# Human Health Impact Analysis of Contaminant in IoT-Enabled Water Distributed Networks
## 4 Results and Discussion  
### Health Analysis Results  
To show the results from the Madrid case study described in the Section 3.1.1, we start explaining the distribution of contaminants based on the water demand of the network. In this work, we used the demand-based method to define the number of water gallons used by each person per day (GPD) to define the distribution of the population. Figure 4 depicts that high demand is focused on the center of the network, while low demand is focused on the top left of the water network. Various demand levels are represented by different colors in the map, where blue represents the deficient water demand and dark red represents the high water demand. In this study, public health impacts have been described as the size of the population receiving a contaminant intake dose above a certain level. To calculate this, we simulate the impact of water contaminants in different locations in the case study used in this work, as shown in Figure 5, and then investigate the impact of the contaminant for each location. Figure 4: Population distribution based on water demand. Table 2 presents the impacts of the contaminant based on where the contaminant has occurred (injected node location) in the case study. This table shows the essential properties of the water contaminants, such as the location, max concentration, max individual dose, and the number of estimated infected people. Referring to Table 2, the locations of the contaminant are selected carefully to include all cases, where Loc.6 represents that the contaminants occurs at the source of the water (Reservoir). This kind of contaminant has a high impact on the number of water nodes in WDS, which leads to a high number of people becoming infected from this contaminant. While Loc. 1 means that a contaminant is present in one of the isolated areas in the case study (see Figure 5), these areas labeled by _nod_3654_; in these areas, the impact of the contaminant on water nodes is small, which leads to a small number of people being affected by this contaminant. From Table 2, we note that the location of the injected node is the essential property of contamination as it recorded a high number of estimated infected people (146,729) when the contaminant occurred in the water source (Loc. 6), even though the contaminant was carrying a lower concentration. While very few infected people, ranging from zero to 2750 people, were recorded when the contaminant occurred in isolated locations (Loc. 2) that have a low population, the contamination was recorded at a higher concentration. On the other hand, the remaining locations--Loc. 3, Loc. 4, and Loc. 5--recorded a number of different infected people with a variable contaminant concentration as well. To examine and investigate the impact of water contaminant based on its occurrence in more details, two different cases were chosen (Loc. 2 and Loc. 6), and the extent of the impact is explained in detail as follows. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Contamination**} & \multirow{2}{*}{**Maximum Concentration**} & & **Number of** \\  & & **Maximum Individual** & **Estimated** \\  & & **Dose (mg)** & **Infected** \\  & & & **People** \\ \hline Loc. 1 & 2993 & 1 & 0 \\ Loc. 2 & 30 & 2 & 2750 \\ Loc. 3 & 44 & 5 & 7217 \\ Loc. 4 & 224 & 11 & 29,017 \\ Loc. 5 & 27 & 16 & 43,996 \\ Loc. 6 & 2 & 91 & 146,729 \\ Mean & 217 & 8 & 18,568 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Infected people based on contamination locations. Figure 5: Areas of the contaminant locations. The first case (Loc. 6, Figure 6) has a contaminant that occurs at the source of the water, which means that the injected node is the reservoir, and this contaminant has a massive impact on the water nodes. From Figure 6, the impact of this contaminant appears at most of the nodes in the network, where the impact denoted by different colors, in which the colors indicate the number of people, has been affected by this contaminant (fatality).