Water is one of the five blessed elements, which exemplify life. Polluted water supplies may source health threat. Because of the prospective for contamination of community water supplies, folks have switched to alternative sources for their uncontaminated drinking water. Bottled (packaged) water is extensively frenzied now-a-days, since it is pure, has better flavour and confers privileged social status on purchaser.1
Fluorides have been documented as an effectual means for the deterrence of dental caries. Though fluoride enters the body through food, water, industrialized exposure, drugs, cosmetics, etc., drinking water is the chief provider (75-90% of daily intake).2 The predicament of unwarranted fluoride in groundwater in India was first reported in 1937 in the State of Andhra Pradesh.3 In India, because of utilization of water with high fluoride concentration, roughly 62 million people including six million children suffer from fluorosis.4 Seventeen states in India have been recognized as endemic for fluorosis and Andhra Pradesh is one of them.
The acceptable limit as given by Bureau of Indian Standards (BIS) and World Health Organization (WHO) is 0.6–1.2 mg/l and 1.5 mg/l correspondingly for fluoride in drinking water.5,6 International studies supports the extensively held view that the majority of bottled waters obtainable contain negligible fluoride in terms of its dental health benefits.7-14
One of the most frequent trends among consumers in current years in different countries, including India, is the substitution of their every day water intake with bottled water, perhaps due to worry about contaminants in natural water supplies (Ahiropoulos, 2006 and Toumba et al., 1994). Sales of bottled water have amplified and diverse types and brands of bottled water are on hand in Indian supermarkets. The changeover of commercial drinking water with bottled water is a grave concern because the advantage of drinking fluoridated water may be vanished.9, 12
The dental caries diminution that derived from consumption of fluoridated water is well renowned and water fluoridation is considered as a cost-effective and secure defensive measure (Weinberger, 1991).10 Successful and safe preventive fluoride programs entail an consciousness of the precise concentration of drinking water either community or bottled. When suggesting fluoride supplements, dentists should be conscious of the fluoride content of bottled waters used by child patients, particularly brands with a concentration elevated than 0.3 ppm (Ahiropoulos, 2006).12 In addition, the fluoride content of the bottled water may be highly unpredictable among diverse brands, and that may source dental fluorosis particularly in infants and children when receiving larger concentration than the most favourable levels suggested for their age group (Ahiropoulos, 2006).12 Manufacturers are encouraged to list the dietary contents of their product but labelling of the fluoride levels of the products may not be lawfully obligatory in some countries and even when fluoride concentration appears on the bottle labels, they may not always be exact (Ahiropoulos, 2006).9, 12
Water is thought to be elixir of life. Humankind highly depends on water and its appropriate deployment and management. Although, water has an assortment of uses, conceivably its use as a thirst quenching fluid is the most noteworthy one. An average man (with 53kg-63kg body weight) requires about 3 litres of water in liquid and food daily to keep him healthy. It is also a handy reserve for household, industrial and farming purposes.15, 16 Although it is bountiful in nature, occupying 71% of the earth’s surface, only 1 % is within reach for human utilization. Thus, the excellence of this 1 % drinking-water is an influential ecological determinant of health, as it has an significant impact on wellbeing of people. Water of deprived quality can source diseases like diarrhoea, typhoid, paratyphoid fever, bacillary and amoebic dysentery and it can add to altering rates of diseases which manifest themselves on diverse time scales.17, 18 According to World Health Organization (WHO), mortality caused by water connected diseases is more than 5 million per year.19 Admittance to potable drinking water has enhanced over the last decades in almost every part of the world, but roughly one billion people still lack access to safe water and over 2.5 billion lack access to sufficient hygiene.20 Although the access to potable drinking water is escalating, the quality of drinking water has deteriorated, due to the existence of toxic elements, which even in trace quantities, can pose serious health issues. Perhaps, as a response to this confront of providing safe drinking water, current years have witnessed surfacing and remarkable growth of bottled water industry.21 Also, the ease of accessibility, expediency to carry, better taste, sensible cost and freedom from impurities have made bottled water the choice of drinking water in most of developing and urbanized countries.22
Bottled water is defined as water that is planned for human utilization and that is preserved in bottles or other containers, which has no additional ingredients, except that it may optionally hold safe and appropriate antimicrobial agents.23
The global Bottled Water Industry has developed into a multibillion dollar industry. There has been a noteworthy growth which has been trajectory for the sector. The usage of bottled water in the world is mainly in North America (30%), Europe (29%), Asia (27%), and other parts of the world (14%) and people from all over the world drink about 13×1010 litres of bottled water per annum.24-27
In India, bottled water industry witnessed virtually no activity till 1993, when Bisleri was launched by Parley. But now, India is among the top ten countries in terms of bottled water utilization. Today, bottled water is one of India’s fastest emerging industrial sectors. Further, for the low income population, packed water is also obtainable in the form of comparatively cheaper, hand sealed sachets.28
The ascent in the demand and availability of a huge number of commercial brands of bottled water in the market have led to the recommendation and enforcement of water standards which are set for maximum allowable levels of diverse constituents, which differ from country to country. Thus, bearing in mind, consumer interests and public health, the Indian Union Ministry of Health and Family Welfare issued a announcement on September 29, 2000, for all packaged water manufacturers and traders, according to which ISI certification from Bureau of Indian Standards was made obligatory.29
Trace elements are recognized to have a role in metabolic processes of humans and whose daily prerequisite is less than 100mg. Water and foods, particularly unrefined foods are the chief sources of trace elements. From the unearthing of iron and then iodine as elements indispensable to life, the study of trace elements has developed into a widespread field of research.30 There was mounting awareness of the need for an ample intake of fruit and vegetables established by epidemiological studies. The advantageous effects of these foodstuffs are thought to mirror their importance as sources of micronutrients. This has led to an upsurge in interest in the metabolism and biological functions of trace elements and vitamins.31 The job of trace elements in the development of tooth decay has been an area of study since the recognition of Fluoride’s shielding effects.30 Regional differences in water and food choices may contribute information, as to which trace elements other than Fluorine can influence caries development.30 The recognition of the caries inhibiting effect of minute amounts of Fluoride in the drinking water has motivated curiosity in the possible effects of other trace elements or micronutrients on dental pathology.31
We have less than 100 years of knowledge on role of elements in the human body. It is estimated that 98% of the body mass of man is made up of nine non-metallic elements.32 The four main electrolytes namely sodium, magnesium, potassium, and calcium comprise about 1.89%, while the rest 0.02% or 8.6 g of an average human adults is made up of 11 characteristic trace elements.33 However, this minute part exerts a remarkable influence on all body functions. Most of them arbitrate vital biochemical reactions by acting as a cofactor or catalyst for numerous enzymes. They also act as centres of building stabilizing structures such as enzymes and proteins. The accretion of metals or shortage of these elements may motivate an alternate pathway which might generate diseases. Communication among the trace elements may also act as a scaffold upon which the etiopathogenesis of numerous nutritional disorders lie.34 Although these elements account for only 0.02% of the total body weight, they play important roles, e.g., as active centers of enzymes or as trace bioactive substances.35 Trace elements refers to “elements that occurs in natural and perturbed environments in small amounts and that, when present in sufficient bioavailable concentrations are toxic to living organism.”35 Elements such as iron, zinc, and selenium are vital components of enzymes where they attract or subtract molecules and make possible their conversion to specific end products. Few elements contribute or accept electrons in redox reactions, which results in production and deployment of metabolic energy and have an impact on the structural constancy and to import certain biological molecules. Iron is implicated in the binding, transporting, and release of oxygen in higher animals. Some of the trace elements manage vital biological processes by facilitating the binding of molecules to their receptor sites on cell membrane, by alternating the structures or ionic nature of membrane to prevent or permit specific molecules to enter or leave a cell and in inducing gene expression resulting in the construction of protein involved in life processes.36
Essential elements for human body
• Four organic basic elements: H, C, N, O
• Quantity elements — Na, Mg, K, Ca, P, S, Cl.
• Essential trace elements — Mn, Fe, Co, Ni, Cu, Zn, Mo, Se, I.
• Function suggested from active handling in humans, but no specific identified biochemical functions — Li, V, Cr, B, F, Si, As.37
BIOLOGICAL CLASSIFICATION OF TRACE ELEMENTS
A variety of classifications have been projected by so many authors on elements — both major as well as the trace elements, considered as vital for the normal development and growth.
Classification proposed by Frieden (1981) which alienated the elements into micro, trace, and ultra-trace elements based on the amount found in tissues.
1. Essential trace elements: Boron, cobalt, copper, iodine, iron, manganese, molybdenum, and zinc.
2. Probable essential trace elements: Chromium, fluorine, nickel, selenium, and vanadium.
3. Physically promotive trace elements: Bromine, lithium, silicon, tin, and titanium.38
CATEGORICAL CLASSIFICATION OF TRACE ELEMENTS
It is experiential that there are at least 29 diverse types of elements including metal and non-metals in an adult human body. These 29 elements can be broadly classified into five major groups they are as follows:
• Group I: These elements are the basic components of macromolecules such as carbohydrates, proteins, and lipids. The elements belonging to these groups are carbon, hydrogen, oxygen, and nitrogen.
• Group II: These are nutritionally essential minerals. They are also called as principal elements or macro elements. Their daily prerequisite for an adult human is above 100 mg/day. The deficiency of such elements usually proves lethal unless intervened appropriately. The elements belonging to this group are sodium, potassium, chloride, calcium, phosphorous, magnesium, sulfur.
• Group III: There are the essential trace elements. An element is called as trace element when its prerequisite per day is below 100 mg and insufficiency leads to disorders and may prove fatal. The elements belonging to this group are copper, iron, zinc, chromium, cobalt, iodine, molybdenum, and selenium. Of these, iodine is a nonmetal, while others are metals.
• Group IV: They are supplementary trace elements. Their job is not clear and they may be vital. The elements belonging to this group are cadmium, nickel, silica, tin, vanadium, and aluminum.
• Group V: This group of metals is not vital and their occurrence may produce toxicity. They have no known function in the human body. The elements belonging to this group are gold, mercury, cyanide, and lead.39
?A tentative classification of the elements proposed by Navia, according to their potential to encourage or diminish caries in experimental animals into five groups:
(1) Caries-promoting elements: Se, Mg , Cd , Pt, Pb, Si.
(2) Elements that are mildly cariostatic: Mo, V , Sr, Cu , B, Li , Au .
(3) Elements with doubtful effect on caries: Be, Co, Mn , Sn, Zn, Br, I.
4) Caries-inert elements: Ba, Al , Ni , Fe , Pd , Ti .
(5) Elements that are strongly cariostatic: F, P.
Of all the positive and negative interaction Fl, molybdenum, selenium and siliconium have been considered to produce cariostatic activity while interaction such as molybdenum — fluorine, molybdenum, copper, and siliconium — fluoride are primary interactions for cariostatic process. Cu acts as a caries promoting agent.40
Another issue of concern in drinking water is its pH. The pointer for acidity and alkalinity is known as the pH value. A pH value of 7 means a substance is neutral. The lower value indicates acidity, and an elevated value is a sign of alkalinity. pH of the water should be within normal range of 6.5 – 8.5. Basically, the pH value is a good display of whether water is hard or soft. The pH of pure water is 7. In general, water with a pH lower than 7 is measured as acidic, and with a pH greater than 7 is considered basic. The standard range for pH in surface water systems is 6.5 to 8.5, and the pH range for groundwater systems is between 6 to 8.5.41 Alkalinity is a measure of the capability of the water to resist a change in pH that would tend to make the water more acidic. The measurement of alkalinity and pH is required to establish the corrosiveness of the water. Beyond this range the water will influence the mucous membrane and/or water supply system.42 pH when shifts to acidic range can have erosive effect on teeth. Also acidic environment in oral cavity is favorable for dental caries commencement, whereas alkaline pH of water can lead to neutralization of hydrochloric acid present in gastric juice, thus interfering with normal digestion process. Further, it is noticed that water with low pH is tend to be toxic and with high degree of pH it is turned into bitter taste. Consuming extremely acidic or alkaline water is detrimental, warns the Environmental Protection Agency (EPA). Drinking water must have a pH value of 6.5-8.5 to fall within EPA standards, and they further note that even within the tolerable pH range, slightly high- or low-pH water can be disagreeable for quite a few reasons. High-pH water has a slippery feel, tastes a bit like baking soda, and may leave deposits on fittings, according to the EPA website. Low-pH water, on the other hand, may have a acidic or metallic taste, and may add to fixture corrosion.41, 42
?Water is an indispensable necessity of all life forms. Satisfactory delivery of clean, safe, and germ-free drinking water is crucial for health.25 Access to safe drinking water is a vital agent for human livelihood.43 Unavailability of high-quality drinking water is extensive and this has grim health implications.15 Water associated diseases continue to be one of the key health problems worldwide. The soaring prevalence of diarrhea among children and infants can be traced to the use of unsafe water and insanitary practices.44 In developing countries, 80% of all diseases and over 30% of deaths are linked to drinking water.15
As a preventive measure, utilization of packaged drinking water has augmented in recent years in developing countries.43 The sale and consumption of packaged drinking water continues to raise speedily in most of the developing countries of the world.45 In order to defend public health it is fundamental that the obtainable packaged water is of the uppermost quality.46 The incessant proliferation of these packaged drinking water and their haphazard consumption is of concern to public health. An understanding of their microbiological excellence and safety are therefore relevant. 47
A number of studies have acknowledged the uncovering of coliforms and heterotrophic bacteria in bottled or sachet drinking water counts which far exceeded the national and international standards set for potable water for human consumption.43, 48 Heterotrophic bacteria are non-coliform species of bacteria that utilizes organic matter for its development. The occurrence of heterotrophic bacteria in drinking water is not a sign that the water presents the health peril but poses considerable health risk in immunocompromised individuals. Correspondingly total coliform bacteria may source health risk for infants, young children, and elderly people and in particular to the immunocompromised individual.49
Some bottled water manufacturers may not uphold the microbiological and chemical eminence of bottled waters.50 The bacteria have been found at diverse stages in production of bottled water. Coliforms are the only microbiological contaminants to be regulated by law, in both tap and bottled waters.7 Although the microbial value levels in processed water are often firstly low, bottled mineral water is not a germ-free product and can hold naturally occurring bacteria as well as those introduced during manufacturing or consumer handing.51, 52 Fernanda also stated that natural mineral waters are not free of bacteria, and counts of 104–105 CFU/mL can be reached within a few days after bottling.53 According to plentiful studies, the microorganisms most commonly found in bottled natural mineral waters are aerobic heterotrophs, Pseudomonas spp, A. hydrophila, total and fecal coliform, Escherichia coli, and opportunistic pathogens (Flavobacterium and Mycobacterium).51-54 Huguet et al. described that bottled mineral water includes four viruses (Polivio virus 1, Hepatitis A virus, Norovirus, and the Ms 2 phage). Numerous studies conducted on microbiology of water delivery systems and bottled waters showed fungal growth in water distribution systems and fungi spoilage in bottled mineral waters.55
Although countless studies have been done on individual parameters like physico-chemical quality or bacterial quality, very small numbers of studies have been done on the combined quality assessments of bottled water and community drinking water. Because drinking water may be an important source of mineral intake, the move in consumption from tap water to bottled water may have implications for health and disease. Hence, due to the scanty literature which is available, the present study was done with the aim of evaluating the physical, chemical and microbial qualities of community water and bottled water which were sold in Tirupati City, Andhra Pradesh and of ascertaining compliance with specified International (WHO/FDA/USEPA) and Indian (BIS = IS10500 for bottled drinking water, IS14543 for drinking water) standards.
From the existing literature it was found that the data regarding fluoride concentration, microorganisms and other trace elements in community water and bottled drinking water sold in Tirupati City is scarce. With the supposition that the bottled water is being widely used nowadays, this study was undertaken in order to fill this lacuna. The present study analyzed the fluoride concentration in community water and bottled drinking water sold in Tirupati City. The recognition of the caries inhibiting effect of minute amounts of Fluoride in the drinking water has motivated curiosity in the possible effects of other trace elements or micronutrients on dental pathology. Thus the rationale of the present study was to weigh up the relationship of trace elements present in drinking water and dental caries.
Hence, the present study was designed to appraise fluoride concentration, pH , trace elements, and residual bacterial content in commercially available packaged drinking water and community water supply in Tirupati city, Andhra Pradesh.