Comparison of Fluoride Levels (Total and Extracted) in Young, Old Tea Leaves and Market Tea Samples along with Impact of Tea Infusion on Dental Fluorosis in Fluoride Endemic Villages of Nalgonda District, India

Abstract

Tea is one of the sources for elevating daily fluoride intake and responsible for high prevalence of fluorosis in fluoride endemic areas. Aim of the study was to assess fluoride exposure dose in children and adults from different tea samples (young, old leaves and commercial tea). Six each young and old tea leaves were collected from different tea gardens at Kaziranga National park in Assam, India. Seven commonly consumed commercial-branded tea samples were procured from local markets. Total and extractable fluoride levels were estimated in all the tea samples using fluoride ion selective electrode method. Prepared tea samples were also collected from road side tea shops of fluorosis endemic areas in Nalgonda district, Telangana for fluoride analysis and dose calculation. The results revealed that total and extractable fluoride levels in young tea leaves were comparatively lower than old tea leaves and commercial tea samples (p<0.002). Fluoride exposure doses for children and adults were calculated and compared with the recommended safe fluoride level 0.05mg kg-1d-1. Children were exposed significantly higher fluoride dose through tea than the adults (p<0.04). Consumption of prepared tea delivers fluoride exposure dose from 0.03mg kg-1d-1 to 0.14mg kg-1d-1 for children and 0.01mg kg-1d-1 to 0.06mg kg-1d-1 for adults. Fluoride exposure doses from milk added prepared teas were significantly lower than the other tea infusions from young, old tea leaves and commercial tea samples (p<0.02). The rate of prevalence of fluorosis increases with increase of fluoride exposure doses through tea (p<0.0001). Adopting the recommended good agricultural practices in tea cultivation and use of milk in tea preparation can reduces the excess fluoride burden and fluorosis risk through tea consumption in fluoride endemic areas.