The primary aim of this study is to determine whether a combination of body height, terrain and vehicle mechanical factors confound for the effect of body mass on WBV exposure while using a quad bike under normal rural working conditions. A seat pad mounted triaxial accelerometer and data logger recorded full work day vibration and shock data from 130 New Zealand rural workers. Personal, vehicle and workplace characteristics were gathered using a modified version of the Whole Body Vibration Health Surveillance Questionnaire. Whole-body vibrations were analysed in accordance with the ISO 2631-1 and ISO 2631-5 standards and it is presented as one hour vibration dose value in the Z-direction (1 h VDVZ). Body mass did not demonstrate any significant bivariate association (P > 0.20) with I h VDVZ. However BMI, body height, vehicle weight, sheep farm, dairy farm, 2 shock absorber solid axle rear suspension, flat farmland and engine capacity (cc) all demonstrated threshold bivariate associations (P <= 0.20) with 1 h VDVZ. Body mass, body height, 2 shock absorber solid rear axle suspension, and working on a sheep farm created the strongest multiple regression model explaining 16% of variance in VDVZ. Relevance to industry: The influence of driver's body mass on vibration exposure is strongly influenced by work environment and vehicle mechanical factors and this should be taken in to consideration for research that explores exposures and/or designing seating and suspension systems to attenuate vibration exposures in small on-farm vehicles. (C) 2012 Elsevier B.V. All rights reserved.