Browsing by Author "Archer, Emma"

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    Characterising the role of climate change in perpetuating Zimbabwean farmers' health risks from exposure to endocrine disrupting pesticides
    (2020) Zinyemba, Cliff; Rother, Hanna-Andrea; Archer, Emma
    Climate change and endocrine disrupting chemicals are currently amongst key drivers for a range of non-communicable diseases and adverse human health conditions. Pesticides constitute an important source of endocrine disrupting chemicals. A growing public health concern is the potential relationship between climate change and adaptive increases in agricultural pesticide use. Effectively, with increases in pesticide use, there may be increased potential for elevated pesticide exposures and, thus, increased endocrine disrupting health risks. The aim of this thesis was to assess whether climate change is a key risk perpetuating factor for endocrine disrupting health risks due to increased agricultural pesticide uses and exposures. The study was conducted in Zimbabwe with farmers in the cotton farming district of Rushinga. Three research methods: 1) interviews with farmers, 2) quantitative structure-activity relationship modelling and, 3) stakeholder interviews with government cotton agronomists working in Rushinga district who acted as key informants. Qualitative in-depth interviews were conducted with 50 active smallholder farmers who had grown cotton for a minimum of 30 years. The interviews gathered farmers' perceptions and observations regarding climate change, changes in pest types, pest populations, pesticide use patterns, pesticide handling practices, and adaptive practices, amongst others. Quantitative structure-activity relationship modelling was, further, applied in identifying key risk pesticides of concern. Amitraz, endosulfan, fenvalerate and lambda-cyhalothrin were determined as having a high likelihood of acting as endocrine disruptors, as validated by literature highlighting the four pesticides' hormone-related cognitive, physiological and reproductive adverse health effects. Findings indicated that a number of farmers' adaptative practices were found to be incremental and, potentially, maladaptive, thereby enhancing pesticide use and exposure. This was indicative of climate change's potential for perpetuating pesticide-related endocrine disrupting health risks. Opportunities exist, however, for farmers to reduce pesticide use, and, thus, potential endocrine disrupting health risks through certain autonomous transformational adaptive practices, such as crop switching and cotton acreage reduction. Assistance to farmers by the government and development agencies, for enhancing opportunities for transformational adaptation is therefore recommended. Furthermore, there is need, at policy level, for phasing out pesticides with endocrine disrupting properties. There is, furthermore, a clear need for enhancing farmers' access to, and comprehension of, pesticide risk information through various innovative means, including research translation to reduce exposure risks.
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    Climate Change, Pesticides and Health: Considering the Risks and Opportunities of Adaptation for Zimbabwean Smallholder Cotton Growers
    (2020-12-26) Zinyemba, Cliff; Archer, Emma; Rother, Hanna-Andrea
    There is potential for increased pesticide-related adverse health outcomes in the agricultural sector linked to adaptive increases in pesticide use necessitated, in part, by climate change-related increases in pest populations. To understand the role of adaptation practices in pesticide use and health risks, this study assessed Zimbabwean smallholder cotton farmers’ adaptive responses linked to their climate change perceptions. In depth interviews were conducted with 50 farmers who had been growing cotton for at least 30 years. The study identified farmers’ adaptation practices that increased their pesticide use, as well as those that presented opportunities for reducing pesticide use through non-pesticide-dependent adaptation pathways. The findings show that due to perceived climate change impacts, such as a shorter growing season, farmers were adopting a range of adaptive practices. These included changes in pest management practices, such as increasing pesticide spraying frequencies due to keeping ratoon crops, which were increasing farmers’ overall pesticide use. Such incremental adaptive practices are potentially maladaptive, as they may increase farmers’ pesticiderelated health risks. Other practices, however, such as reducing cotton acreage and diversifying crops, resulting in transformational adaptation, suggest the existence of opportunities for decreasing overall pesticide use or totally eliminating pesticides from the farming system
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    The impact of global climate change on the runoff and ecological sustainability of the Breede River
    (2004) Steynor, Anna C; Hewitson, Bruce; Archer, Emma
    The Breede River catchment in the South Western Cape is already under pressure for its water resources due to its supporting a variety of different land uses. The predominant land use in this catchment is agriculture, which demands the majority of river water for irrigation. The Department of Water Affairs and Forestry are currently investigating the future demand for water from the river, in this respect it is important to know what effect climate change will have on the change in river flow. Self Organising Maps (SOMs) are used to identify changes in the circulation systems contributing to the rainfall of the region and from this the potential change is assessed for the Breede River flow under future climate change. It is assessed that the runoff in the Breede River is expected to change under all the models of ECHAM4, CSIRO and HadAM. The magnitude of this alteration is calculated by using the change in the SOM node frequencies between the present and the future data. This is then subtracted from the present runoff data supplied by DWAF. A source of runoff decrease in the future is agricultural irrigation. The increase in irrigation under climate change is determined by inserting future climate data into an agricultural model. Once the increased amount of water used in irrigation is determined, it is subtracted from the projected future runoff. From this it is determined whether the river will be ecologically sustainable under climate change.