HEALTH REPORT - Mercury Levels in Fish

HEALTH REPORT – December 11, 2002: Mercury¹ Levels in Fish

By George Grow

This is the VOA Special English Health Report.

Two studies are adding to the debate about the health risks of eating fish containing high levels of the metal
mercury. One study suggests that people who eat fish high in mercury may increase their risk of having a heart
attack. Yet another study found no link between mercury and heart disease.

Both studies were published in The New England Journal of Medicine in November.

Mercury is a natural element. Some bodies of water have become polluted with mercury. High levels of the metal
have been found in large fish, such as king mackerel, shark and swordfish. Scientists say mercury can be harmful
to people. For example, it can harm the developing brain of a fetus² or child. So some experts say that pregnant³
women should avoid eating fish containing high levels of mercury.

However, the American Heart Association and other experts have advised Americans to eat fish at least two
times a week. Fish contains important substances, including omega-three fatty acids. These are believed to reduce
the risk of heart disease.

Scientists at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland organized one of the
new studies. They examined medical records of more than one-thousand-four-hundred men from Israel and eight
European countries. They compared men who had suffered a heart attack with healthy men.

The scientists examined mercury levels in the men by studying toenail particles from the men’s feet. The study
found that mercury levels in the men who had a heart attack were fifteen percent higher than those with no
history of heart disease. It also showed that men with the highest mercury levels were about two times more
likely to have a heart attack than men with the lowest levels.

However, a study by the Harvard School of Public Health in Cambridge, Massachusetts disputes the findings.
The Harvard scientists compared two groups of about five-hundred American men. All the men in one group had
suffered a heart attack. The other men showed no evidence of heart disease. The Harvard scientists also examined
toenail particles for mercury. They found no link between mercury and the risk of heart disease.

Many doctors say people should not stop eating fish because of concerns about mercury.

This VOA Special English Health Report was written by George Grow.

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1 mercury   

n.汞，水银，水银柱

参考例句：

• The liquid we can see in thermometers is mercury.我们看到的温度计里的液体是水银。
• Mercury has a much greater density than water.水银的密度比水大得多。

2 fetus   

n.胎，胎儿

参考例句：

• In the fetus,blood cells are formed in different sites at different ages.胎儿的血细胞在不同时期生成在不同的部位。
• No one knows why a fetus is not automatically rejected by the mother's immune system. 没有人知道为什么母亲的免疫系统不会自动排斥胎儿。

3 pregnant   

adj.怀孕的，怀胎的

参考例句：

• She is a pregnant woman.她是一名孕妇。
• She is pregnant with her first child.她怀了第一胎。