C. Hines, C. Striley, R. Biagini, D. Shoemaker, K. Brown, B. MacKenzie, R. Hull, NIOSH, Cincinnati, OH; J. Deddens, University of Cincinnati, Cincinnati, OH.
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E. Kirrane, Coda Research, Durham, NC; J. Hoppin, D. Umbach, D. Sandler, NIEHS, Research Triangle Park, NC.
Pesticide exposure among farmers’ wives is poorly understood. Using self-administered questionnaire data from the Agricultural Health Study, a cohort study of licensed pesticide applicators and their spouses, we investigated patterns of pesticide use among farmers’ wives (n = 31,173). We established five pesticide-use categories based on residential application and lifetime use of 50 pesticides and studied factors associated with each category via polytomous logistic regression, controlling for age and state of residence. Approximately 10% of the wives reported lifetime use of three or more pesticides with predominately agricultural applications, 13% reported using 1–2 agricultural pesticides, 31% reported using relatively low toxicity products, 10% applied to their home or lawn only, and 36% never used pesticides during their lifetime. Of women who reported mixing or applying pesticides, 50% used 2 or fewer products during their lifetime. Those who reported doing field work were more likely to use pesticides. Women whose husbands reported mixing or applying pesticides more than five days per year were more likely to be the heaviest users (OR = 1.4, 95% CI = 1.2, 1.5). In general, household hygiene practices that could increase exposure were positively associated with pesticide use, and these associations appeared strongest among the heaviest users (e.g., wearing work boots indoors: OR = 1.5, 95% CI = 1.3, 1.7). Our findings indicate wide variation in pesticide use among farmers’ wives. Wives who mix or apply pesticides may exacerbate their exposure because they are more likely to engage in other farm work and hygiene practices that could increase pesticide contact.
K. Lee, M. Stoecklin, T. Hennessy, E. Park, L. Beckett, M. Schenker, University of California, Davis, CA.
This study investigated the use of personal protective equipment (PPE) among herbicide handlers in Costa Rica. We determined the association between PPE use and various factors, including demographics, safety attitudes, safety perceptions, and previous symptom experience. The protective effect of PPE use was also assessed by means of biological monitoring. A random sample of 183 herbicide handlers at banana, coffee, and palm oil farms in Costa Rica completed an interviewer-administered questionnaire. In addition, 24-hour urine samples were collected from 119 paraquat handlers on the spray day and analyzed for urinary paraquat to determine the effects of PPE use. PPE use among farm workers was associated with age, crop, attitude toward PPE use, and their safety perceptions of the work habits of other paraquat handlers. Use of PPE was not significantly associated with self-reported health symptoms. Measurement of urinary paraquat from the biological monitoring showed a slight protective effect from coveralls use. Use of PPE on some Costa Rican farms was strictly implemented. We found that several factors were related to PPE use, however, this cross-sectional investigation cannot show causal association. Wearing coveralls appears to provide a slight protective effect based upon biological monitoring measures, but no similar association was found for other types of protective equipment.
K. Lee, R. Domingo-Neumann, R. Southard, University of California, Davis, CA.
Agricultural workers are exposed to high levels of soil dust that may cause respiratory problems. Field sampling of agricultural dust faces logistical problems due to temporal and spatial variations in soil properties, meteorological conditions, and seasonal variability in agricultural field operations. To overcome some of these problems, we developed a laboratory dust generator to provide samples for characterization of dust. The dust generator consisted of a rotating chamber, where soil samples were loaded and tumbled, and a settling chamber, where airborne soil dust samples were collected using size-selective samplers. Operating conditions for the dust generation were evaluated for initial soil mass, air intake, speed of rotation, and sampling time to optimize dust sampling and to prevent excessive drying of the soil during operation. The dust generator provided reproducible soil dust samples. Agricultural dust collected during field operations was compared with laboratory dust generated from soil samples of the same agricultural field plot. X-ray diffractometry and energy-dispersive X-ray analyses showed that the mineralogical and chemical compositions of field and laboratory-generated dusts were similar, indicating that the dust generator reasonably simulates the mechanical processes that produce dust in the field. The results suggest that this laboratory dust generator provides reliable samples of soil-derived dust and could be useful for future studies involving airborne particulate material from soils. Using this laboratory dust generator, we compared the concentrations and sizes of dust generated by soils of different textures over a range of water contents. Results indicate that concentrations of dust generated increase with increasing clay and silt content and decrease with increasing sand and water content. Insights from this study may be useful in prediction of dust emission rates from different soils, which can help in formulating strategies to reduce dust emissions during agricultural operations.
K. Lee, J. Smith Davis, J. Last, University of California, Davis, CA.
Elemental sulfur is the most heavily used agricultural chemical in California. In 2001, annual usage in California was about 47 million pounds of active ingredient. This is about 34% of the total weight of pesticide active ingredient used in production agriculture. Sulfur, a natural substance, is used as fungicide. Sulfur may be a skin irritant in humans. Despite the fact that sulfur is used in the form of a dust, the respiratory health effects of elemental sulfur are not well documented. The purpose of this paper is to address the possible respiratory effect of elemental sulfur using the California pesticide illness database and laboratory experiments in mice. We analyzed the California pesticide illness database between 1991 and 2001. Among 128 reports of definite, probable, and possible illness involving sulfur, 21 cases (16%) were identified as respiratory, with symptoms including difficulty breathing (11), coughing (8), throat irritation (7), congestion (3), wheezing (2), burning chest (2), throat tightening (2), chest pain (1), and sneezing (1). A mouse model was used to examine whether there was an inflammatory response to elemental sulfur. The dust solutions were injected intratracheally into Ovalbumin sensitized mice and lung damage was evaluated. Lung inflammatory response was analyzed via total lavage cell counts and differentials, and airway collagen content was analyzed histologically and biochemically. No significant differences from controls were seen in animals exposed to the sulfur particles. The findings suggest that elemental sulfur itself may not cause inflammatory reaction. However, further studies are needed to understand the possible health effects of chronic sulfur exposure and environmental weathering of sulfur dust.
J. Kangas, K. Louhelainen, O. Lankia, J. Mäittälä, S. Rautiala, P. Rissanen, Kuopio Regional Institute of Occupational Health, Kuopio, Finland.
During the last few years, the structural change in agriculture has been rapid in Finland. The number of active farms has decreased, and the average farm size has grown, which has an influence on the work environment of farmers. The aim of this study was to investigate how the increased number of cattle affects the work environment in new cubicle cowhouses.
Farmers’ exposure to biological and chemical agents were investigated in 20 dairy farms with cubicle cowhouses. The farms had 54 milking cows on average. The concentrations of airborne cultivable fungi and actinobacteria were determined with a six-stage impactor. Furthermore, the total concentrations of microorganisms were determined with filter sampling and direct count in a microscope. Air samples for total dust and endotoxins were collected on membrane filters with portable or piston pumps. Inhalable dust was collected with an IOM-sampler. Dust samples were determined gravimetrically and endotoxins with LAL-method. Concentrations of gases (ammonia and carbon dioxide) were measured with diffusion tubes.
The concentrations of viable microorganisms were low (GM 4–3000 cfu/m3) during the milking and feeding of the cattle. Furthermore, the total microorganism concentration remained at 105 microorganisms/m3 in all measurements. The exposure of the farmers to endotoxins averaged 1400 EU/m3. The total dust levels were low on the stationary sites, but occasionally high concentrations were measured in the breathing zone. The highest levels of inhalable dust were 2.5 and 2.8 mg/m3 during milking work and tending work, respectively. The average exposure of farmers to ammonia was around 10 ppm with some occasional peak-concentrations. The concentrations of carbon dioxide was usually below 3000 ppm.
Compared to the results of our studies from the last decade, the work environment has improved in modern cubicle cowhouses. Reasons for improvements are changes in production methods and an increased use of automation in new cubicle cowhouses.
J. Campbell, K. Chen, M. Tuday, Columbia Analytical Services Inc., Simi Valley, CA.
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P. Dessureault, A. Tellier, Universite du Quebec, Trois-Rivieres, PQ, Canada.
Farming generally means hard work, and manual storing of hay bales in barns is certainly one of the hardest tasks, performed under very hot conditions. Young persons are employed to perform this task, mainly students who are often not acclimatized to heat. Standards WBGT as well as ISO 7933 are based on data collected on men and may not be suitable for heat stress surveillance on teenagers.
During the summer of 2003, seven male teenagers (15 to 18-years-old), were observed over 20 full shifts. Environmental parameters (air velocity, air, globe and wet bulb temperatures, and WBGT values) were recorded inside the barns and outdoors. During the same period, heat strain was monitored under three domains: (1) cardiac strain (recording of heart rate minute by minute), (2) water loss through evaporation (weight prior to and after work with recordings of drinks and micturition volumes), and (3) body temperature (oral temperature prior to and after work). The recommended heart rate limit values were corrected to take into account the age of the subjects.
WBGT values in the barn varied from 25 to 30 degrees. No significant rises in oral temperature were observed. The water losses approached the ISO 7933 limits (expressed per square meter of body surface area) in many cases. Nevertheless, cardiac strain substantially exceeded the recommended limits in many work shifts. The peak on the one-minute heart rate recordings for each subject exceeded 90% of the physiological maximum heart rate in many instances. Also, heart rate values averaged over a time windows varying from 5 to 90 minutes exceeded recommended corrected values. Average heart rate values for the entire shift in excess of 110 pulses per minute were observed.
Manual storing of hay bales under the conditions observed clearly pose a heat strain problem. Recommendations are formulated.
Posted May 30, 2004