Microplastics and intI1 antibiotic resistance-associated marker in rural water systems: an exploratory GIS-based environmental assessment

Microplastics and antibiotic resistance markers are two emerging contaminants, especially in rural areas with no central waste treatment. This study explored the spatial distribution and co-occurrence of microplastics and the intI1 antibiotic-resistance-associated marker in the rural water bodies in Madavarayapuram, Tamil Nadu, India using a GIS-based exploratory framework implementing the SDG 3, SDG 6, and SDG 13. Seventeen drinking, tap, wastewater and river water samples were collected and analyzed by Fourier Transform Infrared; polyolefins were discovered, predominantly polypropylene in drinking water, despite the latter revealing zero turbidity. The polyolefin fractions varied by site, with tap water containing 95.73% relative polyolefin fraction, the wastewater at 86.79%, and the wastewater having substantial turbidity at 14.3 NTU, suggests that there is variation in relative polymer fractions and turbidity of the screened water based on sampling site. Samples were gathered at many sites along the river, although few samples were taken, so spatial patterns are difficult to analyze. However, there was an important difference between water types in turbidity (Kruskal-Wallis, p = 0.043) but not in polymer composition (p = 0.748). The presence of culturable bacterial populations in each of the samples was confirmed by microbial analysis, and Presence of the intI1 antibiotic-resistance-associated marker (approximately 280 bp) can be detected qualitatively by PCR. However, detection of the intI1 marker by PCR does not guarantee that antibiotic-resistant bacteria are present. The method does not identify antibiotic resistance. The detection of microplastics and the antibiotic resistance gene, intI1, in all environmental water matrices that were tested suggests an associated co-occurrence, however it does not suggest or prove that there is a direct correlation between microplastics and the occurrence of antibiotic resistance transmission. These findings highlight the limitations of conventional monitoring approaches and the need for integrated and thorough rural water supply systems to ensure safety.