Quimica

Liguori et al. BMC Microbiology 2010, 10:19 http://www.biomedcentral.com/1471-2180/10/19

RESEARCH ARTICLE

Open Access

Microbiological quality of drinking water from dispensers in Italy
Giorgio Liguori, Ivan Cavallotti, Antonio Arnese, Ciro Amiranda, Daniela Anastasi, Italo F Angelillo*
Abstract
Background: Water coolers are popular in office buildings and commercial stores and thequality of this source of drinking water has the potential to cause waterborne outbreaks, especially in sensitive and immunocompromised subjects. The aim of this study was to determine the quality of water plumbed in coolers from commercial stores in comparison with tap water in Italy. Methods: For each sample, microbial parameters and chemical indicators of contamination were evaluated andinformation about the date of installation, time since last ordinary and extraordinary maintenance of water coolers was collected. Results: In all samples the chemical parameters (nitrite, ammonium, free active chlorine residual) did not exceed the reference values of the drinking water regulation; the pH value in 86.8% samples of the carbonated waters was lower than the reference limit. Themicrobiological results indicated that the bacteria count at 22°C and 37°C was higher than the required values in 71% and 81% for the non-carbonated water and in 86% and 88% for the carbonated one, respectively. Enterococcus spp. and Escherichia coli were not detected in any of the water samples. Pseudomonas aeruginosa was found in only one sample of the tap water and in 28.9% and 23.7% of the noncarbonated andcarbonated water samples, respectively. No statistically significant differences in bacterial counts at 22°C and 37°C have been found between the non-carbonated and carbonated water from the sampled coolers in relation with the time since the last filter was substituted. The bacteriological quality of tap water was superior to that of non-carbonated and carbonated water from coolers. Conclusion:The results emphasize the importance of adopting appropriate routinely monitoring system in order to prevent or to diminish the chances of contamination of this water source.

Background It is well known that the quality and safety of the drinking water continues to be an important public health issue [1,2], because its contamination has been frequently described as responsible for thetransmission of infectious diseases that have caused serious illnesses and associated mortality worldwide [3-6]. Clearly, point-ofuse water quality is a critical public health indicator [2]. Over the past decade, there has been a markedly increase in the consumption of water derived from different sources in place of tap water for drinking use in many regions of the world. One of these alternative sourcesis the water from dispensers, which is popular mainly in office buildings and commercial stores, that
* Correspondence: italof.angelillo@unina2.it Department of Public, Clinical and Preventive Medicine, Second University of Naples, Naples, Italy

are often presented as systems that are able to improve some characteristics of water and easy to use and to maintain. However, concerns have beensometimes raised about the quality of this source due to its potential to cause waterborne outbreaks associated with drinking water, particularly in sensitive and immunocompromised populations [2]. International drinking water-quality monitoring programs have been established in order to prevent or to reduce the risk of contracting water related infections. In Italy, the water for human consumption,including the water coming from dispensers, according to the European Community Directive guidelines, is required to be free from any pathogenic microorganism as well as chemical contaminations, which may be hazardous to the human health [7,8].

© 2010 Liguori et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution...