Assessing acetamiprid and chlorpyrifos pesticide concentrations in water and sediments across macadamia orchard and communal area small reservoirs

ABSTRACT

Pesticides are well known for their persistence in the environment their slow degradation and high toxicity. Aquatic environments, while not the target of many pesticide applications, often receive these chemicals from their catchments through runoff dynamics. Here, we assessed pesticide concentrations of acetamiprid and chlorpyrifos in water and sediment across macadamia orchard and communal area reservoirs in the Levubu area, South Africa, using liquid chromatography tandem mass spectrometry. Analysis of acetamiprid and chlorpyrifos associated with sediments in macadamia orchard reservoirs revealed mean pesticide concentrations of 14.48 µg L⁻¹ and 5.67 µg L⁻¹, respectively, whereas, in communal area reservoirs both pesticides were not detected. Acetamiprid was not detected across reservoir water, whereas the mean pesticide concentration of chlorpyrifos of 6.51 µg L⁻¹ (macadamia orchard) and 0.13 µg L⁻¹ (communal area) were detected. Significant differences were observed for chlorpyrifos concentrations in water samples between macadamia orchard and communal area reservoirs, whereas acetamiprid and chlorpyrifos indicated non-significant differences in sediments. The results indicate that macadamia orchard reservoirs are highly contaminated by acetamiprid and chlorpyrifos. Consequently, these pesticides can alter water quality and ecosystem functioning by reducing species diversity, adjusting community structure, altering energy flow and nutrient recycling.

KEYWORDS:

• Pesticide pollution
• contamination
• LC-MS
• solid phase extraction
• environmental stressors

Acknowledgments

We would like to thank the Department of Nutrition at the University of Venda for the use of the Shimadzu High Performance Liquid Chromatograph Triple Quadrupole Mass Spectrometer (LCMS-8045). We would like to extend our gratitude to Lutendo Phophi for assisting during sample collection

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets generated and/or analysed during the current study are not publicly available as they are part of a larger study that is currently ongoing but are available from the corresponding author on reasonable request.

Additional information

Funding

We greatly acknowledge the financial support of the University of Venda Niche Grant (UID: FSEA/21/GGES/02) and the National Research Foundation Grant (UID: 138206). Thendo Mutshekwa acknowledges funding from the National Research Foundation of South Africa [NRF (ZA)] Postgraduate Bursary.

Notes on contributors

Thendo Mutshekwa

Thendo Mutshekwa recently completed his PhD Environmental Sciences studies at the University of Venda and was awarded an NRF Postdoctoral Fellow.

Lutendo Mugwedi

Lutendo Mugwedi is a Senior Lecturer of Environmental Sciences at the University of Venda and Chair of the Vhembe Biosphere Reserve, South Africa.

Babra Moyo

Babra Moyo is Technical Officer and a PhD Chemistry candidate at the University of Venda, South Africa.

Ntakadzeni E. Madala

Ntakadzeni E. Madala is an Associate Professor of Biochemistry and currently Acting Deputy Dean Teaching and Learning, Faculty of Science, Engineering and Agriculture, University of Venda, South Africa.

Ryan J. Wasserman

Ryan J. Wasserman is an Associate Professor of Zoology at Rhodes University and also a Research Associate, South African Institute of Aquatic Biodiversity.

Farai Dondofema

Farai Dondofema is a Chief Technician and Lecturer at the University of Venda.

Tatenda Dalu

Tatenda Dalu is a Senior Lecturer of Aquatic Ecology at University of Mpumalanga and also a Research Associate, South African Institute of Aquatic Biodiversity.