Fluoride is one of the abundant elements found in the Earth's crust and is a global environmental issue. The present work aimed to find the impact of chronic consumption of fluoride contained groundwater on human subjects. Five hundred and twelve volunteers from different areas of Pakistan were recruited. Cholinergic status, acetylcholinesterase and butyrylcholinesterase gene SNPs and pro-inflammatory cytokines were examined. Association analysis, regression and other standard statistical analyses were performed. Physical examination of the fluoride endemic areas' participants revealed the symptoms of dental and skeletal fluorosis. Cholinergic enzymes (AChE and BChE) were significantly increased among different exposure groups. ACHE gene 3'-UTR variant and BCHE K-variant showed a significant association with risk of fluorosis. Pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) were found to be increased and have a significant correlation in response to fluoride exposure and cholinergic enzymes. The study concludes that chronic consumption of high fluoride-contained water is a risk factor for developing low-grade systemic inflammation through the cholinergic pathway and the studied cholinergic gene SNPs were identified to be associated with the risk of flurosis.

Department of Biosciences COMSATS University Islamabad Park Road Tarlai Islamabad 45550 Pakistan

Department of Chemistry Faculty of Science University of Hradec Kralove Hradec Kralove Czech Republic

Department of Chemistry Faculty of Science University of Hradec Kralove Hradec Kralove Czech Republic; Andalusian Research Institute in Data Science and Computational Intelligence University of Granada 18071 Granada Spain; Biomedical Research Centre University Hospital in Hradec Kralove Sokolska 581 50005 Hradec Kralove Czech Republic

Department of Mathematics COMSATS University Islamabad Park Road Tarlai Islamabad 45550 Pakistan

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