Abstract
Drinking or heated water can have a wide range of disturbing odours which have many various causes. A well known example is sulphane (hydrogen sulfide) odour, reminiscent of rotten eggs, ...which naturally occurs in some underground waters. Less known and hitherto unexplained is this odour arising from hot water in water heaters. As a response to complaints by consumers we investigated 14 sites and thanks to experimental work in one of these recognised a complex mechanism at work. For production of sulphane to occur in a water heater the following conditions must be met: presence of sulphate-reducing bacteria, presence of sulphates, reduction properties of water indicated by a very low nitrate content (highest value was 10 mg/L, mostly <2 mg/L), and presence of sacrificial magnesium anode. We identified four possible remedial measures, some of which are less effective or only short term, or have an undesirable side-effect (corrosion). The most effective measure was replacement of the magnesium anode for an aluminium or zinc anode, which retains the anticorrosion protection of the heater.
This epidemiological study of ecological type deals with the analysis of relationship between drinking water hardness and health status of inhabitants of the Slovak Republic. This relationship was ...investigated in two groups of more than 50,000 inhabitants living in 53 different municipalities. The first group was supplied with drinking water with low hardness, and the second group was supplied with drinking water with increased hardness. The health status of the population of both groups was monitored by means of health indicators, which represented 15-year average values, for 1994–2008. We investigated four major causes of death, namely cardiovascular, oncological, gastrointestinal and respiratory tract mortality, and evaluated the average life expectancy. The health status of inhabitants supplied with drinking water with increased hardness was significantly better than the health status of people supplied with drinking water with low hardness. For example, the relative mortality for cardiovascular diseases, oncological diseases, digestive tract diseases and respiratory diseases was 56%, 62%, 128% and 121% higher in the population supplied with soft drinking water compared to the population supplied with hard water, respectively. In addition, life expectancy was more than 4.5 years higher in the population supplied with hard drinking water. Our observation confirms the findings of previous studies on relationship between the water hardness and human health.
Objectives: The use of alternative water sources such as rainwater or greywater (i.e., wastewater excluding water from toilets) for non-potable purposes may save water but, on the other hand, can ...also pose health risks to users. The main health risks come from microorganisms (such as bacteria, viruses, fungi, and protozoa). This work aims to analyse especially microbiological quality of rainwater and greywater used inside buildings in detail and to expand the existing knowledge about the potential health risks associated with these alternative water sources. It also considers methodological problems during E. coli and coliform bacteria detection. The final objective is to discuss requirements and appropriate indicators for monitoring recycled water quality. Methods: We examined 30 buildings with non-potable water systems in the Czech Republic and analysed a total of 137 samples of rainwater and 120 samples of greywater. From these 30 buildings, eleven, 5 of which used rainwater and 6 of which used greywater, were sampled regularly for 1-2 years for basic chemical parameters, various faecal indicators, C. perfringens, Legionella spp. and P. aeruginosa. Occasionally, samples were analysed also for the presence of environmental mycobacteria, amoebas, viruses, and selected pathogens. Results: Nearly three quarters of rainwater samples contained the faecal indicators E. coll or enterococci, or both, and in samples from several buildings also Clostridium perfringens was repeatedly detected. Untreated and treated rainwater were in respect to microbiological quality similar, suggesting that treatment processes were not very efficient. In greywater samples, beside faecal indicators, also P. aeruginosa and thermotolerant amoebas were repeatedly detected. Treatment technologies used for greywater were more efficient than those for rainwater systems. Conclusion: Based on the results we evaluated appropriate indicators for monitoring recycled water quality and drafted the first Czech regulation for non-potable water.
The US EPA health risk assessment method is currently widely used to assess human health risks for many environmental constituents. It is used for risk assessment from the exposure to various ...contaminants exceeding tolerable or safe reference doses, determined e.g., for drinking water, soil, air and food. It accepts widely that excess contents of non-essential elements (e.g., As, Pb or Sb) in environmental compartments represent a general risk to human health. However, contrary to toxic trace elements, deficient contents of essential (biogenic) elements e.g., F, I, Se, Zn, Fe, Ca or Mg may represent even higher health risk. Therefore, we propose to extend the human health risk assessment by calculating the health risk for deficient content and intake of essential elements, and to introduce the terms Average Daily Missing Dose (ADMD), Average Daily Required Dose (ADRD) and Average Daily Accepted Dose (ADAD). We propose the following equation to calculate the Hazard Quotient (HQ) of health risk from deficient elements: HQ
= ADRD/ADAD. At present, there are no reference concentrations or doses of essential elements in each environmental compartment in world databases (Integrated Risk Information System IRIS, The Risk Assessment Information System RAIS). ADRD and ADMD can be derived from different regulatory standards or guidelines (if they exist) or calculated from actual regional data on the state of population health and content of essential elements in the environment, e.g., in groundwater or soil. This methodology was elaborated and tested on inhabitants of the Slovak Republic supplied with soft drinking water with an average Mg content of 5.66 mg·L
. The calculated ADMD of Mg for these inhabitants is 0.314 mg·kg
·day
and HQ
is equal to 2.94, indicating medium risk of chronic diseases. This method extending traditional health risk assessment is the first attempt to quantify deficient content of essential elements in drinking water. It still has some limitations but also has potential to be further developed and refined through its testing in other countries.
The case of spoilage of flavoured and sweetened soft drink occurred in the Czech Republic in 2019. After drinking it, the consumer was admitted to a hospital with sickness. The spoilage was caused by ...mould and an odorous substance, 1,3-pentadiene. The mechanism of food spoilage, with the formation of 1,3-pentadiene arising from the decarboxylation of sorbic acid and mould growth, is described. This could be the second case history reported worldwide of an allergic reaction to penicillin explaining how penicillin might get into the beverage. We hypothesise three possible causes of the health problem experienced with allergic reaction to penicillin or other mycotoxin produced by Penicillium mould as the most probable one.
The modern, risk-based approach requires that only those pollutants which are likely to be present in a given water supply should be monitored in drinking water. From this perspective, defining an ...adequate approach to the monitoring of pesticides in areas with intensive agriculture is currently one of the greatest issues of regulation. This article shows the development and detailed results of pesticide monitoring in drinking water in the Czech Republic (CR). More than 4000 water supply zones serving around a 9.5 million population are routinely monitored, with nearly 250 thousand analyses of over 200 different pesticides and their metabolites being performed every year, with a non-compliance rate of
ca.
0.3%. In 2017, pesticides accounted for most derogations in the CR, concerning a total of 64 water supply systems serving more than a 250 thousand population. A representative survey targeting 21 selected chemicals showed that 75% of water supply systems contained up to 11 pesticides per sample. The most commonly found were metabolites of the herbicides used to protect oilseed rape, maize, and sugar beet: acetochlor ESA, alachlor ESA, metazachlor OA, and chloridazon-desphenyl. The health risk assessment did not reveal any risks from these chemicals, even at the highest levels detected or in the most abundant mixtures, to the most vulnerable population (infants). Nevertheless, the increased presence of pesticides undermines the public's trust in drinking water safety.
The modern, risk-based approach requires that only those pollutants which are likely to be present in a given water supply should be monitored in drinking water.
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