In areas where waste management is inadequate, the welfare of free-roaming animals can be significantly affected by the ingestion of plastic waste, potentially impacting human livelihoods and health. However, the effect of plastic pollution on terrestrial animals is poorly understood. Using a combination of methodologies from animal behaviour, environmental and social sciences, this study assesses the effects of plastic pollution on donkeys, cattle and their owners in Kenya. Behavioural observations suggested that donkeys and cattle preferentially fed at waste sites, where 1 in every 10–20 items ingested were plastic. Faecal sampling also showed much higher concentrations of microplastics than those reported in previous studies of farmed cattle and significantly higher concentrations in the faeces of donkeys and cattle grazing at waste sites compared to rural areas. Survey data showed that the majority of livestock owners believed that plastic pollution was a problem, and nearly a third of local residents had witnessed an animal becoming ill following plastic ingestion, reporting mortality rates of 78%. Triangulating data from multiple methods highlights the risks terrestrial plastic pollution poses to domestic animals, demonstrating the need for interdisciplinary projects that tackle this important issue by addressing the interconnectedness of human behaviour, animal welfare and environmental health.

This perspective article invites readers to (re)imagine research as a means of practicing right relations with the places we inhabit and descend from. We anchor our work in a Kanaka Hawaiʻi, a Native Hawaiian cosmogeny and epistemology, one that recognizes all life as kin. We begin with the central question, “Where have the sand turtles gone?” to explore how a Kanaka Hawaiʻi-informed perspective, grounded in the genealogical creation chant, ke Kumulipo, can guide plastics research in Hawaiʻi. We elaborate this perspective through a moʻolelo, a story of a collaboration between a Kanaka Hawaiʻi cultural practitioner and a French and Swedish plastics researcher along the shores of Kapua, Waimānalo. By tracing the transformation of a conventional scientific study, we aim to grow entry points for research that is accountable to the place and the genealogical descendants of those specific lands, who have inherited the privilege and responsibility to steward them. We conclude by discussing how this perspective might offer critical insights for global environmental policy, such as the UN Plastic Treaty, urging a shift from treating Indigenous Peoples as stakeholders to honoring them as rights-holders. Ultimately, this work is a call to research in ways that honor the original peoples of the places where we are blessed to live, work, and research, particularly in ways that amplify the knowledge traditions and lifeways birthed from those specific lands. We write this piece for and with Waimānalo as a living, reciprocal co-author. We hope the experiences shared here return to and strengthen those places and people.

Negotiations by more than 180 States during the Intergovernmental Negotiating Committee (INC) session 5.2 to develop a legally binding instrument with the purpose to end plastic pollution have, once again, concluded without a treaty. This is especially disastrous for developing States and marginalized peoples (such as indigenous communities and waste pickers), who are disproportionately suffering from plastic pollution. In this article, we show that developing States were underrepresented at the INC-5.2 negotiations in Geneva: Their delegations were on average only half as large (~5 delegates) when compared to delegations from Western European States (~13 delegates) and those from States with a high and very high Human Development Index (~10 delegates). In addition, more than 230 industry representatives participated in INC-5.2, exerting influence in diverse ways, both during official negotiations and through side events, organized by lobbying organizations. Finally, we discuss the importance of how treaty negotiations were organized: Simultaneously occurring negotiation formats (such as contact groups and informal meetings) put smaller delegations at a disadvantage, causing procedural injustice, which falls under the responsibility of the INC Secretariat.

Plastic pollution is an emerging threat to our marine and terrestrial environments. International policy development to mitigate this pollution is currently underway; however, the process is complex. In parallel, local, national and regional initiatives are being developed. The research community is advocating for strong regulations based on robust evidence of the harm and severity of plastic pollution on oceans, land and for humans. However, the research community comprises different disciplines, research traditions and methodological approaches. This heterogeneity is in its core a great advantage, but only when we manage to build on each other where “synthesis” occurs. Currently, there remains a divide between the physical and social sciences, with research predominantly skewed toward the physical sciences, focusing on concentrations, fate and impact of plastic pollution.

In this article, I question the lack of philosophical discussions about the foundation of our research on plastic pollution, our knowledge claims, our views of “clean,” “pristine” and nature itself, as well as of the need for such discussions. I also propose a possible way forward to bridge the gap between disciplines and research traditions, fostering real interdisciplinarity.

The present study aimed to elucidate the extent of microplastic (MP) contamination in the Guandu River basin. Samples were collected from surface waters using a Manta trawl at 11 sites in two seasonal periods. MPs abundance was 6.1 ± 4.9 particles m−3 in the cold-dry season, and 2.3 ± 1.1 particles m−3 in the warm-rainy season. Four shapes and 12 colors were identified, indicating a high degree of particle diversity. Fragments were the most common, followed by fibers. The frequent colors were black, blue and transparent. Eleven plastic polymers were identified using micro-Fourier transform infrared spectroscopy analysis; the dominant ones were polyethylene and polypropylene. Artificial cellulose particles (including the semisynthetic polymer rayon) were also detected in high relative abundance. No significant difference in MP abundance was found between seasons and limnic conditions. There was a significant trend toward higher abundance of MPs near areas with greater urban influence and lower abundance in reservoirs surrounded by less urbanized areas (upstream river). Therefore, MPs appeared to be influenced by land use and occupation, with higher abundance in more urbanized areas, suggesting an urban–rural effect.