Physicochemical Properties And Biological Component Of Tap Water In Talamban, Cebu City, Philippines: A Review Of Related Literature

Access to safe water is a fundamental requirement for good health and is also a human right (Bain, et al. ). Diseases related to contamination of drinking-water constitute a major burden on public health. The principal risk to health is from ingestion of water contaminated with feces containing pathogens that cause infectious diseases such as cholera and other diarrheal diseases, dysenteries, and enteric fevers (White et al. ).

Composition of tap water

Tap water contains minerals and heavy metals determined were sodium, magnesium, potassium, calcium, chromium, manganese, iron, nickel, copper, zinc, arsenic, cadmium and lead while the non-metal elements were fluoride, chloride, nitrate and sulphate. Most of the inorganic elements found in the samples were below the maximum permitted levels recommended by international drinking water standard limits, except for iron and manganese. Iron concentration of tap water from one of the locations was higher than the standard limit. (Amin I. et al) The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples (Amin I. et al. ).

Common sources of tap water

Groundwater is naturally very hard, but is otherwise a good quality and it is also the main source of drinking water for the city of Antalya, Turkey. Although the public usually exaggerates the health effects of hardness. (Evrim C. et al)Water samples in 81 participating households were collected from their drinking-water sources, transport vessels, treated water, and a drinking cup. The samples were collected according to the standard method described in the guidelines of the World Health Organization for the quality of drinking-water. ( Simonne R. et al) Piped tap water was collected from three taps in Yangon and Nay Pyi Taw of Myanmar. Drinking water was collected from various sources including public pots, nonpiped taps, piped taps, and bottled waters. (Hiroshi S. et al)3. Tap water and its physico-chemical properties Water is an essential factor in life, which is why it is important to test it before used in agriculture, industry, or household. In order to ensure it is safe for either consumption or use, we have to determine its different physico-chemical parameters. The parameters to be used solely depends on the water’s use; if either it were for consumption, agricultural or etc. Pure water only contains H2O, but this does not exist in nature because there are other factors affecting it and in result of that it would often contain minerals, microbiological and bacteriological impurities. Parameters include temperature, pH, biological oxygen demand, total dissolved solids, electrical conductivity, total hardness and dissolved oxygen.

Temperature

Water temperature is known to be the “abiotic master factor” because of its effects on aquatic organisms. It also controls the rate of all chemical reactions in water. If ever there would be a drastic change of temperature in water, it could affect all the processes in it along with the organisms inhabiting in it. For example, in a study conducted by Marr and Ingraham variations in the temperature of growth and in the composition of the medium alter the proportions of individual fatty acids in the lipids of Escherichia coli. 3. 2 pHThe pH is also important because this determines the solubility and biological availability of chemical constituents such as nutrients and heavy metals. Thus, the lower the pH levels, the higher would be the solubility of these metals; therefore, increasing the toxicity of water. As stated by Napacho and Manyele (2010), in most natural waters, pH is controlled by the carbon dioxide-carbonate-bicarbonate equilibrium system. An increased carbon dioxide concentration will lower the pH, whereas a decrease will cause it to rise. The pH value of water may also be affected by domestic sewage (generally neutral or slightly alkaline), industrial wastes (may be strongly acidic or alkaline depending on the type of industry), etc.

Biological oxygen demand

Biological Oxygen Demand (BOD) is one of the most important parameter of physicochemical properties since it affects the growth of organisms present in it, as well as, chemical and physical processes. The supply of oxygen in water often increases drastically due to human influence, which may lead to the the growth of unwanted bacteria and microorganisms in water. During summer, oxygen supply is increased due to intense sunlight and longer days, thus, increasing the photosynthetic activity in plants found in water (Krishnamurthy R, 1990).

Total dissolved solids

Total dissolved solids (TDS) are the amount of organic and inorganic matter found in water. There are specific types of TDS, which are calcium, potassium, magnesium, sodium, iron, chlorides, lead, bicarbonates, and sulfates. This should be closely monitored because if ever there is an extreme change of TDS it can negatively impact our health if in contact with our bodies, but not all are negative because some are beneficial to our health such as minerals and organic matter. It depends entirely on the substance present in the water. In elevated level of TDS, by itself, does not indicate that the water presents a health risk. However, elevated levels of specific ions included in the TDS measurement, such as nitrate, arsenic, aluminum, copper, or lead, could present health risks.

Total Hardness

Waters become hard primarily due to excessive presence of bicarbonate, chloride and dissolved sulphate in water primarily (Gupta et al. , 2013). Also, total hardness is a measurement of the mineral content in a water sample that is irreversible by boiling. Therefore, total hardness can be equivalent to the total calcium and magnesium hardness. Hard water is not seriously harmful to human health. However, water with a high level of hardness could cause serious problems in industrial settings wherein water hardness is typically monitored to prevent costly failures in components like cooling towers, boilers and other equipment that contains or processes water.

Electrical conductivity

Conductivity is the measure of capacity of a substance or solution to conduct electrical current through the water. (Gupta et al. , 2013). This ability is directly related to the concentration of ions in the water. These conductive ions come from dissolved salts and inorganic materials such as alkalis, chlorides, sulfides and carbonate compounds. Compounds that dissolve into ions are also known as electrolytes.

Dissolved oxygen

Dissolved oxygen refers to the level of free, non-compound oxygen present in water or other liquids. It is an important parameter in assessing water quality because of its influence on the organisms living within a body of water. In the research study done by Sarin et al. , iron release from corroded iron pipes is the principal cause of “colored water” problems in water distribution systems. When DO was present in water, higher amounts of iron release was observed during stagnation in comparison to flowing water conditions.

Common bacteria found in tap water

According to Khan et al. , 2016, chlorination is commonly used to control levels of bacteria in drinking water; however, viable bacteria may remain due to chlorine resistance. What may be concerning is that surviving bacteria, due to co-selection factors, may also have increased resistance to common antibiotics. This would pose a public health risk as it could link resistant bacteria in the natural environment to human population.

Escherichia coli

Escherichia coli is the predominant nonpathogenic facultative flora of the human intestine. Some E. coli strains, however, have developed the ability to cause disease of the gastrointestinal, urinary, or central nervous system in even the most robust human hosts. Diarrheagenic strains of E. coli can be divided into at least six different categories with corresponding distinct pathogenic schemes. Taken together, these organisms probably represent the most common cause of pediatric diarrhea worldwide. This review discusses the current level of understanding of the pathogenesis of the diarrheagenic E. coli strains and describes how their pathogenic schemes underlie the clinical manifestations, diagnostic approach, and epidemiologic investigation of these important pathogens. (Notaro,J. P. ,& kaper, J. B. , 1998. ) Factors that affect the probability of genetic transformation of Escherichia coli by plasmids have been evaluated. A set of conditions is described under which about one in every 400 plasmid molecules produces a transformed cell (Hanahan,1983).

Vibrio spp

Vibrio is a genus of ubiquitous bacteria found in a wide variety of aquatic and marine habitats; of the >100 described Vibrio spp. , ~12 cause infections in humans. Vibrio cholerae can cause cholera, a severe diarrheal disease that can be quickly fatal if untreated and is typically transmitted via contaminated water and person-to-person contact. Non-cholera Vibrio spp. can cause vibriosis — infections normally acquired through exposure to seawater or through consumption of raw or undercooked contaminated seafood (Baker-Austin, et al. , 2018). The incidence of vibriosis is rising, perhaps owing in part to the spread of Vibrio spp. favoured by climate change and rising sea water temperature.

Staphylococcus spp

Staphylococcus aureus is a member of the micrococcaceae family. On microscopical examination, the organisms appear as gram-positive cocci in clusters. It is distinguished from staphylococcus species on the basis of the gold pigmentation of colonies and positive results of coagulase, mannitol-fermentation, and deoxyribonuclease test. Staphylococcus aureus remains versatile and dangerous pathogen in humans. The frequencies of both community-acquired and hospital-acquired staphylococcus infections have increased steadily, with little change in overall morality. The treatment of these infections have increased steadily because of the emergence of multidrug-resistant strains. Micrococcus causes acute suppurative inflammation (phlegmon), produces, when more extensive and intense actions on the human system, the most virulent forms of septicaemia and pyaemia. (Lowy, Franklin D. ,1998)

Presence of staphylococci resistant to antibiotics is of concern, as is the possible spread of resistance determinants among Staphylococcus species. During the past several years, a series of staphylococcal isolates that demonstrated reduced susceptibility to vancomycin or other glycopeptides has been reported. A total of 22 Staphylococcus spp. isolates recovered from clinical sources was studied for antibiotic and heavy metal resistance patterns and plasmid profiles. Isolated strains were biochemically identified by conventional tests followed by use of API Staph system. (Ug, A. , & Ceylan, Ö. ,2003. )

Pseudomonas spp

Pseudomonas spp. is a genus of Gram-negative, rod-shaped bacteria of the Pseudomonadaceae family. Pseudomonads are aerobic, although some species also grow under anaerobic conditions. In this study, >10% of all imipenem-nonsusceptible isolates of Pseudomonas spp. and Acinetobacter spp. were attributable to MBL production, and these MBL-producing isolates were detected in 62. 5% of the participating hospitals.

Our finding indicates that MBL-producing P. aeruginosa is more prevalent in Korea than in other countries and that MBL-producing Acinetobacter spp. is increasing. The percentage of hospitals with MBL-producing isolates might have been higher if a larger number of imipenem-nonsusceptible isolates had been collected for this study. (Lee, k, et al. ) Fluorescent Pseudomonas spp. have been studied for decades for their plant growth-promoting effects through effective suppression of soilborne plant diseases. The modes of action that play a role in disease suppression by these bacteria include siderophore-mediated competition for iron, antibiosis, production of lytic enzymes, and induced systemic resistance (ISR). The involvement of ISR is typically studied in systems in which the Pseudomonas bacteria and the pathogen are inoculated and remain spatially separated on the plant, e. g. , the bacteria on the root and the pathogen on the leaf, or by use of split root systems. Since no direct interactions are possible between the two populations, suppression of disease development has to be plant-mediated. In this review, bacterial traits involved in Pseudomonas-mediated ISR will be discussed (Ug, A. , & Ceylan, Ö. , 2003).

Bacillus

A century ago, when a young scientist detected that a bacterium which Pasteur had thought to be a coccus was in fact a short rod, Pasteur’s comment was, “I wish I could convey to you how little that information excites me” (Duclaux, 1896).

Obviously, Pasteur was interested in microorganisms mainly for what they do rather than what they are. Whereas this remains a legitimate interest today, early bacteriologists felt that, with the increasing diversity of organisms isolated, there was a need to arrange bacteria distinctly. The easiest way to do this was to put them into groups with common properties, to study the relationships of such groups and their role in nature, and to develop methods that would enable scientists to identify new isolates with already known groups. (Claus, D. , & Fritze, D. (1989) A classification for crystal protein genes of Bacillus thuringiensis is presented. Criteria used are the insecticidal spectra and the amino acid sequences of the encoded proteins. Fourteen genes are distinguished, Toxicity studies with single purified proteins demonstrated that every described crystal protein is characterized by a highly specific, and sometimes very restricted, insect host spectrum. Comparison of the deduced amino acid sequences reveals sequence elements which are conserved for Cry proteins (Höfte, H. , & Whiteley, H. R. , 1989).