Determination and speciation of arsenic in drinking water samples by X-ray spectrometry technique.

Arsenic is ranked as the first compound in the Substance Priority List 2023 by the Agency for Toxic Substances and Disease Registry (ATSDR). The most prominent entrance to the human body is through drinking water wherein the predominant species are arsenite and arsenate. The more toxic As(III) has rigorously threatened human health worldwide; hence, speciation and separation are the need of the hour. In this article, we have reported a simple method of arsenic speciation by wavelength dispersive X-ray fluorescence (WD-XRF) spectrometer. Valence to core (VtC) electronic transitions, i.e., AsKß2,5 fluorescence lines were used for arsenic speciation. This speciation study by WD-XRF entails direct measurement of activated alumina pellets containing arsenate and arsenite species adsorbed from water sample without separation of the trivalent and pentavalent species. This is the first report wherein the X-ray technique has been explored for speciation analysis of arsenic and the biggest advantage of the method lies in its applicability to direct analysis of synthesized nanotubes or other solid-phase extraction sorbents entrapping both the arsenic species. For determination of total arsenic using activated alumina as adsorbent, the most intense AsKα1,2 analytical lines were used and the instrumental limit of detection and the lower limit of quantification were 0.23 µg/L and 0.89 µg/L, respectively. For speciation, these limits were calculated to be 50 µg/L and 200 µg/L, respectively.

Prenatal arsenic exposure stymies gut butyrate production and enhances gut permeability in post natal life even in absence of arsenic deftly through miR122-Occludin pathway.

This discourse attempts to capture a few important dimensions of gut physiology like microbial homeostasis, short chain fatty acid (SCFA) production, occludin expression, and gut permeability in post-natal life of mice those received arsenic only during pre-natal life. Adult Balb/c mice were fed with 4 ppm arsenic trioxide in drinking water during breeding and gestation. After the birth of the pups, the arsenic water was withdrawn and replaced with clean drinking water. The pups were allowed to grow for 28 days (pAs-mice) and age matched Balb/c mice which were never exposed to arsenic served as control The pAs-mice showed a striking reduction in Firmicutes to Bacteroidetes (F/B) ratio coupled with a decrease in tight junction protein, occludin resulting in an increase in gut permeability, increased infiltration of inflammatory cells in the colon and decrease in common SCFAs in which butyrate reduction was quite prominent in fecal samples as compared to normal control. The above phenotypes of pAs-mice were mostly reversed by supplementing 5% sodium butyrate (w/w) with food from 21st to 28th day. The ability of butyrate in enhancing occludin expression, in particular, was dissected further. As miR122 causes degradation of Occludin mRNA, we transiently overexpressed miR122 by injecting appropriate plasmids and showed reversal of butyrate effects in pAs-mice. Thus, pre-natal arsenic exposure orchestrates variety of effects by decreasing butyrate in pAs-mice leading to increased permeability due to reduced occludin expression. Our research adds a new dimension to our understanding that pre-natal arsenic exposure imprints in post-natal life while there was no further arsenic exposure.

Effects of Spirulina (Arthrospira platensis) as a drinking water supplement during cyclical chronic heat stress on broiler chickens: Assessing algal composition, production, stress, health and immune-biochemical indices.

Spirulina, the blue green algae is considered to exhibit multifaceted benefits on both human health and animal production. Three hundred sixty day old unsexed broiler chicks of CARIBROVISHAL strain were assigned to five treatment groups each comprising nine replicates of 8 chicks. The experiment was carried out during the hot humid summer season (Mid-April to May) under deep litter rearing system with uniform managemental conditions. Birds were administered orally with Spirulina through drinking water in the morning (06:00-12:00 PM) on daily basis throughout the experimental period at 5, 10, 15 and 20 gL-1 concentration. Spirulina supplementation neither improved nor compromised production performance of broilers reared during hot climatic condition. Results based on one way analysis of variance indicated a significant effect on haemoglobin and total red blood cell count. Serum lipid content and transaminases were reduced, while serum protein concentration was higher (P < 0.01) in the groups administered with 15 and 20 gL-1 of Spirulina. The extent of imparting shank pigmentation was improved in all the supplemented groups. Cell mediated and humoral immunity against Phytoheamagglutunin-P and Newcastle disease vaccination respectively were maximized (P < 0.05) at 20 gL-1. These findings provide direct evidence of dose-related modulation of production, physiological and immunological attributes by Spirulina engendering its further investigation as a potential source of drinking water supplement for stress alleviation in broilers. From the results, it may concluded that Spirulina can be incorporated at 15 or 20 gL-1 for achieving optimal improvement of health and welfare attributes in broilers reared during hot summer without compromising production.

Investigation on spatial variability and influencing factors of drinking water iodine in Xinjiang, China.

BACKGROUND AND OBJECTIVES: Xinjiang is one of the areas in China with extremely severe iodine deficiency. The health of Xinjiang residents has been endangered for a long time. In order to provide reasonable suggestions for scientific iodine supplementation and improve the health and living standards of the people in Xinjiang, it is necessary to understand the spatial distribution of iodine content in drinking water and explore the influencing factors of spatial heterogeneity of water iodine content distribution. METHODS: The data of iodine in drinking water arrived from the annual water iodine survey in Xinjiang in 2017. The distribution of iodine content in drinking water in Xinjiang is described from three perspectives: sampling points, districts/counties, and townships/streets. ArcGIS was used for spatial auto-correlation analysis, mapping the distribution of iodine content in drinking water and visualizing the distribution of Geographically Weighted Regression (GWR) model parameter. Kriging method is used to predict the iodine content in water at non-sampling points. GWR software was used to build GWR model in order to find the factors affecting the distribution of iodine content in drinking water. RESULTS: There are 3293 sampling points in Xinjiang. The iodine content of drinking water ranges from 0 to 128 µg/L, the median is 4.15 µg/L. The iodine content in 78.6% of total sampling points are less than 10 µg/L, and only that in the 3.4% are more than 40 µg/L. Among 1054 towns' water samples in Xinjiang, 88.9% of the samples' water iodine content is less than 10 µg/L. Among the 94 studied areas, the median iodine content in drinking water in 87 areas was less than 10 µg/L, those values in 7 areas were between 10-40 µg/L, and the distribution of water iodine content in Xinjiang shows clustered. The GWR model established had found that the effects of soil type and precipitation on the distribution of iodine content in drinking water were statistically significant. CONCLUSIONS: The iodine content of drinking water in Xinjiang is generally low, but there are also some areas which their drinking water has high iodine content. Soil type and precipitation are the factors affecting the distribution of drinking water iodine content, and are statistically significant (P<0.05).

Associations of Community Water Lead Concentrations with Hemoglobin Concentrations and Erythropoietin-Stimulating Agent Use among Patients with Advanced CKD.

BACKGROUND: Although patients with kidney disease may be particularly susceptible to the adverse health effects associated with lead exposure, whether levels of lead found commonly in drinking water are associated with adverse outcomes in patients with ESKD is not known. METHODS: To investigate associations of lead in community water systems with hemoglobin concentrations and erythropoietin stimulating agent (ESA) use among incident patients with ESKD, we merged data from the Environmental Protection Agency (EPA) Safe Drinking Water Information System (documenting average 90th percentile lead concentrations in community water systems during 5 years before dialysis initiation, according to city of residence) with patient-level data from the United States Renal Data System. RESULTS: Among 597,968 patients initiating dialysis in the United States in 2005 through 2017, those in cities with detectable lead levels in community water had significantly lower pre-ESKD hemoglobin concentrations and more ESA use per 0.01 mg/L increase in 90th percentile water lead. Findings were similar for the 208,912 patients with data from the first month of ESKD therapy, with lower hemoglobin and higher ESA use per 0.01 mg/L higher lead concentration. These associations were observed at lead levels below the EPA threshold (0.015 mg/L) that mandates regulatory action. We also observed environmental inequities, finding significantly higher water lead levels and slower declines over time among Black versus White patients. CONCLUSIONS: This first nationwide analysis linking EPA water supply records to patient data shows that even low levels of lead that are commonly encountered in community water systems throughout the United States are associated with lower hemoglobin levels and higher ESA use among patients with advanced kidney disease.

Effects of Allium sativum on IFN-γ and IL4 concentrations in mice with cystic echinococcosis.

The aim of the current investigation was to assess the impacts of methanolic extract of Allium sativum (MEAS) on IL-4 (a cytokine derived from Th2 cells) and IFN-É£ (a cytokine derived from Th1 cells) levels in mice infected with Echinococcus granulosus. Sixty healthy BALB/c female mice were used in this study. Each animal was intraperitoneally injected with 1500 protoscoleces. The infected animals were randomly divided into six groups: albendazole (100 mg/kg), MEAS 10 (10 mg/kg), MEAS 20 (20 mg/kg), MEAS 40 (40 mg/kg), MEAS 80 (80 mg/kg) and control group with no treatment. The studied animals received albendazole and/or MEAS through drinking water for 30 days. Serum IFN-γ concentration significantly increased in the MEAS 20 and 80 groups in comparison to the control, albendazole and MEAS 10 groups (P < 0.05). The serum IL-4 level showed no significant difference between the trial groups. The findings of this study showed that MEAS at 20 and 80 mg/kg concentrations enhanced Th1 cell response in mice with cystic echinococcosis.

Quality and management status of the drinking water supplies in a semiarid region of Northeastern Brazil.

Surface and groundwater resources in the Seridó Region (Brazilian semiarid) were investigated to evaluate their current quality conditions and suitability for domestic use. The water was characterized in terms of physical, chemical, and radiological parameters; including those required by the Brazilian Drinking Water Quality Standard (DWQS). Information about major and trace elements and radiological aspects of the water are reported for the first time. Salinization was confirmed as a key problem in the region, driven natural and anthropogenic. Overall, water has poor organoleptic characteristics. The concentration of most trace elements was below the recommended level, except for uranium and selenium in groundwater. Gross alpha and beta activities higher than the recommended levels were also recorded in several water samples, mostly from the investigated aquifers. In these samples, a detailed radionuclide analysis is required to estimate the effective dose received by the local population. Overall, the results show that water from the investigated region is not suitable for human consumption unless proper treatment is applied. Water requires proper treatment to decrease the content of dissolved salts, toxic elements, and radionuclides responsible for the high gross alpha and beta activities.

Almond skin extract mediated optimally biosynthesized antibacterial silver nanoparticles enable selective and sensitive colorimetric detection of Fe+2 ions.

The safety of drinking water is one of the most important public health issues as very high concentrations of metal like iron acts as a useful surrogate for other heavy metals. The present study demonstrates the use of almond skin extract (ASE) for simple and rapid synthesis of antibacterial silver nanoparticles (AgNPs) for the development of a highly selective and sensitive colorimetric method for the detection of Fe+2 in water samples. The optimization of various biogenic synthesis parameters showed ASE:AgNO3 ratio of 4:1,1 mM of AgNO3, pH 6 and incubation for 10 min at 70 °C were the optimum conditions. The test of antibacterial activity against widely used, representative Gram-negative and positive bacteria showed that AgNPs exhibit good activity against all five tested bacterial strains and comparatively were more effective against Gram-negative bacteria. Further, the test of AgNPs as a colorimetric probe for the detection of 20 different metal ions demonstrated that AgNPs were highly selective and sensitive towards the detection of Fe+2. The study of sensitivity of Fe+2 detection showed 245 ppm as the Limit of detection whereas, the intra-day recovery of Fe+2 in the range of 87.2-100.1 % with %RSD in the range of 4.2-6.5 % and inter-day recovery of Fe+2 in the range of 92.02-96.59 % with %RSD in the range of 2.9-3.8 % demonstrated the excellent precision and accuracy of the assay method. Thus, our AgNPs based selective and sensitive assay can be applied to the analysis of iron in drinking water samples.

Sources, Fraction Distribution and Health Risk Assessment of Selenium (Se) in Dashan Village, a Se-Rich Area in Anhui Province, China.

Soil, rock, potable water, animal food and human hair samples were collected from the Dashan village, a typical selenium (Se)-rich area of China. Se content and fraction distribution were determined to trace the source of soil Se and evaluate the potential health risk to humans. Total Se contents in soils ranged from 0.60 to 10.46 mg kg- 1. The fractions of soil Se followed the order: residual Se (R-Se) > organic-bound Se (O-Se) > acid soluble Se (A-Se) > exchangeable Se (E-Se) > water soluble Se (W-Se). Total Se contents in rocks ranged from 0.07 to 24.8 mg kg- 1. The dietary Se intake of local residents was estimated to be 261.2 µg day- 1 and hair Se content varied from 0.34 to 1.35 mg kg- 1, suggesting that the potential health risk should be concerned. Weathering of carbonaceous rock was speculated to be the primary source of soil Se according to the contents of Se in rocks, the distribution of Se in soil profiles and the relationships between Se and other elements in soils and parent rocks.

Uranium in drinking water: a public health threat.

Uranium (U) has no known essential biological functions. Furthermore, it is well known for its toxicity, radioactivity, and carcinogenic potency. Impacts on human health due to U exposure have been studied extensively by many researchers. Chronic exposure to low-level U isotopes (radionuclides) may be interlinked with cancer etiology and at high exposure levels, also kidney disease. Other important issues covered U and fertilizers, and also U in soils or human tissues as an easily measurable indicator element in a pathophysiological examination. Furthermore, phosphate fertilization is known as the important source of contamination with U in the agricultural land, mainly due to contamination in the phosphate rock applied for fertilizer manufacture. Therefore, long-term usage of U-bearing fertilizers can substantially increase the concentration of U in fertilized soils. It should also be noted that U is an active redox catalyst for the reaction between DNA and H2O2. This review is aimed to highlight a series on various hydro-geochemical aspects in different water sources and focused on the comparison of different U contents in the drinking water sources and presentation of data in relation to health issues.

Hydrazone chemistry mediated toehold strand displacement cascade and its application for 5-hydroxymethylfurfural analysis.

Hydrazone chemistry has been firstly explored as capturing mode for interface supported toehold strand displacement cascade (TSDC). The method has been further established for analysis of 5-hydroxymethylfurfural (HMF) based on hydrazone chemistry-mediated TSDC. HMF containing aldehyde group can be covalently captured by hydrazine group around magnetic bead through the formation of hydrazone bond, so as to inhibit the immobilization of hybrid duplex and the occurrence of TSDC. Thereby, HMF will cause the change of the fluorescence of modified magnetic bead. With simplicity, specificity, and sensitivity, the method has been successfully applied to analyze HMF in food samples. This paper gives a new insight to explore capturing mode for interface supported TSDC and the established method can be extended for analysis of saccharic derivatives.

Which Type of Water Is Recommended for Patients with Stone Disease (Hard or Soft Water, Tap or Bottled Water): Evidence from a Systematic Review over the Last 3 Decades.

PURPOSE OF REVIEW: The role of the mineral constituents in water and their role in kidney stone disease (KSD) have been a long-standing subject of debate. The aim of our systematic review was to evaluate the relevance of different types of water in stone disease. RECENT FINDINGS: Studies to date have had varying results regarding the importance of hardness of water which is mostly determined by its calcium content. Other elements including magnesium and bicarbonate also play a crucial role in prevention of renal stones. Patients with stone disease are provided varying advice due to a lack of consensus on the types of water recommended. Increased fluid intake prevents stone formation. Our review of the literature suggests that hard water and bottled mineral water might be helpful for calcium stone formers. High calcium content in them leads to hypercalciuria; however, other factors also influence stone formation and the overall impact seems to be a reduction in calcium stone formation. The mineral content varies across different water types but high magnesium and bicarbonate content in water is also recommended for kidney stone patients.

Evaluating the effect of dam construction on the phosphorus fractions in sediments in a reservoir of drinking water source, China.

It is widely acknowledged that dams affect sediment transport and water quality. To support water management of reservoirs, it is useful to explore how the fractions of phosphorus (P) in sediments were changed after the dam was built. The aim of this study was to assess the spatial and temporal trends of the P fractions in sediments from the Miyun Reservoir, a pivotal drinking water supply for Beijing City, the capital of China. Nine surface sediment samples, together with a sediment core, were collected. The concentrations of total P (TP) and their fractions were then determined by using a sequential extraction method. The results showed that the reservoir was classified into three areas spatially based on the TP concentrations, i.e., high (Baihe area), medium (transitional area), and low (Chaohe area) concentrations. The concentrations of iron-bound P (BD-P) and metal oxide-bound P (NaOH-P) were higher in the Baihe and Chaohe regions than those in the transitional area and tended to increase with water depth. Dam construction can lead to the concentrations of P increased in sediments and further increase the potential of internal P loadings. This study revealed the effect of dam construction on sedimentary P accumulation. The results will be helpful in better understanding the mobility and bioavailability of P in the aquatic ecosystem, which aim to achieve a more highly targeted environmental management for this important region.

Correlations of water iodine concentration to earlier goitre frequency in Sweden-an iodine sufficient country with long-term iodination of table salt.

BACKGROUND: Before iodination of Swedish table salt in 1936, iodine deficiency resulting in goitre and hypothyroidism was common. Sweden has become iodine sufficient, as shown in a national survey in 2007, proving its iodination fortification programme effective for the general population. The objective of this study was to collect drinking water from water treatment plants nationally and test if water iodine concentration (WIC) correlated to urinary iodine concentration (UIC) of school-aged children in a national survey 2007 to former goitre frequency in 1929 and to thyroid volume data in 2007. METHODS: In 2012, 166 treatment plants, located in 57% (166 of 290) of all Swedish municipalities, were asked to collect drinking water samples of approximately 10 ml. In 2007, tap water samples of the same volume were collected from 30 randomly selected schools for the national survey. Analysis of WIC was done in both treatment plants in 2012 (n = 166) and tap water in 2007 (n = 30). The correlation of WIC to the children's UIC and thyroid volume after iodination was tested based on data from the national survey in 2007. The association of WIC to former goitre frequency was tested based on pre-iodination data, derived from a map of goitre frequency drawn in 1929. RESULTS: The median WIC from water treatment plants was 4.0 µg/L (range 0-27 µg/L). WIC was similar in coastal and inland areas, for both ground and surface water. WIC correlated with historical goitre areas and was lower in the goitre areas than in non-goitre areas (p < 0.001). WIC in the same municipalities as the schools correlated with the UIC of children (p < 0.01), but not with their thyroid volume. CONCLUSIONS: WIC still contributes to iodine nutrition in Sweden, but iodination overrides the goitre effect.

Field Research on Mixing Aeration in a Drinking Water Reservoir: Performance and Microbial Community Structure.

Field research on the performance of pollutant removal and the structure of the microbial community was carried out on a drinking water reservoir. After one month of operation of a water-lifting aeration system, the water temperature difference between the bottom and the surface decreased from 9.9 to 3.1 °C, and the concentration of the dissolved oxygen (DO) in the bottom layer increased from 0 to 4.2 mg/L. The existing stratification in the reservoir was successfully eliminated. Total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) concentrations were reduced by 47.8%, 66.7%, and 22.9%, respectively. High-throughput sequencing showed that Proteobacteria, Bacteroides, and Actinomycetes accounted for 67.52% to 78.74% of the total bacterial population. Differences in the bacterial changes were observed between the enhanced area and the control area. With the operation of the water-lifting aeration system, the populations of bacteria of the main genera varied temporally and spatially. Principal component analysis pointed out a clear evolution in the vertical distribution of the microbial structure controlled by the operation of the aeration system. Permutational analysis of variance showed a significant difference in the microbial community (p < 0.01). Redundancy analysis showed that physical (water temperature, DO) and chemical environmental factors (Chl-a, TOC, TN) were the key factors affecting the changes in the microbial communities in the reservoir water. In addition, a hierarchical partitioning analysis indicated that T, Chl-a, ORP, TOC, pH, and DO accounted for 24.1%, 8.7%, 6.7%, 6.2%, 5.8%, and 5.1% of such changes, respectively. These results are consistent with the ABT (aggregated boosted tree) analysis for the variations in the functional bacterial community, and provide a theoretical basis for the development and application of biotechnology.

Source apportionment of micronutrients in the diets of Kilimanjaro,Tanzania and Counties of Western Kenya.

Soil, water and food supply composition data have been combined to primarily estimate micronutrient intakes and subsequent risk of deficiencies in each of the regions studied by generating new data to supplement and update existing food balance sheets. These data capture environmental influences, such as soil chemistry and the drinking water sources to provide spatially resolved crop and drinking water composition data, where combined information is currently limited, to better inform intervention strategies to target micronutrient deficiencies. Approximately 1500 crop samples were analysed, representing 86 food items across 50 sites in Tanzania in 2013 and >230 sites in Western Kenya between 2014 and 2018. Samples were analysed by ICP-MS for 58 elements, with this paper focussing on calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se), iodine (I), zinc (Zn) and molybdenum (Mo). In general, micronutrient supply from food groups was higher from Kilimanjaro,Tanzania than Counties in Western Kenya, albeit from a smaller sample. For both countries leafy vegetable and vegetable food groups consistently contained higher median micronutrient concentrations compared to other plant based food groups. Overall, calculated deficiency rates were <1% for Cu and Mo and close to or >90% for Ca, Zn and I in both countries. For Mg, a slightly lower risk of deficiency was calculated for Tanzania at 0 to 1% across simplified soil classifications and for female/males, compared to 3 to 20% for Kenya. A significant difference was observed for Se, where a 3 to 28% risk of deficiency was calculated for Tanzania compared to 93 to 100% in Kenya. Overall, 11 soil predictor variables, including pH and organic matter accounted for a small proportion of the variance in the elemental concentration of food. Tanzanian drinking water presented several opportunities for delivering greater than 10% of the estimated average requirement (EAR) for micronutrients. For example, 1 to 56% of the EAR for I and up to 10% for Se or 37% for Zn could be contributed via drinking water.

Amyotrophic lateral sclerosis incidence following exposure to inorganic selenium in drinking water: A long-term follow-up.

Some studies have reported an association between overexposure to selenium and risk of amyotrophic lateral sclerosis (ALS), a rare degenerative disease of motor neurons. From 1986 through 2015, we followed a cohort in Northern Italy that had been inadvertently consuming tap water with unusually high concentrations of inorganic hexavalent selenium from 1974 to 1985. We had previously documented an excess incidence of ALS in this cohort during 1986-1994. Here, we report extended follow-up of the cohort for an additional 21 years, encompassing 50,100 person-years of the exposed cohort and 2,233,963 person-years of the unexposed municipal cohort. We identified 7 and 112 incident ALS cases in the exposed and unexposed cohorts, respectively, yielding crude incidence rates of 14 and 5 cases per 100,000 person-years. A Poisson regression analysis, adjusting for age, sex and calendar year, produced an overall incidence rate ratio (IRR) for ALS of 2.8 (95% confidence interval (CI) 1.3, 6), with a substantially stronger IRR in 1986-1994 (8.2, 95% CI 2.7, 24.7) than in 1995-2015 (1.5, 95% CI 0.5, 4.7), and among women (5.1, 95% CI 1.8, 14.3) than men (1.7, 95% CI 0.5, 5.4). Overall, these results indicate an association between high exposure to inorganic selenium, a recognized neurotoxicant, and ALS incidence, with declining rates after cessation of exposure and stronger effects among women.

Fabrication of glucose-derived carbon-decorated magnetic microspheres for extraction of bisphenols from water and tea drinks.

Glucose-derived carbon-decorated magnetic microspheres were synthesized by an easy hydrothermal carbonization method and used as a high-efficiency adsorbent to extract bisphenols in water and tea drinks. The as-prepared carbon-decorated magnetic microspheres had a well-defined core-shell structure with a shell thickness of about 5 nm. The microspheres possessed high saturation magnetization at 60.8 emu/g and excellent chemical stability in aqueous solution. The experimental parameters affecting the extraction efficiency, including extraction time, pH, adsorbent dosage, desorption solvents, desorption time, and solution volume were evaluated. Electrostatic and π-π interactions were the major driving forces during extraction. Overall, a new magnetic solid-phase extraction method of determining bisphenols was developed on the basis of as-prepared magnetic microspheres. The method had a wide linear range, low limits of detection (0.03-0.10 µg/L), and high recoveries (85.4-104.6%).

Effect of water source and feed regime on development and phenotypic quality in Anopheles gambiae (s.l.): prospects for improved mass-rearing techniques towards release programmes.

BACKGROUND: In many malaria-endemic sub-Saharan countries, insecticide resistance poses a threat to existing mosquito control measures, underscoring the need for complementary control methods such as sterile and/or genetically-modified mosquito release programmes. The sibling species Anopheles gambiae and An. coluzzii are responsible for malaria transmission in most of this region. In their natural habitat, these species generally breed in clean, soft water and it is believed that divergent preference in their larval breeding sites have played a role in their speciation process. Mosquito release programmes rely on the rearing of mosquitoes at high larval densities. Current rearing protocols often make use of deionised water regardless of the strain reared. They also depend on a delicate balance between the need for adequate feeding and the negative effect of toxic ammonia and food waste build-up on mosquito development, making managing and improving water quality in the insectary imperative. METHODS: Here, we investigated the impact of water source and feed regimes on emergence rate and phenotypic quality of mosquitoes in the insectary. First-instar larvae of An. gambiae (Kisumu strain) and An. coluzzii (Mopti and VK3 strains) were reared in three water sources with varying degrees of hardness (deionised, mineral and a mix of the two), with a daily water change. Larvae were fed daily using two standardised feeding regimes, solution and powder feed. RESULTS: Water source had a significant impact on mosquito size and development time for all strains. Earlier emergence of significantly larger mosquitoes was observed in mineral water with the smallest mosquitoes developing later from deionised water. Wing-length was significantly longer in mineral, mixed water and in powder feed, irrespective of sex, strains or water types. Deionised water was the least favourable for mosquito quality across all strains. CONCLUSIONS: Mineral water and powder feed should be used in rearing protocols to improve mosquito quality where the optimal quality of mosquitoes is desired. Although results obtained were not significant for improved mosquito numbers, the phenotypic quality of mosquitoes reared was significantly improved in mineral water and mix water. Further studies are recommended on the impact mineral water has on other fitness traits such as longevity, fecundity and mating competitiveness.