Table 4

21 day versus 90 day inhalation studies

Project number	TPM μg/l	Nasal reserve cell hyperplasia	Total vocal cord hyperplasia	Total vocal cord metaplasia
3125⁶⁹ (21 day)	Sham	−	−	−
	SS 2	−	−	−
	SS 6	−	+	+
3127⁷⁰ (90 day)	Sham	−	−	−
	SS 2	+	+	−
	SS 6	+	+	+