P L A T F O R M
P E S E N T A T I O N S

Livestock-Handling Injuries
Douphrate D, Colorado State University
Livestock-handling injury is an intrinsic occupational hazard of farming, and studies examining this problem are few. A study at the High Plains Intermountain Center for Agriculture Health and Safety at Colorado State University used workers’ compensation data to investigate livestock-handling injuries in agriculture. The purpose of this study was to determine the costs, consequences, and contributing factors associated with livestock-handling injuries among dairy farmers, cattle/livestock raisers, and cattle dealers.

Applying Community-based Participatory Research Principles: Cultural Considerations
Doyle E, Baylor University
For decades, health care providers and health researchers have endeavored to empower medically underserved communities. Yet, cultural differences, insensitive research approaches, and data collection that resulted in no community gains have driven a wedge of distrust and frustration between communities in need and those who possess the resources to help. Despite these challenges, researchers and the communities they serve have much to gain through collaborative partnerships. The guiding principles of community based participatory research (CBPR) can be used to develop a collaborative approach that benefits all partners. In this presentation, an overview of the theoretical principles, characteristics, and benefits of CBPR will serve as a backdrop for describing practical application strategies and examples. Some basic tips for how to initiate a CBPR partnership and resources for learning more about CBPR will be provided.

Developmental Effects of Pesticides on Children in Salinas
Harley K, University of California, Berkeley
The CHAMACOS Study is a cohort study of children from farmworker families living in the Salinas Valley, California who have been followed from before birth to age 7. Pregnant women were enrolled in 1999-2000, and maternal pesticide exposure during pregnancy was assessed using questionnaires, home inspections, environmental samples, and blood and urine measures. The children have been assessed at multiple time points to determine the effects of early pesticide exposure on growth and development. Decrements in neurodevelopmental functioning and increased odds of pervasive developmental disorders have been found among children with higher in utero exposure to organophosphate and organochlorine pesticides.

Determinants of Cholinesterase Inhibition in Pesticide Handlers
Hofmann J, PNASH, University of Washington
Organophosphate (OP) insecticides are widely used in agriculture in the United States and abroad. Overexposure to OPs can inhibit cholinesterase (ChE) enzyme activity, which plays a critical role in regulating transmission of nerve signals in the body. In 2004, the Washington State Department of Labor and Industries (L&I) initiated a new ChE monitoring program for agricultural workers who handle OPs. Washington is only the second state in the US to establish a ChE monitoring program. During the 2006 and 2007 spray seasons, we recruited agricultural pesticide handlers in the ChE monitoring program for a cross-sectional study evaluating potential risk factors for ChE inhibition. A total of 154 study participants completed a computer-based survey about workplace practices and conditions, including: 1) pesticide-handling activities performed and spray equipment used; 2) crops treated and pesticides applied; 3) duration and frequency of handling activities; 4) use, condition, and storage of personal protective equipment; 5) use of decontamination facilities; 6) pesticide safety trainings received; 7) non-routine exposures; and 8) acute exposure events. Almost all study participants were Hispanic or Latino (99%), and most were educated in Mexico (90.3%). Results of the survey will be reported in this presentation. We will identify work practices, workplace conditions, and behaviors that may be associated with risk of pesticide overexposure, as determined by ChE inhibition. Ultimately, we hope to use the results of this study to characterize potential mechanisms of pesticide overexposure in order to reduce such exposures in the future.

Fine Particulates and Cardiovascular Disease
Kaufman J, University of Washington
A growing body of research has shown that exposure to increased concentrations of fine particulate air pollution (particles less than 2.5 microns) are associated with increased mortality and disease. As the resea rch has grown more sophisticated, it now appears that most of the excess disease from these exposures are due to heart and vascular conditions rather than lung disease. This talk will provide an update on this area of research, a discussion of how these effects might be occurring, and a description of some current research that is ongoing on this subject.

Panel: Research with Populations at Risk –Lessons learned from Research and Community Partner Perspectives.
Levin J (Chair), Roman-Muniz N, Vu T, Byrd S, Shadbeh N, Sanchez V, University of Texas at Tyler, Colorado State University, Centro de Communidad y Justicia, Oregon Law Center - Indigenous Peoples Program
Using an interview format, the panel members will draw upon their experiences as researchers and agricultural workers to describe research challenges related to access, trust, language, culture, and participant benefit. Lessons learned and recommendations will also be explored.

Panel: Biomonitoring State of the Science: Where Is New Technology Going?
Murphy H (Chair), Gee S, Keifer M, Simpson C, PNASH – University of Washington, University of California, Davis,
PNASH – University of Washington, PNASH – University of Washington
Many older pesticide products such as the organochlorines and organophosphates have either been taken off the market or are being phased out. To replace them a large number of products whose health effects are largely unknown are being introduced. To understand the impact of these agents on human health, both clinicians and epidemiologists need biomarkers to document human exposure. The EPA recently hosted a meeting to discuss the possibility of requiring the pesticide industry to provide usable biomarkers of human exposure as part of the registration process. This panel will discuss a few methods that can be used to make biomonitoring feasible. These include measuring pesticide adducts in serum albumin, urinary metabolite immunoassays, and nanotechnology which uses mass accelerator spectrometry to measure labeled micro-dosed subjects.

Musculoskeletal Symptoms and Exposure to Knee Flexion Among Dairy Farmers
Nonnenmann M, University of Texas, Tyler
Dairy farmers have reported a high prevalence of musculoskeletal symptoms (MSS) in Scandinavian studies. No study had yet investigated the prevalence of MSS or exposure to risk factors for MSS among US dairy farmers. In order to gather information on this subject of MSS data dairy farmers (N=813) were mailed questionnaires assessing farm information, and prevalent MSS. Tasks such as milking and tractor use were examined for associations with prevalent MSS. Also, measures of knee flexion were recorded during milking and feeding tasks for 23 dairy farmers. The response rate to the questionnaire was 44%. Low back, knee, and shoulder MSS were most prevalent at 67%, 60% and 54%, respectively. Low back MSS were associated with milking, tractor use, and cleaning stalls. Also, milking in a stanchion resulted in more exposure to knee flexion compared to feeding in a stanchion, and milking or feeding in a parlor. Our conclusions were that low back, knee and shoulder MSS may be highly prevalent among U.S. dairy farmers. Milking, tractor use and cleaning animal stalls were associated with MSS. Additionally, working in a stanchion milking facility resulted in greater exposure to physical risk factors for knee MSS compared to working in a parlor milking facility. Future studies on ergonomic interventions may reduce MSS among dairy farmers.

New Understandings in Nose to Brain and Other Exotic Connections
Pinkerton K, Western Center – University of California, Davis
The site of action through which airborne particles elicit biological changes in the respiratory tract is often dictated by particle respirability, biopersistence (durability), and retention (dose), as well as physicochemistry. Depending on their source, airborne particles can be comprised of a complex mixture of carbon, metals, and polyaromatics, such as in the case of combustion particles, or they may exist in a relatively pure form, but may represent a range of physical characteristics (e.g., solid, liquid, amorphous or fiber-like in shape). Physicochemical characteristics not only influence a particle's ability to deposit in certain regions of the respiratory tract, but also its propensity to be retained within or translocated to specific regions or cellular compartments in the respiratory system and/or be transported to other target organ systems. While the respirability and probability of particle deposition in the respiratory tract is based on many factors e.g., size, solubility, shape, density), particle size best determines by what mechanism and to what extent airborne particles will enter and deposit in the nasopharyngeal, racheobronchial, and alveolar regions of the lung. These factors also affect the extent and location in which particles induce inflammatory, fibrogenic, and biochemical processes that can ultimately lead to structural remodeling of the respiratory system as well as systemic passage of effects to non-respiratory targets.

Panel: Bioaerosols in Dairy Barns
Pinkerton K (Chair), Reynolds S, Meschke S, Schenker, M, Western Center – University of California, Davis, HICAHS – Colorado State University, PNASH – University of Washington, Western Center – University of California, Davis
The purpose of this panel is to foster discussion among panel members and conference participants on the diversity of bioaerosols present in the agricultural setting. Emphasis will be in the dairy setting in barns, free stalls and milking parlors. The location of barns, relative levels of bioaerosols, sampling methods and timing of sampling will be reviewed. Consistency in bioaerosol profiles based on geographical location within the scope of the Agricultural Health and Safety Centers will be detailed. Sampling methods for bioaerosols and bacterial culturing will be compared and contrasted for accuracy and efficacy.

Occupational Exposures for Tasks in Colorado Dairies
Reynolds SJ, Lester BR, Mehaffy J, HICAHS – Colorado State University,
Department of Environmental and Radiological Health Sciences
The dairy industry is rapidly changing in the western US, and it is a leading contributor to the economy in Colorado. In 2004 Colorado had 679 operations with 102,000 head of milking cows and produced 2.2 billion pounds of milk. The region had 3,730 operations with 326.3 million head of cows. More than 90% of the workforce in Colorado and other regional dairies is Hispanic, and they often speak little English. Workers on dairies are exposed to hydrogen sulfide, ammonia, other gases, and aerosols, including bacterial endotoxins that can adversely affect their respiratory health. The goal of this study was to characterize occupational exposures for various tasks, including milking, feeding, maintenance, working sick cows, and driving tractors at two Colorado dairies. Overall, the only significant differences between the different tasks at the individual dairies occurred at Dairy 1. For IOM samplers, inhalable endotoxin concentrations for working calves was significantly higher (p<0.05) than for working sick cows and distributing feed. For Button samplers, inhalable endotoxin concentrations for milking were significantly higher (p<0.05) than for working calves. For total samplers, total endotoxin concentrations for milking were significantly higher (p<0.05) than for working calves. There were no significant differences between tasks at Dairy 2, and there were no significant differences between tasks as a whole. Levels of inhalable particulates were similar to other milking studies, but they were 2-3 times higher than those found in other feeding studies. Levels of inhalable endotoxin were more than 25 times higher than other milking studies and up to 2-3 times higher than other feeding studies. Overall, particulate levels did not exceed current US occupational exposure limits. Particulate and endotoxin levels may be reduced for milking tasks by increasing ventilation rates inside the milking parlors and for feeding tasks by installing or properly maintaining tractor cabin filtration systems.

Ergonomics and Dairy Operations
Rosecrance J, HICAHS – Colorado State University
Dairy production in the US is steadily moving to large-herd farms due to associated economies of scale and a host of other economic and social conditions. This productivity has been driven by advanced technological equipment and an industrialization of dairy production. These new mega-herd dairy operations will introduce significant occupational risk factors for workers. A study at the High Plains Intermountain Center for Agriculture Health and Safety at Colorado State University seeks to identify upper extremity workplace risk factors associated with musculoskeletal symptoms among workers in different style dairy parlors. The study will assess the risk for traumatic injury as it relates to worker body positioning and animal behavior in different parlor configurations as well as identify parlor safety interventions through active participatory partnerships with large-herd dairy operations in a multi-state region.

Inorganic Dust Exposure in Western Agriculture – Not Just a Nuisance
Schenker M, MD, MPH, Western Center – University of California, Davis
Most studies of agricultural respiratory disease have focused on allergic diseases caused by organic dusts in the agricultural workplace. Exposures to inorganic (mineral) dusts among agricultural workers may be substantial, particularly among farmers and farm workers in dry agricultural climates. Total dust exposures above 50 mg/m3, and respirable dust concentrations up to 5 mg/m3 are commonly seen. Dust composition reflects the soil components, and is dominated by mineral silicates but may have a substantial percentage of crystalline silica. An increasing body of research has documented the magnitude and composition of this dust exposure, the in-vitro toxicity of these dusts, the independent epidemiologic association of these dusts with respiratory symptoms, and the pathologic changes observed in lung tissues of exposed workers. This talk will summarize data on all of these research findings, as well as findings on the use of protective measures to reduce agricultural dust exposure. Inorganic dust exposure in agriculture is not just a “nuisance,” and multidisciplinary efforts are needed to reduce exposure to these dusts.

W O R K S H O P S

Wednesday, November 12

Listening to the Community: Mismatch Between Indigenous Farmworkers’ Occupational Safety and Health Needs and Current Practices - Indigenous Farmworkers Lead in Addressing Occupational Safety and Health Issues
Shadbeh N, Sanchez V, Oregon Law Center’s Farmworker Program - Indigenous People’s Program
A significant number of Oregon's farmworkers who farm labor-intensive crops speak one of the indigenous languages of Mexico rather than Spanish as their primary language. Many of these languages are no longer written in commonly understood ways. Partners in Promoting Occupational Safety and Health of Indigenous Farmworkers recognize that language and cultural gaps are only two of the factors contributing to health and safety disparities. Equally important are the gaps in state and federal laws, including trainings that are inadequate or at times irrelevant to the reality of the lives of indigenous farmworkers. These barriers can lead to feelings of isolation and disrespect among the workers. The project partners have used a multitude of approaches that center on creating leadership opportunities for indigenous farmworkers and on bringing tangible change to the communities. Among the most successful is a promotores program in which the project's indigenous partners mentor other indigenous farmworkers as promotores. The promotores teamed with the partnership to raise the awareness of the state and federal regulators on occupational health and safety issues of indigenous farmworkers in one-on-one meetings and in a variety of public forums.

1. Describe the multi-track method in which indigenous community members have begun
   to bring about tangible change within the community;
2. Describe methods used to increase the base knowledge of workers about health and safety
   through routes that were identified by communities as the most effective; and
3. Discuss how this multiple track approach has incorporated the thoughts, concerns, and presence
   of indigenous farmworkers within the project, thereby reducing feelings of isolation and disrespect.

Fluorescent Tracers Manual: Pesticide Safety Education Tool Hands-on Workshop
Galvin K, PNASH – University of Washington
Fluorescent tracers (FTs) mimic pesticide contamination on skin, clothes, and surfaces. FTs are common ingredients in laundry detergents that emit visible light under long-wave ultraviolet (black) light. Like some pesticides, FTs are not visible under normal light. Unlike pesticides, they glow under black light to show areas of contamination. This technique, with immediate visual feedback, provides an interactive way to learn about pesticide contamination and decontamination. It is also an excellent teaching tool that transcends literacy and language barriers. Fluorescent tracers were developed as a research tool to assess dermal pesticide exposures. This manual draws on the knowledge of educators and researchers worldwide and translates their experience into a user-friendly booklet. Each unit is a complete package, including a curriculum, a key message, step-by-step instructions, and a supply list. Three types of training are presented: Quick Demos that can be done in a large group; Hands-on Activities that use scripted-role plays and instructor led-demonstrations for handlers to practice decontamination and other procedures; and Workplace Pesticide Applications that have tracer in the tank along with the pesticides. During this hands-on workshop, participants will practice using the tracers in activities and demonstrations from the manual. We will also include tips and tricks so that
participants will be ready to use fluorescent tracers to enhance their pesticide safety training classes.

D I S C U S S I O N S

Wednesday, November 12

Using Community-Based Participatory Research to Identify and Address Occupational
Work Hazards among Contract Forest Workers
Hoare L, Campe J, Jose J, PNASH - University of Washington, Bocanegra Evergreen Labor Center
In Washington State, the percentage of Latinos in the contract forest labor workforce continues to increase. . This includes harvesting special forest products (SFPs), tree planting, and fire fighting. Due to the nature of their work and their socioeconomic status, these workers are often “invisible.” It is important to understand who composes this “invisible” workforce in order to effectively address issues of worker health and safety. This session will focus on how using community based participatory methods can be an effective way to communicate with this population. Facilitators will highlight their experience of using community-based participatory research methods to understand and address health and safety issues among SFP harvesters on the Western Olympic Peninsula. This population is mainly composed of Latino immigrant workers who speak a diverse set of languages. For their economic livelihood, they harvest floral greens, salvage cedar, evergreen boughs, and mushrooms from the forest Facilitators will address both the challenges and rewards that they encountered using community-based participatory methods with this population. Roundtable discussion will focus on the effectiveness and challenges of community-based participatory research; participants sharing their strategies for working with diverse populations; and the contract forest labor workforce in Washington State.

Risk Factors for Pesticide Overexposure among Agricultural Pesticide Handlers
Hofmann J, PNASH – University of Washington
Despite our best efforts, Data from the Washington State Cholinesterase (ChE) Monitoring Program suggest that agricultural pesticide handlers continue to be overexposed to pesticides during applications and while performing other handling activities. In this roundtable discussion we will talk about likely sources of occupational pesticide exposure among handlers and discuss potential ways to prevent such exposures in the future. The discussion will focus on work practices and workplace conditions, including: 1. pesticide handling activities performed and spray equipment used; 2. crops treated and pesticides applied; 3. duration and frequency of handling activities; 4. use, condition, and storage of personal protective equipment; 5. use of decontamination facilities; 6. pesticide safety trainings received; 7. non-routine exposures; and 8. acute exposure events. Particular emphasis will be placed on the results of recent studies that evaluated potential sources of overexposure among agricultural pesticide handlers in Washington State. We also hope to discuss future research needs for identifying and addressing risk factors for pesticide overexposure.

Toward Outcome Evaluation in Federally Funded Health Programs
Holmquist-Johnson H, HICAHS - Colorado State University
Program evaluation with an outcomes focus is increasingly important to federally funded program managers and funders. During this round table, participants will introduce evaluation approaches that are appropriate to use when attempting to measure the impact of health programs. What is needed to achieve measuring outcomes in federally funded health programs will also be discussed. Outcomes are benefits to clients from participation in health programs. Outcomes may often be confused with program outputs or units of services, e.g., the number of clients who went through a program. We will discuss the difference between outcomes and outputs in the context of health programs. The advantages and barriers to outcome evaluation will be discussed. Finally, participants will be provided with a list of evaluation books and on-line resources.

Biomonitoring Phase II: A Discussion of Existing and Potential Technologies
Keifer M, PNASH – University of Washington
This session will delve more deeply into the existing and developing technological opportunities for biomonitoring for pesticide exposure. Participants should be prepared to share their knowledge and opinions about where biomonitoring should go, how it should be changed, and who should be exploring and financing the new directions.

Childhood Agricultural Injuries in the US: Current Status, Winning Strategies, and Major Gaps
Lee B, National Children's Center for Rural and Agricultural Health and Safety
Since the US Congress adopted and funded a national initiative for childhood agricultural injury prevention in 1996, there has been measurable progress. Injuries among family farm children have declined more than 40 percent. The rate of decline is less remarkable when we include all children who visit and work on farms. NIOSH has funded about 50 extramural research projects, several internal research efforts including surveillance, and a national center to serve as a liaison for researchers, educators, and the farming community. The private sector continues to fund two major educational programs. A few initiatives, such as the national “Keep Kids Away from Tractors” campaign, have been jointly funded by NIOSH and agribusinesses. Research studies have identified some interventions effective in reducing injuries among children. However, these interventions are not yet widely adopted. Potential interventions based on financial incentives, including reduced insurance premiums, have not yet been tested. Policy options have been explored but are not likely to be adopted in the near future. Several gaps in knowledge remain. The Roundtable Discussion will provide an opportunity for participants to get “on the same page” in terms of current national perspectives, then explore options for future research and local/regional interventions

Translation and Dissemination Through Agricultural Partnerships
Rosecrance J, HICAHS – Colorado State University
The purpose of this roundtable workshop is to share experiences (successes and failures) related to research-to-practice (R2P) efforts in agricultural safety and health. Dr. Rosecrance will begin the roundtable with a discussion of the HICAHS project: Translation and Dissemination through Agricultural Partnerships. The HICAHS translation and dissemination project builds on a ten-year foundation of partnership development in agricultural safety and health in the high plains intermountain region of Colorado and surrounding states. The goal of this project is to enhance the translation and transfer (dissemination) of research findings, technologies, and information through agricultural community-initiated small grants and HICAHS research projects. Knowledge generated from community-initiated small grants and HICAHS research is translated into user-specific media and disseminated by utilizing a participatory approach with an extensive network of established agricultural partnerships. A participatory “Agricultural Extension Model,” which is considered one of the most successful in securing users’ adoption of research results (Rogers, 2003), serves as the framework of the proposed projects. Within this framework, theories work behavior (Campbell et al., 1993), planned behavior (Ajzen, 1991), the organization of work model (NORA Organization of Work Team, 2002), as well as social marketing principles are incorporated to enhance effective translation and dissemination of agricultural health and safety knowledge. HICAHS personnel work directly with key agricultural partners (change agents and end-users) such as Cooperative Extension, agricultural associations, insurance companies, migrant health services that have direct access to end-users such as owners, ranch hands, farm families and children, and seasonal and migrant farmworkers.

The Health Consequences of Sub-standard Farmworker Housing
Schenker M, Western Center, University of California, Davis
Housing conditions of many American farm laborers are poor. Many health risks are associated with housing conditions of farmworkers and their families, including anxiety, depression, gastrointestinal illness, exposure to toxic agricultural chemicals, increased risk of infectious disease. This session will discuss what is known about housing conditions of hired farmworkers and associated health effects.

Thursday, November 13

Community Air Exposures to Pesticides – Public Concerns and Known Risks
Fenske R, Yost M, PNASH, University of Washington
This discussion will focus on the evaluation of off-target movement of pesticides during and following agricultural applications. The discussion leaders will provide background regarding recent studies of fixed-wing aircraft applications on potatoes and power blast applications in orchards and will explain the basic methods for measuring human exposures in these situations. The discussion will then address: 1. How to place results in a risk assessment framework; and 2. Possible mitigation strategies. Participants are encouraged to bring their own ideas regarding these issues to the discussion.

Tools for Ergonomic Assessment of Agricultural Work
Johnson PW, Cheng H, Blood R, Studhalter M, University of Washington, Environmental and Occupational Health Sciences, Industrial Engineering Group
With the evolution of ambulatory electronic measurement devices, assessing physical exposures in the workplace has become more economically and practically feasible. Over the last decade, memory and battery life capabilities have greatly increased. With the miniaturization of microelectronics, these devices are now smaller and less obtrusive and cumbersome for workers to wear. This session will cover the major classes of ambulatory instruments that can be used for assessing physical exposures in the agricultural workplace. Topics to be discussed will include EMG equipment for measuring and assessing muscle activity; electrogoniometers and inclinometers for measuring wrist, arm, shoulder and back posture; and a brief discussion of accelerometer-based equipment for measuring exposures to whole body and hand arm vibration. With each class of equipment, the strengths, weaknesses, challenges, and difficulties will be discussed. In addition, software analysis strategies and role and relevance of the variance of the various parameters will also be covered. Finally, the session will conclude with a brief discussion of new and emerging technologies for physical exposure assessment.

Asthma and Environmental Factors in Farmworker Children: Current Evidence,
Intervention Strategies, and Research Needs
Karr CJ, Postma J, University of Washington
Asthma is a priority health concern among communities and providers of health care for farmworker children in the Pacific Northwest. An evolving evidence base derived largely from urban settings supports the role of a number of environmental factors in exacerbating asthma in US children. This session will examine the state of the evidence for environmental factors and asthma disease status that are relevant for farmworker children. Review of the toxicological and epidemiological basis for emerging exposures of concern such as pesticides and phthalates will be discussed in addition to more well-defined exposures such as endotoxin and allergens. Approaches and effectiveness of intervention approaches that are relevant for farmworker communities will be addressed. Lastly, identification of priority data gaps and research opportunities to address these will be explored.

How Can We Overcome the Economic and Cultural Barriers to Preventing and
Treating Heat Illnesses?
Murphy H, PNASH - University of Washington
Key to managing heat stress and preventing its related illness is insuring that workers stay adequately hydrated, take timely rest breaks, and wear clothing that will not overheat them. Rapid cooling by wetting down and fanning an overheated victim is life saving. But implementing these measures is difficult due to a number of economic and cultural barriers. For instance, workers who are paid by the piece will not want to stop to take water, lavatory, or rest breaks. Many workers, especially women, prefer to wear dark clothing in the fields as well as dress in multiple layers in the belief it physically blocks the tanning properties of the sun, keeping their skin light. Finally, it is a common belief that the body will undergo shock and stress if cooled too rapidly, especially if wetted down when overheated, leading to arthritis and other chronic conditions. What are the best approaches to overcoming these and other obstacles to the prevention and treatment of heat illness? Bring your experience and ideas to this important roundtable discussion.

Aerosols in the Agricultural Setting
Pinkerton K, Graduate Students, Western Center - University of California, Davis
Approximately five million workers in the United States engage in the agricultural industry with potential exposure to a wide variety of respiratory toxins. Proper characterization of airborne particles in human exposure settings and relating these conditions to exposure/dose-response relationships could provide a future basis for establishing predictive measures of toxicity, as well as for developing aerosol testing strategies to establish standards to protect agricultural worker health. While our understanding of the mechanisms of particle toxicity has evolved tremendously since the first recognition of airborne crystalline silica particles as a unique health hazard, there is still much that is not understood regarding how particles elicit different biological responses under certain exposure conditions found in the agricultural setting. This roundtable discussion will focus on the types of aerosol exposures that may arise in the agricultural setting and those aerosol properties that must be considered.