Mechanisms of pulmonary disease in F344 rats after workplace-relevant inhalation exposure to cross-linked water-soluble acrylic acid polymers

Table 2 Histopathological findings of the lung after a single inhalation exposure to CWAAP-A

Experimental period	Initial sacrifice			3 d recovery
Exposure concentration (mg/m³)	0	40	100	0	40	100
No. of animals examined	6	3	3	6	3	3
Histopathological findings
Lung
Alveolar collapse with inflammatory cell infiltration	0	0	0	0	3**	3**
					< 2 >	< 2 >

Values indicate number of animals bearing lesions
The value in angle bracket indicate the average severity grade index of the lesion. The average severity grade is calculated using the following equation: Σ(grade × number of animals with grade)/number of affected animals
Grade: 1, slight; 2, moderate; 3, marked; 4, severe. Significant difference: *p < 0.05; **p < 0.01; ***p < 0.001 by Chi square test compared with the respective controls

ISSN: 1465-993X