Agricultural Dust Research Articles

Characteristics of Agricultural Dust Emissions from Harvesting Operations: Case Study of a Whole-Feed Peanut Combine

The rapid development of peanut mechanization has increased the amount of dust expelled from peanut mechanized operations, which degrades the air quality and endangers the health of agricultural workers. Therefore, the purpose of this study is to figure out the characteristics of dust emission from mechanized peanut harvesting. To this end, the particulate matters of diameters ≤ 2.5 μm and ≤10 μm and the total suspended particles were sampled in real time during peanut harvesting in Henan Province, China, and the airborne particle concentrations and particle size distributions were measured. The dust particles discharged during the mechanized peanut harvesting were concentrated within the 2~30 µm size range. When the wind speed was reduced below the settling velocity of the largest particles, the more massive particles were carried in the downwind. The amount of free silica in the dust samples was determined by X-ray diffraction analysis. Both the total dust and free silica concentrations exceeded the occupational exposure and threshold limits. To improve the characteristics of dust emission, the microstructure and dispersion of the dust were also investigated. Reducing the agricultural operations during periods of high wind speed, low crop-moisture content, and low air humidity is recommended for reducing the dust exposure of workers. The results will provide guidance and technical support for reducing the dust emissions of mechanized harvesting operations, improving air quality, and reducing the health hazards to operators.

Combined positive matrix factorization (PMF) and nitrogen isotope signature analysis to provide insights into the source contribution to aerosol free amino acids

Free amino acids (FAAs) are particularly interesting because they play an important role in the atmosphere, but their origins are not well understood. This study measured the concentrations of FAAs and water-soluble ions as well as δ15N values of Glycine (Gly) in total suspended particle (TSP) samples collected at Nanchang in 2017. The correlation of total FAAs concentrations with meteorological conditions and atmospheric oxidants showed that secondary formation processes could be an important contribution sources for FAAs in the atmosphere. Moreover, the concentrations of FAAs in aerosols may be affected by the wind directions and the regions where air mass passed. The correlations of FAAs with water-soluble ions and PMF analysis indicated that the concentration of FAAs in Nanchang aerosols was influenced by agricultural activities and dust sources, mixture of natural origins and biomass burning and mixture of secondary formation process and biomass burning. Interestingly, we also found that coal combustion and vehicle emission are not the sources for atmospheric FAAs. Based on δ15N values of free Gly, a Bayesian model was performed to obtain the individual fractional contributions of free Gly from major sources (natural and biomass burning sources) to aerosol Gly. Subsequently, applying fractional contributions of free Gly from biomass burning obtained by Bayesian model to the analysis result of PMF, the overestimated of the contribution of secondary formation processes and natural sources to atmospheric FAAs concentration caused by biomass burning source could be excluded. Our findings suggest that combining δ15N values of free Gly and PMF analysis could provide further information on the sources of atmospheric FAAs.

Farmer’s Lung Disease

Occupational lung disease is a lung disease or disorder that occurs due to the inhalation of dangerous particles, mist, vapors, or gases while a person is working. The materials accumulate in the respiratory tract or lungs. The type of lung disease that occurs depends on the size and type of the inhaled material. Substances that cause occupational lung disease are toxic materials called noksa. Noksa is a substance that can cause damage to the anatomical structure of body organs and cause respiratory tract function disorders. The lung disease that many farmers experience is often called farmer's lung disease (FLD). FLD is part of hypersensitivity pneumonitis (HP). HP, also known as extrinsic allergic alveolitis, is a group of lung diseases caused by the inhalation of various antigenic organic materials. The most common cause is exposure to agricultural biological dust derived from straw, mold spores, or other dust. HP can be a secondary reaction due to repeated and prolonged inhalation of specific antigens in sensitive individuals. Diagnosis of FLD is often inaccurate. Many of these cases are diagnosed as idiopathic interstitial lung disease. A complete anamnesis should be performed, especially regarding the history of exposure to moldy hay, previous work, and domestic animals, to determine the existence of a history of exposure to the antigen and to confirm the diagnosis.

Assessing Personal PM2.5 Exposure and Respiratory Virus Infections among Farmworkers in the Southeastern United States

BACKGROUND AND AIM: Occupational studies have identified exposure to particulate matter (PM) air pollution as an emerging concern among crop farmworkers, with previous data suggesting that harvesting tasks contribute to the highest occupational PM exposures among this population. Particulates from agricultural dust may be composed of multi-pollutant mixtures of pesticides, heavy metals, mineral silicas, and microbes. Moreover, chronic respiratory conditions, as well as mortality attributable to acute respiratory infections, are notably elevated among crop farmworkers. In the United States, this workforce is comprised primarily of migrant and immigrant populations that face a multitude of social inequities. METHODS: Our pilot study uses personal air samplers to assess occupational exposure to respirable agricultural dust (PM2.5) among a hard-to-reach and vulnerable population of mostly Mexican-American farmworkers harvesting crops in the southeastern US. Participants worked in fernery harvesting, nursery greenhouses, and strawberry harvesting. We conduct prospective, weekly follow-up of participants during influenza season to determine the incidence of acute respiratory symptoms and viral respiratory infections. RESULTS:We collected nasal swab biospecimens from symptomatic participants and tested these samples for SARS-Cov-2 and 20 different respiratory pathogens using a panel array (Biofire). Thus far, we have collected n=30 occupational PM2.5 exposure samples. A majority of occupational PM2.5 exposure levels were above the US EPA limit for annual PM2.5 concentration, with four participants exposed above the OSHA PEL. Of the participants that enrolled in weekly follow-ups (n=20), four participants reported acute respiratory symptoms. Molecular analysis of collected biospecimen were positive for human rhinovirus (n=2), SARS-Cov-2 (n=1), and two samples are pending laboratory analysis. CONCLUSIONS:Follow-up of participants and chemical analysis of PM2.5 filters is ongoing. To our knowledge, this is the first study to assess occupational PM2.5 exposure and incidence of respiratory infections in Southeastern US-hired farmworkers, while characterizing the chemical composition of occupational dust exposures. KEYWORDS: COVID-19, Epidemiology, Exposure assessment, Infectious diseases, Particulate matter, Occupational exposures

Future Seasonal Drought Conditions over the CORDEX-MENA/Arab Domain

Seasonal drought is often overlooked because its impacts are less devasting than meteorological or hydrological drought. Nevertheless, short-term drought can have significant impacts on soil moisture content, agricultural crop yield, and sand and dust storms. Using data obtained from bias-corrected regional climate modelling (RCM) outputs, future seasonal drought is investigated over the water-scarce Arab domain using SPI-3. The climate modelling outputs include three downscaled mainframe GCMs downscaled using a single RCM for two climate scenarios: RCP4.5 and RCP8.5. Results across the region exhibit spatial and temporal variability. For example, Rift Valley, in the eastern sub-Sahara, projects less frequent and less severe drought, particularly during the winter (DJF) months. Conversely, the Morocco Highlands and adjacent Mediterranean coast signals a dramatic increase in drought by end-century during winter (DJF) and spring (MAM). Moderate increase in drought indicated in the greater Mashreq in spring (MAM) can be linked to sand and dust storm risk. Thirdly, autumn drought (SON) is linked to increased forest fire risk in the Levant. Projected increases in drought frequency and severity call for adaptation measures to reduce impacts.

A high docosahexaenoic acid diet alters lung inflammation and recovery following repetitive exposure to aqueous organic dust extracts

Agricultural workers, especially those who work in swine confinement facilities, are at increased risk for developing pulmonary diseases including asthma, chronic obstructive pulmonary disease, and chronic bronchitis due to exposures to fumes, vapors, and organic dust. Repetitive exposure to agricultural dust leads to unresolved inflammation, a common underlying mechanism that worsens lung disease. Besides occupational exposure to dusts, diet also significantly contributes to inflammation and disease progression. Since DHA (docosahexaenoic acid), a polyunsaturated omega-3 fatty acid and its bioactive metabolites have key roles in inflammation resolution, we rationalized that individuals chronically exposed to organic dusts can benefit from dietary modifications. Here, we evaluated the role of DHA in modifying airway inflammation in a murine model of repetitive exposure to an aqueous extract of agricultural dust (three-week exposure to swine confinement dust extract, HDE) and after a one-week resolution/recovery period. We found that mice fed a high DHA diet had significantly increased bronchoalveolar lavage fluid (BALF) levels of DHA-derived resolvins and lower TNFα along with altered plasma levels of endocannabinoids and related lipid mediators. Following the one-week recovery we identified significantly reduced BALF cellularity and cytokine/chemokine release along with increased BALF amphiregulin and resolvins in DHA diet-fed versus control diet-fed mice challenged with HDE. We further report observations on the effects of repetitive HDE exposure on lung Ym1+ and Arg-1+ macrophages. Overall, our findings support a protective role for DHA and identify DHA-derived resolvins and endocannabinoids among the potential mediators of DHA in altering airway inflammation in chronic agricultural dust exposure.

Assessing the contribution of the ENSO and MJO to Australian dust activity based on satellite- and ground-based observations

Abstract. Despite Australian dust's critical role in the regional climate and surrounding marine ecosystems, the controlling factors of the spatiotemporal variations of Australian dust are not fully understood. Here we assess the connections between observed spatiotemporal variations of Australian dust with key modes of large-scale climate variability, namely the El Niño–Southern Oscillation (ENSO) and Madden–Julian Oscillation (MJO). Multiple dust observations from the Aerosol Robotic Network (AERONET), weather stations, and satellite instruments, namely the Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging SpectroRadiometer (MISR), are examined. The assessed multiple dust observations consistently identify the natural and agricultural dust hotspots in Australia, including the Lake Eyre basin, Lake Torrens basin, Lake Frome basin, Simpson Desert, Barwon–Darling basin, Riverina, Barkly Tableland, and the lee side of the Great Dividing Range, as well as a country-wide, austral spring-to-summer peak in dust activity. Our regression analysis of observed dust optical depth (DOD) upon an ocean Niño index confirms previous model-based findings on the enhanced dust activity in southern and eastern Australia during the subsequent austral spring and summer dust season following the strengthening of austral wintertime El Niño. Our analysis further indicates the modulation of the ENSO–dust relationship with the MJO phases. During sequential MJO phases, the dust-active center moves from west to east, associated with the eastward propagation of MJO, with the maximum enhancement in dust activity at about 120, 130, and 140∘ E, corresponding to MJO phases 1–2, 3–4, and 5–6, respectively. MJO phases 3–6 are favorable for enhanced ENSO modulation of dust activity, especially the occurrence of extreme dust events, in southeastern Australia, currently hypothesized to be attributed to the interaction between MJO-induced anomalies in convection and wind and ENSO-induced anomalies in soil moisture and vegetation.

Size-segregated chemical source profiles and potential health impacts of multiple sources of fugitive dust in and around Bhopal, central India

PM2.5 and PM10 fugitive dust samples from multiple sources (construction, demolition, industrial, agricultural fields, and bare ground) were collected in triplicate for each size bin, from 18 distinct locations in and around Bhopal, central India. The dust samples were dried, sieved, and re-suspended in a chamber fitted with a suitable sampling system, to collect PM2.5 and PM10 samples onto Teflon and Quartz filters. The filters were subjected to gravimetric and chemical analyses. Trace elements, water-soluble ions, and thermal-optical carbon fractions were quantified using a variety of analyses. These species were then used to develop PM10 and PM2.5 chemical source profiles of the fugitive dust sources. As expected, crustal species were abundant in all source categories. For industrial dust, Fe contribution to mass in both size fractions was about 11.4% and above the upper continental crustal abundance. Further, the source profiles generated for each source were different from their counterparts in the US EPA SPECIATE database and profiles reported in literature. Thus, it will be useful to utilize profiles generated in this study to enhance receptor model performance for the study region. However, collinearity analysis of the profiles revealed that PM10 agricultural and bare ground dust; and PM2.5 construction and demolition dust profile pairs may not be separated by receptor models. Finally, a human health risk assessment revealed that construction and industrial dust may pose significant risk to the population. The Incremental Lifetime Cancer Risk (ILCR) metric revealed that adults (2 × 10−5) and children (1 × 10−5) were susceptible to cancer risk from exposure to metals in PM2.5 fugitive dust. Further, children were more vulnerable than adults. This finding merits further investigation of oxidation state and solubility/bioavailability of Cr and Ni in fugitive dusts.

A Narrative Review of Occupational Air Pollution and Respiratory Health in Farmworkers.

The agricultural crop sector in the United States depends on migrant, seasonal, and immigrant farmworkers. As an ethnic minority group in the U.S. with little access to health care and a high level of poverty, farmworkers face a combination of adverse living and workplace conditions, such as exposure to high levels of air pollution, that can place them at a higher risk for adverse health outcomes including respiratory infections. This narrative review summarizes peer-reviewed original epidemiology research articles (2000–2020) focused on respirable dust exposures in the workplace and respiratory illnesses among farmworkers. We found studies (n = 12) that assessed both air pollution and respiratory illnesses in farmworkers. Results showed that various air pollutants and respiratory illnesses have been assessed using appropriate methods (e.g., personal filter samplers and spirometry) and a consistent pattern of increased respiratory illness in relation to agricultural dust exposure. There were several gaps in the literature; most notably, no study coupled occupational air exposure and respiratory infection among migrant, seasonal and immigrant farmworkers in the United States. This review provides an important update to the literature regarding recent epidemiological findings on the links between occupational air pollution exposures and respiratory health among vulnerable farmworker populations.

Gone with the Wind: Microbial Communities Associated with Dust from Emissive Farmlands.

Dust is a major vehicle for the dispersal of microorganisms across the globe. While much attention has been focused on microbial dispersal in dust plumes from major natural dust sources, very little is known about the fractionation processes that select for the "dust microbiome." The recent identification of highly emissive, agricultural land dust sources in South Africa has provided the opportunity to study the displacement of microbial communities through dust generation and transport. In this study, we aimed to document the microbial communities that are carried in the dust from one of South Africa's most emissive locations, and to investigate the selective factors that control the partitioning of microbial communities from soil to dust. For this purpose, dust samples were generated at different emission sources using a Portable In-Situ Wind Erosion Lab (PI-SWERL), and the taxonomic composition of the resulting microbiomes was compared with the source soils. Dust emission processes resulted in the clear fractionation of the soil bacterial community, where dust samples were significantly enriched in spore-forming taxa. Conversely, little fractionation was observed in the soil fungal communities, such that the dust fungal fingerprint could be used to identify the source soil. Dust microbiomes were also found to vary according to the emission source, suggesting that land use significantly affected the structure and fractionation of microbial communities transported in dust plumes. In addition, several potential biological allergens of fungal origin were detected in the dust microbiomes, highlighting the potential detrimental effects of dust plumes emitted in South Africa. This study represents the first description of the fractionation of microbial taxa occurring at the source of dust plumes and provides a direct link between land use and its impact on the dust microbiome.

Simulated Dust Transport in the Convective Boundary Layer

AbstractSoil dusts are an important source of aerosol in agricultural regions and can affect the Earth's radiation budget through the modification of cloud properties, and in particular, through their ability to act as ice nucleating particles. In order to impact cloud properties, agricultural soil dusts need to be transported from the point of emission to cloud‐relevant altitudes. Vertical transport within the planetary boundary layer is strongly controlled by turbulence and is challenging to represent accurately in regional and global models. Large‐eddy simulations (LES) are run at resolutions capable of resolving most of the turbulent energy directly and can thus better simulate vertical transport. In this study, we leverage the LES ARM Symbiotic Simulation and Observation (LASSO) large‐eddy simulations to simulate vertical transport of agricultural dust within the turbulent boundary layer using a modified version of the stochastic dispersion model FLEXPART‐WRF. We find that the modified model is better capable of simulating particle transport due to turbulence, and that particle size was the greatest factor in determining particle lifetime. Individual meteorology and particle density had intermediate effects upon particle transport, while release height had little effect upon simulation results. Finally, we utilize a quasi‐single column model (QSCM) approach to determine how our results compare to a parameterized treatment of turbulence. The QSCM simulations led to greater tracer transport out of the boundary layer, with ramifications for any studies utilizing a Lagrangian stochastic model to understand tracer dispersion. These results highlight the importance of accurately simulating turbulence for understanding particle transport.

Anthropogenic Perturbations to the Atmospheric Molybdenum Cycle

AbstractMolybdenum (Mo) is a key cofactor in enzymes used for nitrogen (N) fixation and nitrate reduction, and the low availability of Mo can constrain N inputs, affecting ecosystem productivity. Natural atmospheric Mo aerosolization and deposition from sources such as desert dust, sea‐salt spray, and volcanoes can affect ecosystem function across long timescales, but anthropogenic activities such as combustion, motor vehicles, and agricultural dust have accelerated the natural Mo cycle. Here we combined a synthesis of global atmospheric concentration observations and modeling to identify and estimate anthropogenic sources of atmospheric Mo. To project the impact of atmospheric Mo on terrestrial ecosystems, we synthesized soil Mo data and estimated the global distribution of soil Mo using two approaches to calculate turnover times. We estimated global emissions of atmospheric Mo in aerosols (<10 μm in diameter) to be 23 Gg Mo yr−1, with 40%–75% from anthropogenic sources. We approximated that for the top meter of soil, Mo turnover times range between 1,000 and 1,000,000 years. In some industrialized regions, anthropogenic inputs have enhanced Mo deposition 100‐fold, lowering the soil Mo turnover time considerably. Our synthesis of global observational data, modeling, and a mass balance comparison with riverine Mo exports suggest that anthropogenic activity has greatly accelerated the Mo cycle, with potential to influence N‐limited ecosystems.

Source attributions of Cadmium contamination in rice grains by Cadmium isotope composition analysis: A field study

Cd contamination in rice grains has become a topic of great concern because of the high health risks associated with the long-term consumption of Cd-contaminated rice. Identification of Cd sources in rice grains by scientific methods is important for controlling heavy metal pollution and protecting human health. Here, the Cd concentrations and Cd isotopic compositions of rice plants (root, stem, leaf, and grain) and topsoil, and possible pollution sources (agricultural fertilizers, industrial dust, and automobile exhaust) were analyzed using an instrument of inductively coupled plasma mass spectrometry (ICP-MS) and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The results showed variations in the Cd isotopes of different components of rice plants and the fractionation coefficient of rice grains relative to topsoil (Δ114/110Cdrice grains−topsoil = 0.25‰). The contributions of pollution sources to rice grains were realized by combining the Cd isotopic composition with an isotopic mixing model (Isosource). The analysis showed that all three possible pollution sources contributed to the Cd in the rice grains in the field, the average Cd contribution of industrial dust, agricultural fertilizers and automobile exhaust was 87%, 9%, and 4%, respectively. Our study provides a feasible method for the identification of pollution sources of Cd in rice grains at the field scale and demonstrates that Cd isotopic composition is one of the powerful tools to trace the pollution sources of Cd in crops.

Biochar Fine Particles Enhance Uptake of Benzo(a)pyrene to Macrophages and Epithelial Cells via Different Mechanisms

Biochars are widely used as soil amendments and are major sources of agricultural dusts. Inhalation of biochar fine particles can increase the exposure of respiratory systems to mutagenic and carci...

Human Health Risk Assessment by Dietary Intake and Spatial Distribution Pattern of Polybrominated Diphenyl Ethers and Dechloran Plus from Selected Cities of Pakistan.

A class of intractable bio accumulative halogenated compounds polybrominated diphenyl ethers (PBDEs) was studied. Specifically, PBDEs and dechloran plus (DP) contamination in wheat and the assaulted environment—agricultural soil and dust—from metropolitan cities of Pakistan was the focus. The exposure of brominated flame retardants (BFRs) to humans, their probable toxicological impact on health, source apportionment, and the spatial tendency of BFRs were studied. Chromatographic analysis was performed, and concentrations (ng g−1) of ΣPBDE and ΣDP in soil, dust, and cereal crops were estimated in a range from 0.63 to 31.70 n.d. to 6.32 and n.d. to 3.47, respectively, and 0.11 to 7.05, n.d. to 4.56 and 0.05 to 4.95, respectively. Data analysis of source apportionment reflected that the existence of solid and e-waste sites, long-range transport, urban and industrial fraction can be the potential source of PBDE and DP pollution. Moreover, potential hazardous risks to human health across the study area via the dietary intake of cereal foods were deemed trifling, and were gauged on the basis of existing toxicological data.

South Africa’s agricultural dust sources and events from MSG SEVIRI

Abstract Geomorphological dust research in Southern African has focused on natural sources in Namibia and Botswana. Here we aim to identify South Africa’s dust sources using the Spinning Enhanced Visible and Infra-red Imager data (SEVIRI) between 2006 to 2016. A total of 334,497 images identified 178 dust plumes on 75 dust days, which originate mostly from the Free State, between June to January. Source areas consist of commercial agriculture, grass and shrublands. Half of all event days in the record occurred between 2015 and 2016, a severe drought, according to the Standardised Precipitation Evapotranspiration Index. Crop statistics report a decline in maize cover from 1.2 to 0.6 million hectares and a pronounced increase in fallow cover, confirmed by a below average Normalized Difference Vegetation Index. Transport-capacity appears to be enhanced during drought years and on the increase in wind records. All dust event days adhere to a diurnal wind pattern, irrespective of synoptic conditions and most trajectories head towards the Indian Ocean. In terms of both frequency and extend, SEVIRI events are minor when compared to the northern hemisphere. However South Africa’s major dust sources differ in that they appear to be mostly associated with anthropogenic activities especially rainfed agriculture. The emission potential from natural surfaces remains to be examined. Fire however is not a common precursor in dusty years. The widespread Luvisols and Arenosols, are rich in silt and sand, extend into the wider interior, including the Kalahari, where future climate scenarios by others have predicted increases in dust emissions.

A High Docosahexaenoic Acid Diet Alters the Lung Inflammatory Response to Acute Dust Exposure.

Agricultural workers are at risk for the development of acute and chronic lung diseases due to their exposure to organic agricultural dusts. A diet intervention using the omega-3 fatty acid docosahexaenoic acid (DHA) has been shown to be an effective therapeutic approach for alleviating a dust-induced inflammatory response. We thus hypothesized a high-DHA diet would alter the dust-induced inflammatory response through the increased production of specialized pro-resolving mediators (SPMs). Mice were pre-treated with a DHA-rich diet 4 weeks before being intranasally challenged with a single dose of an extract made from dust collected from a concentrated swine feeding operation (HDE). This omega-3-fatty-acid-rich diet led to reduced arachidonic acid levels in the blood, enhanced macrophage recruitment, and increased the production of the DHA-derived SPM Resolvin D1 (RvD1) in the lung following HDE exposure. An assessment of transcript-level changes in the immune response demonstrated significant differences in immune pathway activation and alterations of numerous macrophage-associated genes among HDE-challenged mice fed a high DHA diet. Our data indicate that consuming a DHA-rich diet leads to the enhanced production of SPMs during an acute inflammatory challenge to dust, supporting a role for dietary DHA supplementation as a potential therapeutic strategy for reducing dust-induced lung inflammation.

Dispersion of Irregular Particles during Free Fall

This paper describes an experimental set up to examine the relationship between powder properties on powder flow pattern during filling operation. For this purpose, the free fall velocities of four types of agricultural dusts (i.e. castor sugar, oat, semolina and tea powder) in a rectangular enclosure were captured using a Particle Image Velocimetry (PIV). The result reveals that oat powder portrayed greater cloud dispersion due to its flaky shape and a lower bulk density. The characteristics of oat powder allowed more air to be dragged into the particle stream and forced the particle to be dispersed and suspended in air due to drag force and terminal velocity. The result presented here may facilitate improvements in dust control and measures in powder industries.

Analysis of Pulmonary Complement Protein Expression Following Organic Dust Exposure

Author(s): Ibrahim, Sarah; Sveiven, Stefanie; Nordgren, Tara | Abstract: Organic dust, as found in agricultural farm work, is ranked among the highest occupational exposure hazards by the CDC. Agricultural dust containing endotoxins, pesticides, mold, and other chemicals, contributes to increased rates of respiratory diseases among these workers. Human bronchial epithelial cells (HBEC), which line upper airways, are frequently exposed to pathogens. Understanding the role of HBEC in inflammation following dust exposure (DE) is necessary to understand the mechanisms underlying inflammatory diseases. The complement system, a nonspecific and non-adaptable defense mechanism, is composed of circulating proteins that promote inflammation by attacking the cell membranes of pathogens and recruiting immune cells that secrete mediators of inflammation. We characterized complement protein expression in DE-treated HBEC using previously generated SWATH proteomics data and Western blotting. Western blotting identified that DE treatment in HBEC mediates the release and activation of C3, while data identified via SWATH-MS proteomics indicated significant upregulation of CD59—a regulator of complement activation. These data suggest that DE-HBEC may regulate complement activation and aim to elucidate the mechanisms by which HBEC promotes the complement system, and thus induce pulmonary inflammation in the presence of organic dust.

Agricultural Dust Exposures and Health and Safety Practices among Western Australian Wheatbelt Farmers during Harvest.

Background: Agricultural farmworkers are routinely exposed to high levels of airborne dust particles that have been linked to adverse health outcomes. Methods: This study measured personal and environmental exposures to dust particulates by farmworkers during harvesting activities. Farmers completed a workplace survey with regards to their health and safety awareness and practices and researchers observed general farm safety practices on selected farms using a checklist. Results: In this study, farmers were noted to commonly work extended hours and shifts during harvest due to rigid timing deadlines. Results showed that 40% of farmers were exposed to concentrations of inhalable particles greater than SafeWork Australia’s workplace exposure standards for grain dusts, assuming a 16 h working day over 5 shifts. Twenty-two percent were exposed to concentrations that were above the adjusted standard for 12 h shifts. Survey results showed that three-quarters of farm owners provided new workers with some type of induction related to farm safety, however this was mostly undertaken in an arbitrary manner. Despite noting that farming was a dusty occupation and reporting to use protective measures to reduce harmful dust exposures, no workers were observed to wear respiratory protection when working outside of the protection of a vehicle cabin. Conclusion: This study identified substantial gaps in health and safety knowledge among farm managers and workers, and improved education and training are highly recommended.