The hydration status and needs of workers at a north-west Queensland fertilizer plant

The aims of this article were to assess fluid loss rates and to develop fluid intake targets for workers in a harsh (hot and dry) environment. This prospective observational study recruited 127 workers from the WMC Fertilizers operations at Phosphate Hill during September 2002 and February 2003. A series of assessments was made (including am and pm urine specific gravity and weight measurements and fluid intake measurements), and a questionnaire relating to hydration and urinary and faecal excretion was used. Detailed workplace and body weight specific fluid input targets were developed. Workers in direct sunlight lost significantly more fluid and were less likely to maintain their fluid balance compared with those working in air conditioning or shade. Two thirds of the participants arrived dehydrated for their shifts. This research provides specific evidence-based hydration guidelines for workers in harsh environments and highlights the importance of facilities and behaviours away from the workplace to optimally hydrate workers