密歇根新闻广播 化学事故之后40年密歇根人体内PBB指标仍超常

In 1973, a plant owned by Velsicol Chemical made a mistake and shipped a toxic¹ flame retardant chemical to a livestock² feed plant. The chemical is called polybrominated biphenyl, or PBB. It took about a year to discover the accident. Millions of Michiganders ate contaminated beef, chicken, pork, milk and eggs.

All these years later, researchers are finding that PBB exposure is linked to health problems.

Michele Marcus is a professor of epidemiology, environmental health and pediatrics at Emory University Rollins School of Public Health and Emory University School of Medicine.

She's in Michigan this week to talk about her latest research findings at a conference at Alma College.

PBB sticks around in your body

Marcus says over the past two years, her team has tested more than 800 people across the state.

"We have found that six out of 10 of the people that we tested still have levels that are elevated as a result of the PBB accident," she says. "We compared the levels of PBB in the people that we tested in Michigan to levels that were measured ten years ago on a random³ sample of the U.S. population."

She says six out of 10 Michiganders had PBB levels higher than 95% of the U.S. population.

"It means that the PBB is still lingering in people's bodies and that's a very long time. It's 40 years later. And we are concerned that the health effects we have found are continuing among the people who were exposed themselves, but also among their children and grandchildren," she says.

Health effects over multiple generations

She says her team has found that among the women who were exposed to high levels of PBB, there are slightly more breast cancer cases than they expected.

"Among girls, the daughters of women who were highly exposed, we found that they experienced their first menstrual periods a full year earlier than girls who were unexposed, and now that these girls are adults, we find that they have a very high rate of miscarriages⁴. And that the rate of miscarriages is proportional to the PBB exposure that they experienced," says Marcus.

Marcus says at the conference, she's presenting preliminary data on the potential for epigenetic changes that are associated with PBB exposure. Those are changes in how genes⁵ are expressed.

"That really sets the stage for our just-funded research," she says. "We will be recruiting multi-generational families where the father was exposed but not the mother, and looking at the children and the grandchildren so we can see if these epigenetic changes are passed along in the absence of actual PBB exposure."

She says her new research project has three goals. One is to determine whether epigenetic marks are being transmitted across generations.

They're also going to test a substance that may be able to help speed elimination⁶ of PBB from the body.

"When the results are in, we will let people know if we've been able to successfully help people eliminate PBB from their bodies. Because PBB is very slowly eliminated. It takes about 15 years for you to eliminate about half of the PBB in your body. So we are going to try an intervention⁷ that we think may help speed the elimination," she says.

She says the third goal is to educate the public and doctors so they understand that people who have been exposed to PBB in Michigan may have a higher risk of breast cancer, pregnancy⁸ problems and thyroid problems, so they can be monitored.

You can learn more about Emory's PBB registry for people who were exposed to the chemical here, and you can learn more in our special series on the PBB mix-up and legacy⁹ of pollution in St. Louis, Michigan here.

1 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。

2 livestock   

n.家畜，牲畜

参考例句：

• Both men and livestock are flourishing.人畜两旺。
• The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。

3 random   

adj.随机的；任意的；n.偶然的(或随便的)行动

参考例句：

• The list is arranged in a random order.名单排列不分先后。
• On random inspection the meat was found to be bad.经抽查，发现肉变质了。

4 miscarriages   

流产( miscarriage的名词复数 )

参考例句：

• Miscarriages are usually caused by abnormal chromosome patterns in the fetus. 流产通常是因为胎儿的染色体异常造成的。
• Criminals go unpunishedareconvicted and are miscarriages of justice. 罪犯会逍遥法外，法律会伤及无辜，审判不公时有发生。

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 elimination   

n.排除，消除，消灭

参考例句：

• Their elimination from the competition was a great surprise.他们在比赛中遭到淘汰是个很大的意外。
• I was eliminated from the 400 metres in the semi-finals.我在400米半决赛中被淘汰。

7 intervention   

n.介入，干涉，干预

参考例句：

• The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
• Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。

8 pregnancy   

n.怀孕，怀孕期

参考例句：

• Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
• Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。

9 legacy   

n.遗产，遗赠；先人(或过去)留下的东西

参考例句：

• They are the most precious cultural legacy our forefathers left.它们是我们祖先留下来的最宝贵的文化遗产。
• He thinks the legacy is a gift from the Gods.他认为这笔遗产是天赐之物。