Environmental Toxicology and Chemistry in Africa: Tackling Legacy and Emerging Pollutants
Tarryn Lee Botha, University of Johannesburg; Olawale Otitoju, Federal University Wukari; Iseult Lynch, University of Birmingham; Beatrice Opeolu, Cape Peninsula University of Technology
The Program Committee of SETAC Dublin dedicated a session highlighting the breadth of excellent science being undertaken in Africa, by and with African researchers, that covered the range of pollutants, approaches and solutions being developed. To that end, the session proposal spanned approaches to tackle both legacy and emerging pollutants with an aim to facilitate knowledge sharing, community building and stimulate new collaboration opportunities.
Our first (but definitely not last) Environmental Toxicology and Chemistry in Africa session brought together scientists from around the world. The session had both in-person and virtual participants who engaged in lively discussions on a range of important topics. Presentations included the establishment of a contaminant data and knowledge-sharing portal in South Africa, informal recycling of lead-acid batteries in Malawi, the toxicity of pyrethroid leached from insecticide-treated fishing nets, and indoor and outdoor air pollution monitoring in Senegal. In keeping with the overall conference theme, data collection and integration as a basis for science-based environmental decision-making was a key focus, and discussions were lively and wide-ranging, also speculating on the potential for different solutions and how to nudge practice towards more sustainable and less environmentally polluting approaches.
The first presentation of the session, by Tarryn Botha from the University of Johannesburg in South Africa, described the progress towards the establishment of a Geographic Information System (GIS)-based (spatially tagged) open-source database and knowledge hub for emerging contaminants in water in South Africa. The idea was very well received and will form a nucleus around which to integrate similar environmental data from across the African continent, leveraging the open-source nature of the tools. Botha noted some of the challenges in developing a shared understanding between the coding experts and the pollutant and water experts, but that the outcome was so rewarding that it outweighed any discomfort from working across knowledge boundaries.
Next up was University of Manchester PhD student Christopher Kinally. He presented his collaborative research with the informal waste sector in Malawi on mapping the processing and recycling of solar lead-acid batteries. Only 15% of Malawi is connected to the national electricity grid, meaning that most households rely on solar grids that use lead-acid batteries, often of inferior quality and thus lasting very short times. Because the batteries often last < one third of their official lifespan, there is a thriving informal recycling market to regenerate the worn-out cathodes and recycle the batteries. Large amounts of lead-acid are deposited directly into the surrounding soil as part of this process, leading to significant environmental damage. This is contributing to environmental levels above the World Health Organisation levels (10 μg/L for drinking water and 0.5 μg/m3 for Pb in air) with consequent long-term health risks. The informal waste workers that Kinally interviewed and shadowed in their work did not seem to be affected nor overly concerned by the health risks. A lively discussion followed, with suggestions for using this knowledge to drive policy and practice change towards more environmentally benign approaches.
University of Florida PhD student Deirdre Love presented her work exploring the leaching of pyrethroid from insecticide-treated nets, which are widely used throughout Africa to prevent mosquito bites while sleeping. Pre-Covid fieldwork by other members of the University of Florida team anecdotally found that the nets are being illegally re-purposed for fishing due to the tight mesh structure and availability of these nets, with consequent negative impacts on fish and aquatic systems. Based on the leaching amounts identified, exposure concentrations were set for the fish toxicity experiments, which focused on understanding the mode of action. Oxidative stress was found to be the major impact, based on monitoring of oxidative-stress-related biomarkers. Even low concentrations of pyrethroid were found to be harmful to the aquatic organisms, and thus the discussion considered whether there was a suitable number of washing steps that might make these nets safe for use in fishing. There was push-back from the audience both on legal grounds and on the basis that the nets are not suitable for fishing, as the small mesh size means juvenile fish are captured, resulting in threats to the sustainability of fisheries resources. The group agreed that the use of mosquito nets for fishing should be considered illegal. The potential to make them safe for other applications was also discussed. Love noted after her presentation that she had never received so much interest in her work before the Dublin meeting; she declared herself a big fan of the Africa-focussed session.
The final presentation in the session was by Anthony Verdin, Université du Littoral Côte d’Opale, France, on air pollution in Dakar, Senegal. Verdin presented a case-study on outdoor and indoor exposure, working with 150 participants who were either housemaids (indoor occupational exposure) or bus drivers and traders (outdoor occupational exposure) from urban and rural sites and assessed their exposure both in the home and outdoors to air pollutants including volatile organic compounds (VOCs) and particulate matter of 2.5 microns or less (PM2.5). A clear correlation between the location (home or bus) and the pollutants exposed was yet to be confirmed. The discussions reflected on the challenges of working with volunteers, ethical considerations of working with personal and human health data, and how the data can be utilized to drive policy change and improve the occupational environments for the workers – the importance of local and Indigenous knowledge was clear.
Due to a combination of the popularity of SETAC Dublin, which meant that registration was capped after the early-bird deadline, and some challenges with securing visas, none of our originally selected poster pitch presenters were able to be in the room. We therefore had an informal open invitation for researchers to stand up and say a few words about their posters, whether they were in this session or others, as long as they were broadly Africa-focused. Four volunteers pitched their posters without slides, and this informal format worked so well that we will keep it for next year.
While acknowledging that the global pandemic from 2020–2023 limited opportunities for travel and fieldwork, we reiterate the critical importance of inclusion of African researchers (Indigenous peoples, scholars, non-profit organizations and governments) in all research in or about Africa, and to ensure that African scientists have a voice in the framing and telling of their science and their stories.
We highlight especially the recent CARE principles for Indigenous Data Governance, which complements the FAIR principles for data generally, and strive for “Collective Benefit, Authority to Control, Responsibility, and Ethics” in terms of Indigenous knowledge. The CARE principles are “people and purpose-oriented, reflecting the crucial role of data in advancing Indigenous innovation and self-determination. These principles complement the existing FAIR principles encouraging open and other data movements to consider both people and purpose in their advocacy and pursuits.”
From a SETAC perspective, part of this involves recognition of the very high costs involved for African researchers in participating in SETAC Europe meetings – we, as the session organizers, would like to continue and extend the reach of this first “Environmental Toxicology and Chemistry in Africa” session at future meetings. But to do this effectively, SETAC Europe may consider measures to offset some of the costs of participation for African researchers. For example, ring-fencing some travel grants, introducing best poster and best prize awards for African researchers specifically (as these come with free registration for the subsequent SETAC Europe meeting) or other means. Several participants noted that their families had to cover their costs for SETAC Dublin, and that the registration was more than one month’s salary for them, even as professors. An additional aspect is a call for European and other researchers with an interest in or focus on Africa to participate in the SETAC Africa meetings every other year as this opens clear lines of collaboration and strengthens the CARE principles for research in Africa. African scientists come with a unique perspective on the socio-economic challenges and geological backgrounds. For example, some metal levels considered high elsewhere, may in Africa be within a normal background value due to the surrounding geology. The SETAC Africa 11th Biennial Conference takes place in Accra, Ghana from 8–11 October 2023, and you are warmly invited to join. Please also join us next year in Seville for the second Environmental Toxicology and Chemistry in Africa session.
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