**6.3 Human health survey**

Human health survey has been conducted in the present study area to analyze the fluorosis hazards with respect to F− content in the selected endemic villages of T. Annavaram, Talrapalli, Datlavaripalem, Marellavaripalem, and Upplapadu. Dental health survey collected 659 data samples on people, including the males (213), females (214), and children (232) to understand the severity of fluorosis hazard in this area. The results of dental survey carried out in the selected villages of study area are presented in **Table 5**.

The results of dental survey population are compared with the Dean's Classification Index (1942) of tooth surface (15; **Table 6**). The results of Dental Fluorosis Index (DCI) and Community Fluorosis Index (CFI) are presented in **Table 7**. Out of the 76 members surveyed in T. Annavaram, the people who come under questionable, very mild, mild, moderate, moderately severe, and severe categories are 2, 7, 12, 16, 11, and 6 respectively. These contribute 71.05% of the fluorosis (**Figure 5a**). In Talrapalli, 180 people are surveyed. The mentioned categories are 20, 18, 14, 14, 4, and 4 respectively, which contribute 41.11% of the fluorosis (**Figure 5b**). Datlavaripalem records the highest dental hazard in the people in the respective categories are 17, 32, 19, 22, 17, and 21 (**Figure 5c**). These are contributes 88.27% of the fluorosis. In the Marellavaripalem, the total surveyed people are 155. Out of which, the questionable, very mild, mild, moderate, moderately severe, and severe categories are 15, 18, 14, 12, 11, and 14 respectively, contributing 74.33% of


**Table 4.**

*Classification of Na+ , Cl− and HCO3 2− + CO3 2− based on TDS range.* *Fluoride Geochemistry and Health Hazards: A Case Study DOI: http://dx.doi.org/10.5772/intechopen.105156*


**Table 5.**

*Results of dental survey in the selected villages of study area.*


#### **Table 6.**

*Dean's classification [14].*

the dental fluorosis (**Figure 5d**). The lowest dental fluorosis (34.29%) is recorded in the Upplapadu village (**Figure 5e**) where the questionable, very mild, mild, moderate, moderately severe, and severe categories are 5, 8, 10, 6, 3, and 11 respectively. The above data indicate the different degrees of fluorosis according to varying concentrations of F in drinking water. In the present study area, the concentration of F varies from 0.5 to 12.4 mg/L in pre-monsoon groundwater and 0.14 to 16.0 mg/L in post-monsoon groundwater.

**Figure 6** indicates that the dental fluorosis in the surveyed villages is high in children (64.87%) compared to men (63.35%) and women (58.38%). This could be due to effect of the drinking water on children, in particular as their body tissues are in their growth stage [31, 32]. The effect of fluorosis is higher in males compared to female. Generally, the males take more drinking water and diets than the females due to their greater physical activity. This is also supported by the significant positive correlation between average F content in groundwater and the percentage of dental fluorosis.

#### **6.4 Community fluorosis index**

Community Fluorosis Index (CFI) was calculated based on the symptoms of dental fluorosis with respect to DCI [14, 23]. Criteria for people with symptoms of dental fluorosis are identified and classified in each category based on CFI. CFI is the ratio of the number of people affected in each category and Dean's numerical weight to total number of affected people (Eq. (1)). If CFI is greater than 0.6; fluorosis is considered to be a public health problem in that area [14, 23–25].

Higher prevalence rates of endemic fluorosis are observed in four out of five screened villages. The CFI values of T. Annavaram, Datlavaripalem, Marellavaripalem, and Uppalapadu are 1.51, 1.60, 1.41, and 0.86 respectively which may cause public health problems. Tarlapalli village is the only one showing CFI value (0.58) is less than 0.6, where there is no fluorosis hazard was observed (**Table 7**).

The above dental survey in the study area indicates that there is different degree of fluorosis hazard due to varying concentration of F in drinking water, quantity of water consumption, intake of nutrients at risk, dietary substance, hot climate condition and long period exposure after digestion of in human body [33].



*Results of dental fluorosis and community fluorosis index.*

*Fluoride Geochemistry and Health Hazards: A Case Study DOI: http://dx.doi.org/10.5772/intechopen.105156*

**Figure 6.**

*Histogram showing the dental hazards in the study area.*
