Emerging contaminants in rural water: microplastic pollution and its association with agricultural, livestock, and industrial activities in Ecuador.

Abstract

Microplastic (MP) contamination has emerged as an environmental threat not only in marine systems but increasingly in terrestrial and subsurface environments, where monitoring is often limited. This study investigates the presence, types, and distribution of microplastics in rural drinking water systems in southern Ecuador, with a focus on their association with land-based anthropogenic activities-agriculture, livestock, and local industry. A total of 169 samples were collected from 29 community-managed systems; 61.5% tested positive for MPs. Detected polymers included polyethylene terephthalate (PET), polyamide 6, polyethylene, polyvinyl chloride (PVC), and polyester. PET was the most frequently observed, reaching concentrations up to 20 particles per sample, particularly in livestock-dominated catchments. More chemically complex MPs (e.g., PVC, thermoplastics) were predominantly detected in zones with industrial influence. Statistical analysis and spatial visualization (heatmaps) revealed strong correlations between MP distribution and land use type, suggesting that rural MP contamination originates from diffuse and localized terrestrial sources. These findings highlight the potential for MPs to infiltrate groundwater systems via poorly managed soil-water interfaces in rural settings. The results support the urgent need for targeted monitoring, plastic waste control, and water infrastructure improvements to mitigate risks to groundwater and public health.