In addition to emerging chemical contaminants, there is also the threat of emerging pathogens – those that are appearing in human populations for the first time, or have occurred before but are increasing in incidence or are expanding into areas where they have not been reported (WHO 2003a). Not only do water-related diseases remain a leading cause of global morbidity and mortality, but several studies have confirmed that the variety of disease is expanding and the incidence of many water-related microbial diseases is increasing (WHO 2003a). Pathogens can emerge as a result of new environments or changes in environmental conditions,.
