A review of the effect of high fluoride content of water on health and environment and the strategy adopted for its prevention and control, with special reference to India

Abstract

This study aimed to (1) review the reported levels of fluoride in drinking waters, food stuffs and other environmental media around the world, and the current magnitude of prevalence of fluorosis observed in human being and animals, with special reference to India and (2) critically evaluate the strategy adopted for prevention and control of the fluorosis problem in India by conducting questionnaire surveys with professionals from 11 endemic districts, and high school students of two schools located at an endemic area with high fluorosis incidences. Through a comprehensive literature review, it was able to identify 18 endemic states in India with high fluoride levels in their drinking waters while having various degrees of fluorosis problems. These states were further classified into three categories, namely high (>10 mg/L fluoride in drinking waters), moderate (5-9.9 mg/L) and low (1-4.9 mg/L) endemic regions. There were five, nine and four states falling into the high, moderate and low endemic categories, respectively. High fluoride concentrations were observed in the soil near industrial sites, foodstuffs and beverages, and tea leaves. Also, adverse effects of fluoride on terrestrial and aquatic plants, terrestrial vertebrates and invertebrates, and aquatic vertebrates and invertebrates, were observed and demonstrated in laboratory conditions. The questionnaire survey with Indian professionals in 11 fluoride endemic districts found that although all districts had received funds for combating fluorosis problems, there had been delays in executing the associated health promotion, monitoring and treatment programmes in some districts and the utilisation of the fund for the programmes was quite slow. Staff appointment, staff training, medical treatment provision, education and awareness activities, referral hospital facility provision, vehicle facility, monthly reporting, clinical survey and water and urine samples testing, timely monitoring and supervision, and involvement of various medical staff, were found to be inadequate in most districts. In the questionnaire survey conducted at the two high schools, one of the schools (school A) was supplied with alternate source of filtered water (i.e., with normal fluoride concentration) and the second school (school B) was one, which had non-defluoridated ground water supply for drinking (i.e., with high fluoride concentration). This survey found that the awareness about signs of fluorosis, field visit of health worker, cause and preventability of fluorosis, and perception of spread of fluorosis, was comparatively better amongst students of school A than that of school B. Both the schools’ students had positive attitude towards cooperation, prevention and control efforts being made for fluorosis.