Sludge accumulation in an anaerobic pond and viability of helminth eggs: a case study in Burkina Faso

Accumulation rates and pathogen concentrations in primary stabilization pond sludges in developing countries are important parameters for adequate sludge management and the safeguarding of public health with sludge reuse in agriculture. An anaerobic pond has been investigated for sludge accumulation rates and helminth egg viability after four years of operation in Burkina Faso. The rate of sludge accumulation was measured at 0.037 m3/capita-year or 2.26 kg dry weight/capita-year. An equation describing vertical distribution of total solids in the accumulated sludge was found to be adequately represented by a regression equation. Influent helminth egg concentrations were reduced on average by 90% in the anaerobic pond effluent. Ascaris lumbricoides and Ancylostoma sp. were the most common eggs present in the sludge after four years of operation. The average concentration of helminth eggs in pond sludge was 536 eggs/g TS, and the percentages of viability ranged from 10.8% (47 viable eggs/g TS) to 57.2 (1,772 viable eggs/g TS, with an average rate of 36% (336 viable eggs/g TS). From a sludge depth and section study, egg viability was found to be randomly distributed in the sludge layer.

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A Multi-Site Time Series Study of Hospital Admissions and Fine Particles: A Case-Study for National Public Health Surveillance

PsycEXTRA Dataset ◽

10.1037/e519172012-018 ◽

2007 ◽

Author(s):

Francesca Dominici

Keyword(s):

Public Health ◽

Time Series ◽

Public Health Surveillance ◽

Fine Particles ◽

Hospital Admissions ◽

Health Surveillance ◽

Time Series Study ◽

National Public Health ◽

Series Study

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Viability of nematode eggs in high rate algal ponds: the effect of physico-chemical conditions

Water Science & Technology ◽

10.2166/wst.2000.0683 ◽

2000 ◽

Vol 42 (10-11) ◽

pp. 371-374 ◽

Cited By ~ 8

Author(s):

S. Araki ◽

J. M. González ◽

E. de Luis ◽

E. Bécares

Keyword(s):

Hydraulic Retention Time ◽

Pilot Scale ◽

High Rate ◽

Sterile Water ◽

Egg Viability ◽

High Rate Algal Ponds ◽

Helminth Eggs ◽

Physico Chemical ◽

Nematode Eggs ◽

Chemical Conditions

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

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Identifying Public Health Problems

10.1093/oso/9780190681050.003.0005 ◽

2018 ◽

Author(s):

Scott Burris ◽

Micah L. Berman ◽

Matthew Penn, and ◽

Tara Ramanathan Holiday

Keyword(s):

Public Health ◽

Health Problems ◽

Health Priorities ◽

Disability Adjusted Life Years ◽

Quality Adjusted Life Years ◽

Disability Adjusted Life ◽

Life Years ◽

Study Designs ◽

Quality Adjusted Life

Chapter 5 discusses the use of epidemiology to identify the source of public health problems and inform policymaking. It uses a case study to illustrate how researchers, policymakers, and practitioners detect diseases, identify their sources, determine the extent of an outbreak, and prevent new infections. The chapter also defines key measures in epidemiology that can indicate public health priorities, including morbidity and mortality, years of potential life lost, and measures of lifetime impacts, including disability-adjusted life years and quality-adjusted life years. Finally, the chapter reviews epidemiological study designs, differentiating between experimental and observational studies, to show how to interpret data and identify limitations.

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A protocol for sampling vascular epiphyte richness and abundance

Journal of Tropical Ecology ◽

10.1017/s0266467408005786 ◽

2009 ◽

Vol 25 (2) ◽

pp. 107-121 ◽

Cited By ~ 24

Author(s):

Jan H. D. Wolf ◽

S. Robbert Gradstein ◽

Nalini M. Nadkarni

Keyword(s):

Tree Height ◽

Dry Weight ◽

Mantel Test ◽

Tree Size ◽

Tree Level ◽

Trunk Diameter ◽

Host Trees ◽

Epiphyte Communities ◽

Vascular Epiphyte

Abstract:The sampling of epiphytes is fraught with methodological difficulties. We present a protocol to sample and analyse vascular epiphyte richness and abundance in forests of different structure (SVERA). Epiphyte abundance is estimated as biomass by recording the number of plant components in a range of size cohorts. Epiphyte species biomass is estimated on 35 sample-trees, evenly distributed over six trunk diameter-size cohorts (10 trees with dbh > 30 cm). Tree height, dbh and number of forks (diameter > 5 cm) yield a dimensionless estimate of the size of the tree. Epiphyte dry weight and species richness between forests is compared with ANCOVA that controls for tree size. SChao1 is used as an estimate of the total number of species at the sites. The relative dependence of the distribution of the epiphyte communities on environmental and spatial variables may be assessed using multivariate analysis and Mantel test. In a case study, we compared epiphyte vegetation of six Mexican oak forests and one Colombian oak forest at similar elevation. We found a strongly significant positive correlation between tree size and epiphyte richness or biomass at all sites. In forests with a higher diversity of host trees, more trees must be sampled. Epiphyte biomass at the Colombian site was lower than in any of the Mexican sites; without correction for tree size no significant differences in terms of epiphyte biomass could be detected. The occurrence of spatial dependence, at both the landscape level and at the tree level, shows that the inclusion of spatial descriptors in SVERA is justified.

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Modelling Environmental Impact on Public Health using Machine Learning: Case Study on Asthma

2020 5th International Conference on Innovative Technologies in Intelligent Systems and Industrial Applications (CITISIA) ◽

10.1109/citisia50690.2020.9397488 ◽

2020 ◽

Author(s):

Lakmini Wijesekara ◽

Liwan Liyanage

Keyword(s):

Public Health ◽

Machine Learning ◽

Environmental Impact

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Changes of Walking Activity During the First Cycle Phases of COVID-19 Pandemic: A Case Study of Seoul, Korea

HERD Health Environments Research & Design Journal ◽

10.1177/19375867211026571 ◽

2021 ◽

pp. 193758672110265

Author(s):

Youngjun Park ◽

Haekwon Chung ◽

Sohyun Park

Keyword(s):

Public Health ◽

Physical Inactivity ◽

Voluntary Participation ◽

Walking Activity ◽

Significant Difference ◽

Before And After ◽

Acceleration And Deceleration ◽

Preliminary Study ◽

The Government

Aim: This study explores the changes in regular walking activities during the phases of the pandemic. Background: With the spread of COVID-19 transmission, people are refraining from going out, reducing their physical activity. In South Korea, COVID-19 broke out in the 4th week of 2020 and experienced the first cycle phases of the pandemic, such as outbreak, widespread, and decline. In response to the pandemic, the government encouraged voluntary participation in social distancing campaigns, and people reduced their outside activities. Methods: This article examines the decrease and increase of the Prevalence of Regular Walking (≥30 min of moderate walking a day, on ≥5 days a week) by the COVID-19 phases. This study is based on weekly walking data for 15 weeks in 2020, via the smartphone healthcare app, which is managed by 25 public health offices of the Seoul government. Results: According to the findings, the level of prevalence of regular walking (PRW) has a significant difference before and after the outbreak, and every interval of the four-stage COVID-19 phases, that is, pre-pandemic, initiation, acceleration, and deceleration. The level of PRW sharply decreased during initiation and acceleration intervals. In the deceleration interval of COVID-19, the PRW kept increasing, but it has not yet reached the same level as the previous year when the COVID-19 did not exist. Conclusions: As a preliminary study, this study explains empirically how COVID-19 changed PRW in Seoul. It would be helpful to enhance our understanding of the changes in physical inactivity in the pandemic period.

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