We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Characterizing the Atmospheric Concentration, Transformation, and Cloud Condensation Nuclei Activity of Nanoplastic Particles
Summary
Scientists found tiny plastic particles floating in the air around Houston, with concentrations varying greatly across different locations. These nanoplastics can change chemically when exposed to sunlight and air pollution, potentially allowing them to travel long distances around the globe through the atmosphere. This matters because we're still learning how breathing in these microscopic plastic particles might affect human health, and this study shows they're more widespread in our air than previously understood.
Nanoplastic particles (NPPs) are emerging anthropogenic pollutants identified from urban to remote areas. Characterizing the spatial and temporal distribution, process, and cloud-forming potential of atmospheric NPPs improves understanding of their environmental processes and climate impacts. This study provides the spatial and temporal distribution of several types of nanoplastic particles in the Houston area, including polystryene (PS), polyethylene (PE), polyethylene terephthalate (PET), and Polyvinyl chloride (PVC), showing an average concentration ranging from tens to hundreds of nanogram per cubic meter, with high spatial variability.In addition, we also presented the first quantified heterogeneous reaction rate and lifetimes of polystyrene (PS) NPPs against common atmospheric oxidants. The atomized PS NPPs were introduced to a Potential Aerosol Mass (PAM) oxidation flow reactor with ·OH exposure of 0 to 1.5 × 1012 molecule cm-3 s, equivalent to atmospheric exposure from 0 to 18 days, assuming ambient ·OH concentration of 1 × 106 cm-3. The decay of the PS mass concentration was quantified by monitoring tracer ions, C6H6+ (m/z 78) and C8H8+ (m/z 104), using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The pseudo-first-order rate constant of PS particles reacting with ·OH, kOH, was determined to be (3.2 × 0.7) × 10-13 cm3 molecule-1 s-1, equivalent to a half-lifetime of a few hours to ~80 days in the atmosphere, depending on particle sizes and hydroxyl radical concentrations. The hygroscopicity of 100 nm PS NPPs at different ·OH exposure levels was quantified using a cloud condensation nuclei counter (CCNC), showing a two-fold increase of hygroscopicity parameter upon 27 days of atmospheric photo-oxidation.Overall, the above results suggest that atmospheric processes can be an important part of the total plastic cycle in the environmental systems, faciliating both short range and long range transport of plastic globally.