Review of adverse health effects of odours in field studies

Exposure to environmental odours from industrial and agricultural premises, in addition to inducing annoyance responses in a dose-dependent manner, have been shown to be either directly associated with gastric symptoms as well as general health-related complaints under extreme exposure conditions, or indirectly mediated through odour annoyance under moderate odour exposure conditions. In order to examine the influence of hedonic tone (pleasantness-unpleasantness) and perceived odour strength (intensity) on symptom reporting the results of two pertinent field studies were analysed. In the vicinity of six industrial plants (sweets, rusk, textile, seed-oil, fat, cast iron) and eleven livestock operations (poultry, pig, cattle) assessment of odour exposure was done by means of systematic field inspections. Effect assessment was done by means of direct interviews (industrial: N=1456, agricultural: N=1053) using questionnaires covering odour annoyance, symptom reporting and relevant covariates. Multiple logistic regression analysis was used to establish dose-response associations between odour frequency, intensity and hedonic tone as independent variables and symptom reporting as dependent variable. Exposure-symptom associations are strongly influenced by hedonic tone, whereas intensity has no additional predictive value. Adding odour annoyance to the regression model shows that symptom reporting is exclusively mediated by annoyance.