密歇根新闻广播 关注伊利湖中的毒性爆发

 

There's a bloom of cyanobacteria in Lake Erie right now. Scientists with the National Oceanic and Atmospheric¹ Administration are predicting it could become the second worst on record.

The bacteria produce a toxin² called microcystin. A year ago, that toxin led to a ban on drinking water in Toledo and a few Michigan communities. Officials say microcystin can cause skin irritation³ and could affect the liver and nervous systems if you consume it in large amounts.

This week, Toledo officials said they detected low levels of microcystin in untreated water from Lake Erie. But they say right now, their treatment system is removing the toxin and city water is safe to drink.

Joel Mazur is the commissioner⁴ of field operations with the Toledo water department.

"We're light years ahead of where we were before in terms of water treatment," Mazur says.

He says they've stepped up monitoring and added more treatment steps to take out the toxin.

"We're able to detect the issues in the lake far sooner than we were before and treat it," he says.

This year's bloom

We took a boat ride with local officials, environmental groups and reporters to get a look at this year's bloom.

Sandy Bihn is with Lake Erie Waterkeeper. She holds up a glass of lake water with little green blobs floating in it.

"It's not nearly as dense⁵ as it was last year when we were out here, because the bloom has moved further east which is good for the Toledo intake⁶," she says.

We're three miles away from shore when Joel Mazur points out Toledo's water intake crib. He says they put in an advanced warning system after last year's crisis. So now, there's a monitor in the intake crib.

"Now that we're detecting microcystin in the water, we have crews that actually come out now and they are taking samples and taking it to the lab so we can have daily monitoring of the levels of microcystin that are in the water today," Mazur says.

There's a water quality dashboard on the city's website. Right now, city water is at the "watch" level. That means they've detected microcystin in the lake but not in tap water.

Phosphorus in Lake Erie

In June, Governor Snyder joined Ohio Governor John Kasich and Ontario Premier⁷ Kathleen Wynne in a pledge to cut phosphorus into Lake Erie by 40 percent over the next 10 years.

Phosphorus gets into the lake from farm fertilizer, wastewater from cities, and leaking septic tanks along with other sources.

Sandy Bihn says we need better monitoring of all these sources.

"We know that ag is a huge contributor," she says. "I mean, we know what the categories are. We don't know the specific locations and amounts, that's what we're missing."

She says officials need to track exactly how much phosphorus is coming from each source.

Bill Myers agrees with her. He's the president of the Lucas County Farm Bureau.

"I'm tired of hearing hypotheticals on where things are coming from," he says. "We need to know for sure what areas are contributing and target the highest levels with the quickest response to get the hugest decrease as fast as we can."

This spring, Ohio enacted⁸ a law that bans farmers from spreading fertilizer on frozen or rain-soaked fields. It's intended to cut back on phosphorus that runs off those fields.

A cyanobacteria puzzle

Scientists are trying to solve a mystery about these toxic⁹ blooms.

Greg Dick is an associate professor of earth and environmental sciences at the University of Michigan.

"One of the really interesting findings so far has been that as we track these blooms through the season, the bloom develops and it progresses and it's toxic," Dick says. "But then towards the end of the summer we still have a really strong bloom with very dense cyanobacteria, but the toxicity¹⁰ of that bloom changes. And in particular the toxicity of the bloom drops off."

He says they could find some clues in the DNA¹¹ of these bacteria. Some strains have the gene¹² to produce the toxin and others don't. Dick says they're testing a hypothesis that nitrogen could affect how toxic the blooms become.

1 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

2 toxin   

n.毒素，毒质

参考例句：

• Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
• Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。

3 irritation   

n.激怒，恼怒，生气

参考例句：

• He could not hide his irritation that he had not been invited.他无法掩饰因未被邀请而生的气恼。
• Barbicane said nothing,but his silence covered serious irritation.巴比康什么也不说，但是他的沉默里潜伏着阴郁的怒火。

4 commissioner   

n.（政府厅、局、处等部门）专员，长官，委员

参考例句：

• The commissioner has issued a warrant for her arrest.专员发出了对她的逮捕令。
• He was tapped for police commissioner.他被任命为警务处长。

5 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

6 intake   

n.吸入，纳入；进气口，入口

参考例句：

• Reduce your salt intake.减少盐的摄入量。
• There was a horrified intake of breath from every child.所有的孩子都害怕地倒抽了一口凉气。

7 premier   

adj.首要的；n.总理，首相

参考例句：

• The Irish Premier is paying an official visit to Britain.爱尔兰总理正在对英国进行正式访问。
• He requested that the premier grant him an internview.他要求那位总理接见他一次。

8 enacted   

制定（法律），通过（法案）( enact的过去式和过去分词 )

参考例句：

• legislation enacted by parliament 由议会通过的法律
• Outside in the little lobby another scene was begin enacted. 外面的小休息室里又是另一番景象。 来自英汉文学 - 嘉莉妹妹

9 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。

10 toxicity   

n.毒性，毒力

参考例句：

• The hoarse grunt or squeal is characteristic of toxicity.嘶哑的哼声和叫声是中毒的特征。
• Dieldrin is related to aldrin,and its toxicity to earthworms is similar.狄氏剂与艾氏剂有关，对蚯蚓的毒性是相似的。

11 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

12 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。