Clean Dirt Reviews
Plain english literary digests of scientific articles about natural degradation of persistent organic pollutants
Welcome to Clean Dirt Reviews
This repository provides plain english mini reviews of scientific articles relating to soil processes that assist in the degradation of a class of chemicals known as persistent organic pollutants or so called POPs.
What are POPs?
POPs are some of the most persistent organic pollutants that humans could have developed.
Stockholm Convention
The type of pollutants discussed here were identified by the Stockholm Convention, a global treaty adopted by 183 countries with aim to eliminate or restrict the production of these chemicals (http://www.pops.int/). All of the currently listed compounds (30 compounds or compound classes at the time of writing) in this treaty remain a significant risk for environmental and human health.
If you have seen news or movies that relate to soil and groundwater contamination it is likely that the contaminant in question was one of those chemicals discussed here. If you have a scientific background and are interested to find out more you might find this repository useful.
Halogenation
Most of them are chlorinated compounds including the better known pesticide DDT but some compounds are fluorinated, such as PFAS and PFOA while others are brominated. The chlorine, flourine or bromine often determines the ‘behaviour’ of these chemicals in our environment.
Sources
They were mostly produced and marketed as agricultural pesticides or are byproducts in the production of pesticides. Others are produced for industrial uses or are released unintentionally through industrial processes.
Risks
Health and environmental risks of these compounds are associated with their persistence, toxicity, the large scale at which they were releases globally, their long-range transport and tendency to accumulate in animal and human tissue.
Here to stay
Due to their extreme persistence POPs will remain part of our environment and food-chain for another few hundred years unless we figure out how to enhance natural degradation processes. Hence, reviews on this site aim at exploring degradation processes of POPs that can occur naturally in soils but are currently too slow (or may even have stopped completely).
Natural degradation
For the long-term I believe that natural degradation is the only realistic strategy to minimise potential risks associated with residues of POPs in our environment globally. However, we need to understand biodegradation processes much more before we can use them effectively.
More information can be found on our resources page (it is still under development).
Contact me anytime or comment on individual reviews to get a conversation going.
"POPs will remain part of our environment and food-chain for another few hundred years unless we figure out how to enhance natural degradation processes"
Recent Reviews
PFAS - the new POP on the block
Nguyen, T. M. H., Bräunig, J., Thompson, K., Thompson, J., Kabiri, S., Navarro, D. A., … Mueller, J. F. (2020). Influences of Chemical Properties, Soil Properties, and Solution pH on Soil–Water Partitioning Coefficients of Per- and Polyfluoroalkyl Substances (PFASs).
Does organic matter matter?
Graphical abstract reused with permission from Elsevier (23.11.2020).
Krohn, C., Jin, J., Wood, J. L., Hayden, H. L., Kitching, M., Ryan, J., Fabijański, P., Franks, AE., Tang, C. (2021). Highly decomposed organic carbon mediates the assembly of soil communities with traits for the biodegradation of chlorinated pollutants.
An example of POP persistence from an era of peak-POP-use
Nash, R. G., & Woolson, E. A. (1967). Persistence of chlorinated hydrocarbon insecticides in soils. Science, 157(3791), 924–927. https://doi.org/10.1126/science.157.3791.924
Credit to Nic Uren for providing me with this article.
Why read this article?
Biography
In project 1C of the Biosolids Training Centre we aim to make anaerobic digestion more efficient. Anaerobic digestion is an essential but error-prone, biological wastewater treatment process and we are investigating its microbiome and metabolome to develop biomarkers that can be used for diagnostics and prevention of common problems.
After a tortuous industry career path that took me from Germany to Vietnam and Hong Kong/Shenzhen, I decided to pursue a path into academia and develop new skills and expertise. I studied the degradation of chlorinated legacy pollutants such as dieldrin that contaminate agricultural surface soils since several decades. My PhD experience could be summed up with: “Amplicon sequencing, microbial diversity, chlorinated pollutants, organic matter and how everything connects”.
In 2021 I joined the ARC Training Centre for the Transformation of Australia’s Biosolids Research, right after finishing my PhD. Here I can build on my graduate experience to develop new skills with aim to have significant impact on improving biosolids reuse in Australia.
More details available on LinkedIn
Interests
- Wastewater, sludge and anaerobic digestion
- Bioinformatics
- Chlorinated pollutants
- Soil organic matter
- How everything connects
Education
PhD in soil sciences and soil ecology, 2021
La Trobe University
Bachelor of Science (Major in Agricultur and Env. Geo Sciences), 2017
La Trobe University
A tortuous path leading to this point
Recent accomplishments
Thesis submission
Thesis title: Exploring the Potential of Microbial Diversity in Dissipating Legacy Pollutants in Surface Soils
Presenter at the SSA conference, Cairns
Presentation title: ‘Association of soil organic matter fractions with the assembly of soil communities for the biodegradation of chlorinated pollutants’
Winning Team (La Trobe) National Soil Judging Competion 2021 - Cairns
Soil judging competitions involve university students competing to correctly identify soil features, classify soil profiles, and interpret soil capability
BIF003x: Statistical Analysis in Bioinformatics
Eight week self-paced course on how to use the R environment to perform statistical analysis on biological big datasets
See certificatePresenter at the MEEM symposium
Microbial Ecology and Environmental Microbiology (MEEM). A symposium designed to promote communication/collaboration for those interested in microbial ecology, environmental microbiology, evolutionaly microbiology and related disciplines
PH526x: Using Python for Research
Short course on how to apply Python research tools in practical settings.
See certificateOrganiser and host of inaugural Ian Sargeant Student Awards
Organiser and host for the inaugural student competition and award on World Soil Day which is named in honour of Dr. Ian Sargeant.
Presenter at the 7th International Soil Organic Matter Symposium, Adelaide
Statistics and R
See certificateReceiver of the Frank Gibbons Award
CSIRO Undergrad Vacation Scholarship Placement
10 week research program, investigating the effects of organic broad acre biostimulants, inoculants or extracts (i.e. alternative fertilisers) on seed germination, root growth and microbial activity. Final report submission and presentation at the student symposium in Canberra
My tortuous path
Melbourne
RMIT University
The hard work and many many hours at my desk while neglecting everything else, is coming to fruition. In my job as an Industry Centre Postdoc, it all comes together. I finally feel that my/our work can add value, even if only a tiny bit.
Melbourne
La Trobe University
From undergraduate studies straight into PhD research. Thesis title: “Exploring the Potential of Microbial Diversity in Dissipating Legacy Pollutants in Surface Soils”
After graduating with a Bachelor of Science I felt truely liberated from nonsense. I finally seem to have the tools to search for truth while keeping my own biases at bay. As I discovered, that is not always easy.
This re-learning of thinking was hard and accompanied by many challenges. Do it if you can! Personal growth guaranteed.
G’day Sydney
Webster Holdings
Following love and life. From South Easy Asia to Australia. At this stage it felt like just another relocation. Now I know to call Australia home.
Continued to do what I knew best until then. However, I slowly realised that I needed more. A little bit of forced encouragement through a redundancy was needed for a final decision to change my career. An new journey of discovery was ahead with a big leap of faith into the unknown.
Hong Kong / Shenzhen, Neih hou and Ni hao
Wise Pearl Limited
Continuing on the path of fulfillment and discovery… This time playing with the dragon.
It was tough and character-building work for a factory. Overall a great experience.
Ho Chi Minh City, ‘Xin Chào’
Melcosa Vietnam
Tried to figure out how this export stuff really worked. Working with European clients while getting a real taste of life in Saigon. From an overseas internship to managing new business for export.
This amazing city seeded my path forward. No less because of the people I met - one of which would forever change me.
Hamburg
More filter coffee please
First taste of independence and a daring move to the ‘big’ city. After growing up in small-community suburbia this was really exciting. Learned the import/export trade at the headoffice of a German retailer.
Alveslohe
Moin moin
From suburbian small towns to small countryside villages. A life-detour back to the former family farm.
Hasloh
Moin
Ins Leben gestartet. Life started here. The good old times with lots of memories that help with the nostalgia ;)