Crippling fluorosis occurs at what level -

Ans. is 'd' i.e., 10 mg/liter Crippling fluorosiso This occurs at fluoride level > 10 mg/litre (PPM). Patient is crippled and bed ridden.Fluorosiso Fluorine is considered as 'two edged sword' because excess intake causes endemic fluorosis and inadequate intake causes dental caries.o The recommended level of fluoride in drinking water is 0-5 - 0-8 mg/litre (PPM). But the recommended maximum permissible limit is 1.5 mg/litre.o The major source of fluorine to man is drinking water.o Endemic fluorosis occurs when drinking water contains increased amount of fluorineDental fluorosisIt occurs during first 7 years of life (period of tooth calcification).It occurs at fluoride level >1.5 mg/litre (PPM).Fluoride is deposited in enamel of teeth. Mottling is the earliest sign which affect upper incisors and is confined to permanent teeth.Skeletal fluorosisIt occurs at fluride level 3-6 mg/litre.Fluoride is deposited in bones. There is osteosclerosis, calcification of ligaments, back stifness with restriction of spine movements (earliest sign ), and flexion deformities of joint.There is no impairment of mental faculties.Recentally, a new form of fluorosis has been identified, which is characterized by genu valgum and osteoporosis of lower limbs. It occurs in people wrhose staple diet is Sorghum (jawar).Crippling fluorosisThis occurs at fluoride level > 10 mg/litre (PPM). Patient is crippled and bed ridden.o Defluridation of water is done by Nalgonda technique, developed by National Environmental Engineering Research Institute (NEERI), Nagpur. It involves chemical treatment of water by lime and alum in sequence followed by flocculation, sedimentation and filteration.o Household level defluridation can be done by : (i) Nalgonda technique, (ii) Alumina, and (iii) Phosphates.