1.   In this way carcinogenic substances such as lead, mercury etc., which normally remain at the bottom of lakes and rivers, are reintroduced to the water supply.

2.   This may mean that blacks metabolize carcinogenic substances more slowly, making them more prone to cancer, said the researchers.

3.   Carcinogenic substances are those listed by the International Agency for Research on Cancer or the U.S. National Toxicological Program as promoting cancer.

4.   It is a highly carcinogenic substance blamed for causing liver and other cancers.

5.   Italy has introduced measures to check for the presence of carcinogenic substances in low grade olive oil, the Health Ministry said Tuesday.

6.   There are growing fears that staples like fries and potato chips contain high levels of a potentially carcinogenic substance called acrylamide.

7.   TSNAs are among the most carcinogenic substances in tobacco smoke.