AN ENVIRONMENTAL AND RESPIRATORY HEALTH SURVEY OF WORKERS IN A GRAIN MILL IN THE JOHANNESBURG AREA, SOUTH-AFRICA

A respiratory health survey was conducted in a grain mill and the relationship of health indicators to quantitative measures of airborne dust, fungal, and bacterial contamination was examined. Respiratory symptoms were more prevalent in the high dust exposure categories; lung function levels were also higher in the high dust exposure categories, consistent with a ''healthy'' worker effect. Workers in the three higher dust exposure categories showed either no change or a decrease in lung function over the working week, while workers in the low exposure category demonstrated an improvement in lung function over the working week. Total dust and microbiological (fungal and bacterial) load were found to be significantly related to each other, and the relationship of microbiological load to lung function level and changes over the working week were similar to those found for total dust. (C) 1993 Wiley-Liss, Inc.