A new study will test a novel technology for assessing the removal of pathogens in New Zealand’s drinking water filtration systems in the hope of preventing outbreaks of gastroenteritis.
Christchurch-based researcher Dr Liping Pang from ESR (the Institute of Environmental Science & Research) has received $1.06 million in project funding from the Health Research Council of New Zealand (HRC) to lead the study with a team that includes scientists from the University of Otago and NIWA, and end-users from Canterbury District Health Board and Invercargill City Council.
Dr Pang’s team will test novel “surrogate” particles that have been modified to mimic the physical and chemical properties of specific pathogens. The particles will be tagged with unique DNA markers or dye to help assess the effectiveness of filters to remove certain pathogens from drinking water supplies.
The new study will target protozoa such as Cryptosporidium and viruses like rotavirus, adenovirus and norovirus – the most frequently detected pathogens in surface waters in New Zealand and overseas.
A previous study estimated that each year about 35,000 New Zealanders succumb to gastroenteritis caused by waterborne pathogens lurking in our networked drinking water supplies. That figure jumps to about 93,000 New Zealanders if non-networked systems are included.
Dr Pang says that because testing for pathogens is expensive, labour intensive, and often impractical, the current tools for assessing the removal of pathogens from New Zealand’s water supplies are limited to testing turbidity (i.e., the cloudiness of water) for protozoa, and E.coli for bacteria. However, she says protozoa can break through treatment filters even when turbidity levels meet the guidelines, and the absence of E.coli (an indicator of faecal contamination) is no guarantee that there are no viruses present.
“We will trial our simple, harmless, and inexpensive surrogate testing system at a pilot-scale drinking water treatment plant in Invercargill that uses rapid sand filtration - the most common filtering method for protozoan removal in New Zealand. We will also test virus removal in point-of-use filtration systems, commonly used in rural settings, which filter water at the actual ‘point’ where it is being used,” says Dr Pang.
“Our findings will directly benefit the 1.95 million New Zealanders that use networked drinking water supplies with rapid sand filtration and hundreds of thousands of rural populations that use domestic point-of-use filtration systems.”
HRC Chief Executive Professor Kath McPherson says the outbreak of gastroenteritis in Havelock North is a reminder of just how important it is to invest in research and technology that can help safeguard our communities’ water supplies, especially with the expansion of human activities.
“The pathogens under investigation in this study pose serious public health concerns due to their extremely high infection risk, prolonged survival, and resistance to chlorination. Dr Pang’s research will help water suppliers and communities improve their practices to ensure the safety of our drinking water supplies and reduce the significant health and economic burden of gastroenteritis,” says Professor McPherson.
Contact information:
Dr Liping Pang
ESR Institute of Environmental Science & Research
Phone: 0800 ESR MEDIA (0800 377 633)
For HRC comment:
Professor Kathryn McPherson
Chief Executive, Health Research Council of New Zealand
Phone: (09) 303 5204 | Mob: 021 706 766