Fluid Intake and Hydration Status of Forest Workers -- A Preliminary Investigation


  • Graham Bates Curtin University, Australia
  • Richard Parker Centre for Human Factors and Ergonomics, New Zealand
  • Liz Ashby Centre for Human Factors and Ergonomics, New Zealand
  • Tim Bentley Centre for Human Factors and Ergonomics, New Zealand


Dehydration and its milder form hypohydration have both short term and long term health effects. In the short term poor, body hydration impairs cognitive performance, physical strength and aerobic power, rendering the worker prone to injury and heat illness. In the long term the potential consequences of hypohydration are kidney stones and bladder cancer. The aim of this study was to evaluate hydration status of forest workers in New Zealand and their preferred fluid replacement. The specific gravity (sg) of urine was used as an indicator of body fluid status. In addition daily fluid loss was compared with a tested algorithm of sweat rate to better understand if workers are hydrating at the desired rate. The results of this preliminary study clearly demonstrate that loggers are working at sub-optimal hydration levels and are consuming inappropriate fluids to replace sweat losses. The hypohydrated state of these workers may pose both an immediate and long term health and safety risk.






Technical Papers