Accepted World Health Organization Research Articles

Wastewater treatment from a typical multisystem hospital using chemically modified banana peels: Taguchi parametric optimization and characterization

The study aims to develop an eco-friendly solution for addressing contaminants in hospital wastewater. To achieve this, banana peel, a cost-effective and easily available agricultural waste, was chemically modified using sulfuric acid and sodium hydroxide. The hospital wastewater was analyzed using an Atomic Absorption Spectrometer to identify the presence of heavy metals. The physicochemical properties were measured and compared against the standards set by the World Health Organization (WHO). Scanning electron microscopy and Fourier-transform infrared spectroscopy were used to characterize the chemically modified banana peel. Batch adsorption was conducted with the wastewater using the prepared adsorbent. The effect of contact time, mixing rate, temperature, and adsorbent dosage was examined to know the removal efficiency of the adsorbent. The experimental design incorporates Taguchi OA design to optimize the process. The total heavy metals discovered in the wastewater were As, Cd, Fe, Cu, Ni, Cr, Pb, Mn and Zn. The percentage of Cd, Fe, Cu, Ni, Cr and Pb removed were 79.5%, 87.9%, 56.9%, 89.0%, 88.5% and 93.5%, respectively, at temperature, adsorbent dosage, mixing rate and contact time of 30 °C, 3 g, 700 rpm and 60 min, respectively. The physicochemical properties remain within the acceptable WHO range except the turbidity. At optimum point, the percentage removal of Cd, Fe, Cu, Ni, Cr, Pb and Zn were 64.3%, 80.5%, 51.4%, 82.3%, 72.4%, 86.6% and 72.1%, respectively; while, the conductivity, pH, TDS, and turbidity value were, respectively, 20.57 mS/cm, 6.8, 10.16 mg/l, and 86.31 NTU. Characterization revealed the existence of active functional groups on the adsorbent surface enhancing the hospital wastewater treatment and change in its morphological structure after the treatment was noticed. In conclusion, the modified banana peel was effective for the treatment of hospital wastewater.

Assessment of Groundwater Quality in Owerri and Its Environments, Southeast Nigeria

Physico-Chemical and bacteriological characteristics of eleven boreholes located within Owerri city were examined. The bacteriological analyses were carried out using the method of inoculation and incubation of specimens and counted on colonies. Titration method was used to determine chlorides and nitrates while Cu2+, Zn2+ and Mn2+ used atomic absorption spectroscopy (AAS). Iron concentration was read off using benzylideneacetone (BDA) Lovibondcolour comparator while the total dissolved solids were determined gravimetrically. The water is usually clear at average temperature of 27˚C. The bacteriological parameters are within the acceptable World Health Organization (WHO) standard and safe for human consumption. The pH is 6.0 -7.5, total dissolved solids vary from 12.4mg/l to 49.4mg/l. The anions of chloride and nitrate are 67mg/L to 125mg/L and 0.003 mg/L to 23.1 mg/L respectively. Concentrations of cations include iron; 1.86mg/l, copper; 1.2mg/l, zinc; 2.1mg/l and manganese; 0.05mg/l. The results show that the groundwater within the city is suitable for drinking and other uses compared to the WHO standard. The environmental conditions of the borehole locations as well as the total drill depth should be emphasized. Government monitoring agency should ensure adequate drill depth to at least 200ft in the south- western area and north- eastern areas from 250ft to 300ft as this may reduce the injurious variations in the geochemical parameters in some boreholes.

Semen parameter variability among users of at-home sperm testing kits

BackgroundDespite the generally accepted World Health Organization guidelines on semen analysis, an individual’s results can display significant variation when performed across time or in different laboratories. Semen parameters are in fact highly variable measures that can differ significantly between various analyses. Numerous researchers have discovered a wide range of semen parameters within each individual male, but only a few studies included the analysis of semen parameters variability in patients with infertility. The aim of this study was to evaluate the inter- and intra-individual variability of semen parameters in men of reproductive age with normozoospermia and those with oligozoospermia.MethodsFive hundred and thirteen who provided ≥ 2 semen samples (798 samples in total) using an at-home mail-in kit over a period of about 2 years were enrolled in the study. Semen samples collection using Give Legacy at-home mail-in semen collection kit; semen analysis at a CLIA-certified laboratory.ResultsThe degree of intra-subject variation across all semen parameters was lower in men with normozoospermia compared to men with oligozoospermia. Men with normozoospermia furthermore demonstrated a level of intra-subject variation that was lower than inter-subject variation across all measured parameters. No association was observed between intra-subject coefficients of variation in any of the semen parameters, including sperm concentration, sperm count, motile sperm count, total motility, progressive motility, the percentage of sperm with normal morphology, and the age, duration of abstinence, and BMI of the men.ConclusionThe results of this observational study confirm the significant variability in semen parameters in men with normozoospermia and oligozoospermia, as measured from at-home semen collection kit samples. This further underscore the importance of securing multiple samples for analysis to provide a robust assessment of male fertility.

COVID-19 vaccine trials: The use of active controls and non-inferiority studies.

Background:Recently emerging results from a few placebo-controlled randomized trials of COVID-19 vaccines revealed estimates of 62%–95% relative reductions in risk of virologically confirmed symptomatic COVID-19 disease, over approximately 2-month average follow-up period. Additional safe and effective COVID-19 vaccines are needed in a timely manner to adequately address the pandemic on an international scale. Such safe and effective vaccines would be especially appealing for international deployment if they also have favorable stability, supply, and potential for implementation in mass vaccination campaigns. Randomized trials provide particularly reliable insights about vaccine efficacy and safety. While enhanced efficiency and interpretability can be obtained from placebo-controlled trials, in settings where their conduct is no longer possible, randomized non-inferiority trials may enable obtaining reliable evaluations of experimental vaccines through direct comparison with active comparator vaccines established to have worthwhile efficacy.Methods:The usual objective of non-inferiority trials is to reliably assess whether the efficacy of an experimental vaccine is not unacceptably worse than that of an active control vaccine previously established to be effective, likely in a placebo-controlled trial. This is formally achieved by ruling out a non-inferiority margin identified to be the minimum threshold for what would constitute an unacceptable loss of efficacy. This article not only investigates non-inferiority margins, denoted by δ, that address the usual objective of determining whether the experimental vaccine is “at least similarly effective to” the active comparator vaccine in the non-inferiority trial, but also develops non-inferiority margins, denoted by δo, intended to address the worldwide need for multiple safe and effective vaccines by satisfying the less stringent requirement that the experimental vaccine be “at least similarly effective to” an active comparator vaccine having efficacy that satisfies the widely accepted World Health Organization–Food and Drug Administration criteria for “worthwhile” vaccine efficacy.Results:Using the margin δ enables non-inferiority trials to reliably evaluate experimental vaccines that truly are similarly effective to an active comparator vaccine having any level of “worthwhile” efficacy. When active comparator vaccines have efficacy in the range of 50%–70%, non-inferiority trials designed to use the margin δo have appealing properties, especially for experimental vaccines having true efficacy of approximately 60%.Conclusion:Non-inferiority trials using the proposed margins may enable reliable randomized evaluations of efficacy and safety of experimental COVID-19 vaccines. Such trials often require approximately two- to three-fold the person-years follow-up than a placebo-controlled trial. This could be achieved, without substantive increases in sample size, by increasing the average duration of follow-up from 2 months to approximately 4–6 months, assuming efficacy of the active comparator vaccine has been reliably evaluated over that longer duration.

Evaluation of vermifiltration of cassava effluent using earthworm

The objective of this study was to evaluate the vermifiltration of different cassava effluent concentrations using of earthworms by applying standard methods. Results for physiochemical parameters before treatment ranges from 3. 91 to 5.94, 28.6to 28.7(μS/cm), 12480 to 13999 (mg/l), 7900 to 9511(mg/l), 168 to 207(mg/l), 8068 to 9718(mg/l), 225 to 284(mg/l), 114 to 132(mg/l), 1040 to 1680(mg/l), 400 to 540(mg/l), 52 to 72(mg/l), 24 to 40(mg/l), 20 to 30(mg/l), 33 to 65(mg/l) for pH, Temperature, EC, TDS, TSS, TS, COD, BOD, Hardness, chlorine, calcium, magnesium, sodium and potassium, respectively, while after treatment ranges from 6.45 to 10.1, 28.6 to 29, 12021 to 12621(μS/cm), 8100 to 9846(mg/l), 199 to 211(mg/l), 8299 to 10057(mg/l), 260 to 291(mg/l), 140 to 120(mg/l), 760 to 1160(mg/l), 260 to 440(mg/l), 48 to 62(mg/l), 22 to 39(mg/l), 19 to 28(mg/l), 31 to 60(mg/l) for pH, Temperature, Electrical Conductivity (EC), TDS, TSS, TS, COD, BOD, Hardness, Chlorine, Calcium, Magnesium, Sodium and Potassium, respectively, across the different concentrations (100%, 75%, 50% and 25%) of cassava effluent. It was therefore, observed that the use of earthworm in the treatment of cassava effluent was effective, though, it could not treat the cassava effluent to the acceptable World Health Organization (WHO) Standards for irrigation use. Keywords: physiochemical characteristics, cassava, effluent concentrations, vermifiltration

Iron Depletion, Iron Deficiency, and Iron Deficiency Anaemia Among Children Under 5 Years Old in Kilimanjaro, Northern Tanzania: A Hospital-Based Cross-Sectional Study

Background: Iron depletion results from reduced iron stores, and it is an early stage of disease progression before iron deficiency, which leads to iron deficiency anaemia (IDA). IDA is associated with delayed infant growth and development, diminished cognitive function, poor academic performance, decreased exercise tolerance, and impaired immune function. This study aimed to determine the prevalence of iron depletion and IDA and factors associated with low ferritin levels among children under 5-years-old receiving care at Kilimanjaro Christian Medical Centre (KCMC) in Moshi, Tanzania. Methods: Under-5 children presenting at KCMC were successively enrolled and screened for iron depletion and IDA using complete blood count and serum ferritin levels. The generally accepted World Health Organization cut‑off levels for normal haemoglobin (Hb) and ferritin level were used. Iron depletion, iron deficiency, and IDA prevalences were estimated in relation to the combination measures of haemoglobin, mean corpuscular volume, and ferritin levels. Dietary and sociodemographic characteristic of the children were recorded after parents or caretakers provided informed consent. Data analysis was conducted using SPSS version 21.0. Results: A total of 303 children aged 2 to 59 months were enrolled in the study. Anaemia was detected in169 (55.8%) children. Children aged 2 to 12 months had a higher prevalence of anaemia (n=101, 60.1%). The overall prevalences of iron depletion, iron deficiency with no anaemia, and IDA were 2.6% (n=8), 9.6% (n=29), and 28.1% (n=84), respectively. Low ferritin levels were detected in 124 (40.9%) children. Drinking more than 500 ml of cow's milk per day was associated with an increased risk of anaemia (adjusted odds ratio [AOR] 5.6; 95% confidence interval [CI], 2.6 to 12.1) relative to those not drinking cow's milk. Children whose families had meals that included beef more than 3 times per week were less likely to have low ferritin (AOR 0.6; 95% CI, 0.3 to 1.3), though the difference was not significant. Conclusion: The IDA prevalence among children in the Kilimanjaro area was high, with more than 50% of infants being anaemic. Drinking cow's milk was associated with an increased risk of IDA. Future community-based research is recommended to elucidate more details about iron deficiency in the general population.

Iron Depletion, Iron Deficiency, and Iron Deficiency Anaemia Among Children Under 5 Years Old in Kilimanjaro, Northern Tanzania: A Hospital-Based Cross-Sectional Study.

Background:Iron depletion results from reduced iron stores, and it is an early stage of disease progression before iron deficiency, which leads to iron deficiency anaemia (IDA). IDA is associated with delayed infant growth and development, diminished cognitive function, poor academic performance, decreased exercise tolerance, and impaired immune function. This study aimed to determine the prevalence of iron depletion and IDA and factors associated with low ferritin levels among children under 5-years-old receiving care at Kilimanjaro Christian Medical Centre (KCMC) in Moshi, Tanzania.Methods:Under-5 children presenting at KCMC were successively enrolled and screened for iron depletion and IDA using complete blood count and serum ferritin levels. The generally accepted World Health Organization cut-off levels for normal haemoglobin (Hb) and ferritin level were used. Iron depletion, iron deficiency, and IDA prevalences were estimated in relation to the combination measures of haemoglobin, mean corpuscular volume, and ferritin levels. Dietary and sociodemographic characteristic of the children were recorded after parents or caretakers provided informed consent. Data analysis was conducted using SPSS version 21.0.Results:A total of 303 children aged 2 to 59 months were enrolled in the study. Anaemia was detected in169 (55.8%) children. Children aged 2 to 12 months had a higher prevalence of anaemia (n=101, 60.1%). The overall prevalences of iron depletion, iron deficiency with no anaemia, and IDA were 2.6% (n=8), 9.6% (n=29), and 28.1% (n=84), respectively. Low ferritin levels were detected in 124 (40.9%) children. Drinking more than 500 ml of cow's milk per day was associated with an increased risk of anaemia (adjusted odds ratio [AOR] 5.6; 95% confidence interval [CI], 2.6 to 12.1) relative to those not drinking cow's milk. Children whose families had meals that included beef more than 3 times per week were less likely to have low ferritin (AOR 0.6; 95% CI, 0.3 to 1.3), though the difference was not significant.Conclusion:The IDA prevalence among children in the Kilimanjaro area was high, with more than 50% of infants being anaemic. Drinking cow's milk was associated with an increased risk of IDA. Future community-based research is recommended to elucidate more details about iron deficiency in the general population.

Rural Assessment of Groundwater Quality Parameters: A Case Study of Pepel Northern Sierra Leone

Majority of the population in Pepel depend on groundwater for domestic and other purposes. However, in spite of the high potential of groundwater in this region and the number of boreholes drilled by Aid Agencies, study reveals that there is still a serious problem with adequate availability and quality of groundwater supply. Watersamples from 35 selected borehole wells were collected from June – September 2016. Water samples were collected from each well for quality analyses within Pepel, Port Loko districts for Physicochemical and bacteriological analysis. The parameters tested are pH, Temperature, Color, Total Dissolved Solid, Conductivity,Calcium, Nitrate, Manganese, Chloride, Fluoride, Iron, Copper, Turbidity and Sulfate. The result obtained was compared with World Health Organization (WHO) standards for water quality. Results have shown that boreholes in Pepel have high average yield of (2.04 m3/hr. The productivity of the boreholes in Pepel cansupply enough water to the locals in the area and that most of the physical parameters are within acceptable WHO limits for drinking water quality. The entire water samples that were analyzed for chemical parameters indicated that the samples did not exceed the acceptable WHO limits. More than half of the borehole watersamples 19 (54 %) out 35 boreholes showed lower pH values that are below WHO recommended pH limits of 6.5-8.5, while 17 (46% ) out 35 boreholes fall within WHO recommended pH limits. This shows that many of the sample borehole waters from the study areas indicated a tendency to towards acidity. Thus, these water sources are acidic. The acidity of water may be attributed to marshy and sandy sulphate soils. Acids lower pH and bases increase pH of water. Fluctuation in pH reflects the biological activity and changes in the natural chemistry of waters, as well as pollution. However, 67% of the wells yielded water of good bacteriological quality.

Groundwater Monitoring in the Gneisso-Basaltic Fractured Rock Aquiferous Formations of Kumba, Southwest Region Cameroon: Seasonal Variations in the Aqueous Geochemistry and Water Quality

The objective was to determine and monitor seasonal changes during four hydrological seasons: Wet season (September), Wetdry season (December), Dry season (March) and Drywet season (June) in the groundwater aqueous geochemistry and its domestic-agro-industrial quality using physicochemical parameters and hydrogeochemical tools: Temperature, Electrical Conductivity EC, pH, Total dissolved solids TDS, Ionic ratios, Gibbs diagrams, Piper diagrams Durov diagrams, total hardness HT, Water quality index WQI, Sodium adsorption ratio SAR, Percent Sodium %Na, Kelly’s Ratio KR, permeability index PI, Magnesium adsorption ratio MAR, Residual sodium carbonate RSC and Wilcox diagram. Field physicochemical parameters ranged from: Wet season; pH 3.9 - 6.9; Temperature, 23.3°C - 29.1°C; EC, 10 - 1900 μS/cm; TDS, 6.7 - 1273 mg/L; Wetdry, pH, 5.7 - 11.7; Temperature, 23.6°C - 28.3°C; EC, 1 - 1099 μS/cm, TDS, 0.67 - 736.33 mg/L; Dry pH, 5.7 - 13.1; Temperature, 26.3°C - 30.2°C; EC, 12 - 770 μS/cm, TDS, 8.04 - 515.9 mg/L and Drywet, pH, 4 - 7.4; Temperature, 25.8°C - 30.7°C; EC, 10 - 1220 μS/cm, TDS, 6.7 - 817.4 mg/L. Seventy-two groundwater samples, 18 per season were analysed. All ionic concentrations fell below acceptable World Health Organization guidelines in all seasons. The sequence of abundance of major ions are; Wet, Ca+ > Mg2+ > Na+ = K+ > NH4+, HCO3? > Cl? > NO3? > SO42? > HPO42?; Wetdry Ca+ > K+ > Mg2+ > Na+ > NH4+, HCO3? > Cl? > SO42? > NO3? > HPO42?; Dry Ca+ > K+ > Mg2+ > Na+ > NH4+, HCO3? > Cl?> NO3? > SO42? > HPO42?; Drywet NH4+ > Ca+ > K+ > Mg2+ > Na+; Cl? > HCO3? > NO3? > SO42? > HPO42?. Groundwater ionic content was due to rock weathering and ion exchange reactions. CaSO4 is the dominant water type in Wet and Wetdry seasons; followed by CaHCO3, Na + K-Cl Wet, CaSO4 and CaHCO3 Wetdry; MgCl Dry and Drywet followed by CaCl, CaHCO3 Dry and CaSO4, CaHCO3 Dry-Wet. The dominant hydrogeochemical facies are Ca-Mg-Cl-SO4 followed by Na-K-SO4 Wet and Ca-Mg-HCO3? in all other seasons. Ion exchange, Simple dissolution and uncommon dissolution are the processes determining groundwater character. The water quality indices; WQI, HT, SAR, %Na, KR, PI, MAR,RSC and Wilcox diagrams, indicate that groundwater in Kumba is 80% - 100% excellent during the Drywet &Wet seasons, 5% - 10% unsuitable during the Wetdry & Dry seasons for domestic use while being excellent-good for Agro-Industrial uses in all other seasons. Physicochemical parameters in some areas exceeded permissible limits for drinking. All hydrogeochemical parameters vary with seasons and these variations show the impact of annual cycles of seasonal changes on the aqueous geochemistry of groundwater in Kumba.

English

This study seeks to assess the bacteriological, physicochemical and some trace metals levels in water samples from seven boreholes and a hand-dug well within communities of Golden Star Wassa Mine Limited in Ghana. Five of the sampling sites were slightly acidic and were below the lower limit of the acceptable World Health Organization (WHO) and Ghana Standard Authority (GSA) permissible guidelines for pH. However, sampling from Kubekro well BH04, Akyempim BH07 and at New Akosombo BH06 reported pH mean of 6.9±0.352, 6.7±0.696 and 6.6±0.283, respectively. Well BH02 and that of BH06, respectively reported True Colour mean values of 36.5±6.097 and 17.4±1.930 true colour units (TCU) which were above the WHO/GSA permissible value of 15 TCU. Electrical conductivity, total dissolved solids (TDS), alkalinity, and total hardness were below their respective WHO/GSA permissible limits in the sampling sites with 100% compliance. Pb, Zn, As, Hg, Cu, and Fe recorded a marginal degree of non-compliance with their respective WHO/GSA guideline values of 0.01 mg/L for Pb, 3.0 mg/L for Zn, 0.01 mg/L for As, 0.006 mg/L for Hg and 0.3 mg/L for Fe in all the sampling sites except Cu. All the boreholes indicated a non-detectable microbial load (total coliforms and Escherichia coli) except the hand-dug well at Kubekro Well (BH02) which showed some amount of total coliform bacteria load of 6±6.594 coliforms forming unit (CFU). The mechanised borehole groundwater sources within the study area, except the well at BH02 is good for drinking, and hence have not been adversely impacted by mining operations baring the continuous impoundment of the gold processing tails or slurry. Key words: Groundwater, physicochemical, microbial and trace metal parameters, sampling sites.

Point-of-Use Water Filtration for Arsenic: A Sustainable and Simple Solution in Resource-Poor Settings

Lack of access to potable drinking water due to contamination from harmful metals is one of the most pressing public health issues globally. In areas close to mining and smelting operations, significant contamination from arsenic and other harmful metals can compound contamination from harmful microorganisms in drinking water. In response to this dual hazard, this study tests a prototype design of an improved point-of-use water filter for resource-poor areas and exposed populations. This project builds upon previous research that has demonstrated the effectiveness of clay pot filters impregnated with silver in reducing coliform bacteria. A compatible attachment comprised of activated charcoal in the form of bone char was added to the clay pot filter with the purpose of enabling the combined filter system to remove arsenic. The experiment tested the designed attachment with source water having an arsenic concentration of 500 parts per billion (ppb) to investigate the combined filter’s ability to reduce the arsenic to acceptable World Health Organization drinking water standards of 10 parts per billion or below. The results demonstrate a significant decrease in the arsenic concentration to below the 10 ppb standard with the bone char attachment, as well as a decrease in the arsenic concentration with the clay pot filter alone. These results warrant further investigation into the potential for clay pot filters with a charcoal layer to reduce arsenic concentrations in drinking water and demonstrate a potential additional benefit in arsenic removal by utilizing inexpensive bone char material in conjunction with the clay pot filter.

Audit of visual outcome of cataract surgeries in a private eye hospital in Port Harcourt, Nigeria

Aim: The aim was to determine the quality of cataract surgeries in Port Harcourt, and ascertain the difference in the outcome, if any, between small incision cataract surgery (SICS) and extra capsular cataract extraction (ECCE). Materials and Methods: This is a retrospective study carried out in a Private Eye Hospital in Port Harcourt between August 2006 and November 2012. Case notes of 83 consecutive patients (92 eyes) who had either SICS OR ECCE with posterior chamber intraocular lens (PCIOL) were included in the study. Demographic data and data concerning ocular and systemic co-morbidities were retrieved from patients' case notes. Best-corrected visual acuity was measured with Snellen's chart preoperatively, and 6 weeks following surgery. The visual outcome was categorized, using the World Health Organization (WHO) recommendation, as good (>6/18), borderline (6/24-6/60), or poor (<6/60). Statistical software package Epi-info version 6.04d was used to analyze our data. Result: A total of 92 eyes of 83 patients who had cataract surgeries was included in the study. Sixty-seven eyes (73%) had ECCE + intraocular lens (IOL) while 25 eyes (27%) had SICS + IOL. At 6 weeks postoperative, 66.3% of cases had good visual outcome while about 9.8% of cases had a poor outcome. Conclusion: Since only 66.3% of cases had good visual outcome and 9.8% had poor outcome, cataract surgical outcome in Port Harcourt is below the acceptable WHO standards of >85% and <5% for good and poor outcomes respectively. Steps to improve good outcome will include proper postoperative hygiene of patients, good preoperative evaluation of all cases, and improvement in surgeons' skills. Good visual outcome was associated more with ECCE (71.7% of 67 eyes) than SICS (52% of 25 eyes) probably due to inadequate experience of the surgeons in SICS. This difference was, however, not statistically significant.

Preliminary Assessment of Physicochemical Properties of Borehole Water in the vicinity of Public Health Facilities in Nasarawa State, Nigeria

Water samples were collected from boreholes in the vicinity of public health facilities in Nasarawa State, Nigeria, for the evaluation of physicochemical parameters, using standard methods. Water pH from Keana was acidic (6.01 - 6.91), except at Chiata (9.34). pH values at Kuru (10.15) in Toto, Zalli (10.61) in Wamba, MCWC Obi (10.03) at Obi and Jangwa (10.31) in Awe were above the World Health Organization (WHO) permissible limits, so also nitrate contents in Ayele (11.04 mg/l) at Nasarawa, Chiji (12.14 mg/l) in Toto, Karmo (12.14 mg/l) in Toto, Main Market (12.02 mg/l) at Keffi, Sabo Gari (12.04 mg/l) at Keffi, Angiri (12.06 mg/l) in Lafia, Ugah (13.02 mg/l) in Lafia, and Agwa Sule (13.05 mg/l) in Obi. The highest and the lowest conductivity (EC) values were recorded in borehole water from Nasarawa and Kokona respectively, while the highest phosphate content was recorded at Agyemo in Doma. The hardness level of water was highest at Karu and lowest in Doma, while alkalinity at Toto was highest, and lowest in Keffi. TDS, EC, alkalinity and total hardness levels were within the acceptable WHO and Standard Organization of Nigeria (SON) standards for ground water, which suggested that water from the boreholes were safe.

Context Is Paramount in the Assessment of Meta‐analytical Evidence: Reply

We appreciate Cavallin et al. [1] commenting on ourmanuscript. They remark that our study selection demon-strates heterogeneity in body mass index (BMI) groupswith regard to (1) clinical outcomes and (2) diseasepathology, emphasizing these limitations as ‘‘weak points.’’In our study we aimed at deriving the best possibleevidence from the available studies in the literature toinform clinical practice. As a result, we applied the inter-nationally accepted World Health Organization classifica-tion for categorizing obese and non obese patientsaccording to body mass index above and below 30 kg/m

Detection of ocular disease by a vision-centre technician and the role of frequency-doubling technology perimetry in this setting

AimTo document the detection of significant ocular pathology by a vision-centre technician in an emerging economy World Health Organization recommended eye care delivery setting, and determine whether a frequency-doubling perimeter...

Is the NHANES III Femoral Neck Database Discordant With the Total Hip and Trochanteric Region Databases?

The results of dual-energy X-ray absorptiometry (DXA) testing frequently leads to a significant clinical treatment decision, based on T-score or Z-score results. Using the nearly universally accepted World Health Organization (WHO) criteria, which in turn are based on the validity of the population database, a flawed database may lead to an incorrect and deleterious clinical categorization. We have observed that the Hologic National Health and Nutrition Examination Survey III (NHANES III) femoral neck scores are frequently disproportionately low compared with scores in the other major hip regions and that the discordance is statistically significant. Although the WHO now uses the femoral neck T-score (in postmenopausal women and men 50 yr or older), many clinicians still use the lowest (worst) T-score in any 1 of 3 major scan regions—femoral neck, total hip, or lumbar spine—suggesting that patient misclassification may occur, leading to the potential for unnecessary pharmacologic intervention.

Heavy metals pollution profiles in streams serving the Owabi reservoir

Water samples from five sampling points on four rivers, Owabi, Akyeampomene, Pumpunase and Sukobri, representing the main streams serving the Owabi reservoir were analysed for some pollution indicators using standard methods. Heavy metals (Zn, Cu, Mn, Cu, Pb and As) concentrations and some physical parameters of the water samples were determined. Electrical conductivity and pH of waters from all the streams were found to be within the acceptable limits of the World Health Organization (WHO). All the streams showed high turbidity values above WHO limits. Of the heavy metals determined in the water samples, Fe, Mn, Zn and Cu concentrations in all the streams were within the acceptable WHO limits, whiles Pb and As appeared to be higher than the acceptable limits in all the streams. The highest concentrations of most of the heavy metals were recorded at the Kronum site on Owabi stream. There was a statistically significant positive correlation between pH and some metals at all the sample points (p = 0.05). The results showed that all the streams were polluted and must be treated before consumption. It was also recommended that, human activities within the catchments should be monitored closely to minimise their polluting impacts on the water quality. Key words : Heavy metals, Owabi, pollution, water quality, WHO.

The prevalence of low vision and blindness in Canada

The purpose of this study was to ascertain the prevalence and primary causes of visual impairment in a representative Canadian population. We reviewed a representative sample of patients who attended ophthalmologists' offices in a medium-sized Canadian city between 1996 and 2001 in order to estimate the prevalence of visual impairment. Demographic data, visual diagnoses, best-corrected visual acuities (BCVA), and visual field information were recorded. Visual status was categorized based on accepted World Health Organization (WHO) and North American criteria. Population data were obtained from the Canadian census. The prevalence of low vision and blindness in our population was 35.6 and 3.8 per 10 000 individuals, according to the WHO classification, and 71.2 and 23.6 per 10 000 individuals, using the North American definition. Among individuals with some vision loss (vision worse than 20/40), cataract and visual pathway disease were the most common causes, together accounting for 40% of visual impairment. Age-related macular degeneration and other retinal diseases were the next most common causes of vision loss. Diabetic retinopathy and glaucoma were less frequently encountered as causes of visual impairment. The overall prevalence of low vision and blindness in Canada are in keeping with data from large population-based studies from other developed nations. Cataract, visual pathway disease, and macular degeneration are the leading causes of visual impairment. These results are important for enhancing our understanding of the scope of vision health in Canada and may direct future health planning and cost-utilization research.

Misinterpretation of Osteodensitometry With High Bone Density

Osteodensitometry is increasingly used to identify low bone density resulting from osteoporosis. The universally accepted World Health Organization (WHO) criteria for assessing bone mineral density (BMD) contrasts individual T-scores to peak BMD in healthy adult control populations. In this scheme, "osteoporosis" refers arbitrarily to T-values below -2.5, "osteopenia" to values between -1.0 and -2.5, and "normal" to values above -1.0. Although individually rare, numerous conditions cause supranormal BMD in children and adults. Increasingly, elevated BMD is detected by osteodensitometry, especially dual-energy X-ray absorptiometry. Illustrated here, the absence of upper limits for BMD in the WHO criteria jeopardizes recognition of high-BMD disease for all age groups. This oversight requires correction using Z-scores.

Results of treatment of hyperlipidemias; short term effect on cholesterol metabolism.

There has been a recent tendency to reduce the different forms of hyperlipidemia to fewer categories and to attempt a more unified approach to the dietary management of the hyperlipidemias(l). There is some justification for this approach, but the H.G.H.McMaster Lipid Research Clinic still uses the internationally accepted World Health Organization classification(2) based on Fredrickson et al. This is because we believe that this classification of hyperlipoproteinemia(HLP) with, all its imperfections has etiological, genetic, epidemiological, diagnostic and therapeutic potential. It should be remembered that in all 5 types of hyperlipoproteinemia that plasma cholesterol levels may be elevated, although this is most commonly seen in types IIa and b, III and IV HLP. The majority of this discussion will be devoted to the one parameter namely plasma lipids, which are routinely measured in the Lipid Clinic. No attempt will be made to elaborate on other important cholesterol pools--the liver, the intestine and its contents, adipose tissue and other tissue stores.