Rural environment and risk factors of amyotrophic lateral sclerosis: a case–control study

Abstract

The aetiology of sporadic ALS is still unknown. Links with several environmental factors have been suggested, and some epidemiological studies have shown an increased incidence of ALS in rural populations. This study was designed to investigate risk exposures in a well-delimited rural population and to assess whether rural residency or occupations, such as farming, were associated with an increased risk of developing ALS. A prospective case-control-study of 108 sporadic ALS cases matched by age and sex to 122 controls was performed in Brittany from 2006 to 2008. A strong association was found between agricultural activity and ALS (odds ratio: 2.919; p = 0.01), while rural residence itself did not influence the risk of the disease. Bulbar forms of onset prevailed among agricultural workers as compared with other occupations (55 vs. 26%; p = 0.009). These results suggest a potential role of exposure to agricultural chemicals or contact with animals linked to agricultural work. The prevalence of bulbar forms of onset in agricultural workers has not been reported before. In addition to variable methodological approaches, differences in agricultural practices could explain the discrepancy between these findings and other studies.

Clinical, demographic and prognostic features of sporadic amyotrophic lateral sclerosis in Northern Turkey

“…In a study performed with 108 sporadic ALS patients, it was found that contact with agricultural chemicals or with animals associated with agriculture played a potential role in the disease [19]. Additionally, working in the agricultural field or living in urban regions have been indicated as potential risk factors for the development of ALS [19,20]. study.…”

Epidemiology of amyotrophic lateral sclerosis patients in a centre in Buenos Aires

“…Rural environment was proposed, in some series 16,17 , as a risk factor for sALS, due to the eventual exposure to different toxic substances which are handled in farms working activities. So, a strong association was found between agricultural activity and sALS, while rural residence, by itself, did not influence the risk of the disease in one of those studies 18 . Differences in agricultural practices could explain the discrepancy between different findings done by different authors [16][17][18] .…”

“…So, a strong association was found between agricultural activity and sALS, while rural residence, by itself, did not influence the risk of the disease in one of those studies 18 . Differences in agricultural practices could explain the discrepancy between different findings done by different authors [16][17][18] . Occupation as a risk factor for sALS has been subjected to analysis in several studies.…”

Amyotrophic Lateral Sclerosis and Occupational Exposures: A Systematic Literature Review and Meta-Analyses

“…Another 46 relevant publications [3,9,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98] not fulfilling good scientific standards regarding the exposures under study are summarized in Table 2.…”