Health and Environment

The role of infectious disease in the loss of biodiversity

2024-09-16T13:21:11+08:00

Discussion of the relationship of infectious disease and biodiversity loss most commonly is framed in terms of the impact of diminishing biodiversity on zoonotic diseases among humans. Less examined is the role of infectious disease as a direct driver of biodiversity loss through species declines, local extirpations, and global extinctions. Recent studies, however, suggest that infectious diseases in wildlife populations are emerging at notably high rates. The diversity of emerging infectious diseases, magnified by the likelihood that there will be an increased frequency of outbreaks over time, have raised concern that infectious disease may play a strong role in wildlife species extinctions. The purpose of this Commentary is to draw attention to the growing role infectious pathogens are having in wild animal biodiversity loss and ecosystem disruption, changes which, in turn, rebound on human health and wellbeing.

Environmental and chemical determinants of contamination and survival of Vibrio cholerae in water sources in Bukavu in the Democratic Republic of the Congo

2024-07-22T15:46:52+08:00

Introduction: Cholera is endemo-epidemic in Bukavu. The aim of the study was to assess the environmental determinants of permanent contamination of spring and well water and to evaluate some of the chemical factors responsible for the persistence of Vibrio cholerae in water consumed by cholera patients.
Methods: Conducted in the Bukavu health district from September 2020 to September 2021, this was a cross-sectional. The potential of hydrogen (pH) of the water was evaluated before comparing it with the survival of Vibrio cholerae. A total of 641 latrines, 92 water sources, and wells were surveyed, with 298 samples analyzed in the laboratory.
Results: Out of the 641 latrines surveyed, 367 (57%) were found to be unsanitary; 54 (59%) of the water sources and wells were also deemed unsanitary. In total, 57% of the water samples were found to contain Vibrio cholerae, with 90% exhibiting an alkaline pH, of which 54% tested positive for the bacteria. Conversely, 10% of the samples had an acidic pH, with 80% of those containing Vibrio cholerae. The pH levels of the water remained alkaline both during the epidemic (95%) and post-epidemic (84%), thereby favoring the survival of Vibrio cholerae serotypes Ogawa and Inaba in these water sources. An acidic pH was observed to increase the likelihood of Vibrio cholerae survival in these waters by a factor of 3.39.
Conclusion: Spring and well water are consistently contaminated with Vibrio cholerae due to the unsanitary conditions of nearby latrines. The presence of Vibrio cholerae serotypes Inaba and Ogawa in these water sources is further influenced by the alkaline and acidic pH levels.

Study of thermal comfort in some standard school buildings: A case of Madagascar island

2024-07-11T12:58:03+08:00

This study focuses on thermal comfort in some classroom school buildings of the Malagasy Ministry of National Education, located in the city of Diego-Suarez, characterized by a warm tropical climate throughout the year. This study was carried out in December 2023, then between January and February 2024. The analysis is based on the adaptive approach, using questionnaires and taking measurements of thermal parameters via weather sensor. During study hours from 7:30 a.m. to 11:30 a.m. in the morning and 2:30 p.m. to 5:30 p.m. in the afternoon, the questionnaires are completed at the same time as in-situ measurements are taken. In total, 223 questionnaires were completed by the occupants including (students and teachers), distributed in four classrooms of two different primary schools. The results reveal that the percentage of thermal acceptance inside the old school reaches 35%, compared to only 15% for the modern school. The majority of respondents believe that the air flow speed is more favorable in the old building, with a perception of comfort at 60%, compared to 40% for the modern building.

Determination of some heavy metals and physicochemical properties in contaminated soils of open waste dumpsite in Awka, Anambra State

2024-01-15T17:13:31+08:00

The current study was designed for the assessment of cadmium, chromium, lead, nickel, zinc and manganese and some physicochemical properties of soils collected from an open dumpsite in Awka, Nigeria. Soil samples at the depth (0-20 cm) were randomly collected at the dump field and were analyzed for physicochemical parameters and heavy metals using standard analytical methods. The results show that the main dumpsite had a high sand content (91.48% ± 0.26%) with a low silt 4.07% ± 0.03% and clay 4.65% ± 0.00%. The pH of the dumpsite soils was 6.07 ± 0.04 which is an acidic pH. Organic matter (%) and organic carbon (%) were 3.84 ± 0.06 and 2.23 ± 0.04 respectively. The EC (µS cm^-1) was 476.9 ± 0.00 while the ECEC (cmol/kg) 18.93 ± 0.04. The bulk density (g cm^-3) was 1.32 ± 0.00 and the porosity (%) of the dump soil was 41.40 ± 0.00. Total metal concentrations of Cd, Cr, Pb, Ni, Zn and Mn were also analyzed and the concentrations of the heavy metals at dumpsitewas obtained (28.35 ± 0.21 to 149.10 ± 0.01 mg/kg). Metal contamination at dumpsite was in the order of Mn ˃ Zn ˃ Pb ˃ Cd ˃ Cr ˃ Ni. The study evidently indicates the presence of heavy metal contamination in the dumpsite even though some of them fell below the critical permissible concentration level. However, it is their accumulation and persistence in the soils of the dump site that may be a cause of concern for their surrounding environment and organisms.

Modeling and simulation of absorption solar air conditioning to reduce energy consumption: A case of some cities in tropical region

2024-01-08T19:17:19+08:00

Buildings are one of the most important infrastructure sectors in today’s society. However, in Madagascar, most hotels, malls, hospitals use fossil fuels to meet energy needs, especially in the traditional air conditioning system. they consume a considerable amount of energy that has negative effects on the environment. The emergence of solar cooling systems is a very interesting solution to this problem because the use of renewable energies in this sector contributes to a significant reduction of greenhouse gas emissions in the environment. Madagascar is one of the countries with high renewable energy potential, notably solar energy estimated at 2000kWh/m².an.At present, the rate of exploitation of this potential for the operation of the solar absorption cooling system coupled with the building is still non-existent. This energy is clean, sustainable, profitable and environmentally friendly. This is the main objective of this work which uses this energy source to ensure thermal comfort in a building in Madagascar and contributes to the development of this system. The TRNSYS software helped us to model and simulate this system. To do this, first we will select 4 big cities of the big island, a building of total surface 80 m² was used. Then, the hourly thermal loads of this building for the whole year were simulated using the TRNbuild sub-program using meteorological data for a typical year of the selected cities. The dimensions of the components of the solar absorption air conditioning system were obtained using the maximum loads of the building. The results of the simulations show, the system meets the cooling load needs of the building with the climatic conditions of each selected city.

Evaluation of selected physicochemical properties of River Otamiri, Imo State

2024-01-04T15:19:47+08:00

Surface water monitoring is essential, especially when the water is normally used for industrial, agricultural, and domestic purposes. The study determined the physicochemical properties of the River Otamiri using the American Public Health Association standard methods for water analysis. In this study, river water samples were collected five times during the dry season from four sampling points (WSP-1, WSP-2, WSP-3 and WSP-4) along the watercourse of the river in Owerri West Local Government Area of Imo State. The levels of the selected physicochemical parameters were compared with the National Standard for Drinking Water Quality (NSDWQ) guidelines. The findings showed that the pH (4.99±0.11 – 6.30±0.08), dissolved oxygen (4.16±0.01 – 6.45±0.03), total hardness (17.10±1.78 – 27.80±2.54), chloride (68.30±0.58 – 91.90±0.64), and sulphate (39.55±3.32 – 51.21±2.11) were below the acceptable limit of the National Standard for Drinking Water Quality (NSDWQ). However, electrical conductivity (1116±29.75 – 1419±28.54), turbidity (18.90±2.81 – 31.70±8.13) and nitrate (45.50±3.06 – 69.90±2.11, except in water sample point-4) were above the recommended limit according to the NSDWQ guideline, while temperature levels (26.90±0.04 – 28.40±0.02) were within the acceptable limit. The study concludes that the River Otamiri is contaminated. It is therefore advisable to purify water from the river before use for domestic and industrial purposes.

A qualitative study on the morbidity experiences of under-five children in oil spill communities

2023-05-02T15:01:02+08:00

Introduction: Under-five years old (U5) children that reside in oil spill communities are exposed to various pollutants, and therefore are prone to respiratory symptoms and diseases. This study aimed to develop a deeper understanding on the lived experiences of U5 children residing in these communities.
Methods: The study was done in August, 2022 , on eleven caregivers/parents of U5 children, aged 26-45 years old via purposive sampling. This study utilized a phenomenological research design through in-depth interviews and audio recordings.
Results: Findings revealed that numerous oil spills have occurred, and are still occurring. According to the respondents, these spills are caused majorly by poor maintenance of old, rusted pipelines of oil companies; and pipeline vandalism, leading to land, water and air pollution. Results also showed that these spills have led to several adverse respiratory health (RH) experiences in U5, including cough, catarrh, chest pain and other health emergencies that have resulted in frequent hospital visitations and admissions like difficulty/fast breathing, pneumonia, hemoptysis, exacerbation of previously existing conditions, asthma development, etc. The destruction of their source of livelihood, have contributed to worsening these symptoms.
Conclusion: U5 children living in crude oil polluted areas are burdened with a high prevalence of respiratory symptoms and diseases. Implementation of already existing regulatory laws on oil pollution, prompt clean-up of oil spills, provision of standard health facilities, and trained health personnels, were some of the measures recommended to curb the menace of crude oil spills and its RH effects.

Potentially toxic element contamination and risk assessment of borehole water within a landfill in the Nnewi metropolis

2023-04-26T16:09:56+08:00

Borehole water has been used as a vital source of water for many communities. The pollution of these boreholes by potentially toxic elements using unlined solid waste dumpsites has posed a significant risk to the populace living around the dumpsite. This study investigates the environmental impact of potentially toxic elements on borehole water within the vicinity of an unlined dumpsite in the Nnewi metropolis. The upstream and downstream samples (16 each) were collected in wet and dry seasons. The potentially toxic elements analysis wasperformed using the methods of the American Public Health Association (APHA) under the required conditions. The quality of the boreholes was assessed using the World Health Organisation (WHO) acceptable limits for drinking water. The risk assessment was estimated for carcinogenic and non-carcinogenic risks using ingestion and dermal routes. The results show that the borehole water wascontaminated with potentially toxic elements through leachate infiltration, which exceeded the WHO permissible limits for drinking water at both locations and seasons. The upstream borehole samples were more contaminated than the downstream samples for both seasons, due to their proximity to the pollution source. The hazard indices of the ingestion and dermal routes showed that the borehole water poses serious cancer and non-cancer health risks for both locations. The results revealed that children are more susceptible to cancer and non-carcinogenic health threats than adults for both locations and seasons. The pollution indices of borehole water for wet season (9.028 and 5.728) and dry season (7.107 and 5.328) for upstream and downstream samples respectively, were polluted and the pollution was higher in the wet season. The borehole water samples were unsuitable for drinking water and should be treated before use.

Pollution indices of heavy metal contaminants in typical agrarian soil samples in Ihiala, South-East Nigeria

2022-08-16T09:41:35+08:00

The contamination of soil with toxic metals poses serious threats to the survival of living organisms including humans. We determined the contamination levels of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and nickel (Ni) in soil samples from a typical agrarian soil in Nigeria, using various single and complex geochemical indices along with principal component analysis (PCA) for source determination. Ten soil samples (S1-S10) were collected from depths of 20 cm, with a clean shovel and brush from farmlands in Ihiala, South-East Nigeria. Three single pollution indices: geoaccumulation index (I_geo), pollution index (PI) and ecological risk index (E_r), as well as four complex indices: pollution load index (PLI), Nemerow pollution index (PI_Nemerow), average single pollution index (PI_ave) and Potential ecological risk (RI) were used for the geochemical analysis. The mean soil levels of Cd (1.94ppm) and Pb (60.83ppm) exceeded their corresponding world averages. The results of the single pollution indices of the soil samples revealed heavy Cd, moderate Pb and low Ni, Cr and Cu contaminations, while the PI_avg, PI_Nemerow and RI graded the soil samples as moderately to seriously polluted. The correlation analysis revealed that the general contamination was mostly contributed by Cd and partly by Cr. The findings showed that Cd and Pb were the main heavy metal soil contaminants in the area. The levels of toxic metals found in the soils could pose health and ecological risks. The probable sources of these metals include pesticides use and poor waste disposal systems.

Assessment of vanadium pollution and ecological risk in some selected waste dumpsites in Southeastern Nigeria

2022-06-06T18:45:39+08:00

Waste disposal on dumpsites has resulted in significant vanadium pollution of the soil and ecosystem. This study assessed the pollution status and potential ecological risk of vanadium in some selected waste dumpsites in southeastern Nigeria. In this study, the soil samples were taken from the active waste dumpsites using a stainless-steel soil auger at a depth of 0 - 20 cm. Five sub-samples were taken from each sample location. A control sample was taken from an area devoid of industrial activities and waste dumps. Soil samples were air-dried at room temperature, pulverized with an agate mortar and pestle, and stored using appropriately labeled polythene bags prior to analysis. Vanadium analysis was conducted using an FS240AA atomic absorption spectrophotometer, and the data generated was analysed using IBM SPSS version 20.0 and Ms-Excel 2007. The mean vanadium concentrations in the studied waste dumpsites were found to be in the following order: Okpuno-Egbu dumpsite > Nekede dumpsite > Enyimba dumpsite > Rice-mill dumpsite. Acceptable potential ecological risk indices were observed in the Rice-mill, Enyimba, and Okpuno-Egbu dumpsites, while Nekede dumpsite recorded a high potential ecological risk. Furthermore, the pollution load index revealed that all the studied dumpsites were heavily polluted. Statistical analysis revealed no significant variations in vanadium concentrations in the studied dumpsites (p>0.05). Additionally, there was a strong and positive correlation between the dumpsites of Enyimba/Nnewi (r = 0.634), Nekede/Nnewi (r = 0.615), and Nekede/Rice-mill (r = 0.842). This indicated that the metal found in the dumpsites is of the same origin.