Tracking Airborne Microplastics Using Natural (and Coal Enhanced) Radioactive Isotopes

[NNadir]

The paper I'll discuss briefly in this post is this one: Tracing the Transport and Residence Times of Atmospheric Microplastics Using Natural Radionuclides Kunliang Jiang, Jingmin Zhu, Kaijun Su, Xilong Wang, Guoliang Li, Mingyue Deng, and Chaowen Zhang Environmental Science & Technology 2024 58 (35), 15702-15710.

I'll cut to the chase with some excerpts:

Research on microplastics (plastic particles less than 5000 ?m in size) initially focused on the marine environment (1) and has since expanded to include terrestrial ecosystems. (2?6) Accumulating evidence indicates that microplastics in the atmosphere can travel above ocean surfaces and even to distant locales via global atmospheric transport. (7,8) However, key questions remain to be answered regarding the vertical exchange and horizontal transport processes of atmospheric microplastics.

Atmospheric microplastics can be deposited on the ground through dry and wet atmospheric fallout, substantially contributing to the presence of microplastics in water and soil environments. (9) Atmospheric transport is emphasized as a crucial pathway impacting the source–sink dynamics of plastic pollution across different ecosystems. (10) Additionally, owing to their ability to adsorb chemicals, bacteria, and viruses, microplastics are recognized as a novel element within the realm of air pollution. (11?14)

Radon-222 (²²²Rn, half-life = 3.82 days), a noble gas and decay product in the ²³⁸U series, is released from the soil matrix at a constant rate, with >99% of ²²²Rn in the atmosphere emanating from continental sources. (15) As the long-lived daughters of ²²²Rn (Supporting Figure 1), (16,17) ²¹⁰Pb, ²¹⁰Bi, and ²¹⁰Po are rapidly adsorbed onto solid particles upon formation, with their fates aligning with those of aerosol-bound particles. The ²¹⁰Po/²¹⁰Pb ratio enables the estimation of the residence time of aerosols (RTA), based on two assumptions: (1) the measured atmospheric particulate matter (PM) is treated as a single entity, and (2) all particle-reactive radionuclides produced by 222Rn decay are scavenged from the atmosphere before reaching a new area. Beryllium-7 (⁷Be, half-life = 53.3 days), a cosmogenic radionuclide, originates from the spallation of oxygen and nitrogen nuclei induced by cosmic rays in the stratosphere and upper troposphere. (18,19) The majority of sup]7Be production (67%) occurs in the stratosphere, and it typically does not reach the troposphere except during thinning of tropopause folds near the jet stream at midlatitudes in the spring. (15,20) Due to their distinctly different source terms but well-established source distributions, ⁷Be and ²¹⁰Pb are widely employed as powerful atmospheric tracers for studying the origins and transport processes of air masses. (15,21)

As PM contains microplastics, active particulate samplers are considered appropriate tools for collecting atmospheric microplastics. (22) Aerosol samples are typically collected by filtering a large volume of air via specialized aerosol collection equipment, (15) enabling simultaneous analysis of filtered microplastic particles and trapped natural radionuclides on the filters. However, plastic and nonplastic particles are intermixed during the atmospheric filtration process, rendering separation of their adsorbed radionuclides impossible. Chen et al. (23) reported that the transport dynamics of plastic particles are generally similar to those of nonplastic particles. Thus, the fates of aerosols are closely linked to those of plastic particles.

Herein, we utilized aerosol tracers (⁷Be, ²¹⁰Pb, and ²¹⁰Po) to trace the origins and transport processes of atmospheric microplastics for the first time in Tianjin, a coastal city in China. The aims of the study were to (i) document the temporal variations in and features of atmospheric microplastics; (ii) examine the origins, transport processes, and residence times of microplastics; and (iii) explore the correlations between microplastics and other components of the atmosphere...

Some graphics:

The cartoon introducing the paper:



Others:



The caption:

Figure 1. Study area and sampling device employed in this investigation.

The caption:

Figure 2. Temporal fluctuations in the abundance of atmospheric microplastics in Tianjin from March 2022 to February 2023.

The caption:

Figure 3. Variations in shape, color, and size of atmospheric microplastics across four seasons. (a–d) Shapes of microplastics during four seasons; (e–h) colors of microplastics during four seasons; (i–l) sizes of microplastics during four seasons.

The caption:

Figure 4. Polymer composition and surface morphology of microplastics. (a) Spectra of common polymer fiber types; (b, e) polymer composition and surface morphology of microplastic fibers; (c, f) polymer composition and surface morphology of microplastic fragments; (d, g) polymer composition and surface morphology of microplastic films. PA, polyester amide; PAL, polyacrylate; PBd, polybutadiene; PE, polyethylene; PE–PP, poly(ethylene-co-propylene); PET, poly(ethylene terephthalate); PMA, poly(N-methyl acrylamide); PP, polypropylene; PS, polystyrene; PS-MA, poly(styrene-co-maleic acid); PVA, poly(vinyl alcohol); RA, rayon.

The caption:

Figure 5. ⁷Be, ²¹⁰Pb, and ²¹⁰Po concentrations and ratios in aerosols throughout the year. (a) Concentrations and ratios of ⁷Be and ²¹⁰Pb throughout the year; (b) concentrations and ratios of ²¹⁰Pb and ²¹⁰Po throughout the year; (c) residence times of aerosol particles throughout the year.

The caption:

Figure 6. Correlations among atmospheric microplastics, radionuclides, and meteorological parameters (n = 18). MPs, atmospheric microplastics; RT, residence time; PM2.5, fine particulate matter; PM10, inhalable particulate matter; PM, total particulate matter; AQI, air quality index; TEMP, temperature; RH, relative humidity; ATM, atmospheric pressure; AWS, average wind speed; MWS, maximum wind speed; AWD, average wind direction; MWD, maximum wind direction.

I've noted here and elsewhere that people like to carry on about radionuclides released from, say, Fukushima, even though there is very little, if any, evidence that these releases have actually killed anyone, but the same people are disinterested in how many people are killed by air pollution generated by coal combustion, which in a typical decade will result in tens of millions of deaths. I wonder if we could get these people to give a shit if they understood that coal ash is (gasp! freakout! gasp!) radioactive, since it contains uranium and all of its radioactive daughters.

This paper notes that coal combustion complicates their work:

Furthermore, Ouyang et al. (41) observed that coal combustion caused an enrichment of ²¹⁰Po in fly ash particles, which could lead to elevated ²¹⁰Po levels in the urban atmosphere when mixed with aerosols in air and long-distance transport. Tianjin begins its urban centralized heating in November. Therefore, we hypothesize that the peak residence time of urban atmospheric particles in November may be correlated with increased ²¹⁰Po levels from coal consumption.

Anyway...

From the conclusion to the paper:

...This study was limited by the range of detectable microplastic particle size, which varied from 20 ?m to 5 mm. Additionally, radionuclides were found to leach from all particle sizes. Challenges remain in developing methods to effectively separate microplastic particles from total suspended particulates during active particulate sampling. An important achievement of this study is the development of a method utilizing natural radionuclides ⁷Be, ²¹⁰Pb, and ²¹⁰Po to explore the transport processes and residence times of atmospheric microplastics...

Have a nice day tomorrow.

[dweller]

1. I only made it this far

“Additionally, owing to their ability to adsorb chemicals, bacteria, and viruses, microplastics are recognized as a novel element within the realm of air pollution. (11?14) “

🫤


We are so fucked …


Have a nice day of your shortened life
😐


✌🏻

[NNadir]

2. I've lived a long life, long enough. The implications are worse for those who will follow.

It is for them I have regrets, what my generation did to all those to follow.

History will not forgive us, nor should it.

[cachukis]

3. Question: Will humans be able to adapt to the

inclusion of microplastics and radionuclides in our daily dealings?
Have we not been contending with smog, say, for sometime?
I camped in a cabin alongside Interstate 75 near Forsyth, GA recently.
The amount of soot on the hand rails darkened my hands.
Should I be worried.

Alice in Venice, FL.

[NNadir]

4. Since it appeared on Earth, life has always been bathed in radioactivity, since the planet has always been...

...radioactive. This may be a major mechanistic driver of evolution, along with kinetic chemical and biochemical effects.

Potassium is an essential element in all living things, and it has always been radioactive. ⁴⁰K has a half life of 1.227 billion years.

As for micro and nano plastics, they are new, but probably, if not likely, to be similar to soot in their biological effects; it's not yet understood. It's not pretty.

Uranium, of course, exists, with all of its decay daughters in its decay series. Human activities, mining - fossil fuel mining is a major source of radioactivity releases; there are flow back water ponds in Pennsylvania that are more radioactive than the seas outside of the big bogeyman at Fukushima, because of the release of ²²⁶Ra. Of course uranium mining and refining also releases daughter isotopes.

It is probably the case that life expectancy, which has risen dramatically over the recent centuries, will begin a decline because of these environmental effects, the most serious of which may - probably is - extreme global heating. We may already be seeing that.

Individual lives will be - are - affected, but life itself is amazing, if nothing else, for its adaptability. Living things will adapt. There already are microorganisms that can metabolize some plastics.

I hope this helps with any anxiety.

None of this means we should not do everything to slow, even arrest, dramatic changes to our environment. We're playing a very dangerous game where humanity is concerned.

[cachukis]

5. Love the answer. I am too old to have anxiety about

what's coming. Have read about microorganisms processing some plastics.
I suspect you are right about declining life spans, but they have been extended by medicines and technology.
I think the schmutz we breathe will outpace the technology to extend our ability to survive it.
I concur that heat is more immediate.
Humanity's self serving lust for enjoyment may not last for most.
We are swimming in a sea of nano plastics and I guess nothing but catastrophe will raise an eyebrow.
Just thinking about my grandkids and what we have left them.