AJC... Health Watch April 23, 1996
By Amanda Husted, STAFF WRITER
Pregnant women exposed to the secondhand smoke of co-workers or family members pass some of the blood-borne chemicals to their unborn babies, researchers say, though babies of smokers have much higher levels of the chemicals.
The study, released this week at a meeting of the American Association for Cancer Research in Washington, says the compounds can cause genetic damage and may be a prelude to childhood leukemia and other cancers.
Researchers at the University of Louisville studied 410 pregnant women, measuring levels of three tobacco carcinogens in. the mothers and their-newborns - benzo(a)pyrene, which causes lung and skin cancer; 4-aminobiphenyl, which causes bladder cancer; and acrylonitrile, which causes liver cancer.
All three substances attach themselves to hemoglobin, the Oxygen-carrying protein in red blood cells. The carcinogens continue to circulate through the babies' blood for the life of the red cells -- about four months.
The study found that levels of the three chemicals were four to five times higher in the passive smokers' babies than in the nonsmokers' infants, and they were 10 to 20 times higher in the cigarette smokers' babies.
Infants in the study will be followed for years to see if those exposed to the chemicals have a higher incidence of cancer than nonsmokers' babies.
In a second study presented at the meeting, researchers said cooking beef too long and at high temperatures raises risks of cancer.
Researchers studied Nebraskan farmers, 176 with stomach cancer and 503 healthy people, looking at how they cooked red meat. Those who preferred their meat medium, medium-well or well-done are about three times more likely to get stomach cancer than those who ate their beef rare or medium rare.
The reason may be that carcinogens known as heterocyclic amines form when animal protein known as creatinine is heated to high temperatures.