71.   Although vehicles are the main source of air pollution in Chinese cities and the fastest-growing source nationwide, coal-burning industries account for the largest portion.

72.   Although medical experts are careful to note that the link between air pollution and asthma attacks is anecdotal, Nancy Lynch is more certain.

73.   Although the chief cause of such pollution is diesel truck traffic, critics of the transportation authority argue that it should lead the way in reducing air pollution.

74.   Although the region has reduced its two other main sources of air pollution, carbon monoxide and ozone, pollution from airborne particles is as troublesome as ever.

75.   Amtrak contends that by using electric engines rather than diesels and by getting people out of planes and cars, the new trains will cut air pollution.

76.   And a number of state senators from the towns surrounding Bridgeport feared increased traffic and air pollution.

77.   An even greater motivator for reducing ozone levels may be the ill effects of air pollution.

78.   And environmental groups, frustrated at developments in Washington, have put intense pressure on the governor to take a leading role in fighting air pollution and global warming.

79.   And federal rules pay more attention to outdoor air pollution than to indoor pollution, which can pose graver, more easily remediable, risks.

80.   And Massachusetts suffers from air pollution created in New Jersey, New York and Connecticut.