密歇根新闻广播 美专家呼吁多研究致癌化学混合物

 

Scientists study chemicals for their potential to cause cancer, but usually they examine them one at a time.

And yet, we're exposed to mixtures of different chemicals every day.

Dr. William Goodson is a senior scientist with the California Pacific Medical Center Research Institute.

He's the lead author of a new paper in the journal Carcinogenesis. He worked with a team of more than 170 scientists around the world to examine what we know about the potential for mixtures of chemicals to cause cancer.

Here's an excerpt¹ from the paper's abstract:

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible² estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic³ environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals.

Why study mixtures?

Goodson says we know very little about the mixtures of chemicals we're exposed to.

Up until now, he says, researchers have focused on whether or not individual chemicals can, on their own, cause cancer. There just haven't been many studies on how chemicals might work together to lead to cancer.

"Because it's more complicated to do," he says.

"And what we're realizing, and what this group spent several days talking about, was that there's reason to think that it doesn't take one chemical to take it all the way from normal to cancer."

Goodson says different chemicals, when combined, might lead to a carcinogenic mixture.

"One chemical can take it part way, another chemical will take it another portion of the way and maybe a second, third, or fourth chemical will take it all the way," he says.

He says this concept is still just theoretical.

"But we think it really needs to be looked at very carefully," Goodson says.

Beginning the process

He says testing mixtures of chemicals is tricky⁴.

"Probably the biggest challenge is trying to figure out which mixtures you're going to test, and that requires making some educated guesses about which ones to look at," Goodson says.

And it won't be cheap.

"It's going to require a lot of effort to put this together," he says. "No company's going to take this on because nobody is going to make money by deciding what mixtures are unsafe. It really requires a funding effort and an organizational effort, really probably on a federal level."

He also noted⁵ that many big-name organizations fundraise for cancer research, but there are gaps in the types of research they fund.

"They will talk about prevention, but if you look at their portfolio⁶ of research, almost none of them actually do anything looking at chemicals, and certainly not mixtures of chemicals," Goodson says.

1 excerpt   

n.摘录，选录，节录

参考例句：

• This is an excerpt from a novel.这是一部小说的摘录。
• Can you excerpt something from the newspaper? 你能从报纸上选录些东西吗？

2 credible   

adj.可信任的，可靠的

参考例句：

• The news report is hardly credible.这则新闻报道令人难以置信。
• Is there a credible alternative to the nuclear deterrent?是否有可以取代核威慑力量的可靠办法？

3 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。

4 tricky   

adj.狡猾的，奸诈的；(工作等)棘手的，微妙的

参考例句：

• I'm in a rather tricky position.Can you help me out?我的处境很棘手，你能帮我吗？
• He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题，只做了个笼统的表述。

5 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

6 portfolio   

n.公事包；文件夹；大臣及部长职位

参考例句：

• He remembered her because she was carrying a large portfolio.他因为她带着一个大公文包而记住了她。
• He resigned his portfolio.他辞去了大臣职务。