Table 1.

The number of OTA-contaminated samples out of the total number of samples collected from the three geographic areas in the different years. Values with different letters are significantly different to each other with the Chi-square analysis (p < 0.05).

Geographic origin	2003	2004	2005	2006	2007	Total
Northern Italy	3/22c	1/12c	0/0c	2/19c	5/10c	11/63c
Central Italy	1/9c	0/9c	0/0c	0/9c	0/3c	1/30c
Southern Italy	20/22a	12/30c	9/26c	4/22c	5/11b	50/111b
Total	24/53	13/51	9/26	6/50	10/24	62/204