With a new academic year in full swing, we welcome two new Grantham Institute PhD students joining the innovative Producing Rational Evidence for Parasiticide Prescription (PREPP) team at Imperial. The team explores and evaluates the environmental risks posed by veterinary medicine pollution to gauge ecological impacts and to explore possible solutions.
In this Q&A blog, we ask Roseline O’Kelly and Margarita White what their research project is about, its impact and significance in the field of health, and what they hope to achieve.
Roseline supervisors: Professor Guy Woodward, Professor Leon Barron, Dr Gareth Roberts, Dr Peiyu Zhang
Margarita supervisors: Dr Helena Rapp-Wright, Professor Channa Jayasena, Professor Leon Barron
Roseline and Margarita are funded by the Natural Environment Research Council (NERC) via the SSCP DTP at the Grantham Institute.
What is your project about?
Roseline
Both pesticide pollution and rising temperatures are predicted to intensify in the coming decades, yet we have little understanding of how these impact freshwater ecosystems. Previous studies have tested these stressors separately, focusing on a few species in simple laboratory settings. As a result, our understanding of the real-world environmental impacts of pesticide remains unclear.
During my PhD, I will research how pesticides and temperature interact from individual organisms to food webs and whole freshwater ecosystems. To address this gap, I’ll work at local-to-national scales using low-cost ‘next-generation’ sensors, complemented with biomonitoring tools in controlled environment rooms and experiments in the large-scale Silwood mesocosms (i.e., 96 artificial ponds). This will enable me to link pesticide concentrations in fresh waters to organisms and see how it affects the functioning of the wider ecosystem.
Ultimately, I will be disentangling for the first time how interactive impacts of pesticides and temperature across time, space and biological levels, from molecules to ecosystems.
Margarita
My PhD project is centered on human health, more specifically looking at whether dietary exposure to pesticides can affect male fertility. This is an issue that has become more prevalent in recent years and is being investigated in more detail.
The project will focus on testing human tissue samples including semen for a select group of pesticides, prioritised by parameters such as toxicity, popularity of use, and their historical detection in food residues, according to the Pesticide Residues in Food (PRiF) database.
A significant part of the work will also be dedicated to developing reliable analytical methods to detect pesticides in biological samples at low levels of concentration. Often, preparation techniques such as solid-phase extraction will be used to extract and concentrate the compounds within the samples. This project is vital to further understand the potential impacts of pesticides on male reproductive health and is strongly aligned with the Grantham’s research goals.
What is the impact and significance of your research to health?
Roseline
Spillover from pesticide use has made these toxic chemicals among the most concerning pollutants in UK rivers, causing a wide range of lasting impacts on wildlife and ecosystems.
Further, pesticides don’t act alone in ecosystems. With global average temperatures rising at an accelerating rate, ecosystems are also exposed to novel conditions and a combination of stressors. It is crucial to understand how pesticides and temperature interact, especially in the context of climate change, as warming is likely to amplify or alter the effects of pesticides in unpredictable ways.
My PhD will deliver new insights into how these stressors operate across space and time, from local urban heat island effects to future climate change scenarios within our increasingly warmer and polluted world.
Margarita
Due to their widespread use across the world, pesticides are a growing concern for human health. There are multiple routes of exposure, including direct exposure through inhalation or skin absorption, or ingesting residues found in food, primarily fresh produce.
Previous studies have shown that pesticide exposure can negatively affect sperm quality and function in humans. However, most of this research has concentrated on occupational exposure and far less is known about the impacts of dietary intake.
My PhD will specifically focus on the ingestion of pesticide residues found in food and their impacts on male fertility. Therefore, this project will be crucial in better understanding this route of exposure in male reproductive health.
What does success look like for your project? What would you like to see, try, achieve?
Roseline
I am deeply fascinated by freshwater ecosystems, and all the incredible wildlife it sustains. Given the major pressures on these ecosystems, I am determined to find clear evidence that informs and protects fresh waters from the unintended consequences of pesticide pollution under climate change.
Beyond my thesis, success would be reflected in producing papers in top journals, presenting at international conferences, and becoming an expert across ecotoxicology, climate science, and freshwater ecology. This would allow me to improve regulations and inform policies that address pesticide pollution, especially in vulnerable regions where the risks are heightened.
Proudly, the prospect of being the first person from the Dominican Republic to earn a PhD from Imperial would be an incredible personal accomplishment. I am incredibly grateful and excited for this opportunity, funded by the Natural Environment Research Council (NERC), to work with the Grantham Institute, to grow through this PhD and be part of Silwood Park’s extensive legacy in pure and applied ecology.
Margarita
Since the decline in male fertility is such a growing concern, my PhD project will play an important role in future research in this area. Alongside developing a reliable and reproducible analytical method to detect pesticides in human semen samples, I am aiming to investigate links between pesticide exposure through diet and potential effects on male reproductive health. This research can help towards more understanding on dietary advice and raise public awareness, so people can make more informed and safer choices about what they eat.
The Grantham Institute has provided an exceptional platform to advance my research, offering access to a wide network of experts in toxicology, analytical chemistry, and reproductive science. I also hope I can take advantage of the valuable opportunities to publish in high-impact, peer-reviewed journals and to share my work at leading conferences. I have always been drawn to a career in research, motivated by the challenge of addressing critical global health issues and a strong desire to make a meaningful contribution. I am incredibly excited to start this project as it presents a unique opportunity to achieve my goals while addressing a crucial gap in current scientific knowledge.
