WATER SYSTEM SAFETY


industry will be widespread and significant. For the consumer, it provides uncertainty over product selection and availability, not to mention a considerable increase in the estimated cost of reduced lead copper alloys and other metal substitutes. The change in prescribed lead levels in plumbing products was made in spite of assurances from the then Australian Chief Health Officer, Prof. Brendan Murphy, that ‘There is no evidence of adverse effects on human health from the consumption of lead in drinking water in Australia’, and ‘The concentration of lead set in the drinking water guidelines is very conservative, so that it can be sure to protect the most vulnerable people, such as very young children and pregnant women’.


Largely isolated cases The earlier noted cases of non-compliance of lead in water in Australia appear to be largely isolated cases, where several factors conspired to contribute to the elevated lead water concentrations, including use of non-compliant materials, unsatisfactory water system management, and significant periods of stagnation. It is therefore difficult to determine whether these examples represent a wider problem reflective in potable water sourced by the public across the population, and as such, what the quantifiable health benefits from the prescribed changes in material properties will be. This was further supported by the ABCB’s 2021 Regulation Impact Statement (RIS), which concluded that significant evidence exists to suggest that the contribution plumbing makes to the problem is much smaller than that presented by the Consultation RIS, and may be negligible relative to all other sources. This would further support the view expressed in the Consultation RIS that Australia’s drinking water is currently very safe. Evidence presented in the RIS highlighted that surveillance monitoring of blood lead levels in Victoria between 2011-2014 showed that the vast majority of persons recording a blood lead level (BLL) above the notifiable level of 10µg/dL had an occupational risk factor as the identified source (81%).8


For those with a non-


occupational risk factor, only 3% (2011) and 6% (2014) were linked to potable water as a risk factor, with no cases linked to lead in plumbing in 2012 and 2013. Further, several studies have determined lead from potable water to contribute a relatively minor proportion of the overall lead consumption for children > 1 year old and for adults, with other exposure sources such as food, dust, and soil, being of far more concern.9-11


Other more significant risk factors Where comparable data are available, the likely health risks associated with lead contamination of potable water in Australia are considerably lower than


Figure 2: Representative fluorescence images of live (green) and dead (red) stained bacteria on Acetal, Stainless Steel 304, Stainless Steel 316, Brass 352, and Special Brass.


those associated with infections from microbial contamination of potable water systems with bacterial opportunistic pathogens, termed opportunistic premise plumbing pathogens (OPPPs). For example, in Queensland, the number of infections from the non-tuberculous mycobacteria (NTM) OPPPs is many times greater than the number of BLL cases above a moderate level (5 µd/dL) that have a non-occupational source as the identified risk factor (Figure 1a). While sources of NTM may be water, soil, or dust,12


plumbing materials and water supplies are a major contributor to NTM cases.13 NTM are a particularly pervasive group of opportunistic bacterial pathogens that often result in slowly progressive and destructive disease that can affect both immunocompromised and healthy individuals.14, 15


The number of NTM


infections in Queensland has in recent years been on the rise, a trend that mirrors that occurring internationally.16-22


(Figure


1b) (The broader health impacts of OPPPs are discussed later in this article.)


Resources allocated This raises the question as to why such significant resources have been assigned by regulators and governing bodies to address the issue of lead in water, while little, if any, consideration has been given to addressing the likely far greater problem of microbial contamination of building water infrastructure; a problem that is widely recognised as being of immediate and significant concern for the healthcare sector.23 Overall, the plumbing industry has been broadly supportive of the goal of reducing lead levels in plumbing products and materials in contact with potable water. However, there have been concerns from some stakeholders, and those in the scientific community, that there has been a rush to implement changes without proper consideration of the potential unintended consequences that the policy changes


may have on other important aspects of water quality that affect public health. Of particular concern is how the


increasing use of replacement materials, including low-lead copper alloys (i.e. low- lead brass), stainless steel, and polymers (i.e. polypropylene, polyethylene, acetal copolymer, and others), may have a far greater impact on the quality of our drinking water due to the problem of microbial contamination of drinking water infrastructure by OPPPs.


recent evidence has suggested that


Microbial contamination of potable water infrastructure Microbial contamination of potable water infrastructure has been of growing concern, with studies in several countries highlighting the role of OPPPs in the spread of waterborne infections.12, 24-31


The


‘opportunistic’ in OPPP comes from the fact these organisms preferentially infect individuals with underlying illnesses or weakened immune systems. It is therefore of no surprise that in the healthcare industry infections from OPPPs have already been identified as a public health crisis, with waterborne opportunistic pathogens noted as a major and preventable source of hospital-acquired infections (HAIs). In the US, 1.7 million nosocomial infections occur each year, with 1 in 7 people dying as a result of a HAI.32


While nosocomial infections may be


derived from a number of sources, hospital tap water has been described as ‘the most overlooked, important, and controllable source of HAI’, 23, 33


with the most


common OPPPs including Pseudomonas aeruginosa, non-tuberculous mycobacteria (NTM), such as mycobacterium avium complex (MAC), Burkholderia cepacian, Acinetobacter spp., and Legionella pneumophilia.34-38


Hospital-acquired pneumonia infections It is estimated that hospital-acquired pneumonia infections caused by waterborne Pseudomonas aeruginosa


August 2022 Health Estate Journal 29


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72