The application of hedonic tone in odour pollution sensory evaluation

In order to enrich the sensory evaluation indicators of odour pollution in China, a 9-point hedonic tone method was used to determine the hedonic tone of samples at different odour concentrations from three typical odour emission sources including rubber products, bakery and landfill. A comprehensive evaluation model of odour pollution and hedonic tone was put forward by analyzing the relationship between odour concentration (odour index) and hedonic tone, that is, the annoyance potential of source = odour index × hedonic tone. The results showed that the hedonic tone of rubber products and landfill sites was negative value, while that of food processing was positive value. The relationships between the odour concentration and hedonic tone from the three kinds of emission sources are in line with the quadratic polynomial model. In addition, the correlation coefficients all reached above 0.99. The annoyance potential calculation results showed that the annoyance potential of rubber products and the landfill was -200.91 and -144.80 respectively, and that of food processing was 79.66. Applying this method, the different odour sources could be distinguished more intuitively, especially for the sources that have similar odour concentrations and different odours. Then the key emission sources and key emission units could be accurately identified. The research indicated that hedonic tone reflects the psychological impact of odour on people and its harmful degree more accurately, and it is necessary to apply hedonic tone to odour pollution sensory evaluation.