Distribution and risk assessment of microplastic pollution in a rural river system near a wastewater treatment plant, hydro-dam, and river confluence

Research published in the journal Scientific Reports discusses the ways microplastics enter riverine systems. The study focuses on the rural Raquette River, in New York, and evaluates distinct locations where microplastic may enter the river. The highest microplastic concentrations were found mostly downstream of a wastewater treatment plant, upstream of the hydro-dam, and in the river confluence.

Abstract: Rivers are the natural drainage system, transporting anthropogenic wastes and pollution, including microplastics (plastic < 5 mm). In a riverine system, microplastics can enter from different sources, and have spatial variance in concentration, physical and chemical properties, and imposed risk to the ecosystem. This pilot study presents an examination of microplastics in water and sediment samples using a single sample collection from the rural Raquette River, NY to evaluate a hypothesis that distinct locations of the river, such as downstream of a wastewater treatment plant, upstream of a hydro-dam, and river confluence, may be locations of higher microplastics concentration. In general, our results revealed the presence of high microplastic concentrations downstream of the wastewater treatment plant (in sediments), upstream of the hydro dam (both water and sediment), and in the river confluence (water sample), compared to other study sites. Moreover, the risk assessment indicates that even in a rural river with most of its drainage basin comprising forested and agricultural land, water, and sediment samples at all three locations are polluted with microplastics (pollution load index, PLI > 1; PLIzone = 1.87 and 1.68 for water and sediment samples respectively), with risk categories between Levels I and IV (“minor” to “danger”). Overall, the river stands in a “considerable” risk category (PRIzone = 134 and 113 for water and sediment samples respectively). The overall objective of this pilot study was to evaluate our hypothesis and advance our understanding of microplastic dynamics in rural river systems, elucidating their introduction from a point source (wastewater treatment plant), transit through an impediment (hydro-dam), and release into a vital transboundary river (confluence of Raquette-St. Lawrence Rivers).

Atmospheric pollution includes microplastics. A team of researchers from Cornell University have determined that the shape of microplastics play a key role in how they travel. Using a model to simulate the atmospheric transportation of microplastic fibers has shown that common flat fibers travel farther in the lower atmosphere than spherical shaped fibers.

“We can now more accurately attribute the sources of microplastic particles that will eventually be transported to the air,” lead author Qi Li said. “If you know where they’re coming from, then you can come up with a better management plan and policies or regulations to reduce plastic waste. This could also have implications for any heavy particles that are transported in the lower atmosphere, like dust and pollen.”

In a scientific statement, the American Heart Association lays out its concerns about the adverse health consequences caused by exposures to environmental toxicants and pollutants, and cardiovascular diseases in young people. The article provides evidence that connects climate change and congenital heart disease, airborne pollution and Kawasaki disease, blood lead and blood pressure, endocrine-disrupting chemicals and cardiometabolic risk factors, perfluoroalkyl and polyfluoroalkyl substances, and other sources of pollution to adverse childhood health effects, especially relating to heart health.

The results of this Greenpeace survey demonstrate that there is overwhelming public support for the Global Plastics Treaty to cut plastic production, end single-use plastics and advance reuse-based solutions. Conducted in 19 countries with over 19,000 respondents, the survey shows strong support for cutting the production of plastic, at over 8 in 10 people (82%1), and for protecting biodiversity and the climate by cutting plastics production (at 80%1). As many as 9 out of 10 people (90%2) support a transition away from single-use plastic packaging to reusable and refillable packaging, while 75%1 support a ban on single-use plastic. Likewise, 80% of people are concerned3 about the impacts of plastic on the health of their loved ones and 84% of parents are concerned about these impacts on the health of their children.

The high level of support for ambitious action on plastics is similar across all the countries surveyed, but particularly strong in most of the Global South countries where plastic pollution levels are higher. Support for all the statements was well above 50%, with the lowest percentage still at 60%1, in support of a statement that lobbyists from the fossil fuel industry and chemical industries should not be allowed to take part in negotiations, for the Global Plastics Treaty to be successful.

The overwhelming show of public support sends a strong message to the Governments negotiating the Global Plastics Treaty—the public expects political leaders to address pollution from the full life cycle of plastics, by cutting plastic production and banning single-use plastics. A failure to do so will carry political consequences.

  1. ‘Strongly agree’ and ‘Somewhat agree’ responses combined
  2. ‘Essential’, ‘Very important’, and ‘Fairly important’ responses combined
  3. ‘Very concerned’ and ‘Somewhat concerned’ responses combined

Scientists find that interlocking and dismantling popular plastic toy building bricks generate microplastics and nanoplastics. These plastic fragments may pose a health risk to children who play with the bricks.

Abstract: Microplastics and nanoplastics have become noteworthy contaminants, affecting not only outdoor ecosystems but also making a notable impact within indoor environments. The release of microplastics and nanoplastics from commonly used plastic items remains a concern, and the characterisation of these contaminants is still challenging. This study focused on evaluating the microplastics and nanoplastics produced from plastic building bricks. Using Raman spectroscopy and correlation analysis, the plastic material used to manufacture building blocks was determined to be either acrylonitrile butadiene styrene (correlation value of 0.77) or polycarbonate (correlation value of 0.96). A principal component analysis (PCA) algorithm was optimised for improved detection of the debris particles released. Some challenges in microplastic analysis, such as the interference from the colourants in the building block materials, was explored and discussed. Combining Raman results with scanning electron microscopy – energy-dispersive X-ray spectroscopy, we found the scratches on the building blocks to be a significant source of contamination, estimated several thousand microplastics and several hundred thousand nanoplastics were generated per mm2 following simulated play activities. The potential exposure to microplastics and nanoplastics during play poses risks associated with the ingestion and inhalation of these minute plastic particles.

Microplastics are reservoirs for microbial communities. Scientists are finding that microbes associated with microplastics tend to have biocidal-, metal-, and antibiotic-resistant genes. This “plastiome” could perpetuate harmful antibiotic resistant genes in microbes in the environment. Scientists assess microbial communities on plastics in two rivers near Tokyo, Japan.

Abstract: Aquatic microplastics (MPs) act as reservoirs for microbial communities, fostering the formation of a mobile resistome encompassing diverse antibiotic (ARGs) and biocide/metal resistance genes (BMRGs), and mobile genetic elements (MGEs). This collective genetic repertoire, referred to as the “plastiome,” can potentially perpetuate environmental antimicrobial resistance (AMR). Our study examining two Japanese rivers near Tokyo revealed that waterborne MPs are primarily composed of polyethylene and polypropylene fibers and sheets of diverse origin. Clinically important genera like Exiguobacterium and Eubacterium were notably enriched on MPs. Metagenomic analysis uncovered a 3.46-fold higher enrichment of ARGs on MPs than those in water, with multidrug resistance genes (MDRGs) and BMRGs prevailing, particularly within MPs. Specific ARG and BMRG subtypes linked to resistance to vancomycin, beta-lactams, biocides, arsenic, and mercury showed selective enrichment on MPs. Network analysis revealed intense associations between host genera with ARGs, BMRGs, and MGEs on MPs, emphasizing their role in coselection. In contrast, river water exhibited weaker associations. This study underscores the complex interactions shaping the mobile plastiome in aquatic environments and emphasizes the global imperative for research to comprehend and effectively control AMR within the One Health framework.