In a study of pulmonary effects on guinea pigs, Lacroix et al. (A-30) exposed 18 ovalbuminsensitized guinea pigs and 18 nonsensitized guinea pigs to regular air, benzaldehyde, and acetaldehyde. At the end of exposure, the guinea pigs were anesthetized and allergic responses were assessed in bronchoalveolar lavage (BAL). The following table shows the alveolar cell count 106 by treatment group for the ovalbumin-sensitized and nonsensitized guinea pigs.

Ovalbumin-Sensitized Treatment Alveolar Count 106 no acetaldehyde 49.90 no acetaldehyde 50.60 no acetaldehyde 50.35 no acetaldehyde 44.10 no acetaldehyde 36.30 no acetaldehyde 39.15 no air 24.15 no air 24.60 no air 22.55 no air 25.10 no air 22.65 no air 26.85 no benzaldehyde 31.10 no benzaldehyde 18.30 no benzaldehyde 19.35 no benzaldehyde 15.40 no benzaldehyde 27.10 no benzaldehyde 21.90 yes acetaldehyde 90.30 yes acetaldehyde 72.95 yes acetaldehyde 138.60 yes acetaldehyde 80.05 yes acetaldehyde 69.25 yes acetaldehyde 31.70 yes air 40.20 yes air 63.20 yes air 59.10 yes air 79.60 yes air 102.45 yes air 64.60 yes benzaldehyde 22.15 yes benzaldehyde 22.75 yes benzaldehyde 22.15 yes benzaldehyde 37.85 yes benzaldehyde 19.35 yes benzaldehyde 66.70 Test for differences

(a) between ovalbumin-sensitized and nonsensitized outcomes,

(b) among the three different exposures, and

(c) interaction. Let a ¼ :05 for all tests.