Agricultural Work Environment Research Articles

Development of Soft Skills in Teaching English to Agriculture Students

This study investigates the integration of soft skills within English learning experiences for English for Business Class participants, focusing on their relevance to future careers in agriculture. A narrative research design was employed in the study to delve into participants' English learning journeys and identify the most pertinent soft skills cultivated through learning activities. Semi-structured interviews are the primary data collection technique, allowing in-depth exploration of participants' experiences. Language appraisal and emotional geography analyses dissect the narratives and discern the most relevant soft skills for agricultural graduates. The analysis reveals many soft skills, including communication, problem-solving, decision-making, digital literacy, leadership, teamwork, critical and creative thinking, presentation skills, and reflection, all essential for navigating the complexities of agricultural work environments. These findings underscore the importance of integrating soft skills into English language learning curricula, particularly for students pursuing careers in agriculture. The study has implications for updating learning methodologies, refining teaching materials, and designing English learning activities tailored to the specific needs of agricultural professionals

The efficiency of nuisance relief by filtering facepiece respirators used by workers exposed to agricultural odours.

The study aimed to evaluate the effectiveness of filtering facepiece respirators (FFRs) in reducing odour nuisances in agricultural work environment. Additionally, an assessment was conducted on the microbiological contamination of FFRs and the functionality of Time4Mask application in enhancing workplace safety. Two types of FFRs were used for the study: with absorbing properties and reference ones. The research was carried out in 6 livestock rooms during a 1-week period in early spring (February-March 2021) on a farm in central Poland. The microclimate conditions (thermoanemometer), and particulate matter concentrations (laser photometer) were assessed. Additionally, the odour content in the studied rooms and the breathing zone of FFR users (gas chromatography with mass spectrometry) were evaluated. The number of microorganisms on the respirators was determined (cultivation method), followed by their identification (biochemical tests, taxonomic keys). Breakthrough curves were determined for both FFR types to assess absorption capabilities. The average temperature in the livestock rooms was about 13°C, relative humidity - 53%, air flow velocity - 0.21 m/s, and particulate matter concentration - 0.216 mg/m3. A significant variety of odorants was found in the environment and the breathing zone under the FFRs. Bacterial counts ranged between 2.4 × 101 and 2.6 × 102 CFU/cm2, fungi between 3.2 × 100 and 5.4 × 101 CFU/cm2, xerophilic fungi from 4.4 × 100 to 4.0 × 101 CFU/cm2, mannitol-positive staphylococci between 1.6 × 101 and 1.0 × 102 CFU/cm2, and haemolytic staphylococci from 2.2 × 101 to 4.5 × 101 CFU/cm2, depending on the respirator type. Respirators were colonized by bacteria from the genera: Bacillus, Staphylococcus, actinobacteria Streptomyces sp., and fungi: Candida, Absidia, Aspergillus, Mucor, and Penicillium. Respirators with absorbing properties had over 8-times longer breakthrough time than reference ones. Respirators with activated carbon effectively improved work comfort when exposed to odours. Due to growth of microorganisms in the respirator materials, periodic replacement is necessary. It is crucial to provide workers with information about the safe-use time of respirators, considering environmental conditions. This is achievable using modern IT tools like Time4Mask application. Med Pr Work Health Saf. 2023;76(5):363-75.

Causes and prevention of cattle-handling injuries: An interview study

IntroductionA high proportion of injuries on farms occur while handling cattle. Previous studies have identified risk factors such as worker gender, race and age, and farm size, which are difficult to translate into preventive efforts. ObjectiveThe objective of this study was to identify causes of cattle-handling injuries related to the handler, the cattle and the facilities, which could be used in injury-prevention efforts. MethodsStructured interviews were conducted with 97 persons who had been injured while handling cattle during the previous 12 months. The interviews elicited information about the injury incidents, and the role of the facilities, cattle behaviour and the handler in the incident. The interviews were analysed by an experienced safety researcher and an experienced agricultural work environment advisor, to identify possible preventive actions related to the facilities and handler behaviour. ResultsMost injuries occurred while the cattle were trying to flee something they perceived as unpleasant, such as hoof trimming, or as a result of cattle’s defensive behaviour, such as kicking. Up to 71% of the injuries could have been prevented through changes in the facilities, primarily better-designed transfer alleys, better restraint systems during handling and clinical treatment, and the correction of design flaws in existing installations. Handler behaviour was a factor in all but one injury. Risky work plans were the primary factor in 1/3 of the injuries, as was risk-taking. ConclusionThere is great potential for preventing cattle-handling injuries by improving farm facilities and work practices, to better take handler and animal behaviour into account. Efforts that aim to prevent cattle-handling injuries should focus on eliminating hazardous work practices in well-known high risk situations, where the handler is in a risk zone when cows are fearful or agitated. Stockmanship training is crucial to handling cattle properly and efficiently, when interaction is necessary, but from a safety perspective, it is insufficient as a stand-alone prevention strategy. Successful prevention calls for facility and equipment design to be used to limit direct interaction between handlers and cattle, for instance by introducing barriers between them.

Evaluation of Agricultural Work Environment with Ergonomic Checkpoints in Demangan, Siman, Ponorogo

An ergonomic checkpoint is a method for evaluating the current work environment and implementing a more suitable work environment. When workers do work activities, the work environment is a critical component. Ergonomics is described as studying human factors in the workplace, including anatomy, physiology, psychology, engineering, management, and design. Based on preliminary observations, several activities allow potential hazards to arise, such as farmers’ lack of understanding of Personal Protective Equipment (PPE) when spraying pesticides and farmers’ use of t-shirts as a mask. Farmers repeated movements with a bent body position when planting rice seeds, which can cause potential health problems such as musculoskeletal. Using descriptive observational research, this study tries to objectively establish the conditions of the work environment concerning the circumstances. The Ergonomic Checkpoints method was used for data collecting. The results of the work environment assessment using the Ergonomic Checkpoints method in agriculture in Demangan Village revealed that five aspects that required corrective action, consisting of materials storage, and handling, had two points of incompatibility, machine safety had one moment of incompatibility, premises/workspace had one moment of incompatibility, and welfare facility had one moment of mismatch. Farmers in Demangan village should use Ergonomic Checkpoints to pay attention to the work environment in keeping with agricultural standards.

ROS-Based Unmanned Mobile Robot Platform for Agriculture

While the demand for new high-tech technologies is rapidly increasing, difficulties are presented, such as aging and population decline in rural areas. In particular, autonomous mobile robots have been emerging in the agricultural field. Worldwide, huge investment is being made in the development of unmanned agricultural mobile robots; meanwhile with the development of robots, modern farms have high expectations of increased productivity. However, in the agricultural work environment, it is difficult to solve these problems with the existing mobile robot form, due to the difficulties of various environments. Typical problems are space constraints in the agricultural work environment, the high computational complexity of algorithms, and changes in the environment. To solve these problems, in this paper, we propose a method to design and operate a mobile robot platform that can be used in a greenhouse. We represent a robot type with two drive wheels along with four casters that can operate on path and rail. In addition, we propose a technology for a multi-AI deep learning system to operate a robot, an algorithm that can operate such a robot, and a VPN-based communication system for network and security. The proposed method is expected to increase productivity and reduce labor costs in the agricultural work environment.

Participatory Ergonomic Interventions for Improving Agricultural Work Environment: A Case Study in a Farming Organization of Korea

Farmers are often exposed to risk factors for musculoskeletal disorders through lifting, carrying heavy loads, and sustained or repeated full-body bending. Several relevant studies on ergonomic interventions have been conducted for specific agricultural tasks, such as harvesting and pruning, by experts without involving farmers. This study introduces ergonomic interventions to mitigate risk factors in a farming organization that cultivates peaches as the main crop based on ergonomic analysis of the entire peach farming cycle; subjective and objective evaluations of the proposed interventions are also performed. The ergonomic analysis and interventions were established based on consultations provided by an ergonomist, the government, and the organization members. Engineering controls were introduced for powered carts, sorters, and stools to reduce load carrying and awkward postures; moreover, thermal or cooling vests, winter shoes and gloves, and farmer hats were provided to alleviate cold or heat stresses. Administrative controls such as education/training and adjusting work–rest cycles were also recommended after considering the characteristics of the risk factors identified. The scores of the questionnaire survey from the organization members were high (>4.1 out of 5 for five questions), and postural loads for unstable postures by RULA were significantly reduced so as to avoid fast or immediate changes for the postures or working methods assessed. The study results are expected to help promote farmers’ health and enhance farming efficiency.

THE ROLE OF PEER GROUP EDUCATION IN IMPROVING BASIC LIFE SUPPORT (BLS) ABILITIES OF FARMERSIN LUMAJANG

Farmer-based agricultural nursing integrated emergency risk reduction is needed by increasing the ability of farmers. This study aimed to improve farmers’ basic life support (BLS) capacity using the peer group education approach in Lumajang Regency. This study’s design was a quasi-experimental design with a pre and post-test group design on 209 respondents. Bivariate analysis in this study used the Wilcoxon test to determine the effect of BLS ability before and after peer-group education. The majority of respondents were male, as many as 168 people (80.4%) with a productive age of 35-50, 94 people (45%), and a high school education level of 84 people (41%). Before mentoring was carried out, 72% in the low category increased to 56% having good abilities after being assisted BLS. The application of a peer group education approach is expected to improve safety in agricultural areas and minimize hazardous substances in the agricultural work environment. To improve the farmer’s ability about basic life support, not only with training methods, but it can be obtained from electronic media and print media regarding the application of basic life support.Keywords: Peer Group Education; Basic Life Support; Farmers

Requirements for using information and communication technology in agricultural extension work in Assiut governorate, Egypt

This research aimed to identify the requirements of using information and communication technology in agricultural extension work in Asyut Governorate, and the degree of the impact of these requirements on agricultural extension work in the research area. This research was conducted on the majority all the employees of the agricultural extension agency in the governorate of Assiut, whose number at the time of conducting the research was 135 extension workers, Data were collected through personal interviews by a questionnaire was A prepared to that specially, Frequencies, Percentages, the mean, were used for data presentation and analysis SPSS program. The results could summarize as follows: The results showed that the majority of the respondents (85,0% of them) are aged 50 years or over, and the majority (74,1% of them) are of rural origin, although 74,8% of them don't possess agricultural holdings, and 69,6% of them have a diploma in agriculture, and the majority of them (85.1%) were working in agricultural field for 20 years or more, while 45.2% of them have been working in agricultural extension for 20 years or more, Most of them (77.0% of them) didn't receive training courses in the field of information and communication technology, so the majority of them (91.1% of them) had low benefit from training in this field, and 40.7% of them don't own computers (at home or work), and the majority of respondents (99.3% of them) have a mobile phone, and 48.1% of them have internet (wired, or wireless Wi-Fi) at home, while 47.7% of them don't have internet (wired, or wireless Wi-Fi). 2-. The majority of respondents agreed to the proposed items as requirements for the use of information and communication technology in agricultural extension work, which numbered 24 items with rates ranging between (94.8% - 89.6%) to develop the infrastructure requirements necessary for the use of information and communication technology in agricultural extension work , (97.0% - 92.6%) the requirements for training and qualification of the agricultural extension work environment (workers in the agricultural extension apparatus, and farmers) to suit the use of information and communication technology in agricultural extension work, and (96.3% - 91.1%) To develop a national strategy for the use of information and communication technology in extension work agricultural. The most important requirements for the use of information and communication technology in agricultural extension work were the importance and impact of agricultural extension work from the viewpoint of the respondents, arranged as follows: requirements for the development of a national strategy for the use of information and communication technology in agricultural extension work with an average from 75% to 55%, followed by requirements for training and rehabilitation of the environment agricultural extension work (workers, farmers) to fit the use of information and communication technology in agricultural extension work with an average from 69% to 35%, and ranked last in the requirements for developing the infrastructure needed to use information and communication technology in agricultural extension work, with an average from 67% to 20%.

Approaching Safety through Quality: Factors Influencing College Student Perceptions

Quality management practices have been identified by previous literature as a factor that could potentially reduce the level of safety incidents and hazards in agricultural work environments. The present study used multivariate analysis to examine the effect of independent variables such as quality and safety awareness, work experience, safety and quality management experience, and the perceived importance of safety and quality on the role of quality management practices as a mitigating factor for safety hazards and incidents in agriculture. Variables were measured on a five-point scale using a survey questionnaire. Data were collected from approximately 900 undergraduates enrolled in the College of Agriculture and Life Sciences at a large land grant university in the U.S. The level of student work experience and student perceptions of the importance of quality explained a significant amount of the variance in student views of quality management practices as a mitigating factor for safety hazards and incidents. The findings of this study provide further evidence for using quality management practices as a basis for safety interventions targeted at the agricultural workforce.

Perceptions of Agricultural College Students on the Relationship between Quality and Safety in Agricultural Work Environments.

Agriculture is a high-hazard industry that employs a large number of young workers below the age of 25. Recent studies have documented a strong positive correlation between quality management in agriculture and occupational safety as perceived by agricultural workers. Younger workers have been found to be at higher risk for occupational injuries and fatalities in agriculture. Furthermore, college students in agriculture have minimal exposure to safety and quality management principles in their coursework and thus may not be aware that the two concepts are associated Little research has studied how young workers perceive the relationship between safety and quality and how these perceptions vary based on demographic characteristics. This study builds on prior research that measured the interactions between employee perceptions of safety and quality in an agricultural work environment. Data were collected using a survey instrument adapted from a previously validated instrument. Analysis of 1017 responses showed that students perceived a high impact of quality practices on the reduction of safety hazards and safety incidents. Students' perceptions of quality and safety in agricultural work environments varied by gender, with female students perceiving the relationship between the two at a higher level than males. No significant difference in perceptions was observed based on students' academic classification, age group, field of study, or childhood environment. This study demonstrates that despite limited academic training in safety and quality, pre-professionals perceive the implementation of quality management as a very important factor in mitigating safety hazards and safety incidents. In addition, this study suggests that current academic training in these disciplines must be modified, since no differences in students' perceptions were observed based on academic classification or field of study.

Transcriptional mechanisms and protein kinase signaling mediate organic dust induction of IL-8 expression in lung epithelial and THP-1 cells.

Exposure to the agricultural work environment is a risk factor for the development of respiratory symptoms and chronic lung diseases. Inflammation is an important contributor to the pathogenesis of tissue injury and disease. Cellular and molecular mechanisms mediating lung inflammatory responses to agricultural dust are not yet fully understood. We studied the effects of poultry dust extract on molecular regulation of interleukin-8 (IL-8), a proinflammatory cytokine, in A549 and Beas2B lung epithelial and THP-1 monocytic cells. Our findings indicate that poultry dust extract potently induces IL-8 levels by increasing IL-8 gene transcription without altering IL-8 mRNA stability. Increase in IL-8 promoter activity was due to enhanced binding of activator protein 1 and NF-κB. IL-8 induction was associated with protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) activation and inhibited by PKC and MAPK inhibitors. IL-8 increase was not inhibited by polymyxin B or l-nitroarginine methyl ester, indicating lack of involvement of lipopolysaccharide and nitric oxide in the induction. Lung epithelial and THP-1 cells share common mechanisms for induction of IL-8 levels. Our findings identify key roles for transcriptional mechanisms and protein kinase signaling pathways for IL-8 induction and provide insights into the mechanisms regulating lung inflammatory responses to organic dust exposure.

Effect of Stored Product Mite Extracts on Human Dermal Microvascular Endothelial Cells

Stored product mites commonly occur in agricultural work environments and sometimes in homes in significant numbers. They are a source of allergens that sensitize and induce allergic reactions. This may include atopic dermatitis. The purpose of this investigation was to determine if the common species of storage mites are the sources of molecules that influence the function of human dermal microvascular endothelial cells that regulate the trafficking of inflammatory and immune cells into the dermis during allergic reactions and other skin diseases. Human dermal microvascular endothelial cells were challenged with varying doses of extracts of the storage mites Acarus siro L., Chortoglyphus arcuatus (Troupeau), Lepidoglyphus destructor (Schrank), or Tyrophagus putrescentiae (Schrank) and the secretion of cytokines and expression of adhesion molecules were measured. The role of endotoxin and protein in inducing these responses was evaluated. These stored product mite extracts induced secretion of interleukin-6, interleukin-8, monocyte chemotactic protein-1, and granulocyte/monocyte colony stimulating factor. Some of these effects were induced by protein present in the extracts, some were induced by endotoxin, and some were induced by other substances. C. arcuatus and T. putrescentiae extracts also down-regulated tumor necrosis factor a-induced vascular cell adhesion molecule-1 expression. Stored product mite extracts contain an assortment of molecules, including endotoxins and proteins, which modulate the expression of cell adhesion molecules and the secretion of cytokines by microvascular endothelial cells. These modulating properties varied among mite species indicating that each mite species has a unique set of molecules that is responsible for its activity.

Management of Safety and Quality and the Relationship with Employee Decisions in Country Grain Elevators

Human factors play an important role in the management of safety and quality in an agricultural work environment. Although employee actions and decisions have been identified as a key component of successful occupational safety programs and quality management programs, little attention has been given to the employees' role in these types of programs. This research explored two safety relationships that have theoretical connections but little previous research: the relationship between safety climate and quality climate, and the relationship of the safety and quality climates between the organizational level and the group level within a workplace. Survey data were collected at three commercial grain handling facilities from 177 employees. Employees also participated in safety and quality decision-making simulations. Significant positive predictions were noted for safety and quality climate. Decision-making predictions are also discussed. This research suggests that organizational safety is an important predictor of group safety. In addition, recognizing the larger role that supervisors play in group workplace behavior, more should be done to increase employee perceptions of group-level involvement in quality climate to promote more quality-oriented decision-making by employees.

Prioritizing Environmental Health Risks in the UAE

This article presents the results of a comparative environmental risk-ranking exercise that was conducted in the United Arab Emirates (UAE) to inform a strategic planning process led by the Environment Agency-Abu Dhabi (EAD). It represents the first national-level application of a deliberative method for comparative risk ranking first published in this journal. The deliberative method involves a five-stage process that includes quantitative risk assessment by experts and deliberations by groups of stakeholders. The project reported in this article considered 14 categories of environmental risks to health identified through discussions with EAD staff: ambient and indoor air pollution; drinking water contamination; coastal water pollution; soil and groundwater contamination; contamination of fruits, vegetables, and seafood; ambient noise; stratospheric ozone depletion; electromagnetic fields from power lines; health impacts from climate change; and exposure to hazardous substances in industrial, construction, and agricultural work environments. Results from workshops involving 73 stakeholders who met in five separate groups to rank these risks individually and collaboratively indicated strong consensus that outdoor and indoor air pollution are the highest priorities in the UAE. Each of the five groups rated these as being among the highest risks. All groups rated soil and groundwater contamination as being among the lowest risks. In surveys administered after the ranking exercises, participants indicated that the results of the process represented their concerns and approved of using the ranking results to inform policy decisions. The results ultimately shaped a strategic plan that is now being implemented.

Adult supervision and pediatric injuries in the agricultural worksite

Appropriate supervision is recommended as a strategy to prevent pediatric farm injuries, yet virtually nothing is known about the quality of adult supervision on farms. We therefore explored the nature of adult supervision among pediatric farm injury cases using three theoretically relevant dimensions of supervision: (1) attention, (2) proximity, and (3) continuity. We examined a retrospective case series of 334 pediatric farm injury cases from Canada and the United States that resulted in death or required hospitalization. Patterns of supervision were coded according to the three dimensions. Approximately two-thirds of the injured children (231/334; 69%) had an adult supervisor available ( attention). The supervisor was in close proximity of the child in only about half the cases (169/334; 51%) and it was even less common for the supervision to be continuous (37%). Thus, many injuries occurred when children were inadequately supervised. However, approximately one-third of the injured children (112/334; 34%) had what in other circumstances would be considered adequate adult supervision at the time of their injury event, defined theoretically as having supervision available, proximal, and continuous. Yet, children on farms were injured even in the presence of adequate adult supervision. These findings, along with a growing body of literature examining pediatric farm injuries, suggest a need to develop a new definition of adequate adult supervision within the context of the agricultural work environment, or to consider restricting the access of children, especially the very young, to this hazardous worksite.

Beyond the Bench: Prevention Pays for Farmworkers

Many agricultural growers use pesticides to protect crops and ensure satisfactory yields. Although the United States has some of the strictest laws governing pesticide applications and re-entry into fields after application, a number of studies have demonstrated that farmworkers are still being exposed to pesticides in the fields and that they may take the chemicals home on their skin and clothing, potentially exposing their families. This risk prompted the University of California, Berkeley, Center for Children’s Environmental Health Research to join with community partners Clinica de Salud del Valle de Salinas, the California Rural Legal Assistance Program, and the Central Coast Grower–Shipper Association to conduct a study on ways to alleviate this hazard. The community-based participatory research study employed a field-based technical intervention designed to reduce farmworker exposure to pesticides and the potential for take-home pesticide exposures. The partnership, through its Center for Health Assessment of Mothers and Children of Salinas (CHAMACOS), recruited 130 study participants working at two Monterey County strawberry farms during the summer of 2003. Then they initiated preventive measures to decrease direct exposure to malathion (a pesticide commonly used in strawberry fields) and lessen the amount of pesticide residues workers carried home on clothing, skin, and shoes. “The agricultural work environment is very complex, with changes in weather parameters, soil moisture, crops, tasks, and other factors occurring over short time frames,” says Asa Bradman, CHAMACOS associate director. “We focused on strawberry harvesting to ensure that the crop and task could be held constant. We chose to study malathion because it can be [simultaneously] measured in . . . foliar residue samples, in personal samples such as hand rinse and clothing patch samples, and in urine as the metabolite malathion dicarboxylic acid.” The study began with surveys, urine sampling, and foliage sampling during a pre-intervention process to determine the farmworkers’ initial exposure levels. Intervention activities began a month later. The team provided protective clothing (lightweight coveralls and disposable gloves), educational sessions at the worksite on exposure prevention, shoe boxes and laundry bags to store work clothing and shoes, and a field station with warm water and soap for handwashing. Post-intervention data collection in October of the same year included surveys, urine sampling, hand rinse sampling, clothing patch sampling, and foliage sampling. The initial feedback from the participants indicated that the intervention strategies could lower overall exposure if used on a regular basis. One of the solutions, the use of a hot water heater in the field to provide warm water for handwashing, had never been tried before. During the pre-intervention phase, many farmworkers revealed that they had previously avoided washing their hands while picking strawberries because they believed that washing with cold water, which was all that was available, could cause arthritis. The availability of the warm water led to more handwashing and thus less pesticide residue on hands. The protective clothing and storage for work clothes and shoes also proved helpful to the workers in limiting pesticide exposure. Alicia Salvatore, CHAMACOS intervention study coordinator, says, “Many [farmworkers] reported that they experienced fewer dermal rashes when they used gloves, and almost all workers noticed a marked change in amount of dirt that they carried home at the end of the day on the clothing that they wore under their coveralls. Almost all workers who participated were interested in continuing these behaviors.” Brenda Eskenazi, CHAMACOS director and principal investigator of the project, sees a necessity and potential for these types of measures, and says the partnership will continue to advance that cause. “We believe it is important to develop sustainable interventions—that is, interventions that are cheap and effective in reducing exposure to pesticides,” she says. “This intervention . . . is an important first step in this direction.” Bradman says the growers who participated in the intervention were supportive of the project and plan to continue to use the preventive measures to the fullest extent possible. He adds that the community partners in CHAMACOS are presenting their findings to other growers and agricultural organizations, as well as preparing reports for publication.

Prevalence of exposure to solvents, metals, grain dust, and other hazards among farmers in the Agricultural Health Study

Exposures to multiple chemical, physical, and biological agents in agricultural work environments can result in confounding that may obscure or distort risks observed in epidemiologic studies. The Agricultural Health Study (AHS) is a large epidemiology study being conducted to investigate health risks among pesticide applicators and their families. During enrollment in the AHS, questionnaires were administered to over 52,000 licensed pesticide applicators from North Carolina and Iowa, who were mostly farmers. Questions about the frequency of various farming tasks were used to estimate the prevalence of exposure to solvents (25%), metals (68%), grain dusts (65%), diesel exhaust fumes (93%), and other hazards, including exposure to pesticides. Most of the farmers in the AHS reported performing routine maintenance tasks at least once a month, such as painting (63%), welding (64%), and repair of pesticide equipment (58%). The majority of farmers (74% in North Carolina; 59% in Iowa) reported holding nonfarm jobs, of which the most frequent were construction and transportation. The majority of the farmers enrolled in the AHS (55%) also reported that they mixed or applied pesticides on 10 or more days per year. The associations between the use of pesticides and the frequency with which the farmers in the AHS reported performing various types of specific farming activities were assessed to evaluate potential confounding. Confounding risk ratios calculated for these activities suggest that the magnitude of bias due to confounding is likely to be minimal.

Further studies on inhaled endotoxin-containing bacteria

A highly sensitive, discriminatory, and reproducible assay for changes produced by inhalation of gram-negative, endotoxin-containing bacteria was developed. The assay measures the production of lactic dehydrogenase (LDH) of mice in pulmonary lavages at various time intervals after standardized aerosol exposure. Aerosols of four such bacteria, Enterobacter cloacae, Escherichia coli, Citrobacter freundii, and a heavily mucoid species of Flavobacterium, chosen because of their occurrence in aerosols in agricultural work environments, produce distinctly different patterns of LDH evaluation above those of control mice exposed to saline aerosols. Comparative results obtained from endotoxin-responsive and C3H HeJ endotoxin-resistant mice indicated that endotoxins differed in their ability to induce the LDH release. In the case of the response to Flavobacterium, the enzyme release was due more to a synergistic effect between the glycoprotein slime layer and the endotoxin. More detailed studies with the most toxic strain studied, C. freudii, indicated the LDH response was in part due to a bound endotoxin recognition trigger, partly due to complement activation, and most likely independent of antibodies.