Journal of Nutrition Science Research
Open Access

Water plays a vital role in maintaining the human life and welfare. Pure drinking water is now recognized as a fundamental right of human beings. Around 780 million people do not have access to clean and safe water and around 2.5 billion people do not have proper sanitation. As a result, around 6–8 million people die each year due to water related diseases and disasters [1]. Therefore, water treatment is a top-priority policy agenda in many parts of the world [2]. In the today world, the water use in household supplies is commonly defined as domestic water. This water is processed to be safely consumed as drinking water and other purposes. Water quality and suitability for using indicated by its taste, odor, color, and concentration of organic and inorganic materials [3]. Contaminants in the water can affect the water quality and consequently the human health.

Drinking water is the major need of human life. Fresh water quality is a vital concern for mankind since it is directly linked with public health. Drinking water quality has always been a major issue in many countries, especially in developing countries like Bangladesh [4]. Although safe drinking water is a basic demand for the people of all over the world, a huge proportion of people in the world are deprived from the pure drinking water including Bangladesh [5]. Ground water is decreasing day by day prominently in Asia, South America, North America and ecosystems are threatened [6].

Bangladesh is a low-lying country and is a delta of great three big rivers- The Ganges, the Brahmaputra and the Meghna. In Bangladesh, there are many sources of drinking water such as surface water, ground water and rain water. Surface and ground water are considered as the main sources of drinking water. There is no safe drinking water supply system in rural areas, except some large cities (such as ‘WASA’ in Dhaka city). In Bangladesh most of the people consider that ground water or water from tube wells is free from contamination. For this reason, Hand pumped tube-well water is used as primarily source of safe drinking water in Bangladesh. About 90% of the households use this Hand pumped tube-well technology in Bangladesh [7]. In rural area, most of the people are depended on untreated groundwater and tube wells. It is an estimation that about 11% of all deaths in rural area of Bangladesh are caused by diarrheal disease [8]. It has been estimated that about 80% of all diseases and over one third of deaths in developing countries are caused by the consumption of contaminated water (WHO, 2004). Recent studies suggesting that significant levels of diarrheal disease are caused in part by drinking untreated groundwater [9,10]. Natural water resources such as groundwater in coastal areas of Bangladesh are contaminated by salinity and other heavy metal ions because of salt water intrusion, storm surges and withdrawal of fresh water for using various purposes [11]. In Noakhali region, contaminated groundwater is used by people for their drinking purposes and affected by hypertension, heart failure, kidney failure, skin diseases, carcinogenic diseases, diarrhea and other water borne diseases. For this reason, a detailed study of drinking water quality of Noakhali region is very much important [12]. Although several reports on the assessment of drinking water quality based on physiochemical and Microbiological parameters in Noakhali region have been published by several researchers separately [5,12,13]. Very little information is available about the overall status of water quality of this area. That’s why an investigation was initiated, whose primary objective was to examine the present overall status of drinking water quality of groundwater sources in Noakhali region.

Study Areas

In this study three upazillas of Noakhali district in Bangladesh drinking water were analyzed. Three upazilas were upazila-sadar, Kabirhat upazila, Chatkhil upazila. Coordinates of Noakhali upazilasadar is from 22°50ʹ N to 22°833ʹ N and from 91°6ʹ E to 91°100ʹ E. Coordinates of Kabirhat upazila is from 22°50ʹ N to 22°833ʹ N and from 91°12ʹ E to 91°200ʹ E. And Chatkhil upazila’s coordinate is from 23°3ʹ N to 23°5ʹ N and from 90°57.5ʹ E to 90°95ʹ E (Figure 1).

Figure 1: Noakhali district map.

Sampling

Total samples were nine in numbers. In upazila-sadar maximum people take supply water as drinking water. Some take motor water and some other take tube-well water for drinking. Drinking water samples were collected from three different areas of Noakhali upazila-sadar. First sample was collected from maijdee and it was supply water (1000 feet deep and treated). Second sample was collected from Dattabari and it was motor water (500 feet deep). Third sample was collected from Sonapur and it was tube-well water (450 feet deep).

Most of the people at Kabirhat upazila take tube-well water for drinking. From kabirhat upazila three different areas drinking water samples were collected. First sample was collected from Kabirhathospital road and it was tube-well water (60 feet deep). Second sample was collected from Kabirhat-kalamunshi road and it was tube-well water (70 feet deep). Third sample was collected from Kabirhat-college road and it was tube-well water (150 feet deep).

All most all people at Chatkhil upazila take tube-well water for drinking. From Chatkhil upazila three different areas drinking water samples were collected. First sample was collected from Chatkhil thana road and it was tube-well water (35 feet deep). Second sample was collected from Abu tara nagar road and it was tube-well water (256 feet deep). Third sample was collected from Bodolkot road and it was tubewell water (800 feet deep).

Study Duration

This study duration was from July to September, 2018.

Analysis of Physical Parameters

The pH values, temperature, total dissolved solid, electrical conductivity (EC), salinity of the samples was measured by using precalibrated Multipara-meter, Model PL-700ALS.

Determination of Chemical Parameters

Chloride ion determined in drinking water sample by “Muhr’s Method”. Iron content estimated by packet of reagent in drinking water Sample.

Microbiological Test

Total viable bacterial count by serial dilution process. Total coliform count and E. coli detection by MPN (Most Probable Number) method.

Results

Physical Test Results (Tables 1-4):

Table 1: Findings of pH from different drinking water samples of three upazilas.

Table 2: Findings of electrical conductivity from different drinking water samples of three upazilas.

Table 3: Findings of salts from different drinking water samples of three upazilas.

Table 4: Findings of TDS (Total Dissolve Solids) from different drinking water samples of three upazilas.

Chemical Test Results (Table 5 and 6):

Table 5: Chloride ion test results from different samples of three upazilas.

Table 6: Iron test results from different samples of three upazilas.

Microbiological Test Results (Tables 7-9):

Table 7: TVBC (Total Viable Bacteria Count) results from different samples of three upazilas.

Table 8: Bacterial Growth presence in E.M.B. (Eosin Methylene Blue) Media from different samples of three upazilas.

Table 9: Results of Most Probable Number (MPN) of Coliforms per 100 mL of different samples of three upazilas.

Discussion

Drinking water quality at Noakhali district in Bangladesh is not satisfactory. Contamination, high amount of dissolve solids, higher amount of iron content were the regular scenarios. Though supply water was quite satisfactory in upazillas-sadar but other upazillas drinking water were not satisfactory well.

pH

In this study upazillas-sadar pH was comparatively higher (7.81) than other upazillas. On the other hand, Chatkhil upazila’s drinking water was lower pH (6.18). Ideal pH level of drinking water is 6.5- 8.5 (by WHO). Chatkhil upazila’s drinking water pH was under the acceptable range. In that region drinking water was comparatively acidic. The corrosive nature of acidic water causes metal ion such as iron, manganese, copper, lead and zinc to leach into the water causing elevated level of toxic metals in the water. It may also cause aesthetic problems such as a metallic or sour taste. In previous studies (Prosun et al.) pH of ground water was 7.1 to 8.4. Sadar & Kabirhat upazilas drinking water pH was similar the previous studies but Chatkhil upazila’s drinking water pH were comparatively low. The temperature during testing were 26°-28°C those were similar with the previous studies.

Electrical Conductivity

Electrical Conductivity of drinking water sample at upazillassadar was 1106 μS/cm which was greater than acceptable range (Acceptable range 1000 μS/cm by WHO). Kabirhat upazila’s drinking water conductivity were also higher (1104.33 μS/cm) than acceptable range. Comparatively Chatkhil upazila’s drinking water were in lower (252.1 μS/cm) than others and were in acceptable range. Conductivity measures the water’s ability to conduct electricity. Common ions in water that conduct electrical current include sodium, chloride, calcium and magnesium. Because dissolve salts and other inorganic chemicals conduct electrical current. Conductivity increases as salinity increases. So, upazila-sadar and Kabirhat drinking water sample had higher salinity. Previous studies ^[18] Electrical Conductivity of ground water was 1500 μS to 9711 μS. Sadar & Kabirhat upazilas drinking water conductivity were little-bit lower than the previous studies but Chatkhil upazila’s drinking water conductivity was comparatively very much low.

Salts

Usually, standard limit of salinity for drinking water is zero (recommended by WHO, 1996). Upazila-sadar water sample had comparatively higher salt (554.33 ppm) than other two upazillas water sample. Kabirhat upazila’s water sample were also higher salt (549 ppm) than Chatkhil upazila’s water sample. Chatkhil upazila’s drinking water samples were comparatively lower amount of salt (125.47 ppm).

TDS

Total dissolve solid below 500 ppm is good for drinking water and acceptable range is below 1000 ppm by WHO. In this study upazilasadar TDS in drinking water were 733 ppm, Kabirhat 725.33 ppm, Chatkhil 165.57 ppm. All three upazillas TDS of drinking water were in acceptable range but not quite good for drinking water. Previous studies (Prosun et al.) TDS of ground water was 128 μS to 1660 μS. Sadar & Kabirhat & Chakhil upazilas drinking water TDS were almost similar with the previous studies.

Chloride-ion

Chloride ion in upazillas-sadar and Kabirhat upazilas were very high in amount (Sadar 7326.33mg/L, Kabirhat 1299.83 mg/L) which were higher than acceptable range 250mg/L by WHO. But in Chatkhil chloride ion in drinking water were in acceptable range (236.33mg/L). High amount of chloride ion in drinking water may wash-out beneficiary bacteria from our body.

Iron

Concentrations of iron in drinking water are normally less than 0.3 mg/L by WHO but in this study upazilas-sadar, Kabirhat upazilas, Chatkhil upazila iron content were very much higher than acceptable range. High amount of iron may harm in our body such as damage healthy skin which can lead to wrinkles. Vegetables and other foods cooked in such water will blacken and absorb a bad taste.

Total Viable Bacterial Count (TVBC)

Total Viable Bacterial Count in Chatkhil upazila drinking water samples bacterial load were comparatively lower (3.26×106 CFU/ mL) than others and was almost similar with previous study (Prosun et al). In Kabirhat upazila drinking water sample bacterial load were comparatively higher (7.13 × 106 CFU/mL) than other two upazilas. According to WHO guideline value, the values of TVBC should remain within 1.0 × 103 but the results of three upazilas showed the values were excessively above than the WHO guideline. There is a common believe in Bangladesh that groundwater is relatively free of microorganisms and, therefore, most of the people in rural area consume tube-well water without any treatment. However, the results of this study show clearly that all water samples that were examined were contained highly. Previous study (Prosun et al.) TVBC of ground water was 6.73 × 10³ CFU/mL in upazila-sadar. All the results of this study were comparatively higher than previous studies.

E. coli Detection

Without supply drinking water in upazila-sadar more or less almost all upazillas had E. coli, Pseudomonas, Klebsiella, Enterobacter aerogenes. These water samples were completely polluted by animal or human waste that may causes serious health hazards like bloody diarrhea, severe anemia and so on. According to WHO guideline value E. coli should be absent in drinking water but the result showed the presence of E. coli in every water sample without supply water in upazila-sadar. So, water samples were not suitable for drinking purpose without pretreatment. Previous study (Prosun et al.) E. coli was present in upazila-sadar water sample.

MPN (Most Probable Number) Count

It is very concern able fact that in upazila-sadar most probable number of coliforms were 24.67/100 mL which was very much higher than other two upazilas (Kabirhat 14/100 mL, Chatkhil 16.67/100 mL). Total coliforms include bacteria that are found in water has been influenced by human or animal waste. Fecal coliforms are the group of the total coliforms that are considered to be present specifically in the gut and feces of warm-blooded animals. By these coliforms people may fall in diseases like gastrointestinal illness such as severe diarrhea, nausea and possibly jaundice as well as associated headaches and fatigue.

Noakhali district is in the coastal area near Bay of Bengal. As result the ground water quality of Noakhali is not good. Higher iron levels in these areas water are very common. As far as from sea the ground water iron level as well as microbial load come low than near areas from sea. Supply water of this district cannot provide to all the people. So, maximum people have to take ground unpurified water for living. For escaping from these problems people should take suitable water purification method as they can. Otherwise, their health will be fall in great difficulties by taking such quality water. Awareness about pure drinking water can make them free from many waters borne diseases.