ABSTRACT

Continuous increase in the sale and indiscriminate consumption of packaged drinking

water and untreated water types such as borehole and well waters in Nigeria is of public health significance. Three hundred samples comprising 120 sachets, 60 bottled water brands, 60 borehole and 60 well water samples from five sampling sites in Zaria, North Western Nigeria were analysed microbiologically and physicochemically using standard procedures. Membrane filter technique was used to detect the presence of bacterial indicators of water quality as well as specific pathogens such as Escherichia coli O157:H7 and Enterococcus spp. The research was conducted between June 2014 to February 2015 during the wet and dry seasons. Isolated pathogens were characterized conventionally, using MicrogenTM ID Kits and molecularly by Polymerase Chain Reactions (PCR). The nitrate level in samples of the wells (100%) and borehole (40%) water were above the United States Environmental Protection Agency (USEPA) minimum contamination level of 10mg/l. Cadmium (Cd) and Lead (Pb) contents of boreholes, wells, and brands of sachet waters were above the minimum permissible limits set by NAFDAC (0.003mg/l and 0.01mg/l respectively). However, Lead (Pb) was not detected in the bottled water brands sampled. Total coliforms and Escherichia coli were detected in sachet water brands (80%), bottled water brands (20%), borehole (100%) and well water (100%). Enterococci were recovered from sachet water brands (70%), borehole (100%) and well water (100%). There were no statistically significant differences (P≤0.05) between the total coliform counts of the sachet water brands and borehole water in Zaria, therefore, the purity of sachet water as claimed by the manufacturers is doubtful. Bacteriological counts were higher during the wet season than dry season. Antibiogram of Escherichia coli O157:H7 (80%) and Enterococcus spp (37.6%) isolates showed multiple antibiotics resistance (MAR) with MAR indices of 0.3 and above. Polymerase chain reaction (PCR) amplified some housekeeping genes such as tuf gene of Enterococcus genus and antibiotics resistance genes such as glycopeptides Vancomycin and Teicoplanin resistance gene VANR. Escherichia coli O157:H7 extended spectrum β-lactamase genes: bla-TEM and bla-CTX-M genes. Most of the sachet water brands fell below NAFDAC and WHO drinking water standards and are therefore of doubtful quality and need strict adherence to standards. Efforts need to be intensified in the monitoring of activities in this rapidly expanding industry with a view to raising standards while government at all levels in Nigeria should take the issue of supply of adequately treated water to the public as an essential public service.

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CHAPTER ONE

1.0                                                       INTRODUCTION

Water is a simple molecule, consisting of two hydrogen atoms bonded to an oxygen

atom with molecular formula H2O (Bassem, 2013). It is one of the most important chemical

substances for the sustenance of life and is vital for all known forms of life on Earth; It

constitutes about 75% of the Earth`s surface (UN, 2005; EL-Jakee et al., 2009; Hongyue et

al., 2013). In terms of sheer volume, About 97.5% of all the water on Earth is salt water,

only 2.5% of all the water on Earth is fresh water and 98.8% of that fresh water is frozen in

Antarctica and Greenland icecaps or lies too deep underground to be accessible; only 1.2%

of the Earth’s freshwater is available for withdrawal and human use (Shiklomanov, 2000;

UN, 2005; Bassem, 2013). However, this is continually being polluted by various

anthropogenic activities thereby further reducing the available freshwater for human use.

The drinking water of most communities including Zaria in Nigeria is obtained from various

sources: boreholes, rivers, streams, and well waters. Source water contamination poses a risk

to public health and increases the cost of drinking water treatment.

The threats posed by deteriorating water quality caused by among other things, the

contamination of potable water sources have led the public to seek for alternative potable

water sources. Although access to safe and reliable sources of drinking water is a global

challenge, it is particularly acute in developing countries, including Nigeria (Ivey et al.,

2006).

The production, sale and consumption of plastic bagged drinking water has grown

tremendously over the years in many developing countries such as Nigeria. The plastic

bagged drinking water was introduced into the Nigerian market as a less expensive means of

accessing drinking water than bottled water.

1

1.1       Statement of Research Problem

Estimate of the global burden of water associated human diseases provide a simple

index hiding a complex reality. World Health Organization (WHO) estimates that worldwide

some 2.2 million people die each year from diarrhoeal related diseases. For an estimated

88% of diarrhoeal cause, the underlying cause is unsafe water, inadequate sanitation and

poor hygiene (WHO, 2008; Mosier et al., 2012). Water borne diseases continue to be one of

the major health problems in developing nations, including Nigeria especially on the issues

of safe drinking water quality (Mead et al., 1999). Water borne diseases account for one

third of the intestinal infection worldwide (Hunter and Syed, 2001; Offre et al., 2011).

The high prevalence of diseases such as diarrhoea, typhoid fever, cholera, and

bacillary dysentery among the populace have been linked to the consumption of unsafe water

and unhygienic drinking water production practices (Mead et al., 1999; Park et al., 2010).

Pathogens such as Salmonella species, Shigella species, Vibrio cholerae and E. coli being

seen in human and animal faeces ultimately find their way into water supply through

seepage of improperly treated sewage into ground water, (Dipaola, 1998; Wei et al., 2011).

1.2    Justification for the Study

Most bottle water manufacturers in Nigeria also engage in sachet water packaging

and obtain their raw water mostly from local, municipal piped or well water, however,

adherence to production and analytical stand