Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape
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)...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Public Health and Family Medicine
2021
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613162141908992 |
|---|---|
| access_status_str | Open Access |
| author | Molomo, Ntsubise Regina |
| author2 | Dalvie, Aqiel Mohamed |
| author_browse | Dalvie, Aqiel Mohamed Molomo, Ntsubise Regina |
| author_facet | Dalvie, Aqiel Mohamed Molomo, Ntsubise Regina |
| author_sort | Molomo, Ntsubise Regina |
| collection | Thesis |
| description | 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. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/32859 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:31:45.395Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | Department of Public Health and Family Medicine |
| publisherStr | Department of Public Health and Family Medicine |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/32859 Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape Molomo, Ntsubise Regina Dalvie, Aqiel Mohamed Roosli, Martin Organophosphorus pesticides pesticide biomonitoring urinary dialkyl phosphates rural boys socio-economic factors farm boys and non-farm boys 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. 2021-02-16T09:30:04Z 2021-02-16T09:30:04Z 2020 2021-02-16T08:06:42Z Master Thesis Masters MPH http://hdl.handle.net/11427/32859 eng application/pdf Department of Public Health and Family Medicine Faculty of Health Sciences |
| spellingShingle | Organophosphorus pesticides pesticide biomonitoring urinary dialkyl phosphates rural boys socio-economic factors farm boys and non-farm boys Molomo, Ntsubise Regina Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape |
| thesis_degree_str | Master's |
| title | Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape |
| title_full | Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape |
| title_fullStr | Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape |
| title_full_unstemmed | Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape |
| title_short | Relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the Western Cape |
| title_sort | relationship between urinary levels of organophosphate metabolites and pesticide exposures among rural school boys of the western cape |
| topic | Organophosphorus pesticides pesticide biomonitoring urinary dialkyl phosphates rural boys socio-economic factors farm boys and non-farm boys |
| url | http://hdl.handle.net/11427/32859 |
| work_keys_str_mv | AT molomontsubiseregina relationshipbetweenurinarylevelsoforganophosphatemetabolitesandpesticideexposuresamongruralschoolboysofthewesterncape |