Adverse effects of environmental odours: reviewing studies on annoyance responses and symptom reporting.

Air pollution control authorities dealing with odourous emissions from industrial, municipal and agricultural activities are often faced with many complaints from the public. In Germany, the Directive on Odour in ambient air provides a regulation system for the abatement of odour annoyance. Ambient air quality standards have been established based on investigations of the relationship between ambient odour load and community annoyance reaction. This paper describes a tool for the assessment of annoyance reactions, whereby degree of annoyance is correlated with ambient odour load. Systematic exposure response relations have been established for odour annoyance responses and symptom reporting for a variety of industrial sources. However, the precision of annoyance prediction from odour exposure measures rarely exceeds r2 = 0.17 in such studies. This is partly due to the fact that person-related factors, such as age, perceived health or stress coping styles, modify exposure response relations. The contribution of intensity and unpleasantness (hedonic tone) of ambient odours as modifying the annoyance reaction is currently investigated.