We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
The potential role of groundwater microplastics on arsenic cycling in alluvial aquifers: insights from links of DOM characteristics and microbial community
AI summary Read the abstract
Scientists studying groundwater in China found an unexpected pattern: areas with more microplastic pollution actually had lower levels of arsenic, a toxic contaminant linked to cancer and other health problems. The likely explanation is that microplastics break down into particles that interact with bacteria and minerals in ways that may trap arsenic underground rather than letting it dissolve into water. While this is an early, observational finding that needs more direct testing, it suggests microplastic pollution could have surprising and complicated effects on other contaminants in our drinking water sources.
Groundwater microplastics (MPs) exhibit complex surface properties and produce microplastic-derived dissolved organic matter (MP-DOM), which may potentially interfere with subsurface elemental cycles. DOM can regulate microbial metabolism and further affect arsenic (As) behaviors in aquifers; however, the impacts of MPs and MP-DOM on As migration and transformation in alluvial aquifers remains poorly understood. Herein, we investigated high-As alluvial aquifer systems in the middle Yangtze River basin, using Fluorescence excitation-emission matrices (EEMs) spectra, Ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), 16S rRNA gene sequencing and hydrochemical analysis to reveal the co-existing relationship between As and MPs as well as the potential cycling behavior of As in alluvial aquifers under MPs-containing groundwater conditions. Results indicated that confined groundwater (CG) suffered severe As contamination (14.1-240 μg/L) with relatively low MPs abundance, while unconfined groundwater (UG) had much higher MP concentrations (3.94 × 10 to 1.71 × 10 items/m) but lower As values (0.300-11.2 μg/L). EEMs and FT-ICR MS analysis revealed abundant lignins and specific molecular formulas with higher H/C ratios (>1.5) and lower O/C ratios (<0.50), typical features of MP-DOM. Based on correlation data, we propose that the formation of As-Fe-DOM ternary complexes serves as one plausible pathway for As immobilization, and hydrogen bonding and/or surface complexation between MPs and As may also retain dissolved As. Additionally, MPs may alter microbial communities and enrich As-tolerant and As-metabolizing bacteria (e.g., Methylomonas, Azospira, Acinetobacter) in CG. These functional bacteria can degrade MPs into MP-DOM, which may act as an electron donor and facilitate the reductive dissolution of Fe(III) oxides/oxyhydroxides. It is noteworthy that redox-driven As mobilization remains the dominant geochemical process in the study area, and above MPs-related pathways are only tentative inferences based on field correlations without direct experiment verification. This study provides new observational insights into the co-occurrence of MPs and As in alluvial aquifers and puts forward potential interaction mechanisms for further validation.
More Papers Like This
Effects of arsenic on the transport and attachment of microplastics in porous media
AI summary Read the abstract
Researchers studied how arsenic, a common groundwater contaminant, affects the movement of microplastics through soil. They found that arsenic in water generally reduced how far microplastics traveled by promoting their attachment to soil particles, though this effect depended on arsenic concentration, water flow speed, and soil moisture levels. The findings help predict how microplastics and heavy metals may interact and spread together in underground water systems.
Effect of microplastics on arsenic transport in shallow groundwater of coastal transition zones
AI summary Read the abstract
Scientists found that tiny plastic particles (microplastics) in coastal groundwater can actually help arsenic—a toxic contaminant—travel farther through the water, with plastic from water bottles and packaging (polystyrene and polyethylene) being the worst offenders. This matters because millions of people near coastlines rely on groundwater for drinking, and this research suggests microplastic pollution could make arsenic contamination spread more easily, potentially increasing exposure risks even in areas previously thought safer due to natural filtering.
Regulatory mechanism of microplastics on arsenic bioavailability in a subtropical estuary, China
AI summary Read the abstract
Researchers investigated the regulatory mechanisms by which microplastics influence arsenic bioavailability in sediments of the Min River estuary, a subtropical estuary in China, finding that microplastic pollution alters the dynamics of bioavailable arsenic through interactions with sediment geochemistry and microbial communities.
Contrasting roles of soil aggregates in decoupling solid-phase available As from water-phase risk under microplastic disturbance
AI summary Read the abstract
Scientists found that microplastics in soil can make arsenic look "safer" by locking it into soil particles, even while actually pushing more arsenic into water that drains through the ground. This matters because standard soil tests might miss real contamination risks, meaning farmland exposed to microplastic pollution could be leaking more arsenic into water supplies than current safety checks would suggest.
Exposure to microplastics lowers arsenic accumulation and alters gut bacterial communities of earthworm Metaphire californica
AI summary Read the abstract
Researchers examined how microplastics interact with arsenic contamination in earthworms and their gut bacteria. They found that microplastics actually reduced arsenic accumulation in earthworm tissues by adsorbing the arsenic and lowering its bioavailability. The study suggests that while microplastics altered gut bacterial communities, their presence may lessen arsenic toxicity in soil organisms by changing how the metal moves through the food chain.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.