List of occupational diseases among farmers in Korea: a literature review
Article information
Abstract
A comprehensive list of occupational diseases among farmers is crucial for both compensation and prevention efforts. In Korea, most farmers are self-employed, and some occupational diseases are compensated through farmer safety insurance. However, it is not harmonized with industrial accident compensation insurance and does not adequately reflect the true burden of occupational diseases among farmers. To address this gap, the authors compiled a list of occupational diseases tailored to Korean farmers by reviewing the International Labor Organization’s list of occupational diseases, the Korean Industrial Accident Compensation Insurance List, the occupational disease lists of other countries, and relevant literature on farmers’ work-related diseases.
BACKGROUND
Occupational diseases are defined as those caused by workplace hazards with a higher prevalence or incidence rate compared to the general population.1 These diseases are identified based on the expectation that their occurrence can be reduced by controlling the cause through an integrated interpretation of epidemiological studies and research on their pathogenesis.2,3 Establishing a list of occupational diseases is essential for both prevention and compensation efforts. The International Labor Organization’s (ILO) Recommendation No. 194 encourages member states to develop national lists of occupational diseases for prevention, recording, notification, and compensation.4 The ILO’s list includes open items that allow countries to adapt based on their national conditions and practices.1
In Korea, occupational diseases for workers are established by law. Under Article 34 (Standards for Recognition of Occupational Diseases) of the Enforcement Decree of the Industrial Accident Compensation Insurance (IACI) Act, 12 disease categories and a comprehensive item are provided in Appendix 3.5 Compensation for workers' occupational diseases based on this list, and various occupational health programs are in place to reduce their incidence.
However, most Korean farmers are not covered by the IACI Act. Although there are approximately 2 million farmers in Korea, only 194,000 corporate-employed farmers were eligible for IACI in 2021. As a result, more than 90% of Korean farmers, being self-employed, are not covered by IACI. Instead, farmers’ safety insurance is available to compensate for injuries and diseases; however, this is not mandatory social insurance. Under Article 4 of the Enforcement Decree of the Act on Safety Insurance and Safety Accident Prevention for Farmers and Fishermen, Annex 1 outlines the diseases eligible for compensation in farming work safety accidents.6 However, this list excludes many diseases that are recognized as occupational diseases for workers while including some infectious diseases that are unlikely to occur by farm work (Supplementary Data 1).
Establishing a comprehensive list of occupational diseases for farmers holds significant social value by enabling proper compensation and setting clear goals for disease prevention.
Although occupational diseases in agriculture have been addressed in textbooks such as Agricultural Medicine: A Practical Guide (Springer),7 Agricultural Medicine: Rural Occupational and Environmental Health for the Health Professions (Wiley-Blackwell),8 and Occupational and Environmental Medicine, 2nd Edition (Gyechukmunhwasa),9 no list has been developed considering the prevalence of domestic farmers, their major crops, or relevant hazards.
This study compiles a list of occupational diseases for Korean farmers based on the ILO list, Korea's IACI Act, and lists from other countries. The final list was developed through expert discussions in occupational and environmental medicine and preventive medicine.
METHODS
We reviewed the occupational diseases relevant to domestic farmers, using the ILO’s 2010 revised list of occupational diseases as a reference. First, we assessed whether any of the diseases listed by the ILO were applicable to domestic farmers. Second, we examined the occupational diseases covered under Korea’s IACI Act to identify those relevant to domestic farmers. This process included a review of epidemiological studies on farmers, the International Agency for Research on Cancer (IARC) monographs, and agricultural medicine textbooks. Third, to identify additional diseases specific to Korean farmers beyond those listed by the ILO and the IACI Act, we compared our findings with occupational disease lists from the United Kingdom, France, Germany, and Japan. We also conducted a comprehensive search of domestic literature and reports to ensure no relevant diseases were overlooked. Finally, the final list was determined through expert consensus at a meeting with the researchers involved in this study.
RESULTS AND DISCUSSION
This list of occupational diseases is categorized into three main groups: diseases caused by exposure to occupational activities, occupational diseases according to target organs, and occupational cancer. Diseases related to exposure to hazardous factors are further subdivided into chemical, physical, and biological agents. The list of organ-specific occupational diseases includes respiratory diseases, skin diseases, musculoskeletal disorders, and mental and behavioral disorders. Occupational cancers are presented as specific carcinogen-cancer pairs. The ILO defines “not classified” occupational diseases as those established scientifically or determined by methods appropriate to national conditions and practices considering a direct link between work activities and the onset of the disease.1 We have compiled a list of occupational diseases for Korean farmers in alignment with the ILO recommendations and objectives (Table 1).
Occupational diseases caused by exposure to agents arising from work activities
Diseases caused by chemical agents
Pesticides, carbon monoxide, hydrogen sulfide, and ammonia were identified as chemical hazards responsible for acute and chronic diseases in farmers. The chemical agents listed in the ILO occupational disease list include various organic solvents and metals. However, in agriculture, exposure to metals and organic solvents typically occurs through pesticides. Pesticides are the leading cause of acute poisoning among farmers.10 Carbon monoxide exposure can occur in confined spaces, such as greenhouses and livestock sheds, when using fossil fuel-based heating systems or agricultural machinery with engines.11 Hydrogen sulfide and ammonia are produced from livestock manure and can lead to acute poisoning.12 Carbon monoxide and hydrogen sulfide are asphyxiating gases that pose a significant risk to farmers.
Diseases caused by physical agents
Farmers are typical outdoor workers exposed to sunlight, heat, and cold.13-16 The list of diseases associated with physical factors includes skin diseases, such as sunburn, actinic keratoses, and non-melanoma skin cancer, as well as ocular diseases like photokeratitis, climatic droplet keratopathy, pterygium, and cortical cataract.17-19 Heat-related and cold-related illnesses are also significant concerns. According to the Korea Disease Control and Prevention Agency, most cases of heat-related illness occur among outdoor workers.20 The incidence of heat-related illness among agricultural workers is increasing in Korea. Farmers are at greater risk due to the frequent occurrence of heat waves, farming activities in hot and humid greenhouses, and high-intensity labor.21 Additionally, farmers using agricultural machinery are exposed to noise and vibration. Equipment such as tractors, combiners, grain dryers, pesticide sprayers, and weeders generate noise and vibration levels.22-24
Diseases caused by biological agents and infectious or parasitic diseases
Occupational infectious diseases have varying sources of infection depending on the country and occupation. Tsutsugamushi disease is endemic in Korea and is the most common rickettsial disease among farmers.25 Tick-borne infectious diseases prevalent in Korea include tsutsugamushi disease and severe fever with thrombocytopenia syndrome.26-28 Rodent-borne viral infections include hemorrhagic fever with renal syndrome and leptospirosis.29-31 Bacterial infections from livestock include brucellosis, Q fever, and anthrax.32-35 Tetanus, which is transmitted through soil and feces, and malaria, which is transmitted through mosquitoes, are also notable infections reported in Korea.36-39 Anthrax is designated as a type 1 notifiable infectious disease, whereas the others are classified as type 4 notifiable infectious diseases. Owing to climate change, there is potential for mosquito-borne infectious diseases, such as dengue fever, Zika virus, yellow fever, and Chikungunya fever, to become endemic in Korea. However, as of now, these diseases are mainly brought in by travelers and cannot yet be included in the list of occupational diseases for farmers.40 The Farmer Safety Insurance's list of occupational diseases includes hepatitis virus, human immunodeficiency virus, and tuberculosis, although it is difficult to believe that these diseases commonly occur during agricultural activities.6
Occupational diseases by target organ systems
Occupational diseases categorized by target organs, as presented by the ILO, include respiratory diseases, musculoskeletal disorders, mental health disorders, and skin diseases. We have observed that all of these diseases can also be caused by occupational factors in farmers.
Respiratory diseases
The ILO’s list of occupational respiratory diseases includes pneumoconiosis, asthma, extrinsic allergic alveolitis, chronic obstructive pulmonary diseases (COPD), and upper airway disorders. Farmers are generally not exposed to mineral dust in concentrations sufficient to cause pneumoconiosis.41 However, they are exposed to various allergenic dusts from animals, plants, and mites. The risk of high-concentration exposure increases in enclosed environments such as greenhouses and livestock facilities.42-46
Respiratory diseases like allergic rhinitis, asthma, and hypersensitivity pneumonitis are well-known to result from hypersensitivity reactions.47-51 Additionally, repeated exposure to irritant gases, combustion by-products, and pesticides can lead to the development of COPD.52-54 Several studies have indicated that farmers may have an elevated risk of idiopathic pulmonary fibrosis (IPF), suggesting it could be considered an occupational disease in this population.55-57 However, it is hypothesized that the increased occurrence of IPF among farmers is related to hypersensitivity pneumonitis. A case-control study conducted in Korea found an increased risk of IPF associated with pesticide exposure; however, the association was not statistically significant after adjusting for smoking.56 Furthermore, there is insufficient evidence to conclude that paraquat, which is known to cause pulmonary fibrosis when ingested, also causes pulmonary fibrosis via inhalation during pesticide application.58,59 Importantly, paraquat has been banned in Korea since 2008. Consequently, the current evidence is inadequate to classify IPF as an occupational disease.60
Musculoskeletal disorders
The ILO's list of musculoskeletal disorders includes conditions such as wrist tenosynovitis, elbow bursitis, knee bursitis, epicondylitis, meniscal injuries of the knee, carpal tunnel syndrome, and other diseases. In Korea, the list of occupational diseases affecting farmers includes triangular fibrocartilage complex (TFCC) injuries, rotator cuff disease, cervical spine disorders, lumbar spine disorders, and arthritis affecting the hand, knee, and hip joints.61-65 These musculoskeletal disorders are already widely recognized as occupational diseases under the IACI Act.5 Musculoskeletal disorders are typically multifactorial in origin and closely related to age. Given the aging agricultural workforce, it has been hypothesized that the high prevalence of musculoskeletal disorders in farmers could be attributed to aging. However, epidemiological studies indicate that farmers experience degenerative changes at younger ages than the general population and are exposed to various significant ergonomic factors.66,67 There is substantial epidemiological evidence linking lumbar spine disorders and osteoarthritis with the pathogenesis and exposure to ergonomic factors. On the other hand, epidemiological studies on TFCC injuries, rotator cuff syndrome, and cervical spine disorders are relatively limited. Nonetheless, research on elite sports activities or other occupations with similar biomechanical demands, along with studies on the pathogenesis of these conditions, provides supporting evidence for causal relationships.68-74
Cerebro-cardiovascular disease
Cerebro-cardiovascular diseases are not included in the ILO’s list of occupational diseases. However, recent meta-studies have confirmed that long working hours and job stress are significant risk factors for cardiovascular disease.75-78 In Korea, cerebrovascular disease is recognized as being potentially caused by overwork, and the IACI Act provides compensation for workers who log 52 working hours per week, along with other occupational risk factors, as in the enforcement of the Act.79
Domestic farmers work longer hours than the national average, with working hours often compressed during peak farming seasons. Farmers tend to work intensively during sowing and harvesting periods while also contending with the uncertainty of agricultural production due to climate variability. In addition to psychological stressors, they face physical stressors such as heavy physical labor, extreme heat, and cold.80,81 Studies comparing the incidence of cerebro-cardiovascular diseases between farmers and non-farmers have shown that farmers are at a higher risk of developing these conditions.82,83 The list of occupational cerebro-cardiovascular diseases for farmers includes stroke and ischemic heart disease, which are also recognized under the Enforcement Decree of the IACI Act.
Occupational cancer
Occupational cancer is not included in this list. Lung cancer and lympho-hematopoietic cancer were considered as candidates for inclusion.84,85 In 2012, the IARC classified arsenic compounds (commonly found in pesticides) as group 1 carcinogens, and in 2018, the IARC classified lindane (hexachlorocyclohexanes) as group 1 carcinogen and dichlorodiphenyltrichloroethane (DDT) as group 2A (probable carcinogen).86,87 Arsenic is known to cause lung cancer, whereas lindane and DDT are associated with lympho-hematopoietic cancer. In Korea, the use of lindane was banned in 1979, DDT in 1973, and arsenic compounds in 2000. Therefore, lung cancer and lympho-hematopoietic cancers were excluded from the list of occupational cancers. For other pesticide exposures, the evidence for carcinogenicity remains inconclusive. There is ongoing debate regarding the carcinogenic potential of several pesticides still in use, including tetrachlorvinphos (an insecticide), parathion (an insecticide), glyphosate (a herbicide), malathion (an insecticide), and diazinon (an insecticide).88 However, current evidence is insufficient to definitively establish a causal link between these pesticides and cancer. This warrants periodic reevaluation as future research emerges. In contrast, there is strong evidence supporting the association between ultraviolet radiation exposure and the development of skin cancer, which is discussed in the section on diseases caused by physical factors in this list.17,18,89
Mental and behavioral disorders
Work-related mental illness in agriculture has been overlooked; however, we believe it is a crucial issue. In particular, suicide among older farmers using pesticides remains a serious problem.90,91 Several studies have reported increased risks of stress, suicidal ideation, and depression in farmers. Mental health risk factors related to agricultural activities are strongly associated with financial instability, which is often unpredictable due to factors such as crop pests, disease, and climate change.92
Consequently, there was a consensus that post-traumatic stress syndrome (PTSD) caused by external stressors should naturally be included in the list, along with adjustment disorder or acute stress syndrome, which are already part of the recognition criteria for occupational diseases under workers’ compensation.
Skin diseases
The ILO’s list of skin diseases includes allergic contact dermatitis, irritant contact dermatitis, and vitiligo. This list is directly reflected in the occupational skin diseases recognized in farmers.93 Farmers are frequently exposed to potential plant allergens, grain dust, and animal allergens.94-97 Most insecticides are irritants and can cause allergic skin reactions.98 Vitiligo is also recognized as an occupational skin disease for farmers. Various phenolic compounds (such as nitrophenol, 2,4-dinitrophenol, pentachlorophenol, and 4,6-dinitro-O-cresol) found in pesticides can have toxic effects on melanocytes in the skin.99,100 Additionally, depigmentation can occur following episodes of allergic dermatitis.
CONCLUSIONS
The list of occupational diseases among farmers serves as the first step in evaluating the long-term effectiveness of prevention projects by analyzing statistics on occupational diseases in this population. For this purpose, the list must strike a balance between reflecting scientific evidence and aligning with policy objectives. Additionally, it should be continuously updated based on the latest research findings.
The presented list was developed with a scientific basis for work-relatedness, considering both acute poisoning and chronic exposure, as assessed by experts in occupational environmental medicine and preventive medicine. We also reviewed the literature on occupational diseases among domestic farmers to ensure the list’s relevance to the local context. This list can be used to compile statistics on the occurrence of occupational diseases among farmers and as a tool to evaluate the long-term effectiveness of farmers’ occupational health initiatives.
However, to fully achieve these goals, further research is needed to properly extract and utilize relevant data from the National Health Insurance Service. It is important to note that this is not a definitive list for compensation purposes. To reflect this list of compensable diseases, additional reviews are required concerning legal standards, insurance finances, and the procedures for determining work-relatedness. As research on the health effects of hazardous factors continues, new hazardous substances emerge, and exposure patterns change, the list of occupational diseases for farmers may also need to be revised in the future.
Abbreviations
COPD
chronic obstructive pulmonary disease
DDT
dichlorodiphenyltrichloroethane
HFRS
hemorrhagic fever with renal syndrome
IACI
Industrial Accident Compensation Insurance
IARC
International Agency for Research on Cancer
ILO
International Labor Organization
IPF
idiopathic pulmonary fibrosis
PTSD
post-traumatic stress syndrome
SFTS
severe fever with thrombocytopenia syndrome
TFCC
triangular fibrocartilage complex
Notes
Funding
This research was support by the Rural Development Administration (RDA) through the research project title “Development of criteria for occupational diseases and customized health care programs for farmers” (NRF-SA00018083).
Competing interests
Hansoo Song and Won-Ju Park contributing editors of the Annals of Occupational and Environmental Medicine, were not involved in the editorial evaluation or decision to publish this article. All remaining authors have declared no conflicts of interest.
Author contributions
Conceptualization: Song H. Data curation: Song H. Formal analysis: Song H. Funding acquisition: Park KS. Investigation: Song H, Yoo SJ, Park WJ, Cho S, Sung JH, Park SJ, Yoon SY, Kim K, Kim HM, Ju B, Youn K. Methodology: Song HS. Software: Song H. Validation: Song H. Visualization: Song H. Writing - original draft: Song H. Writing - review & editing: Song H, Choi DP, Kim KS, Park K.
Acknowledgments
The authors thank the Agricultural Worker Safety Team at the National Institute of Agricultural Sciences, Rural Development Administration, for their assistance in facilitating the smooth operation of this study.