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Design of Highly Compact and Cost-Effective Water Purification Systems for Promoting Rural and Urban Welfare
Published in Sundergopal Sridhar, Membrane Technology, 2018
B. Govardhan, Y.V.L. Ravikumar, Sankaracharya M. Sutar, Sundergopal Sridhar
Intake of a low level of fluoride (less than 0.5 ppm) is good for the body to prevent dental caries but long-term ingestion of fluoride is dangerous, which is responsible for fluorosis and is characterized by staining and pitting of teeth. High-level exposure to fluoride may lead to skeletal fluorosis. Fluoride levels in ground water have been reported to be high in almost 19 states in India, which is alarming. Fluoride contamination of ground water is mainly caused by hydro-geological conditions when ground water comes into contact with rocks rich in fluorite (CaF2) mineral, leading to dissolution of fluoride up to its solubility limit of 20 ppm. Water used for drinking should not have fluoride in excess of 1.0 mg/L, as per BIS standards, and 0.5 ppm according to WHO. Fluoride-contaminated regions are mostly characterized by the presence of crystalline basement rocks/volcanic bedrocks with the dissolution of F− promoted by arid/semi-arid climatic conditions, Ca deficient ground water (containing more of NaHCO3), longer ground water residence time and distance from a recharge area (Raj et al., 2017).
Chemical health risks
Published in Blanca Jiménez, Joan Rose, Urban Water Security: Managing Risks, 2009
Inés Navarro, Francisco J. Zagmutt
Endemic skeletal fluorosis was reported in India in the 1930s. It was observed first in Andhra Pradesh bullocks used for ploughing, when farmers noticed the bullocks’ inability to walk, apparently due to painful and stiff joints. Several years later, the same disease was observed in humans. For example, the prevalence of skeletal fluorosis in Rajasthan was examined in adults exposed to mean fluoride levels of 1.4 and 6 mg/L. At 1.4 mg/L over 4% of adults were reported to be affected, while at 6 mg/L, 63% of adults were reported to be affected. A recent (2003) study conducted in Andhra Pradesh, found skeletal fluorosis affecting just between 0.2 and 1% of the population examined, where the maximum drinking water fluoride concentration was 2.1 mg/L.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Toxic metals and other inorganic compounds contaminate water supplies from both human-made and natural sources. Nitrates, common in groundwaters, cause methemoglobinemia or “blue-baby syndrome” in infants. Fluoride, added by many water suppliers in small doses to prevent tooth decay, causes a weakening of the bones called skeletal fluorosis at concentrations above 4mg/L. Radon, a naturally occurring radionuclide, may cause lung cancer from long-term exposures in the air after being released from water
LDL receptor-related protein 5 rs648438 polymorphism is associated with the risk of skeletal fluorosis
Published in International Journal of Environmental Health Research, 2023
Meichen Zhang, Haili Xu, Qun Lou, Fanshuo Yin, Ning Guo, Liaowei Wu, Wei Huang, Yi Ji, Liu Yang, Qiao Li, Sa Wang, Zhizhong Guan, Yanmei Yang, Yanhui Gao
Fluorine is generally widely distributed in nature in the form of chemical compounds and enters the body through drinking water, food, and air. It has two sides to the human body. An appropriate amount of fluoride is beneficial to the formation of teeth and bones, but a long-term and large intake of fluoride can cause fluorosis characterized by dental fluorosis and skeletal fluorosis (Srivastava and Flora 2020). Fluorine has a strong bone affinity, and more than 90% of the absorbed fluorine is distributed in bone tissue, resulting in skeletal fluorosis. Skeletal fluorosis can not only cause movement limitation, muscle atrophy, and joint stiffness but even joint deformity and serious complications (Sellami et al. 2020). Complications caused by skeletal fluorosis increase the psychological burden of patients, reduce the quality of their survival, and impose a certain economic burden on their families, resulting in a serious public health problem (Liu et al. 2020). Unfortunately, there is no clear and effective treatment program for skeletal fluorosis. Therefore, it is necessary to find the risk factors of skeletal fluorosis and provide the basis for the treatment and prevention of skeletal fluorosis (Qiao et al. 2021).
Willingness to pay for fluoride-free water in Tanzania: disentangling the importance of behavioural factors
Published in International Journal of Water Resources Development, 2023
Luciano Gutierrez, Giuseppe Nocella, Giorgio Ghiglieri, Alfredo Idini
The prolonged intake of fluoride-contaminated water can cause dental and skeletal fluorosis. These diseases can seriously affect teeth and bones causing pain in the joints that over time can lead to reduced mobility and in some cases to permanent disability (Fawell & Bailey, 2006; WHO, 2011). Furthermore, the impact of these diseases may lead to social and psychological disorders such as social exclusion and sense of isolation and frustration (Tekle-Haimanot et al., 2006; WHO, 2011). Dental fluorosis gives rise to discoloration of teeth, and in cases where more than 50% of surface enamel has been lost, restoring natural white enamel relies on complex and expensive interventions such as micro- and macro-abrasion or crowns (Sherwood, 2010). These interventions are time-consuming and not easily available and affordable by many members of these rural communities (Khairnar et al., 2015). The health of these populations is dramatically and irreversibly compromised by skeletal fluorosis because currently no standard treatments are available (Yang et al., 2017).
Fluoride and human health: Systematic appraisal of sources, exposures, metabolism, and toxicity
Published in Critical Reviews in Environmental Science and Technology, 2020
Humayun Kabir, Ashok Kumar Gupta, Subhasish Tripathy
Cases of skeletal fluorosis, even severe crippling skeletal fluorosis, have been reported in India, China, and Africa, where individuals ingest exceptionally high amounts of F− from drinking water or burning F− rich coal indoors (Rasool et al., 2018). In the United States, there is no sign of skeletal fluorosis in the general public from consuming drinking water with F− concentrations less than 4 mg L−1. In contrast, people with renal deficiency who consume a large amount of water with F− concentrations 2–8 mg L−1 may be at high risk (Kaminsky, Mahoney, Leach, Melius, & Miller, 1990). The estimation of the dose-response relationship according to studies is complex because of other factors that also influence water consumption and total F− ingestion. The biological effects of F− exposure on mammalian cells are presented in Figure 7.