scholarly journals Estimation of endotoxin inhalation from shower and humidifier exposure reveals potential risk to human health

2007 ◽  
Vol 5 (4) ◽  
pp. 553-572 ◽  
Author(s):  
William B. Anderson ◽  
D. George Dixon ◽  
Colin I. Mayfield
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Cyanobacterial Blooms ◽  
Feed Water ◽  
Adverse Health Effects ◽  
Acute Response ◽  
Drinking Water Distribution ◽  
Treated Drinking Water

This paper investigates potential exposure to endotoxin in drinking water through the inhalation of aerosols generated by showers and humidifiers. Adverse health effects attributable to the inhalation of airborne endotoxin in various occupational settings are summarized, as are controlled laboratory inhalation studies. Data from investigations estimating aerosolization of particulate matter by showers and humidifiers provide a basis for similar analyses with endotoxin, which like minerals in water, is nonvolatile. A theoretical assessment of the inhalation of aerosolized endotoxin showed that while the likelihood of an acute response while showering is minimal, the same is not true for humidifiers. Ultrasonic and impeller (cool mist) humidifiers efficiently produce large numbers of respirable particles. It is predicted that airway inflammation can occur if humidifier reservoirs are filled with tap water, sometimes even at typical drinking-water distribution-system endotoxin concentrations. Higher endotoxin levels occasionally found in drinking water (>1,000 EU/ml) are very likely to induce symptoms such as chills and fever if used as humidifier feed water. While it is unlikely that treated drinking water would contain extremely high endotoxin levels occasionally observed in cyanobacterial blooms (>35,000 EU/ml), the potential for serious acute health consequences exist if used in humidifiers.

scholarly journals The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System

2018 ◽  
Vol 15 (8) ◽  
pp. 1756 ◽  
Author(s):  
Pirjo-Liisa Rantanen ◽  
Ilkka Mellin ◽  
Minna Keinänen-Toivola ◽  
Merja Ahonen ◽  
Riku Vahala
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Drinking Water Distribution System ◽  
Ammonium Oxidation ◽  
Water Age ◽  
Sampling Campaign ◽  
Drinking Water Distribution

We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data included both the obligatory monitoring and a sampling campaign data from a sampling campaign. Seasonality was evaluated by comparing a nitrite time series to temperature and by calculating the seasonal indices of the nitrite time series. The main drivers of nitrite seasonality were the temperature and the water age. We observed that with low water ages (median: 6.7 h) the highest nitrite exposure occurred during the summer months, and with higher water ages (median: 31 h) during the winter months. With the highest water age (190 h), nitrite concentrations were the lowest. At a low temperature, the high nitrite concentrations in the winter were caused by the decelerated ammonium oxidation. The dominant reaction at low water ages was ammonium oxidation into nitrite and, at high water ages, it was nitrite oxidation into nitrate. These results help to direct monitoring appropriately to gain exact knowledge of nitrite exposure. Also, possible future process changes and additional disinfection measures can be designed appropriately to minimize extra nitrite exposure.

scholarly journals Virus contamination from operation and maintenance events in small drinking water distribution systems

2011 ◽  
Vol 9 (4) ◽  
pp. 799-812 ◽  
Author(s):  
Elisabetta Lambertini ◽  
Susan K. Spencer ◽  
Burney A. Kieke ◽  
Frank J. Loge ◽  
Mark A. Borchardt
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Ultraviolet Disinfection ◽  
Drinking Water Distribution Systems ◽  
Virus Contamination ◽  
Drinking Water Distribution

We tested the association of common events in drinking water distribution systems with contamination of household tap water with human enteric viruses. Viruses were enumerated by qPCR in the tap water of 14 municipal systems that use non-disinfected groundwater. Ultraviolet disinfection was installed at all active wellheads to reduce virus contributions from groundwater to the distribution systems. As no residual disinfectant was added to the water, any increase in virus levels measured downstream at household taps would be indicative of distribution system intrusions. Utility operators reported events through written questionnaires. Virus outcome measures were related to distribution system events using binomial and gamma regression. Virus concentrations were elevated in the wells, reduced or eliminated by ultraviolet disinfection, and elevated again in distribution systems, showing that viruses were, indeed, directly entering the systems. Pipe installation was significantly associated with higher virus levels, whereas hydrant flushing was significantly associated with lower virus levels. Weak positive associations were observed for water tower maintenance, valve exercising, and cutting open a water main. Coliform bacteria detections from routine monitoring were not associated with viruses. Understanding when distribution systems are most vulnerable to virus contamination, and taking precautionary measures, will ensure delivery of safe drinking water.

scholarly journals Prevalence of Legionella spp. and Escherichia coli in the drinking water distribution system of Wrocław (Poland)

2020 ◽  
Vol 20 (3) ◽  
pp. 1083-1090
Author(s):  
M. Wolf-Baca ◽  
A. Siedlecka
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Potential Threat ◽  
E Coli ◽  
Drinking Water Distribution

Abstract Drinking water should be free from bacterial pathogens that threaten human health. The most recognised waterborne opportunistic pathogens, dwelling in tap water, are Legionella pneumophila and Escherichia coli. Drinking water samples were tested for the presence of Legionella spp., L. pneumophila, and E. coli in overall sample microbiomes using a quantitative real-time polymerase chain reaction (qPCR) approach. The results indicate a rather low contribution of Legionella spp. in total bacteria in the tested samples, but L. pneumophila was not detected in any sample. E. coli was detected in only one sample, but at a very low level. The qacEΔ1 gene, conferring resistance to quaternary ammonium compounds, was also not detected in any sample. The results point to generally sufficient quality of drinking water, although the presence of Legionella spp. in tap water samples suggests proliferation of these bacteria in heating units, causing a potential threat to consumer health.

scholarly journals Spatiotemporal Changes of Antibiotic Resistance and Bacterial Communities in Drinking Water Distribution System in Wrocław, Poland

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2601
Author(s):  
Agata Siedlecka ◽  
Mirela Wolf-Baca ◽  
Katarzyna Piekarska
Keyword(s):  
Drinking Water ◽  
Antibiotic Resistance ◽  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Resistant Bacteria ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Antibiotic resistance of bacteria is an emerging problem in drinking water treatment. This paper presents the comparison of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) prevalence during the summer and winter season in a full-scale drinking water distribution system (DWDS) supplied by two water treatment plants (WTPs). The effect of distance from WTP and physical–chemical water parameters on its microbial properties was also tested. Bacterial consortia dwelling in bulk tap water were additionally compared by means of denaturating gradient gel electrophoresis (DGGE). The results showed that among ARB, bacteria resistant to ceftazidime (CAZ) were the most abundant, followed by bacteria resistant to amoxicillin (AML), ciprofloxacin (CIP), and tetracycline (TE). Numerous ARGs were detected in tested tap water samples. Only CAZ resistant bacteria were more prevalent in the season of increased antibiotic consumption, and only AML resistant bacteria relative abundances increase was statistically significant with the distance from a WTP. The investigated tap water meets all legal requirements. It is therefore safe to drink according to the law. Nevertheless, because antibiotic resistance could pose a threat to consumer health, it should be further monitored in DWDSs.

Role of inorganic phosphorus in controlling regrowth in water distribution system

1997 ◽  
Vol 35 (8) ◽  
pp. 37-44 ◽  
Author(s):  
A. Sathasivan ◽  
S. Ohgaki ◽  
K. Yamamoto ◽  
N. Kamiko
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Pure Water ◽  
Inorganic Phosphorus ◽  
Drinking Water Distribution System ◽  
Drinking Water Distribution

Conventionally organic carbon is assumed to be the limiting nutrient of regrowth. Inorganic phosphorus in comparison to carbon should be a good candidate for regrowth control because it can be measured and controlled. It may be able to limit regrowth in drinking water distribution systems. In order to clarify whether inorganic phosphorus can really control or limit regrowth, three kinds of bioassays were performed: 1. for different combinations of acetate, phosphorus, and other inorganic nutrients added to different test tubes containing pure water, 2. for different tap water dilutions with pure water, and 3. for different phosphorus addition to test tubes containing all nutrients but phosphorus. The inoculum used was taken from a drinking water distribution system carrying chlorinated groundwater. Results indicated the following: 1. tap water bacteria cannot grow on simple organic carbon source (acetate) alone, 2. not organic carbon but inorganic nutrients limited the growth in tap water, and 3. tap water bacterial growth was suppressed when phosphorus was not present and it was not affected by over-presence of phosphorus when carbon or other nutrients became limiting. This gave a clue that phosphorus might play a major role in controlling regrowth in drinking water distribution system.

Assessment of Lisbon drinking water distribution network biofilm colonization and associated hazards

2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Storage Tanks ◽  
Water Pipe ◽  
Cultural Methods ◽  
Drinking Water Distribution ◽  
And Storage

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.

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