Exposure misclassification of household pesticides and risk perception and behaviour.

The aim of this paper was to compare self-reported household pesticide use or non-use in a questionnaire with reported household pesticide use from an in-depth interview, in order to elucidate any differences, and to study any differential reporting of pesticides. In the in-depth interview we asked for pesticide use, behaviour adopted while using pesticides and risk perceptions as possible factors to explain the reporting of pesticide use. The Avon Longitudinal Study of Parents and Children (ALSPAC) was used as the sampling frame. Eight hundred and thirty one parents filled out and returned the questionnaire. A random sample of 53 users and 94 non-users took part in the interview. Almost 90% of the 94 who did not report the use of pesticides in the questionnaire reported the use of pesticides during the interview. However, those who reported pesticide use in the questionnaire were more likely to report home and garden pesticide use (P < 0.05) in the interview. The parents who reported pesticide use in the questionnaire had a tendency to perceive a lower risk and higher benefit from pesticide use, and tended to be less risk averse when compared with the groups of parents who reported no pesticide use. They bought the pesticides because 'they looked safe', while those who did not report pesticide use bought them because they 'used them before'. The latter were also more likely to state that they did not understand everything on the label and that they thought that it did not provide all the information needed. They were also less likely to feel that they knew what they are doing when using pesticides and felt that pesticide use is relatively dangerous compared with other hazards. In conclusion, pesticide use is underreported in questionnaires, and behaviour and risk perception may affect the reporting.