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Assessment of occupational exposure to aflatoxin.

Selim MI; Popendorf W

NIOSH 1993 Apr; :1-58

20023655

The broad objective of this project was to develop a better means to assess the exposures of farmers to aflatoxin B1 in airborne grain dust. We believe repeated low level exposures during various on-farm grain handling activities represents a significant health risk to farmers and potentially to full-time grain handlers. The project was initially designed in two phases. The first funded phase (Phase I), involved laboratory method development and optimization for the analysis of aflatoxin B1 and other toxins (particularly fumonisin B1) in small airborne grain dust samples. The later portion of Phase I involved pilot-testing the analysis of field samples of bulk corn and airborne dust to establish a correlation between the level of aflatoxin in the dust from these processed bulk corn samples and simultaneously collected air samples. This preliminary data comparing the aflatoxin in bulk and airborne dusts was generated in a small cross-sectional survey of farming operations in Iowa. Surveys of other states in the region of the eastern US are planned to be carried out during the second unfunded phase (Phase II) to confirm the applicability of this correlation over a wider range of temperature, humidity and soil conditions, and local storage or grain handling practices. This method development phase (Phase I) was approved for funding on May 1, 1991. However, actual work on the method developed did not start until July 1, 1991, until receiving the award and hiring needed staff. In spite of these expected delays at the start-up time, the acquisition of the commercial SFE equipment facilitated a great deal of progress in the proposed method development activities. Further delays were also caused by the acquisition and installation of the GC,HPLC/MS system due to the need for a lengthy facility renovation. The objectives of the second phase and new proposed ones, include: 1.To establish a means to estimate a farmer's exposure to airborne aflatoxin (and other mycotoxins) based on its measurement in bulk corn. Implicit in obtaining this goal is to demonstrate a correlation between toxins in bulk grain and in airborne dust on as many on-farm grain handling activities and as wide a geographic area as are feasible. This correlation will greatly extend the utility of future bulk grain surveys for aflatoxin, and it can potentially increase the interest of farmers individually and collectively to the content of aflatoxin or other mycotoxins in their grains because of their repeated and frequent exposure. 2.To identify and quantify other natural toxins such as fumonisin, ochratoxin, and vomitoxin which may be detectable during the course of aflatoxins analysis in grain and grain dust in these same on-farm activities and geographic areas. 3. To assess the change in the aflatoxin and other mycotoxin content of the grain over time as affected by seasonal temperature and humidity, grain moisture content at storage, and grain handling history. The effect of this history upon the correlation of aflatoxin in prepared bulk and airborne samples will also be examined.4. To investigate the primary site (foci) of aflatoxin/mycotoxin within the dust. One indicator of site is the proportion of aflatoxins in particles of different diameter. Our approach to this goal is to assess the effect of seasonal temperature, rainfall or humidity, and grain handling history on the distribution of aflatoxin in particles of different size in airborne dust samples. Again the effect of this history upon this size distribution will also be examined. The long-term objective of this project is to establish the statistical data and exposure model needed to initiate or participate in an epidemiologic assessment of the occupational risk to farmers resulting from their exposure to aflatoxin B1 and other mycotoxins in grain dust. The availability of the Iowa State Health Registry for both cancer and birth defects at the Department of Preventive Medicine and Environmental Health, The University of Iowa, represents a substantial advantage for the long-term objective of this study.

Exposure methods; Agricultural industry; Agricultural workers; Air sampling; Airborne dusts; Farmers; Mycotoxins; Grain dusts; Dust analysis; Dust exposure; Dust sampling; Sampling; Sampling methods; Analytical methods; Temperature effects

University of Iowa, College of Medicine, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, 108 AMRF - Oakdale Campus, Iowa City, IA 52242

1162-65-8; 116355-83-0

19930422

Final Grant Report

192394

Grant

1993

Grant-Number-R01-OH-002857

OEP

Other Occupational Concerns

National Institute for Occupational Safety and Health

IA

University of Iowa, College of Medicine, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, Iowa City, Iowa