Table 1.

Subjects’ participation by acoustic zone, Orio al Serio International Airport (BGY), Italy - June-September 2013

	Reference Zone <60 dBA		Zone A 60-65 dBA		Zone B 65-75 dBA		p*
	N	%	N	%	N	%
Population
(age 45-70 years)	57,571		1,695	100	130
Sampled	346	100	295	100	110	100	0.06
Not traced	15	4.3	10	3.4	3	2.7
Dead	1	0.3	1	0.3	0	0.0
Non-eligible**	10	2.9	9	3.0	7	6.4
Refusals	154	44.5	111	37.6	30	27.3
Enrolled	166	48.0	164	55.6	70	63.6
Eligible	320	100	275	100	100	100	0.004
Refusals	154	48.1	111	40.4	30	30.0
Enrolled	166	51.9	164	59.6	70	70.0

*From chi-square test

**Because of health problems or language difficulties