Sampling for airborne fungi: a statistical comparison of media.

Four broad spectrum media employed for enumeration of fungi from air were compared to determine which would yield the highest number of colony forming units when simultaneously sampling air from the same environment. The four media tested were: Inhibitory Mold Agar, Littman Oxgall Agar, Rose Bengal-Streptomycin Agar, and Sabouraud Dextrose Agar. The number of colony forming units produced on the media were compared by an incomplete four-factor factorial design (day, time, sampler and medium). Analysis of variance of the data indicated that highly significant variation was associated with collection medium and different sampling days. Comparisons among the media were performed by Duncan's multiple range test which demonstrated significantly lower values on Littman Oxgall as compared to the other media. There was no significant difference in the number of colonies produced on Rose Bengal-Streptomycin Agar, Inhibitory Mold Agar, and Sabouraud Dextrose Agar. For a number of reasons, Rose Bengal-Streptomycin Agar is our medium of choice for broad spectrum aeromycological sampling.

Silicosis in silica flour workers.

In July 1979, the health of 86 current and ex-workers at 2 silica mining and milling operations in southern Illinois was examined using a respiratory questionnaire, spirometry, and chest radiographs. None of 25 current workers with less than 1 yr of exposure to silica dust had radiographic evidence of silicosis. For 61 current workers and ex-workers with 1 or more yr of exposure, chest radiographs showed 16 (26%) with simple silicosis and 7 (11%) with progressive massive fibrosis. Of these 23, 8 with simple silicosis and 3 with progressive massive fibrosis began work after the first Mine Safety and Health Administration inspection in 1973. These data and a review of federal dust inspection results between 1973 and 1979 showed that these cases of silicosis could have been prevented by effecting compliance with the existing dust standard.

Silicosis in the 1980's.

At the request of the Mine Safety and Health Administration (MSHA), the National Institute for Occupational Safety and Health (NIOSH) recently investigated the health of workers at two silica flour mills. Both mills have a long history of failure to maintain workplace concentrations of dust containing free silica below the MSHA exposure standard. Thirty-seven percent of sixty-one workers and ex-workers with one or more years of silica dust exposure had chest radiographic evidence of silicosis. Because of the high prevalence of silicosis in workers at these two silica flour producers, MSHA silica dust measurements were reviewed for twenty-five other active U.S. silica flour producers. Eighty-nine percent of the work force in these 27 silica flour producers are employed at workplaces where more than twenty-five percent of the dust samples reviewed were above the exposure standard. Fifty-three percent of all samples were above the MSHA standard. No significant decline in silica dust levels occurred during the period (1974-1979) covered by the data supplied by MSHA. Based on the NIOSH study and MSHA data, it is apparent that the risk of silicosis is very high among workers in this industry. Prevention of this disease will require a concerted effort of government enforcement agencies, workers and management.