Over the next few weeks, we will be presenting a series of features on emerging risks in agriculture, which have been published in academic literature over the past year.
In our first feature, we provide the latest information on respiratory, cardiac and mental health conditions and disorders onset by agricultural work.
Then, in our second feature, we go on to discuss the impact of workplace exposure to biological and chemical agents on agricultural workers.
In the third feature, we cover the impact of occupational exposure to physical agents on workers, as well as environmental and demographic factors which bring about risk.
In the final feature of the series, we look at agricultural risks caused by technological innovation, in addition to risks produced by a new energy harvesting process, known as hydraulic fracturing, or fracking.
CONDITIONS AND DISORDERS
Firstly, we begin by discussing research on recent studies focused on respiratory research, and then we highlight several case studies of specific incidences of occupational respiratory disorders.
This feature article is not the first mention of respiratory risk in agriculture. Indeed, in edition 190 of BC Disease News (here), we reported that Canada’s Department of Employment and Social Development Labour Program were planning to introduce a new occupational exposure limit for grain and flour dust over an 8 hour period, to 3 mg/m3, due to the risk of chronic bronchitis.
Last year, several further studies and articles addressed respiratory disorders in agriculture. Last year, a European Respiratory review offered suggestions for how occupational lung diseases among European workforces might be prevented. Within this review, respiratory risks in the agriculture industry were widely reported[i].
More specifically, an article by Pennsylvania State University outlined common agricultural respiratory disorders, such as Farmer’s Lung, Organic Dust Toxicity Syndrome, Silo Filler’s Disease and Asthma. The University provides advice on how the risks may be reduced, such as the use of personal protective equipment, instalment of ventilation, and monitoring of work conditions[ii].
Farmer’s Lung and Organic Dust Toxicity Syndrome
Farmer’s Lung and Organic Dust Toxicity Syndrome (ODTS) are caused by inhaling airborne mould spores, attached to dust particles. Mould spores are produced by microorganisms that grow on living plants and baled hay, stored grain, or silage. Perfect conditions for accumulation of spores include a moisture content above 30% and temperatures above 70 degrees Fahrenheit. Typically, these disorders are seasonal, as poor ventilation in Winter and Spring, when storage areas are closed, allow mould to develop[iii] [iv].
Farmer’s Lung, also known as farmer’s hypersensitivity pneumonitis (HP), affects normal lung function by causing shortness of breath, chest tightness, fatigue, coughing, muscle ache, chills and fever, akin to flu or pneumonia. ODTS, also known as grain fever, toxic alveolitis and pulmonary mycotoxicosis, shares symptomatic similarities with Farmer’s Lung. As such, both conditions are often misdiagnosed by physicians[v]. From a legal perspective, this could cause issues surrounding limitation in claims.
Image Source: L A M Schmidt et. al, ‘Agricultural seed dust as a potential cause of organic dust toxic syndrome’ (Journal of Occupational and Environmental Medicine)
Organic Dust Toxicity Syndrome – Additional Research
In dairy farming, experiments have been carried out, comparing farms that use manual feeding systems with those that use automated systems, in order to assess whether there is a difference in dust exposure caused by different types of feeding equipment, thereby affecting respiratory risk. Several news articles from 2017 have outlined organic toxic dust syndrome, and offered advice on how farmers can reduce their risk.
Silo Filler’s Disease
Silo Filler’s Disease occurs when nitrogen oxide, a by-product of silage fermentation, is inhaled. Currently the National Institute for Occupational Safety and Health (NIOSH) has indicated that 20 ppm is a level of exposure capable of causing ‘immediate danger to life and health’, resulting in coughing up blood, shortness of breath and chest pain. At 100 ppm, farmers may experience fluid in the lungs, lung swelling and long-term respiratory problems ending in death.
Image Source: PIONEER
A Norwegian study has found that agriculture/fishery workers have been at an elevated risk of suffering from wheezing and asthma attacks in the past 12 months[vi]. Across the Atlantic, the United States Environmental Protection Agency (EPA) provides a summary of findings from a number of studies of asthma in children, some of which included investigation of exposure to agriculture and pesticides[vii].
Previously, in edition 211 of BC Disease News (here), we reported on an Australian study which estimated that 12.4% were exposure to asthmagens from animals, fish or shellfish. Exposure was significantly higher in rural areas compared to major cities. The occupational groups with the highest proportions of exposure to animal derived asthmagens were famers and animal workers. The main circumstance of exposure to asthmagens was from cleaning up after rats and mice.
Moving on to a study, conducted in central Greece, researchers have found a possible association between allergic rhinitis (hayfever) and pesticide sprayers[viii]. This association has been backed up by another study, using data from the 2011 Farm and Ranch Safety Study, which found that farm operators with allergic rhinitis were more likely to be exposed to pesticides, compared to operators without allergic rhinitis[ix]. Elsewhere, a study found that, among 1113 young Danish farmers, high exposure to endotoxin during young adulthood protected against new onset of pollen sensitisation, independent of childhood farm exposure[x].
Image Source: LA Times
Chronic Obstructive Pulmonary Disease
There has also been a review of chronic obstructive pulmonary disease (COPD) in farmers, published in 2017[xi]. This found that farming work was associated with greater risk of developing COPD, depending upon multiple other variables. COPD prevalence ranged from 3% to 68%, across 14 studies. This wide range was attributed to different characteristics of study population, working activities and case definition/diagnosis. Livestock farmers were at higher risk and significant associations were observed for exposure to organic dusts, endotoxins, mites, ammonia, and hydrogen sulphide.
In a recent US case study, a farmer was exposed to anhydrous ammonia for 15-20 minutes, when a pipeline from an ammonia fertiliser tank accidentally filled the cab of the tractor with ammonia. Although the family opted for comfort care, after 12 days in hospital, a medical procedure, known as a tracheostomy, was recommended (a procedure in which a hole in the side of the neck is made to serve as an airway)[xii]. Ammonia is a highly toxic substance which can cause serious respiratory effects, therefore.
In another case study, regarding Farmer’s lung, the sufferer contracted the disorder after inhaling antigens from pet cockatiels[xiii]. From this, it can be inferred that HP is not a disorder exclusively caused by occupational exposure. For arguments on causation, in a hypothetical employers’ liability claim, public exposure to harmful substances can be vital.
Despite the belief that farmers’ active lifestyle is synonymous with a low risk of heart disease, the Irish Heart Foundation has reported that farmers are 7 times more likely to die from cardiovascular disease than other occupations, and this is supported by papers from the study of Irish livestock[xiv] [xv].
Various articles published in the past year have raised awareness of mental health problems in agricultural work[xvi] and have encouraged farmers to seek support for mental health problems,[xvii] [xviii] including stress[xix]. Accordingly, a video application has been developed to allow farmers quicker and easier access to mental health therapists[xx].
In addition, a campaign was launched at the University of Nottingham to include teaching about mental health issues in the agricultural curriculum[xxi]. What is more, agriculture lecturers have instigated interactive sessions about mental health. Guidance has been delivered by trained nurses and guest lecturers. Awareness of the risk of mental health issues in agricultural work is on the rise.
Well-known sources of stress for farmers include commodity prices, weather and diseases. However, several new studies have provided potential additional links between agriculture and mental health disorders. A study of Korean adults found that exposure to pesticides was associated with depression[xxii]. In addition, 22 family farmers, in Western Australia, recently observed that patterns of climate change exacerbated farmers’ worries, and this contributed to cumulative and chronic distress and risk of depression and suicide[xxiii]. Finally, in Australia and the USA, concerns have emerged regarding the potential effects of hydraulic fracturing on mental health[xxiv]. We go on to discuss the occupational risks of hydraulic fracturing in greater detail in the final feature of this series.
Moreover, in Australia, a study found that farmers displayed a greater ‘need for control and self-reliance’ than non-farmers and therefore created a stronger barrier to seeking mental health services[xxv]. If the results of the Australian study are internationally relevant, it is worthwhile to observe the results of a US study, which found that 171 farm operators/workers died from suicide between 1992 and 2010. The suicide rate in farm operators/workers was higher than the rate for all workers[xxvi]. Similarly, a Norwegian study reported that farmers had higher odds of depression and anxiety than other occupational groups, as well as siblings working outside of the farming industry[xxvii].
[i] Matteis, S. D. et al. Current and new challenges in occupational lung diseases. European Respiratory Review 26, 170080 (2017). http://err.ersjournals.com/content/26/146/170080 (Accessed 16 January 2018)
[ii] Farm Respiratory Hazards. Penn State Extension. 18 August 2017. https://extension.psu.edu/farm-respiratory-hazards (Accessed 16 January 2018)
[iii] Riario Sforza, G. G. & Marinou, A. Hypersensitivity pneumonitis: a complex lung disease. Clinical and Molecular Allergy 15, 6 (2017). https://clinicalmolecularallergy.biomedcentral.com/articles/10.1186/s12948-017-0062-7 (Accessed 17 January 2017)
[iv] Miller, R. et al. Hypersensitivity Pneumonitis A Perspective From Members of the Pulmonary Pathology Society. Archives of Pathology & Laboratory Medicine 142, 120–126 (2017). http://www.archivesofpathology.org/doi/pdf/10.5858/arpa.2017-0138-SA?code=coap-site (Accessed 17 January 2018)
[v] Molyneaux, P. L. & Maher, T. M. Time for an International Consensus on Hypersensitivity Pneumonitis. A Call to Arms. Am J Respir Crit Care Med 196, 665–666 (2017). http://www.atsjournals.org/doi/abs/10.1164/rccm.201707-1439ED (Accessed 17 January 2018)
[vi] Abrahamsen, R. et al. Association of respiratory symptoms and asthma with occupational exposures: findings from a population-based cross-sectional survey in Telemark, Norway. BMJ Open 7, e014018 (2017). http://bmjopen.bmj.com/content/7/3/e014018 (Accessed 17 January 2018)
[vii] Understanding How Environmental Factors Affect Children’s Asthma. EPA. 25 October 2017. https://www.epa.gov/sciencematters/understanding-how-environmental-factors-affect-childrens-asthma (Accessed 17 January 2018)
[viii] Koureas, M., Rachiotis, G., Tsakalof, A. & Hadjichristodoulou, C. Increased Frequency of Rheumatoid Arthritis and Allergic Rhinitis among Pesticide Sprayers and Associations with Pesticide Use. International Journal of Environmental Research and Public Health 14, 865 (2017). http://www.mdpi.com/1660-4601/14/8/865/htm (Accessed 17 January 2018)
[ix] Mazurek, J. M. & Henneberger, P. K. Lifetime allergic rhinitis prevalence among US primary farm operators: findings from the 2011 Farm and Ranch Safety survey. Int Arch Occup Environ Health 90, 507–515 (2017). https://link.springer.com/article/10.1007/s00420-017-1217-z (Accessed 17 January 2018)
[x] Elholm, G. et al. High exposure to endotoxin in farming is associated with less new-onset pollen sensitisation. Occup Environ Med 75, 139–147 (2018). http://oem.bmj.com/content/75/2/139?etoc (Accessed 16 January 2018)
[xi] Fontana, L. et al. Chronic Obstructive Pulmonary Disease in Farmers. Journal of Occupational and Environmental Medicine 59, 775–788 (2017).
[xii] Waheed, I. & Fuller, A. Anhydrous ammonia pulmonary toxicity: A significant farming hazard. The Southwest Respiratory and Critical Care Chronicles 5, 41–44 (2017). http://pulmonarychronicles.com/index.php/pulmonarychronicles/article/view/397/864 (Accessed 16 January 2018)
[xiii] Chand, N., Gollamudi, K., Khan, Z. & Shaikh, R. Hypersensitivity Pneumonitis: A Woman With Chronic Dyspnea. J Med Cases 8, 371–373 (2017). http://www.journalmc.org/index.php/JMC/article/view/2953/2262 (Accessed 17 January 2018)
[xiv] Doorn, D. van, Richardson, N. & Osborne, A. Farmers Have Hearts: The Prevalence of Risk Factors for Cardiovascular Disease Among a Subgroup of Irish Livestock Farmers. Journal of Agromedicine 22, 264–274 (2017). http://www.tandfonline.com/doi/abs/10.1080/1059924X.2017.1318728 (Accessed 18 January 2018)
[xv] Doorn, D. van, Richardson, N. & Osborne, A. 0272 Finding a space for health within the context of ‘occupational risk’ and farm policy: ireland’s ‘farmers have hearts’ workplace cardiovascular screening programme. Occup Environ Med 74, A84–A85 (2017). http://oem.bmj.com/content/74/Suppl_1/A84.3 (Accessed 18 January 2018)
[xvi] The stresses of farming can lead to mental health challenges. Michigan State University, 6 July 2017. http://msue.anr.msu.edu/news/the_stresses_of_farming_can_lead_to_mental_health_challenges (Accessed 18 January 2018)
[xvii] Let’s Talk About Farming and Mental Health. Realagriculture, 25 January 2017. https://www.realagriculture.com/2017/01/lets-talk-about-mental-health-in-farming/ (Accessed 18 January 2018)
[xviii] An isolating illness: talking about mental health. The Western Producer, 24 August 2017. https://www.producer.com/2017/08/an-isolating-illness-talking-about-mental-health/ (Accessed 18 January 2018)
[xix] Mental health on the farm: understanding stress. Grainews 25 October 2017. https://www.grainews.ca/2017/10/25/mental-health-on-the-farm-understanding-stress/ (Accessed 18 January 2018)
[xx] Mental health video call app offers support to farmers. Farmers Weekly, 22 November 2017. http://www.fwi.co.uk/farm-life/mental-health-video-call-app-offers-farmers-support.htm (Accessed 18 January 2018)
[xxi] Campaign launched to teach ag students about mental health. Farmers Weekly, 6 July 2017. http://www.fwi.co.uk/farm-life/campaign-launched-to-teach-ag-students-about-mental-health.htm (Accessed 18 January 2018)
[xxii] Koh, S.-B. et al. Exposure to pesticide as a risk factor for depression: A population-based longitudinal study in Korea. Neurotoxicology 62, 181–185 (2017). https://www.ncbi.nlm.nih.gov/pubmed/28720389 (Accessed 18 January 2018)
[xxiii] Ellis, N. R. & Albrecht, G. A. Climate change threats to family farmers’ sense of place and mental wellbeing: A case study from the Western Australian Wheatbelt. Soc Sci Med 175, 161–168 (2017). https://www.ncbi.nlm.nih.gov/pubmed/28092757 (Accessed 18 January 2018)
[xxiv] Haswell, M. R. & Bethmont, A. Health concerns associated with unconventional gas mining in rural Australia. Rural Remote Health 16, 3825 (2016). https://www.ncbi.nlm.nih.gov/pubmed/27951725 (Accessed 22 January 2018)
[xxv] Hull, M. J., Fennell, K. M., Vallury, K., Jones, M. & Dollman, J. A comparison of barriers to mental health support-seeking among farming and non-farming adults in rural South Australia. Aust J Rural Health 25, 347–353 (2017). https://www.ncbi.nlm.nih.gov/pubmed/28618088 (Accessed 19 January 2018)
[xxvi] Ringgenberg, W., Peek-Asa, C., Donham, K. & Ramirez, M. Trends and Characteristics of Occupational Suicide and Homicide in Farmers and Agriculture Workers, 1992-2010. J Rural Health (2017). doi:10.1111/jrh.12245 https://www.ncbi.nlm.nih.gov/pubmed/28464402 (Accessed 18 January 2018)
[xxvii] Torske, M. O., Bjørngaard, J. H., Hilt, B., Glasscock, D. & Krokstad, S. Farmers’ mental health: A longitudinal sibling comparison - the HUNT study, Norway. Scand J Work Environ Health 42, 547–556 (2016). https://www.ncbi.nlm.nih.gov/pubmed/27636024 (Accessed 18 January 2018)