BIOPHYSICO-CHEMICAL PROPERTIES OF SACHET WATER SOLD WITHIN OGOJA METROPOLIS

              ABSTRACT

Twenty samples which consist of  (4) different brands of sachet packaged water samples labeled  A- D  commonly found in Ogoja metropolis of Cross River State were examined for bacteriological and physico-chemical properties to determine their potability . Standard conventional methods were employed for the detection of coliforms and other bacteria. Physical examinations were rigorously carried out for organoleptic quality such as taste, colour, odour, microscopic examination for sediments and other debris as well as chemical and biochemical analysis. Bacteriological examination of samples revealed the presence of the following pathogens: Proteus mirabilis, Klebsiella pneumonia, Pseudomonas aeruginosa, Serratia spp and Chromo bacterium spp at varying concentrations. Chemical analysis revealed the presence of metals ranging from Sodium (Na), Potassium (K) and Zinc (Zn) in all the samples, Lead (Pb), Copper (Cu), and Chromium (Cr) in some of the samples and absence Cadmium (Cd) was apparent from the study. Other chemical compounds such as sulphates, chlorides, nitrates and hardness were detected at tolerable limits. Physical examination of samples showed a variable level of turbidity, colour, pH, hardness, acidity and alkalinity. The result also revealed variable level of taste but none had objectionable odour. The alterations in bacteriological and physicochemical indices of contamination detected from some samples are indications that some of this sachet water do not meet the NAFDAC /WHO standard and so may not be portable and might be principal source(s) of waterborne related diseases that are endemic to humans both young and old within ogoja metropolis.

             INTRODUCTION

Accessibility and availability of fresh clean water is a key to sustainable development and an essential element in health, food production and poverty reduction (Adekunle et al., 2004). Water constitutes four fifths of the body’s weight and performs and supports the internal functions of animals and plants. It is necessary for proper digestion of food and flushing toxins out of the body (Alais et al., 1999).  A number of people in the developing countries lack access to potable water though the provision of clean potable water is essential for human consumption and it is a right and not a privilege to all human beings more than any other environmental factor. Since life is impossible without water people were compelled to accept and use water from whatever source despite the devastating consequences of polluted water on human health (Steiner et al. 1997). Water has found its wildest use in the industry as a medium of heat transfer, heat exchangers; it also functions as raw materials in the beverage and chemical industry.

Report by food and agricultural organization (F.A.O) revealed that in African countries particularly Nigeria, water related disease have been interfering with basic human development (F.A.O, 2007). Degradation of water quality erodes the availability of water to the ecosystem, increasing financial cost for human users, and decreasing species diversity and abundance of resident communities.

The provision of potable water to the rural and urban population is necessary to prevent health hazards. Before water can be described as cportable if it has to comply with certain biological, physical, chemical, and microbiological standards which are designed to ensure that the water is potable and safe for drinking. Portable water is defined as water that is free from diseases, producing micro-organisms and chemical substances deleterious to health (Edet et al., 2012).

Water can be obtained from a number of sources among which streams, lakes, rivers, ponds, rain, springs and well, but unfortunately clean, pure and safe water only exist briefly in nature and is immediately polluted by prevailing environmental factors and human activities (Kolade, 1992).  Water from most sources is therefore unfit for immediate consumption without some sort of treatments or does not reach the W.H.O standard. These water bodies are closely interconnected and may affect each other directly through they have different hydrodynamics properties (Raymond, 1992). However, at a certain level, minerals may be considered contaminants that can make water unpalatable or even unsafe. These substances can be the result of human activities or can be found in nature. Deep ground water is generally of very high bacteriological quality (i.e. pathogenic bacteria or the pathogenic protozoa are typically absent), but the water may be rich in dissolved solids, especially carbonates and sulphate of calcium and magnesium. There may be a requirement to reduce the iron or manganese content of this water to make it acceptable for drinking, cooking, and laundry.  

Consequently, a number of small scale industries are packaging and marketing factory-filled sachet drinking water, popularly called “pure water” that many consider a safer source of portable water (Dodoo et al., 2006). Those who cannot afford the factory bagged sachet go for cheaper unbranded “ice water” which is hand-tied pipe borne water (Obiri-Danso et al., 2003).

The National Agency for Food and Drug Administration and Control (NAFDAC) is mandated to enforce compliance with internationally defined drinking water guidelines, but regulation of the packaged water industry aimed at good quality assurance has remained a challenge to the agency To control this menace of contaminated water in sachets, NAFDAC declared a possible ‘gradual’ nationwide ban on sachet water to allow manufacturers of sachet water to start winding down or change to bottle packaging. Successful implementation of this ban has remained far from reality as the sachet water market is witnessing tremendous growth, especially among the poor and middle social classes. Because of the high use of sachet water utilized on daily bases in Cross-river state, the state government in 2005 commissioned the Cross-river state water board commission (CRSWBC) to take care or portable water within the state which ogoja metropolis is not an exception. 

 Recent statistics shows that 1.2 – 2.4 billion people suffer from lack of portable water and secure sanitation respectively (Sheifan, 2005). Amongst these developing countries, Nigeria in particular is one in which more than half of the population is being affected (Sheifan,2005). Although the demand for sachet water within the metropolis is extremely high and fast increasing at a rate greater than the population growth within the metropolis. Those who cannot afford the factory bagged sachet water go for cheaper unbranded “ice water” which is hand-filled hand-tied pipe borne water (Obiri-Danso et al., 2003).  Access to safe water supply is a serious issue across the globe; therefore, paucity demands the determination of biophysiochemical properties of sachet water sold within Ogoja metropolis in Cross-river state, Nigeria.

             MATERIALS AND METHODS

    3.1           Study Site and Sample Collection

The Sachet water samples were aseptically collected from the sources using sterile bottles.  The water samples were kept between the temperature of 4-10◦C and transported to the laboratory less than two hours of collection and analyzed within 24 hours. A total of seven water samples were collected from Ogoja metropolis of Cross River State between the hours of 8.00 a.m. and 10.00 a. m, when the sampling points were free from contaminations.

   3.2           Preparation of Double Strength MacConkey Broth

Double strength MacConkey broth was prepared according to manufacturer’s instruction (multiplying the manufacturer’s required weight for normal preparation by 2) then dissolved in distilled water and it was mixed thoroughly and gently heated on the hot plate to obtain a homogenous mixture. The mixture was then sterilized at 121⁰C for 15minutes after dispensing into McCartney bottles containing inverted Durham’s tubes. They were allowed to cool before inoculating with water samples.

    3.3             Eosin Methylene Blue (EMB) Agar

This medium was used for the confirmation of the organisms in positive tubes obtained from the presumptive test. It was prepared according to manufacturer’s instruction.

    3.4             Enumeration of Total Heterotrophic Bacteria

Total heterotrophic bacteria in the borehole water samples were enumerated using pour plate method. A five -fold serial dilution (10-1 to 10-5) of the samples were prepared using sterile distilled water.  MacConkey and Nutrient agar media were prepared in duplicate. 1ml of each dilution was introduced into sterile Petri-dishes into which 19 mls of the prepared molten media were added. The cultured plates were allowed to cool and solidify then, they were incubated at 370C for 24 hours and Petri dishes containing discrete colonies were counted.

   3.5            Isolation and Identification of contaminating Bacteria

Cultural, microscopic examination, biochemical tests including sugar fermentation tests were done to identify the pure isolate as described by Cheese brought, 2000.

     3.6         Antibiotic Susceptibility test of the Isolates

Peptone water was prepared according to manufacturer’s instruction and inoculated with each of the test isolates and incubated at 370C for 24hours. Mueller Hinton agar was prepared and poured into sterile Petri dish and allowed to solidify. Each isolate was inoculated into the solidified Mueller Hinton agar using sterile swab sticks.

Antibiotic discs were gently placed unto the inoculated plate using sterile forceps. These were incubated for24hours at 370C and observations recorded.

     3.7 Procedure for Chemical Analysis of Sachet Water in Ogoja   Metropolis

    3.7.1   pH/ Conductivity Determination

Electronic pH meter (Digital) Model Exner GMBH, D4040 NEUSSI with a combined electrode was used. Known buffer solutions of pH 4, and pH 9 were prepared and used to standardize the equipment. The pH readings had been taken and recorded, samples conductivity was measured using a conductivity meter (Radio-meter Copen-Hagen CDM 83).

     3.7.2   ALKALINITY DETERMINATION

50ml of the water sample were pipette into clean 150ml capacity conical flask. Three drops of phenolphthalein indicator were added. There was a little change in the samples; thus, indicating the presence of hydroxide and carbonate. The samples were titrated with 0.05M H2SO4, until the colour disappeared and the titre values were recorded as F value. To the colourless solution, 3 drops of methyl orange indicator were added and titrated further until the colour change from yellow to permanent reddish or orange red colour and recorded as M. The readings were then computed.

      3.7.3    CHLORIDE DETERMINATION

Using the 50ml sample for Alkalinity HCO3 and CO2-3 determination, 1ml of potassium chromate indicator were added into the samples, and were titrated with silver nitrate solution, until a brick red colour appeared. The blank titration was also carried out.

       3.7.4    SULPHATE DETERMINATION

Gravimetric method was used to determine sulphate using Bacl2 as precipitant. 50ml of the sample were measured into a 250ml beaker, and diluted to 150ml with distilled water. 1ml concentrated (HCL), and 4 drops of methyl orange indicators were added. The samples were placed on hot plate. 10ml, of 10% Barium chloride solution were measured into them, and then boiled for 5minutes. The samples were then left overnight for filtration.

         3.7.5    Phosphate Determination

2.5ml water was pipette into 50ml standard flask, 8ml of ascorbic acid solution were added and made up to mark with distilled water, then, allowed to stand for 30minutes for colour development.

          3.7.6         Sodium and Potassium Determination

Serial dilutions were made from the stock solutions (1000mg/L) of Sodium and Potassium and analyzed by a Flame photometer model PF P7 Jenway. The operation procedure of the manufacturer was followed. After, the dilution of the samples, the fuel and flame adjustment control were set, compressor and equipment were put‘ON’. Appropriate filter was placed in position and the nebulizer tube was inserted into a beaker with distilled water, and aspirated for 15minutes. The control knob was use to adjust the blank to zero on the meter. The highest concentrations of the working standards were aspirated and the adjustments were done repeatedly for others, until a stable and agreeable emission results were recorded.

         3.7.7     Toxic Metal Determination

Atomic absorption spectrophotometer (AAS) was used. The procedure for Atomic absorptions spectrophotometer (AAS) is similar to flame emission spectrophotometer (FES). Standard solutions were prepared for each metal using suitable metals of each element to be determined. The instrument was switched ‘ON’ and the required lamp for each metal was fixed. The samples and the standards of each metal were aspirated simultaneously. The absorbance readings were then recorded under the same condition.

RESULTS

The results of physicochemical properties are within the tolerable limit of WHO/NAFDAC standards for portable water except for temperature and alkalinity which are above the tolerable limits (table 1). Though cadmium and Chromium were not detected in most of the samples, it appears some of the samples were contaminated with Zinc and Lead causing the rise in concentration above the WHO/NAFDAC standards. All other heavy metals are within the limits (table2). The determination of bacteriological load of the samples showed the presence of Proteus mirabilis, Klebsiella pneumonia, Pseudomonas aeruginosa,Serratia spp,Chromo bacterium spp at varying concentrations

  Table 1: The Physico chemical properties of some sachet water in Ogoja metropolis of Cross River State

PHYSICO           CHEMICAL PARAMETERS	SAMPLE       A	SAMPLE  B	SAMPLE C	SAMPLE   D	WHO/ NAFDAC STD
Taste	satisfactory	satisfactory	satisfactory	satisfactory	unobjectionable
Temperature oC	28.6± 0.01	29.7± 0.02	28.3± 0.01	29.3± 0.01	Ambient
Conductivity µScm-1	120± 0.03	98± 0.01	136± 0.02	138±  0.03	1000
pH	7.3± 0.03	9.0± 0.01	7.1± 0.01	7.5± 0.03	6.5-8.5
Odour	satisfactory	satisfactory	satisfactory	satisfactory	unobjectionable
Colour	colourless	colourless	colourless	colourless	unobjectionable
Turbidity (NTU)	0.31± 0.01	0.24± 0.04	0.45± 0.02	0.33± 0.01	5.0
Appearance	satisfactory	satisfactory	satisfactory	satisfactory	unobjectionable
TDS (ppm)	42.4± 0.03	38.7± 0.02	33.8± 0.06	45± 0.03	500
Alkalinity (mg/L)	65± 0.01	245± 0.04	54.3± 0.03	58.7± 0.01	98-200
Hardness (mg/L)	73± 0.03	82.3± 0.02	77.5± 0.03		61-150
Nitrates (mg/L)	23.2± 0.01	19.4± 0.03	21.3± 0.01	18.2± 0.03	50
Chloride (mg/L	66.4± 0.01	54.6± 0.01	47.8± 0.03	55.6± 0.02	250
Sulphates(mg/L)	45.5± 0.03	47.3± 0.01	32.5± 0.02	26.8± 0.01	100-1000

Table 2: Distribution heavy metals from some sachet water sold in Ogoja metropolis of Cross River State, Nigeria

Parameters	Sample A	Sample B	Sample C	Sample D	WHO /NAFDAC STD
Na	10.3± 0.10	12.5± 0.05	19.6± 0.01	7.8± 0.21	200
K	0.93± 0.01	1.33± 0.04	3.2± 0.03	2.5± 0.01	12.0
Cu	ND	ND	0.21± 0 .01	ND	1.3
Pb	1.2± 0.03	ND	ND	0.1± 0.04	0.010
Zn	0.2± 0.01	0.42± 0.02	0.33± 0.02	0.31± 0.01	3.00
Cr	ND	ND	0.23± 0.03	0.5± 0.01	0.05
Cd	ND	ND	ND	ND	0.003

Where; ND = not detected

 Table 3: Distribution and frequency of occurrence of microorganisms isolated from some sachet water sold in Ogoja metropolis of Cross River State, Nigeria. 

Microorganisms	Sample A	Sample B	Sample C	Sample D
Serratia spp	-	-	+	+
Proteus mirabilis	-	-	+	+
Klebsiella pneumonia	+	+	+	+
Chromobacterium spp	+	-	-	+
Pseudomonas aeruginosa	-	-	+	-

 Where - = not detected, + = present

DISCUSSION

The introduction of sachet water to consumers was to provide safe, hygienic and affordable instant drinking water to the public. Although this is a laudable idea, current trends seem to suggest that sachet drinking water could be a route of transmission of most water borne diseases. The primary site of lead toxicity is the central nervous system and peripheral nervous system (Waldboh, 1978). Lead in central nervous system reduces neuro-psychological functioning leading to intelligent quotient deficiency (Waldboh, 1978). Lead in amounts over the primary drinking water standard of 0.05mg/L may cause nervous system disorders and brain or kidney damage. Since lead accumulates in body tissue, it is especially hazardous to the foetus or to children under three years old. Appropriate interventions are required to minimize heavy metal contamination of underground water (Waldboh, 1978).Though all the samples fall within the WHO standard .The samples that is above the tolerable limit might be traceable to the source and may be inimical to health.

Turbidity refers to water clarity. The greater the amount of suspended solids in the water, the more turbid it appears, and the higher the measured turbidity. Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites, bacteria and other inorganic compound (Dinrlfo et al., 2010). The turbidity values fall within the WHO range standard. This suggests that the samples are portable. Specific conductance, or conductivity, measures how well the water conducts an electrical current, a property that is proportional to the concentration of ions in solution. Conductivity is often used as a surrogate of salinity measurements and is considerably higher in saline systems than in non-saline systems. (Dodds, 2002). The conductivity values fall within the WHO range and therefore the water is consider suitable for human consumption.

Chloride, in the form of sodium (NaCl), potassium (KCl) or calcium (CaCl₂) is one of the major inorganic anions in fresh and waste-water but in potable water, the salty taste produced by it varies and depends upon the chemical composition of the water. While some waters containing 250 mg chloride in a litre may have a detectable salty taste if the cation is ‘sodium, others may not have if their dominant cations are calcium and magnesium. High chloride content may harm metallic pipes and structures as well as growing plants, cause hypertension and increased concentration of other metals in water (W.H.O, 2003). The chloride content or limit recommended by WHO is 250 mg/L and none of the samples analyzed in this study had higher values than this limit. Sulphates occur naturally in drinking water and health concerns regarding its level have been linked with diarrhea due to its laxative effects especially when there is a change from drinking water with low to drinking water with   high   sulphate   concentrations.  In drinking water, this ion has a secondary maximum contaminant level (SMCL) of 250 mg/dm 3 which is a value provided as a guideline for states and public water works (WHO, 2004a). The sulphate values are within the permissible limit given by W.H.O.  Sulphate doses of 100 to 2000 mg/L have a cathartic effect on humans, resulting in purgation of the alimentary canal. Sulphate is responsible for odour and sewer corrosion. Low concentration of sulphate restricts the growth of phytoplanktons.

          Phosphate is an essential plant nutrient and can play an important role in limiting factor and responsible for the      growth of plants specially phytoplankton in the water systems. Phosphate values are low during winter season     which may be due to anthropogenic source .Phosphate is an essential plant nutrient and can play an          important role in limiting factor and responsible for the growth of plants specially phytoplankton’s in the water systems. This phosphate values are within the permissible limit given by W.H.O.

 The organisms recovered in this study have been previously reported by some other researchers. The organisms isolated in this study were similar to those commonly encountered in water and aquatic environments. Similar organisms have been reported in previous studies on water in Nigeria and outside Nigeria (Okonko et al., 2008; Prasanna and Reddy, 2009; Oyedeji et al., 2010). In a study, Prasanna and Reddy (2009) reported the presence of P. aeruginosa in the water of mobile vendors and ground water of Jeedimetla area, Hyderabad, India. In Cameroun, Kuitcha et al. (2010) reported similar organisms (Klebsiella pneumonia, Proteus vulgaris and Pseudomonas sp.) in their study.  The presence of these bacteria in some brands of sachet water examined in this study was really baffling. These bacteria might have contaminated the water from source (Okonko et al., 2008; Taulo et al., 2008). The presence of these bacteria isolated in the presumed treated sachet water used in this study may be as a result of improper handling, processing and purification procedures, unhygienic handling after production. It may also be attributed to many or more of the following; contamination of treated water by organism’s harbored in connecting tubes to the packaging machines; lack of or poor quality control system, otherwise the level of treatment of the source water would have been identified before packaging; poor treatment mechanism, it is possible that the equipment or machines used in the purification were not functioning effectively. Also, the microbial contaminations of packaged drinking water could be influenced by factors such as their raw water source, treatment process employed and hygienic practices observed in production (Oyedeji et al., 2010).  In this study, K. pneumoniae was reported as the most predominant organism. Bacteria from genus Klebsiella causes numerous infections in human. A variety of nosocomial and community acquired (food borne) infections are caused by K. pneumoniae, one of the most deadly pathogens of Enterobactericeae. Also the presence of P. aeruginosa, in this study, a pathogenic organism renowned for its high resistance to antibiotics, is a cause for concern (Oladipo et al., 2009). Abed and Alwakeel (2007) reported that there is contamination with Pseudomonas sp. in 6.7 % of the water sampled. Presence of P. aeruginosa and P. mirabilis in some vended sachet water was also reported by Oladipo et al. (2009) in Ogbomoso, Nigeria. The P. aeruginosa isolated from the sachet water could probably have come from the raw food materials, apron, dust and palms of the handlers. P. aeruginosa isolated from these samples could be an evidence of cross contamination. P. mirabilis has also been reported by Oladipo et al. (2009) in a study on the bacteriological quality and safety of sachet water, and attributed to burst pipes along distribution lines of drinking water or unhygienic handling of water right from treatment plant used in the production of such water (Okonko et al., 2008; Oladipo et al., 2009).  Presence of these bacteria in water may be unnoticed even in transparent packaged water and the presence of these microorganisms may pose a potential risk to consumers. Even the consumption of such contaminated water may facilitate the widespread of infections and can ultimately lead to outbreak of epidemic (Oladipo et al., 2009). The possible health hazard of drinking contaminated or poorly treated water is tremendous, as water related diseases continue to be one of the major health problems globally (Oladipo et al., 2009). However, transmission of water borne disease is still a major public health concern despites considerable efforts and modern technology being utilized for the production of safe drinking water (Zamberlan et al., 2008) and it is important to know microbial quality of sachet water (Khaniki et al., 2010).  The overall treatment of source water is dependent in the quality of source water, type of sachet water being manufactured and location (Wartburton et al., 1998; Khaniki et al., 2010). The bacteriological quality of sachet water is of paramount importance and monitoring must be given highest priority, this is so because studies have attributed several disease outbreaks to untreated or poorly treated water containing bacteria pathogen that have been isolated from some of this sachet water used in this study. Therefore, maintaining a safe drinking water remains essential to human health as transient bacteria contamination may have implication well beyond a period of acute-self-limited illness. However, to ensure that the bacteriological characteristics of sachet water is safe for human consumption, the Nigeria based National Agency for Food and Drugs Administration Control (NAFDAC) in association with the World Health Organization (WHO), recommended that potable water for human consumption should not contain any microorganism that is known to be pathogenic and the coliform number per 100 ml of water must be zero (WHO, 2006).  It is important to note that the findings of this study suggest that some of the brands of sachet water on sales in Ogoja metropolis of Cross River State, South southern Nigeria revealed the presence of pathogenic organisms in concentrations that make the products unfit for human consumption and do not conform to the international standards. For any water to conform with the international standard such water must be safe bacteriologically, biologically, chemically, and aesthetically. Therefore, some of the sachet water brands are not safe for drinking since pathogenic organisms were found to be present. In line with the assertions of Prasanna and Reddy (2009), we would also like to recommend the proper sanitary survey, design and implementation of water and or/ sanitation projects; regular disinfections, maintenances and supervisions of water sources, and regular bacteriological assessment of all water sources for drinking should be planned and conducted. There is therefore need for NAFDAC to intensify efforts in the routine monitoring of activities in the packaged drinking water industry. The safety of sachet drinking water should be ensured through comprehensive regulatory programs at both the federal, state and local levels. NAFDAC regulations for packaged waters should be protective of public health and there should be continuous adoption of packaged water quality standards. Testing of market samples will be a good way of detecting if the water is actually pure as claimed by these producing companies.  Assessment of sachet water quality at some important stages of production; pre-production, production and postproduction stages at the factories is therefore, suggested in order to ensure their quality and safety. Therefore, all water that fails NAFDAC and WHO regulations should be retreated before they are released to the public for human consumption. Also NAFDAC should intensify effort on batch number, production date and expiry date of all these sample vended in public (Oladipo et al., 2009). High premium should also be placed on ascertaining compliance with Good Manufacturing Practice (GMP) with emphasis on management of raw water source to the consumer product point as recommended by the International Bottled Water Association. Application of good manufacturing practices (GMP), strict process control and personal hygiene should be maintained at processing facilities.  Conclusively, most of the sachet water brands fell below WHO drinking water standards and are therefore of doubtful quality. Efforts need to be intensified in the monitoring of activities in this rapidly expanding industry with a view to raising standards. The presence of pathogenic bacteria in this study may be as a result of improper handling, processing and purification procedures, unhygienic handling after production. Water with such bacteria are not safe for human consumption hence, the water source should be re-examined by the NAFDAC. To reduce contamination, further investigation on sachet water is recommended. Assessment of water quality at some important stages of production; pre- production, production and postproduction stages at the factories is therefore, suggested in order to ensure their quality and safety.

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