Neurological and mental health outcomes among conventional and organic farmers in Indiana, USA
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Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, Indiana, USA
Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, Indiana, USA
Department of Recreation, Park and Tourism Studies, School of Public Health, Indiana University, Bloomington, Indiana, USA
Vincent and Elinor Ostrom Workshop in Political Theory and Policy Analysis, Indiana University, Bloomington
Every farming method, whether conventional or organic, has been associated with some sort of risky behaviors leading to health issues among farmers. Substantial evidence is not available in the literature to determine whether the magnitudes of health outcomes vary between conventional and organic farmers. The study investigated whether self-reported neurological and mental health symptoms differ between conventional and organic farmers living in Indiana, USA.

Material and methods:
A self-reported questionnaire survey collected information from 200 conventional and 157 organic farmers of Indiana on demographic characteristics, depression and neurological symptoms. Statistical analyses were conducted to observe the differences in self-reported symptoms by groups of farmers.

It was observed that the conventional farmers had significantly higher age-adjusted mean neurological symptom score (p<0.01) than the organic farmers. Regression models revealed positive and significant associations of conventional farming with total (β =1.34; p=0.02), sensory (β =0.83; p=0.001) and behavioural (β =0.09; p=0.03) symptoms after accounting for age, income, education and years in farming. Positive but non-significant associations were also observed in conventional farmers with cognitive and motor symptoms, and with all subscales of depression symptoms in the adjusted models.

The findings obtained suggest the importance of a larger study to further explain the difference in mental and neurological health effects in these two categories of farmers.

Khalid M Khan   
Department of Environmental Health, School of Public Health, Indiana University, Bloomington, School of Public Health, Dept. of Environmental Health, 47405 Bloomington, United States
1. NRC: Pesticides in the Diets of Infants and Children. Committee on Pesticides in the Diets of Infants and Children. Commission on Life Sciences. Division on Earth and Life Studies. National Research Council: National Academic Press; 1993.
2. USDA: United States Department of Agriculture, Organic Agriculture. Available at Accessed on June 10, 2016. 2016.
3. Hanson J, Dismukes R, Chambers W, Greene C, Kremen A. Risk and risk management in organic agriculture: Views of organic farmers. Renew Agr Food Syst. 2004; 19(4): 218–227.
4. Ames BN, Profet M, Gold LS. Dietary pesticides (99.99% all natural). Proceedings of the National Academy of Sciences of the United States of America 1990; 87(19): 7777–7781.
5. Ames BN, Profet M, Gold LS. Nature’s chemicals and synthetic chemicals: comparative toxicology. Proceedings of the National Academy of Sciences of the United States of America 1990; 87(19): 7782–7786.
6. Hoar Zahm S, Weisenburger DD, Cantor KP, Holmes FF, Blair A. Role of the herbicide atrazine in the development of non-Hodgkin’s lymphoma. Scand J Work Env Hea. 1993; 19(2): 108–114.
7. Karunanayake CP, Dosman JA, Pahwa P. Non-hodgkin’s lymphoma and work in agriculture: Results of a two case-control studies in Saskatchewan, Canada. Indian J Occup Env Med. 2013; 17(3): 114–121.
8. Weisenburger DD. Human health effects of agrichemical use. Hum Pathol. 1993; 24(6): 571–576.
9. Smit LA, Zuurbier M, Doekes G, Wouters IM, Heederik D, Douwes J. Hay fever and asthma symptoms in conventional and organic farmers in The Netherlands. Occup Env Med. 2007; 64(2): 101–107.
10. Rosenstock L, Keifer M, Daniell WE, Mcconnell R, Claypoole K. Chronic Central-Nervous-System Effects of Acute Organophosphate Pesticide Intoxication. Lancet 1991; 338(8761): 223–227.
11. Hu RF, Huang XS, Huang JK, Li YF, Zhang C, Yin Y, Chen ZH, Jin YH, Cai JY, Cui F. Long- and Short-Term Health Effects of Pesticide Exposure: A Cohort Study from China. Plos One 2015; 10(6).
12. London L, Flisher AJ, Wesseling C, Mergler D, Kromhout H. Suicide and exposure to organophosphate insecticides: cause or effect? Am J Ind Med. 2005; 47(4): 308–321.
13. Khan K, Ismail AA, Abdel Rasoul G, Bonner MR, Lasarev MR, Hendy O, Al-Batanony M, Crane AL, Singleton ST, Olson JR, et al. Longitudinal assessment of chlorpyrifos exposure and self-reported neurological symptoms in adolescent pesticide applicators. BMJ open 2014; 4(3): e004177.
14. Cole DC, Carpio F, Julian J, Leon N. Assessment of peripheral nerve function in an Ecuadorian rural population exposed to pesticides. J Toxicol Env Hea Part A 1998; 55(2): 77–91.
15. Kamel F, Engel LS, Gladen BC, Hoppin JA, Alavanja MC, Sandler DP. Neurologic symptoms in licensed pesticide applicators in the Agricultural Health Study. Hum Exper Toxicol. 2007; 26(3): 243–250.
16. Kamel F, Hoppin JA. Association of pesticide exposure with neurologic dysfunction and disease. Environ Health Persp. 2004; 112(9): 950–958.
17. Costa LG, Giordano G, Guizzetti M, Vitalone A. Neurotoxicity of pesticides: a brief review. Front Biosci: a journal and virtual library 2008; 13: 1240–1249.
18. Werner FM, Covenas R. Classical neurotransmitters and neuropeptides involved in major depression: a review. Int J Neurosci. 2010; 120(7): 455–470.
19. Naismith SL, Norrie LM, Mowszowski L, Hickie IB. The neurobiology of depression in later-life: clinical, neuropsychological, neuroimaging and pathophysiological features. Prog Neurobiol. 2012; 98(1): 99–143.
20. Beseler CL, Stallones L, Hoppin JA, Alavanja MC, Blair A, Keefe T, Kamel F. Depression and pesticide exposures among private pesticide applicators enrolled in the Agricultural Health Study. Environ Health Persp. 2008; 116(12): 1713–1719.
21. Wesseling C, van Wendel de Joode B, Keifer M, London L, Mergler D, Stallones L. Symptoms of psychological distress and suicidal ideation among banana workers with a history of poisoning by organophosphate or n-methyl carbamate pesticides. Occup Environ Med. 2010; 67(11): 778–784.
22. Beseler CL, Stallones L. A cohort study of pesticide poisoning and depression in Colorado farm residents. Ann Epidemiol. 2008; 18(10): 768–774.
23. Torske MO, Hilt B, Glasscock D, Lundqvist P, Krokstad S. Anxiety and Depression Symptoms Among Farmers: The HUNT Study, Norway. J Agromed. 2016; 21(1): 24–33.
24. USDA: United States Department of Agriculture, Census of Agriculture. Available at Accessed on January 14, 2016. 2007.
25. Costa C, Garcia-Leston J, Costa S, Coelho P, Silva S, Pingarilho M, Valdiglesias V, Mattei F, Dall’Armi V, Bonassi S, et al. Is organic farming safer to farmers’ health? A comparison between organic and traditional farming. Toxicol Lett. 2014; 230(2): 166–176.
26. Cross P, Edwards RT, Hounsome B, Edwards-Jones G. Comparative assessment of migrant farm worker health in conventional and organic horticultural systems in the United Kingdom. Sci Total Environ. 2008; 391(1): 55–65.
27. Sorge US, Moon R, Wolff LJ, Michels L, Schroth S, Kelton DF, Heins B. Management practices on organic and conventional dairy herds in Minnesota. J Dairy Sci. 2016, 99(4): 3183–3192.
28. Motsoeneng PM, Dalvie MA. Relationship between Urinary Pesticide Residue Levels and Neurotoxic Symptoms among Women on Farms in the Western Cape, South Africa. Int J Environ Res Public Health 2015; 12(6): 6281–6299.
29. Ihrig A, Triebig G, Dietz MC. Evaluation of a modified German version of the Q16 questionnaire for neurotoxic symptoms in workers exposed to solvents. Occup Environ Med. 2001; 58(1): 19–23.
30. Sekkal S, Casas L, Haddam N, Bouhacina L, Scheers H, Taleb A, Nemery B. Sleep disturbances and neurotoxicity in workers exposed to hydrocarbons. An observational study from Algeria. Am J Ind Med. 2016; 59(2): 129–136.
31. Lundberg I, Hogberg M, Michelsen H, Nise G, Hogstedt C. Evaluation of the Q16 questionnaire on neurotoxic symptoms and a review of its use. Occup Environ Med. 1997; 54(5): 343–350.
32. Radloff LS. The use of the Center for Epidemiologic Studies Depression Scale in adolescents and young adults. J Youth Adolescence 1991; 20(2): 149–166.
33. Radloff LS. The CES-D scale a self-report depression scale for research in the general population. Appl Psychol Meas. 1977; 1(3): 385–401.
34. Fraser CE, Smith KB, Judd F, Humphreys JS, Fragar LJ, Henderson A. Farming and mental health problems and mental illness. Int J Soc Psychiatr. 2005; 51(4): 340–349.
35. Stander VA, Hilton SM, Kennedy KR, Robbins DL. Surveillance of completed suicide in the Department of the Navy. Milit Med. 2004; 169(4): 301–306.
36. Kallioniemi MK, Simola AJ, Kymalainen HR, Vesala HT, Louhelainen JK. Mental symptoms among Finnish farm entrepreneurs. Ann Agric Environ Med. 2009; 16(1): 159–168.
37. Dasgupta S, Meisner C, Wheeler D, Xuyen K, Thi Lam N. Pesticide poisoning of farm workers-implications of blood test results from Vietnam. Int J Hyg Environ Health. 2007; 210(2): 121–132.
38. Kimura K, Yokoyama K, Sato H, Nordin RB, Naing L, Kimura S, Okabe S, Maeno T, Kobayashi Y, Kitamura F, et al. Effects of pesticides on the peripheral and central nervous system in tobacco farmers in Malaysia: studies on peripheral nerve conduction, brain-evoked potentials and computerized posturography. Ind Health 2005; 43(2): 285–294.
39. Thompson AW, Reimer A, Prokopy LS. Farmers’ views of the environment: the influence of competing attitude frames on landscape conservation efforts. Agr Hum Values 2015; 32(3): 385–399.
40. Darnhofer I, Schneeberger W, Freyer B. Converting or not converting to organic farming in Austria: Farmer types and their rationale. Agr Hum Values 2005; 22(1): 39–52.
41. Uematsu H, Mishra AK. Organic farmers or conventional farmers: Where’s the money? Ecol Econ. 2012; 78: 55–62.
42. Sullivan S, McCann E, deYoung R, Erickson D. Farmers’ attitudes about farming and the environment: A survey of conventional and organic farmers. J Agr Environ Ethic. 1996; 9(2): 123–143.
43. Veldstra MD, Alexander CE, Marshall MI. To certify or not to certify? Separating the organic production and certification decisions. Food Policy 2014; 49: 429–436.
44. Hall A, Mogyorody V. Organic farming, gender, and the labor process. Rural Sociol. 2007; 72(2): 289–316.
45. Burton M, Rigby D, Young T. Analysis of the determinants of adoption of organic horticultural techniques in the UK. J Agr Econ. 1999; 50(1): 48–63.
46. Brophy JT, Keith MM, Watterson A, Park R, Gilbertson M, Maticka-Tyndale E, Beck M, Abu-Zahra H, Schneider K, Reinhartz A, et al. Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case-control study. Environ Health-Glob. 2012: 11.
47. APHA: Toward a healthy, sustainable food system. Policy number 200712. Retrieved from Accessed on November 10, 2016. 2007.
48. CDC: Center for Disease Control and Prevention. (2013). One health. Retrieved from Accessed on November 15, 2016. 2013.
49. Carson R, Darling L, Darling L. Silent spring. Boston Cambridge, Mass.: Houghton Mifflin; Riverside Press; 1962.