Perceived annoyance from environmental odors and association with atmospheric ammonia levels in non-urban residential communities: a cross-sectional study

Table 2 Ammonia (NH ₃ ) concentrations measured and modelled at air quality stations and summary of modelled NH ₃ concentrations at the residences

Region	NH₃ concentration at the air quality station (μg/m³)		Number of respondents (and %) exposed to different modelled NH₃ concentration categories at their residences (μg/m³)
	Measured^[a]	Modeled^[b]	0-0.5	0.5-1	1-1.5	1.5-2	2-2.5	2.5-3	3-3.5	>3.5
I	0.16 ± 0.00^a	0.15 ± 0.01^a	11 (100)	0	0	0	0	0	0	0
II	0.62 ± 0.03^b	0.85 ± 0.15^bc	0	7 (22)	14 (44)	8 (25)	3 (9)	0	0	0
III	0.53 ± 0.05^b	0.90 ± 0.12^c	0	13 (43)	10 (33)	4 (13)	1 (3)	1 (3)	0	1 (3)
IV	1.02 ± 0.02^c	1.27 ± 0.16^cd	0	0	8 (25)	8 (25)	10 (31)	3 (9)	3 (9)	0
V	1.34 ± 0.10^d	1.54 ± 0.01^d	0	0	0	1 (3)	18 (58)	6 (19)	1 (3)	5 (16)
VI	N/A	N/A	0	0	0	0	12 (27)	9 (20)	14 (32)	9 (20)

^[a] Annual averaged NH₃ concentration measured at air quality stations in 2008 and 2009, average ± standard deviation.
^[b] NH₃ concentration from emission-dispersion models at the location of the air quality station in 2008 and 2009, average ± standard deviation.
Same letters within columns indicate no significant differences (P > 0.05).

ISSN: 1476-069X