Browsing by Author "Dalvie, Aqiel Mohamed"

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    Ambient air pollution and cardiorespiratory outcomes amongst adult residing in four informal settlements in the Western Province of South Africa
    (2019) Bagula, Herman Joseph; Dalvie, Aqiel Mohamed; Olaniyan,Toyib Adedamola
    Background Many studies investigating the relationship between ambient air pollution and cardiorespiratory outcomes have been conducted in developed countries despite more vulnerable populations in low- and middle-income countries especially in Africa. No studies previous studies have been done in South Africa informal settlements. Aim The aim of the study was to investigate the relationship between ambient air pollutant exposure and self-reported cardiorespiratory outcomes amongst adults residing in four informal settlements of the Western Province of South Africa. Methods This cross-sectional study included 572 adults from four informal settlements (Khayelitsha, Marconi Beam, Oudtshoorn and Masiphumele) in the Western Cape, South Africa. The study made use of Land Use Regression to estimate each participant’s exposure to particulate matter of aerodynamic diameter of 2.5µm (PM2.5) and nitrogen dioxide (NO2). A questionnaire was adapted from the European Community Respiratory Health Survey and National Health and Nutrition Examination Survey questionnaire to collect data on self-reported cardiorespiratory outcomes and specific confounding factors of interest. Results The median age the participants was 39 years (Interquartile Range (IQR): 33 - 45) with 88.5% female. The median NO2 level was 22.4 µg/m3 (IQR: 13.3 - 24.1) and the median PM2.5 level was 10.6 µg/m3 (IQR: 8.7 - 13.1). An increase of 10µg/m3 in annual NO2 level was found to be associated with a 2.9 (95%CI: 1.3 to 6.1) odds of having self-reported chest pain, adjusting for PM2.5 and confounders. No other significant association was found indicating an adverse health effect due to air pollution. Conclusion The study found preliminary circumstantial evidence of an association between annual ambient NO2 exposure and self-reported chest pain (a crude proxy of angina related pain), even at levels below both WHO Air Quality Guidelines and the South African National Ambient Air Quality Standards. However, the results should be interpreted cautiously due to the self-reported nature of the outcome measure and the cross-sectional design of the study.
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    Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape
    (2020) Molomo, Ntsubise Regina; Dalvie, Aqiel Mohamed; Roosli, Martin
    Background: Biomonitoring of pesticides is an objective measure of short-term pesticide exposure as it measures possible exposure in the human body. Current evidence on the relationship between demographic, socio-economic and pesticide exposure risk factors and urinary levels of organophosphate (OP) pesticide metabolites among children is generally incomplete and conflicting in some cases. There is therefore a need for further research. Objectives: This study investigated the relationship between socio-economic, demographic and reported pesticide exposure related activities and characteristics in relation to urinary levels of three dialkyl phosphate (DAP) metabolites (diethyl phosphate (DEP), dimethyl phosphate (DMP) and dimethyl triphosphate (DMTP)) among boys living in the rural areas of the Western Cape, South Africa. Methods: This was an analysis of data collected during a cross- sectional study of 183 boys from three agricultural intense areas in the Western Cape of South Africa between April 2007 and March 2008. Measurements included a questionnaire on demographic, socio-economic and pesticide exposure risk factors and analysis of spot urine samples for DAP metabolites. Results: Most of the boys (70%) lived on farms with a median age of 12 years (range: 5.0 - 19.5 years). The median concentrations of DAP, DEP, DMP and DMTP were 68.3 ng/ml (IQR= 27.9; 129.5), 5.5 ng/ml, 32.6 ng/ml and 16.7 ng/ml, respectively. The sum of the three DAP levels wasinversely associated with age. Children older than 14 years had less DAP levels (β = -68.1; 95% CI: -136.8,0.6) than children 9 years and younger. DAP levels also varied significantly with residential area, with the levels highest in Grabouw (apple farming), followed by Hex River Valley (grape farming) (β= -52.1; 95% CI: -97.9, -6.3) then Piketberg (wheat farming) (β= -54.2; 95% CI:-98.8, -9.7). Other weaker and non-significant associations with increased DAP levels were found with increased household income, member of household work with pesticides, living on a farm, drinking water from an open water source and eating crops from the vineyard and or garden. Conclusion: The study found younger age and living in and around an apple and grape farms, to be associated with increased urinary DAP concentrations among the school children provide evidence that younger age and residential area can be associated with increased urinary DAP concentrations among boys. Additionally, there are other household and behavioural characteristics that are associated with elevated urinary DAP levels. Further studies with larger sample sizes and longitudinal designs to improve the statistical power and the associations found are recommended. The study provided more insight to incomplete and inconclusive evidence of previous studies.