71.   It becomes active only in the presence of tobacco smoke or some other respiratory insult, she said.

72.   Laboratory experiments have shown that chemicals in tobacco smoke can cause the kind of damage to sperm that leads to cancer.

73.   Nicotine is a major toxin in tobacco smoke.

74.   Neighborhood cafes filled with the pungent aromas of fresh-brewed expresso and pungent tobacco smoke are losing their following, according to a recent poll.

75.   One of them, known as NNK, is found in tobacco smoke.

76.   Prolonged irritation from tobacco smoke results in a variety of deleterious changes in the oral mucosa.

77.   Relatives blew tobacco smoke into the mouth to dry out the internal organs and prevent worm infestation.

78.   Secondhand tobacco smoke has also been blamed.

79.   Secondhand tobacco smoke has also been fingered.

80.   She pointed to recent studies connecting secondhand tobacco smoke to childhood asthma.