Plastic Waste in Rivers May Carry Hazardous Microbes, Says Study

A recent study has shed light on a concerning issue i.e., plastic litter in rivers can serve as a channel for dangerous pathogens to travel downstream.

This research, which focused on a river in the UK, uncovered that discarded plastic, along with wooden sticks and the water itself, creates an environment conducive to the proliferation of microorganisms. These microorganisms could potentially serve as a reservoir for bacteria and viruses responsible for human diseases, as well as antibiotic resistance.

Lead author Vinko Zadjelovic, from the University of Antofagasta in Chile, expressed, "Our findings indicate that plastics in freshwater bodies may contribute to the transport of potential pathogens and antibiotic resistance genes." This discovery holds significant implications for human health, as antibiotic resistance is an escalating public health concern. In 2019, infections related to antibiotic resistance claimed an estimated 2.7 million lives worldwide, and by 2050, this number is projected to surge to 10 million deaths, according to the study published in the journal Microbiome.

When plastic finds its way into water bodies, its surface is swiftly colonized by nearby microbes. The research team immersed samples in the River Sowe in Warwickshire and West Midlands, downstream from a wastewater treatment plant, for a week. They observed substantial variations in the microbial communities based on the material sampled.

Wastewater is subjected to treatment and disinfection processes to mitigate microbial hazards and their potential impact on human and environmental health. However, the water samples collected by the researchers in February 2020 contained human pathogens like Salmonella, Escherichia coli (E. coli), and Streptococcus, which is responsible for strep throat. This highlights the urgent need for more rigorous monitoring of wastewater treatment plants, as emphasized by Zadjelovic.

Meanwhile, the plastic and wood samples attracted "opportunistic" bacteria such as Pseudomonas aeruginosa and aeromonas, which pose a risk to individuals with compromised immune systems.

Notably, P. aeruginosa, known for causing infections in hospital patients, was nearly three times more abundant on "weathered plastic," which the researchers manipulated to resemble how plastic breaks down in nature, compared to wood. Additionally, weathered plastic exhibited a higher prevalence of genes associated with antibiotic resistance.

In recent months, British water companies have faced criticism for discharging raw sewage into the country's waterways and underreporting pollution incidents, triggering public outrage.

Rivers play a pivotal role in transporting plastic waste to the world's oceans, contributing an estimated 3.5 thousand to 2.41 million metric tons of plastic annually.

This study underscores the need for comprehensive measures to address the issue of plastic pollution in rivers, including stricter monitoring of wastewater treatment plants and enhanced awareness of the environmental and health risks associated with plastic waste in aquatic ecosystems.