Development of a relative risk model for drinking water regulation and design recommendations for a peri urban region of Argentina

Abstract

Argentina is a developing Latin American nation that has an aim of achieving the United Nations Millennium Development Goals for potable water supplies. Their current regulations however, limit the continued development of improved potable water quality and infrastructure from a microbiological viewpoint. This is since the current regulations are focused solely to pathogenic Eschericia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and fecal indicators. Regions of lower socioeconomic status such as peri-urban areas are particularly at risk due to lessened financial and political ability to influence their environmental quality and infrastructure needs. Therefore, a combined microbiological sampling, analysis and quantitative microbial risk assessment (QMRA) modeling effort were engaged for a peri-urban area of Salta Argentina. Drinking water samples from home taps were analyzed and a QMRA model was developed, results of which were compared against a general 1:10,000 risk level for lack of a current Argentinian standard. This QMRA model was able to demonstrate that the current regulations were being achieved for E. coli but were less than acceptable for P. aeruginosa in some instances. Appropriate health protections are far from acceptable for Giardia for almost all water sources. Untreated water sources were sampled and analyzed then QMRA modeled as well, since a significant number of the community (∼9%) still use them for potable water supplies. For untreated water E. coli risks were near 1:10,000, however, P. aeruginosa and Giardia risks failed to be acceptable in almost all instances. The QMRA model and microbiological analyses demonstrate the need for improved regulatory efforts for the peri-urban area along with improved investment in their water infrastructure.

Environmental and socio-demographic individual, family and neighborhood factors associated with children intestinal parasitoses at Iguazú, in the subtropical northern border of Argentina

“…We associate this result with the high prevalence of Giardia intestinalis we found in the children. The vulnerability of drinking water supply systems to pathogens contamination and the consequent increase of risk of waterborne diseases have been highlighted in several studies [ 89 , 90 ]. Giardia is an anaerobic flagellated protozoa capable of encysting through a complex process of cyst wall formation [ 91 ], being this infective form resistant to common disinfection controls such as chlorine and chloramines [ 92 ].…”

Quantitative Microbial Risk Assessment and Infectious Disease Transmission Modeling of Waterborne Enteric Pathogens

“…A handful of papers considered hand or fomite disinfection [39–41], household-level water treatment [42], or vaccination of animals against waterborne pathogens [43]. In LMICs, there was more emphasis on household water treatment [44–47] and less on wastewater treatment or water management [48–52], the latter primarily coming from upper-middle-income countries. Studies also considered treatment of livestock waste [53] and disinfection of kitchen clothing [54].…”

Socio-demographic influences on the prevalence of enteric helminth and protozoan infections in newly arrived migrant workers in Qatar

“…The vulnerability of drinking water supply systems to contamination by pathogens and the consequent increase of risk of waterborne diseases have been highlighted in several studies (37,38). In addition, the protection of drinking water from these protozoa is a serious problem for water supply organizations around the world.…”