感染的人还会引起胃部不适，甚至腹泻。

FILE - Spinach and other fresh produce should be picked at least 24 hours after rain or irrigation to reduce the risk from Listeria

Listeria can be a serious health threat for pregnant women and older adults. Itcan also threaten people with weak immune systems, like those with HIV, thevirus responsible for the disease AIDS.

对妊娠妇女和老人来说，李斯特氏菌是严重的健康威胁。它还能够威胁免疫力低下的人群，比如那些受艾滋病毒感染的人们。

The bacterium is everywhere in the environment, but usually grows in water.So, crops that are harvested shortly after they have been watered are likely tocontain unsafe levels of disease-causing Listeria.

细菌在环境中随处可见，但是它们通常在潮湿的条件下生存。因此，收割刚灌溉过的谷物有可能含有造成李斯特氏菌的不安全细菌

Martin Wiedmann teaches food safety at Cornell University in New York State. He and other researchers are urging farmers to wait 24 hours after a rainfall orwatering fields before they harvest crops. By waiting, he says, a field hasenough time to dry out.

马丁在美国纽约州康奈尔大学教授食品安全。他和其他研究者要求农民在下雨后或者灌溉后等待24小时在收割谷物。他说，通过等待，稻田有足够的时间变干。

“You're more likely to find Listeria for a very short time. After one day, it dropsback more or less to the baseline normal level that we find (in theenvironment). So, we found this effect in water, but it's very short-lived. Withina day, you are back to normal."

你很有可能在短时间内发现李斯特氏菌，一天后，病菌数量多多少少将会下降到我们能够发现病菌的基本标准线（在三种环境下）。所以，我们在水中发现这种效应，但是病菌活的时间很短。一天之内，就回复到了正常水准。

The findings were reported in the journal Applied and EnvironmentalMicrobiology.

该项发现发表在《微生物应用与环境》杂志上。

In crops like spinach, Listeria levels were 25 times greater when harvestedimmediately after the plants were watered.

像菠菜这样的蔬菜。如果刚刚灌溉就收割，李斯特氏菌含量比平时高25倍。

Martin Wiedmann says the bacterium can also be found in sandwich meat,especially when the meat is not kept to minus-four or minus-five degreesCelsius. He says there are a number of other settings where unsafe levels ofListeria can hide.

马丁指出，三明治里的肉中也有李斯特氏菌，如果肉没有储存在零下四度或者五度的环境下的话。他说李斯特氏菌可以隐藏在多种不安全环境里。

"And so it's important to have the tools in place to control this organismeverywhere from primary production, to food processing plants to retail, tohelping consumers make smart decisions on what foods to eat and how tocook food."

所以要从最初的食品生产到食品加工再到零售，都要采取措施控制病菌滋生，帮助消费者做出明智选择，知道哪个能吃，怎样烹制食物。

Martin Wiedmann notes that Listeria poisoning is less common in developingcountries. In such areas, he adds, foods generally are not left in iceboxes orrefrigeration equipment, another source of bacterial overgrowth.

马丁指出，这种李斯特氏菌在发展中国家很少见，因为在这些地区，食物通常不会储存在细菌会过量繁殖的冰箱里。

I’m Marsha James.

VOA’s Jessica Berman reported this story. Marsha James adapted it forLearning English. George Grow was the editor.

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Words in This Story

irrigation– v. to supply with water by using man-made equipment, such aspipes or waterways

immune system – n. the body’s natural defenses against diseases andinfections

bacterium - n. any one of a group of small living things that can causedisease