Masters Degrees (Occupational and Environmental Health)

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Indoor and outdoor environmental assessment of Durban block hostels : an internal evaluations on exposure measures and outcomes of self supported health and well-being in hostels.
(2007) Buthelezi, Sikhumbuzo Archibald.; Gqaleni, Nceba.
Hostel dwellers form a larger part of the urban population in South Africa (Ramphele, 1999). These hostels were initially created as temporal arrangement for African men moving from rural to urban areas seeking for employment. Due to housing shortage in urban areas they eventually became permanent residential accommodation. However, observations into the environmental conditions in these hostels have raised concerns about the health and well being of residents and neighbouring communities. The area of study was selected on the basis of the current depleted living conditions due to mismanagement of facilities provided by both the occupants and the hostel administrators. The study was a cross sectional descriptive study involving all three Durban Metropolitan block hostels. Assessing (i) the quality of block hostel environment (indoor and outdoor) through visual inspection (walkthrough), (ii) the exposure measures and outcomes (biophysical environment assessment) by means of questionnaire survey, air testing and microbial identification. Sixty three (63) hostel inventory were completed, followed by the administration of 450 questionnaires, and 646 surface and air samples were collected in the indoors of the selected hostel blocks including the control outdoor samples. The demographic profile of the hostel dwellers in the selected hostel blocks revealed that in the five bed type dormitories the habitable space per individual was 3 m 2 to 3.8 m2. Whilst in the ten bed type dormitories the habitable space per individual was 3.3 m 2 to 3.6 m2 . This was not even close to the World Health Organization suggested habitable space of 12 m2 (WHO, 2000) and was therefore regarded as overcrowding. Lack of access control in the hostels exacerbated by the socio-economic demands of the living environments, e.g. unemployment, was to blame for overcrowding. This overcrowding of the hostels was overloading the services, causing enormous number of blockages and bursts of wastewater pipes resulting in the system not functioning. This situation resulted in the accumulation of dampness in the indoor environment, and hence creating conditions favouring the growth of indoor mouldiness in the buildings. This was further supported by evidence that 47% of the occupants in the selected hostel blocks were experiencing respiratory symptoms and 53% experiencing non-respiratory symptoms. The most recorded respiratory symptoms were pulmonary tuberculosis (14.3%), chest tightness (12.2%), sore and dry throat (7%), sinus congestion (7%) symptoms. Whilst the most recorded non-respiratory symptoms were headache (11.5%), dry and itchy skin (11.5%), stomach upset (6.3%) and fatigue (3.6%). Forty five percent (45%) of the respondents were current smokers and 80% of them had a tendency of smoking indoors. The results of the surface and air samples indicated that the level of indoor mould growth in the selected hostel blocks was at 37, 24%. Surface moulds were at 58% and airborne spores were at 42%. Statistical analysis of data revealed a significant relationship between exposure factors and outcomes in the 5, 10 and 15-bed type dormitories. Incidence Risk Rate (IRR) and the p-value (p . 0.01) were used to determine relationships between exposure factors and outcomes. Certain factors were very much supportive in the development of selfreported symptoms in the selected hostel blocks of the three hostels under certain circumstances and these were the hygiene state of the building, leaking pipes, smoking habits and total mea and dg surface moulds. At all levels of the analysis the hygiene state of the building was very much supportive in the development of self-reported symptoms. Other exposure factors were not supportive at all, for example, structural defects, bed-types, different floor levels and participants' perception of overcrowding. A review process of the role of legislation in controlling the adverse health effects revealed that certain aspects of the legislation relating to building standards requirements, sanitation requirements, ventilation requirements, space and density requirements, and air quality standards requirements were violated. Therefore, the findings of the study recommended that a proper management plan must be developed to enhance living standards. This plan shall include a routine maintenance of the building structures, the development of a culture of self-care, as well as access control in the hostels. In addition to that where there are signs of visible moulds on walls and ceilings adequate control measures are highly recommended using commercially available measures in order to provide a healthy living environment. In conclusion is the adoption of a compliance policy towards legal requirements pertaining to building standards as defined in the National Building Regulations Standards Act (Act 103 of 1977). This study has showed that necessary iii steps need to be taken in South Africa in order to combat this problem. Further research need to be taken in order the inhabitable buildings to be better living environment improving the existing building structures.
Natural ventilation, dampness and mouldiness in dwellings in the Waterloo housing development (Durban Metropolitan Area) : a case study of indoor air quality.
(2004) Gansan, Jaisendra.; Ehiri, J. E.; Gqaleni, Nceba.
Dampness can cause the development of moulds in buildings and pose a threat to the quality of the building structure, indoor air quality and health of the occupants. An emerging source of housing related problems are the building materials commonly used in housing construction, which can influence respiratory health. There is concern regarding the quality of the housing stock in the Durban Metropolitan area with regard to dampness and its the potential impact on the health of occupants. To elucidate this issue, a study was conducted to assess natural ventilation, dampness and mouldiness in dwellings of the Waterloo Housing development (Durban Metropolitan Area), between February 2001 and December 2003. A total of 491 randomly selected homes were visually inspected and residents were surveyed by means of a structured questionnaire. Three hundred and eighteen (318) air and surface mould samples were collected in duplicate, totalling 636 samples and analysed in the laboratory. Building characteristics and physical conditions were recorded and noted. Temperature and relative humidity readings were also taken during the survey. After the analysis of the 491 questionnaires, physical conditions of the dwellings were found to be poor and of concern. With the number (1178) and size of habitable rooms in the dwellings; the occupancy of 2414 people with an average of 2.05 persons per room, indicated overcrowding and congestion. About 51% (n=249) of the dwellings surveyed were found to be experiencing dampness (>3m2) and 47% (n=230) had visible surface moulds, primarily on the walls (at least an average of 1m2) . Predominant airborne fungal organism identified included; Aspergillus (23%-indoors, 26outdoors), Cladosporium (47%- indoors, 51%-outdoors), Penicillum (27%-indoors, 26%-outdoors) spp. Natural ventilation was also inadequate in 261 (53%) dwellings, which did not have airbricks. This inadequacy significantly promotes the occurrence of dampness and surface moulds (p < 0.05). With poor ventilation, dampness and mould growth in the dwellings, there was a high number of cases with upper respiratory tract health complaints; like Cough - 25% (n=122), Sinuses - 25% (n=121), flu symptoms 23% (n=llO) lower respiratory infections such as asthma - 27% (n=130), and chest infections - 23% (n=113). Asthma, wheeze, runny nose and allergy to dust were statistically associated with dampness (p < 0.05), mouldiness (p < 0.03) and lack of ventilation (p < 0.01). Buildings separate their occupants from hostile external environments and create a better internal environment for them, therefore dwellings must be constructed in a manner that promotes the health and well being of the occupants. In terms of guiding regulations, there were several omissions and non-compliance with existing local building bye-laws in the construction of houses, leading to adverse implications. Improved workmanship, appropriate material selection and compliance with the relevant guidelines during planning and construction inter alia, are recommended when addressing housing issues, thereby promoting the interest, health and well-being of the users.
Toxicological analysis of house dust collected from selected Durban residental buildings.
(2009) Nkala, Bongani Alphouse.; Gqaleni, Nceba.
Indoor air quality is described as the chemical, physical and biological characteristics of air in a residential or occupational indoor environment. In residential settings, there are many contributions to indoor pollution levels namely; human activities, biological sources and outdoor air. There has been increased focus on house dust due to its potential to contain biological and chemical pollutants in indoor environments. These have the potential to cause harm to human health. The purpose of this study was to conduct toxicological analysis of house dust collected from inside selected Durban residential buildings. The objectives of this study were to isolate, identify and quantify mould occurrence in house dust samples; to measure the occurrence of heavy metals (arsenic, lead and mercury) in house dust; and to analyse the cytotoxicity of house dust on human lung bronchus carcinoma epithelial line (A549) and human lung bronchus virus transformed epithelial cell line (BBM). One hundred and five house dust samples were obtained from households that participated in the South Durban Health Study. In each home, a sample of settled dust was collected, using standardized protocols, then sieved and individually packed into polystyrene bags. The samples were taken from three surface areas namely; living room couches, bed mattresses, and carpets. Well documented methods were used for the isolation, identification and quantification of mould. The samples for heavy metals analysis were sent to Umgeni Water (chemistry laboratory, Pietermaritzburg) where standardised methods were used. Human cell lines were treated with five different dilutions of each house dust extract. Cell viability was assessed using the MTT assay. Toxic effects of house dust extract were analyzed, following house dust extract treatment and cells were stained with double dye (annexin-V- and propidium iodide) and analysed with flow cytometry, and fluorescent microscope. Cytokines were analysed by Microbionix (Neuried, German) using a Luminex®100 plate reader for multiplex human cytokines analysis. There were (n=128) mould types isolated and (n=105) were identified, of which (n=10) were predominately isolated moulds. This was further confirmed by Allerton Provincial Laboratory in Pietermaritzburg. Among the isolated genera in all three surface areas, Rhizopus spp and Penicillium spp were widely distributed throughout surface areas in greater proportion. The overall highest mean which was reported in this study and expressed in colony forming unit per gram (CFU/g) for Penicillium spp ranged (3400 - 62316 CFU/g) obtained from living room couches, followed by Rhizopus spp (5200 - 15990 CFU/g). The mould results were compared with the South African Occupational Health and Safety Act (OHSA) 85 of 1993 as amended suggested guidelines of 1,000, 000 CFU/g. The findings of this study suggest the moulds in the homes studied were below the suggested guideline. However, this does not imply that the indoor conditions are unsafe or hazardous. Instead, the findings act as an indicator of moulds presence indoors. The type of airborne mould, its concentration and extent of exposure and the health status of the occupants of a building will determine the health effects on an individual. Heavy metals were detected in the dust in the following ascending order: arsenic (As) ranged from 1.3 ug/g -18.4 ug/g (mean, 4.26 ug/g), lead (Pb) ranged from 28.0 - 872 ug/g (mean 171.66 ug/g), and mercury (Hg) ranged from 0.6 -19.0 ug/g (mean, 2.22 ug/g). The mean concentration of lead in the dust was within the range of Canadian National Classification guidelines on residential contamination (500 ug/g). There was numerous numbers of samples in this study that exceeded these guidelines. The mean concentration of arsenic was within residential soil guidelines (20 ug/g). Mercury was within limits when compared with Global Hg project guidelines of soil/residential (6.6 ug/g), thought some of samples were notably above this mean. The ability of house dust extract to lower the cell viability which was slightly above 80% (prior treatment) to less than 50% (post treatment) in both cells was observed in this study. The findings in this study showed that dust extract are toxic to human cell lines, and cells undergone a degree of apoptosis and necrosis 62% (A549) and 99% (BBM). The cytokines serve an important role in the non-specific defence external against insults. It was observed that A549 cells up-regulated the release of IL-6 and IL-8 pro-inflammatory cytokines and under-regulated the release of other cytokines analysed (IL-4, IL-13, and TNF-a). BBM cells released IL-4, IL-8 and IL-13 within limit of detection. The presence of moulds in these sampled indoor household dusts, which is comparable with findings elsewhere indoors, show that moulds act as an indicator for building conditions such as dampness, which supports mould growth. Individuals, whether they are sensitized or not, may develop allergic reactions towards spores, thus the elevated numbers of spores quantified in this study are of concern. Some of the heavy metals reported in this study were higher or marginally higher than international norms and guidelines. The findings in this study strongly suggest that house dust extract is toxic to human lung cell lines. It must be noted, however, that this study may not reflect all that happens when a human lung is exposed to house dust. The findings of this study could contribute to the development of South African indoor air guidelines. In conclusion further study needed to be undertaken with respect to air pollution disease such as allergic; the reason being this study shown the reduced expression of cytokines that are involved in allergic inflammation.
Toxicological analysis of South African paraffin.
(2007) Dlamini, Nonhlanhla.; Gqaleni, Nceba.
There is little information available on the relationship between the chemical composition and toxicity of South African paraffin. The aim of this study was therefore to determine an association, if any, between the chemical composition and toxicity of South African paraffin. The objectives were to analyze the chemical composition and potential toxicity of paraffin using an A549 lung cell line. There were two phases to the study. In the first phase of the study the chemical composition of seven (7) paraffin samples was tested at accredited InterTek Testing Services (ITS) according to SABS protocol. In the second phase of the study toxicology studies were conducted using the MTI and Annexin assays to establish the toxicity of the samples. The experiments included dissolving paraffm in a constant volume of ethanol. Results of the chemical analysis of paraffin from local refineries indicated that the major components were aliphatic hydrocarbons (>75%, v/v), olefins (1-8%, v/v), aromatics (1-20%, v/v) and sulphur «0.1%, v/v). Cytotoxicity tests indicated that there were significant (p<0.001) differences in the level of toxicity of the paraffin samples. The chemical composition or formulation was the single most important factor, which determined the degree of toxicity. The toxicity of paraffin dissolved in ethanol was significantly (p<0.001) more toxic when compared to that of undissolved paraffin. Paraffin samples also induced apoptosis and necrosis. It is therefore recommended that the chemical composition of paraffin must be standardized to a consistent less toxic product to ensure the safety of the South African public.

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Browsing Masters Degrees (Occupational and Environmental Health) by Author "Gqaleni, Nceba."