Dear Simon,

many thanks for opening this interesting discussion. I absolutely agree that there is a need for more studies on episodic incidents of air pollution - both in relation to determining causes, assessing impacts and effects as well as developing effective prevention, monitoring, risk reduction measures etc.

I'd be interested, though, to learn more about the terminology you appear to be employing: I don't fully understand the distinction you seem to be making between "ambient air pollution" and "episodic incidents". For many atmospheric parameters, there will be a certain (natural) background level, interrupted by episodic rises or spikes. Is the background level what you refer to as "ambient pollution"?

What kind of parameters or pollutants are you monitoring?

As a result of global warming (and other contributing factors), wild fires (bush/forest/land etc. fires) are increasing in frequency, magnitude as well as duration in many parts of the world. In some of the regions affected by this global trend, wild fires are increasingly becoming a seasonal, i.e., almost PERIODIC phenomenon. I guess in such instances, what we used to refer to as EPISODIC occurrences turn into recurring periodic/seasonal events, thereby not only elevating the overall (annual) background values/amount, but also showing up as seasonal maxima in annual graphs.

Best wishes & looking forward to reading more about your research,

Julius

Estimado Simón:

Tu trabajo es de gran ayuda para entender la contaminación del aire, empero y acorde a los resultados de la COP28 SI es necesaria una investigación continua sobre los incidentes de contaminación del aire porque es crucial comprender sus impactos en la salud y el medio ambiente, así como el desarrollo de estrategias efectivas de mitigación.

Dear Julius Riese,

Many thanks for commenting and for raising some interesting questions.

Terminology is so important and there is a need for me to clarify. Hopefully, the following helps.

Ambient is the average concentration of a pollutant species. It is the background concentration that a population would be exposed to over a longer period - the chronic exposure. This recognises movements in concentrations, with changes measured over longer durations such as 24-hr, etc. This corresponds to the common ‘statutory’ pollutants required to be monitored e.g. PM10, PM2.5, etc. which have longer term standards. Yes, I refer to ambient as being background.

‘Episodic’ defines events typified as higher increases in concentrations of pollutant species over a short duration. Further, the increase is a distinct incident. Such incidents are aberrations from the ambient conditions leading to significant variation against ambient trends. Incidents could be due to changes in circumstances, either (1) meteorological conditions reducing the dispersal of pollutants meaning that they increase in a given area, or (2) an increase in pollution loading such as from chemical incidents (loss of containment of a chemical, or an open uncontrolled fire) or wildfires.

My work has used contemporaneous monitoring undertaken by regulator during industrial open uncontrolled fires that pose a threat to public health. Monitoring data included PM10 and PM2.5 (OSIRIS; 10.1016/j.envint.2017.12.018) and a selection of organic and inorganic species (GasMet FTIR; Article Characterising the ground level concentrations of harmful or...

Your comment about the regular occurrence of bush fires, etc. is an interesting one. Whilst these remain distinct incidents per my definition, I see your argument that their regularity means that they should be a component of the background air pollution concentrations, especially considering particulates from wildfires. And this opens up a new thought: Should we redefine what is meant by background air pollution levels? A percentile of an annual measurement perhaps?

All the best,

Simon.

Dear Jorge,

Thank you for your comments. I agree that we should continue to research air pollution. My focus is on human health but there are also implications for more than just health. Thinking more broadly, the concept of sustainable cities comes to mind as well as essentials for human existence and potential interaction with air pollution such as its impact on Maslow’s Hierarchy (some question this, I however, believe it to be still relevant).