Soil heavy metals are associated with the distribution of multiple sclerosis in Isfahan, Iran.
BACKGROUND
Few epidemiological studies have explored the effects of soil pollution on multiple sclerosis (MS) risk in Asia.


METHODS
Based on catchment areas, Isfahan province is divided into five regions (Central, North, East, West, and South), and Soil sampling performed in catchment area with the highest range of MS prevalence and incidence. Samples were analyzed for cobalt (Co), lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), and absorbable forms of Pb, Cd, and Co. Linear regression is used to examine the association of soil heavy metals with prevalence of MS in central part of Isfahan province.


RESULTS
Multiple sclerosis prevalence ranged from 5.62 to 156.65 in different townships. Based on regression analysis, in case of considering fixed amounts for the rest of elements, a one (SD) increase of absorbable Pb and absorbable Cd are associated with 0.385 (SD) (P < 0.0001) increase and 0.209 (SD) (P < 0.007) decrease in MS prevalence, respectively.


CONCLUSIONS
This study documented a significant association between exposure to absorbable Pb and Cd in soil with prevalence of MS in Isfahan. Further work is warranted to confirm this association and if validated, to understand the mechanisms behind the association.
Department of Neurology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.|Isfahan Research Committee of Multiple Sclerosis (IRCOMS), Isfahan University of Medical Sciences, Isfahan, Iran.
M
M
Etemadifar
Department of Geochemistry, Faculty of Earth Sciences, Kharazmi University, Tehran, Iran.
B
B
Mehrabi
Isfahan Research Committee of Multiple Sclerosis (IRCOMS), Isfahan University of Medical Sciences, Isfahan, Iran. reyhaneh.kiani89@gmail.com.|Department of Geochemistry, Faculty of Earth Sciences, Kharazmi University, Tehran, Iran. reyhaneh.kiani89@gmail.com.
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R
Kiani-Peykani
Isfahan Research Committee of Multiple Sclerosis (IRCOMS), Isfahan University of Medical Sciences, Isfahan, Iran.|Medical Students Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran.
S-H
SH
Abtahi
Department of Biostatistics and Epidemiology, Isfahan University of Medical Sciences, Isfahan, Iran.
K
K
Nekouie-Isfahani
University of Oxford, Oxford, UK.|Evidera, London, UK.
S V
SV
Ramagopalan
Isfahan Research Committee of Multiple Sclerosis (IRCOMS), Isfahan University of Medical Sciences, Isfahan, Iran.|Medical Students Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran.|Department of Neuropathology, University Medical Center, Georg August University, Göttingen, Germany.
M
M
Fereidan-Esfahani
D000328:Adult; D017668:Age of Onset; D002104:Cadmium / Q000032:analysis / Q000633:toxicity; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D007854:Lead / Q000032:analysis / Q000633:toxicity; D016014:Linear Models; D008297:Male; D019216:Metals, Heavy / Q000032:analysis* / Q000633:toxicity; D009103:Multiple Sclerosis / Q000453:epidemiology*; D015995:Prevalence; D012424:Rural Population; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity; D014505:Urban Population; D055815:Young Adult
D019216:Metals, Heavy; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead
Iran; Isfahan; multiple sclerosis; prevalence; soil heavy metal