Pepper mild mottle virus as an indicator and a tracer of fecal pollution in water environments: Comparative evaluation with wastewater-tracer pharmaceuticals in Hanoi, Vietnam

Abstract

We analyzed pepper mild mottle virus (PMMoV) in 36 samples taken from surface water, wastewater, groundwater, tap water and bottled water in Hanoi, Vietnam. We then compared the occurrence and fates of PMMoV with pharmaceuticals and personal care products (PPCPs), which are known wastewater tracers. PMMoV was detected in 94% of the surface water samples (ponds, water from irrigated farmlands and rivers) and in all the wastewater samples. The PMMoV concentration ranged from 5.5×10(6)-7.2×10(6)copies/L in wastewater treatment plant (WWTP) influents, 6.5×10(5)-8.5×10(5)copies/L in WWTP effluents and 1.0×10(4)-1.8×10(6)copies/L in surface water. Among the sixty PPCPs analyzed, caffeine and carbamazepine had high detection rates in surface water (100% and 88%, respectively). In surface water, the concentration ratio of PMMoV to caffeine remained unchanged than that in WWTP influents, suggesting that the persistence of PMMoV in surface water was comparable to that of caffeine. The persistence and the large concentration ratio of PMMoV in WWTP influents to the method detection limit would account for its ubiquitous detection in surface water. In comparison, human enteric viruses (HEV) were less frequently detected (18-59%) than PMMoV in surface water, probably because of their faster decay. Together with the reported high human feces-specificity, our results suggested that PMMoV is useful as a sensitive fecal indicator for evaluating the potential occurrence of pathogenic viruses in surface water. Moreover, PMMoV can be useful as a moderately conservative fecal tracer for specifically tracking fecal pollution of surface water. PMMoV was detected in 38% of the groundwater samples at low concentrations (up to 19copies/L). PMMoV was not detected in the tap water and bottled water samples. In groundwater, tap water and bottled water samples, the occurrence of PPCPs and HEV disagreed with that of PMMoV, suggesting that PMMoV is not suitable as an indicator or a tracer in those waters.

Cross-Comparison of Human Wastewater-Associated Molecular Markers in Relation to Fecal Indicator Bacteria and Enteric Viruses in Recreational Beach Waters

“…Some researchers reported that PMMoV has the potential to be an overly sensitive marker, due to its high concentrations in human wastewater (17,32,33). While this presents an advantage for the PMMoV as a sensitive marker, its presence may also overestimate risk (23).…”

Microbial contamination along the main open wastewater and storm water channel of Hanoi, Vietnam, and potential health risks for urban farmers

“…In addition, these channels receive industrial effluents. In response to these challenges, the system was expanded in recent years to control the water flow out of the city and treat the wastewater with conventional treatment plants and decentralised water management systems (Kuroda et al, 2015). The latter should prevent flooding events, while regulating the water flow with water gates and a series of artificial ponds.…”

Sustainable Urban Water Management: Application for Integrated Assessment in Southeast Asia

“…Noroviruses are selected as a reference pathogen; they are the major cause of viral gastroenteritis worldwide, with an estimated 698.8 million cases and 218,800 deaths annually [52]. The distribution of norovirus concentrations in floodwater was estimated based on the Escherichia coli concentrations simulated using the WEAP model, and the relationship between E. coli concentrations and norovirus concentrations observed in the Nhue River, which flows through Hanoi city [53,54] (this relationship was used in other cities as well). The volume of the unintentional ingestion of floodwater was estimated using the hourly inundation depths in each grid from the inundation model using Flo-2D.…”