Scientific Progress goes Boink!

I recently attended an excellent online webinar hosted by the American Chemical Society and presented by Dr David Constable, Director of their Green Chemistry Institute in Washington DC.  I have known David for a long, long time and share his goals of reimagining chemistry away from our non sustainable dependancy on fossil fuels be they oil gas or coal. David has been an excellent proponent of green chemistry for many years and in a variety of influential roles within a range of industries. His presentation was well attended, a tour de force of the subject and equally well received by the large audience, so why did I log out at the end thinking, “Huh??”. 

Well primarily because I was so disappointed in how much we still have to do in this respect. Around the world International, National and Commercial organisations have all espoused the move to a more sustainable manufacturing ethos, and as chemistry lies at the heart of  so much of that sector, it should surely represent some of the lowest hanging fruit. In many countries, for instance EU member countries, grants and aid, both technical and commercial, are available for those wanting to move their existing processes to safer, more sustainable processes. I was at a loss as to why the clock seemed to be ticking backwards in the US, with so many questions raised about the commercial negative impacts of changing processes. The consensus seemed (I only say seemed!) to be that, ‘If it ain’t broken, don’t fix it!” But maybe it is broken, maybe it does need fixing. International regulations and standards were cited by someone  who clearly thought that if you had met the minimum requirements of a standard then that was all you needed to do. No, I cannot agree; that is where you start from, not where you aim to end up. As push comes to shove. as it surely will do, then doing the bare minimum is not going to protect your revenue stream, it is going to kill it. Customers no longer just want the spec on your product, they want to know how well you managed it’s production.

The pace of change and the rush to safer, more sustainable manufacturing, including chemistry is gaining momentum all over the world. Except maybe in the USA where the rush to make the US great again has led to a resurgence in reliance on a coal based economy. In order to deliver jobs, whether sustainable or not, coal is becoming king in the US and, with the cuts in EPA funding, the required abatement technologies are simply never going to happen. “Make the US Great Again” may well turn into “Make the US Grey Again”

I admire David’s continuing knowledge, enthusiasm and zeal, bit I do worry that his goals are moving away from him for the duration of the current Presidency. Hopefully the next swing of the pendulum will bring the US’s attention back to the damage that unsustainable practices do, for now in the long term, but in the future, when the US tries exporting unsustainably manufactured goods, in the short term as well. 


So long, farewell, au revoir, auf wiedersehen, hyvästi!

DSC_0435Next month I will be “retiring” after nearly 50 years working in Aerosol Science and Technology, first in Research then in Sales and Sales Management. I use quotes, because as many of you will know, I have my own company, so a straightforward “finish work, ride off into the sunset” scenario is somewhat problematic. I have recent customers to continue to support. But, effectively I am out of here! Last one out switch the lights off (Oh, that’s me too)

I have been incredibly lucky to have worked with many people who have given
of their expertise and wisdom across so many fields. Initially I worked in aerosol science as a researcher in one of the world’s then largest and most diverse chemical companies. I was there when John Gage, the inventor of the concentric jet atomiser and constant level reservoir technique was still there. It sounds quaint now, but back then we spent many hours grinding glass jets to obtain the optimum venturi and atomisation – real cutting edge technology!  That was when the importance of passing on our experience to those that come after us was first demonstrated to me. I am grateful to all the other people I have respected and looked up to over the years who have reminded me of this lesson. There really are far too many to name and many won’t even have realised the lesson I had taken away. Sometimes they were teaching me about aerosol science, sometimes they were pointing out the way I should be heading, sometimes they were teaching me about people; most often by being a good example, but sometimes by being a bad example! We can learn just as much from other people’s bad behaviour as we can from shining examples.

No, some have to be named! Huge thanks to Tony Riley, David Constable, Geoff Pigott, Ian Rothwell, Alan Cussens, John Dimmock, Bob Gussman, Roy Harrison, David Mark, Jeff Weed, Gil Sem, Martin Abbott, Kevin Krause, Harriet Pirino, Alan Traylor, Troy Tillman, Hans-Georg Horn, Don Clark, Karen Long, Markku Rajala; the list is endless.

Science and technology have been important to me, but no more so than the personal skills and attributes I came to treasure so much in the people I have worked with and for; reliability, steadfastness, loyalty, and caring just as much for the success of colleagues as for oneself. I won’t do “Dog eat Dog”. Over the last 20 years or so those personal qualities rose to the fore in teams I have worked in, and had the pleasure to lead. I told the teams I have had the privilege to lead that I worked for them and their success, not the other way round. I still believe that and I hope that belief has rubbed off on them.

I have been pleased to work with, and for, some absolute stars, both as colleagues and as clients. We have all come across rogues as well,  but we can learn just as much from them. It is often a lot easier to know what we do not want to become, than to know what we do want to become.

So, we are off on our adventures in our campervan, and I want to thank everyone who has made my professional career what it is. I wish you all every success in the future and look forward to keeping up to date with my fellow rogues  at The Aerosol Society!

A takeaway message? How about, “You have two ears and one mouth. Use them in the same ratio”?

We need to know where the target is!

DSC_0416.jpgI know, it’s been a while since I last wrote on here….

It’s not just that the UK’s new plans to tackle Air Pollution are weak as has been widely reported in the press this week – the main problem is that the new plans have been aimed at entirely the wrong targets!

By and large, the plans are far more about revenue collection than pollution abatement. Local authorities are to be encouraged to retrofit abatement technologies on highly polluting vehicles (within their own fleets) and to charge road users with “highly polluting vehicles” a punitive premium for using the vehicles that a) their government encouraged and underwrote the development of and b) their government encouraged them to buy in the first place. So, most of their plans are about making people pay for using the vehicles they bought in good faith. A scrappage scheme has been announced that will take maybe 15,000 of the older, “more polluting” vehicles off our roads, but is not those vehicles that are causing the rise in observed health effects and all those early deaths that keep being reported.

If you fit an older vehicle with abatement technology on its exhaust, then the particles (all that unsightly black soot) doesn’t go away, it simply gets “re-burned” by a variety of technologies that dramatically increase both the surface area and the number of much finer particles than was there originally. These particles are orders of magnitude more toxic (primarily because of their increased biological availability) than the unsightly soot particles emitted by the oldest of our diesel fleet. They may have looked bad, but they were deposited out very effectively in our conducting airways and excreted in very short order. This means that getting rid of the older vehicles or retrofitting abatement technologies to public fleets could actually make the adverse health effects of our poor air quality worse, not better! At the same time, many such technologies and improvements to engine management systems (even when used properly) increase the amount of NOx gasses emitted by diesel engines. NOx is another target pollutant for regulatory authorities around the world, but it is not an inherent consequence of a diesel engine so much as it is of the abatement technologies used to clean them up.

The problem is that governments around the world have been reluctant to admit that whilst monitoring the mass of airborne particles used to be a good way of monitoring pollution and predicting health crises, it no longer is. The ultrafine particles now emitted by modern diesels are very much more toxic and yet still have a reducing mass contribution to air pollution. If you take a 1 µm particle and divide it into 0.1 particles then you end up with 1000 of them not 10! If you do it again you end up with 1,000,000 particles! And this is the scale of reduction in particle size routinely achieved by modern abatement technologies. Mass concentration is no longer an adequate yardstick by which to measure and to monitor pollution levels in our cities. Suitable monitoring technologies have been repeatedly proven in the field (and more importantly, by the roadside) and yet Regulatory Authorities stick to their mantra of “Mass is best – PM 10 and PM2.5 have worked for decades”. Yes, they have and no-one is suggesting that these parameters be abandoned, but the physical nature of the beast – the pollutants in our air – has changed; the health effects of these pollutants has changed and we have to look at adopting new parameters to better monitor and control what we are all breathing in as we walk along our city streets. You cannot control any aspect of our existence without being able to monitor what happens when we change the inputs. Sadly, it is no longer the pertinent parameter.

If we were to stick with mass concentration results then we would be able to conclusively demonstrate that our air is getting cleaner, and by that parameter that is true Mass concentrations have been going down for years in most major western cities, but ill health potentiated by airborne pollution has risen alarmingly and with no correlation to the mass concentrations so jealously guarded by National and International Governments.

It is time our governments listened to the scientists; pollution is not about opportunities to raise revenues, it is a challenge we must manage to control using a credible management plan. As ever, the first part of any management plan is to know what you are dealing with; where the inputs are coming from; where the changes are happening; why they are happening and what we need to do to investigate those changes and to make things improve.

Post Brexit our UK government will not have the facility to blame Brussels, they will not have a universal “Get out of jail Free” card, they will have to deliver. We have the brains and technology in this country to make real improvements in our lives and our health; we just need the political will and integrity.





Why do we want to measure an Aerosol? And does the Why dictate the How?

I have recently read two very interesting articles on aerosol science. One was by David Harris highlighting the difficulties of creating a dry powder aerosol for respiratory therapy, and the other by Jonathon Symonds announcing the Aerodynamic Aerosol Classifier.  Both articles are interesting, informative and address real and current issues for aerosol science.

But the two articles highlighted an interesting juxtaposition for me;  It has long been appreciated that the behaviour of larger particles, let’s say > 500 nm, is dominated by their inertial, aerodynamic properties. Sometimes this range is referred to as behaving classically, or as within the Newtonian regime, but below that there is a transition range down to about 300nm where inertial and diffusional processes are balanced. Below that lower cut, the behaviour of particles is dominated by their diffusional (or mobility) properties. David rightly points out that upper air way deposition is inertial, dominated by impaction, interception and to a lesser degree, sedimentation. But down in the gaseous exchange regions of the lungs deposition is dominated by diffusional processes. As the air stagnates ultrafine particles go off on their random walks, down the concentration profile to the surface of the bronchioles or alveoli.  Not only are the sites of deposition different within the two regimes, but the nature of that deposition is different as well; inertial impaction traps particles in well-defined and localised sites where dose rates can be extremely high, but dissolution rates can become slower because of that highly localised deposit. For diffusion deposition, the sites are much more diffuse; deposition occurs literally anywhere with the terminal bronchioles or alveoli, so no large concentrations are built up to slow dissolution. At the same time because of the huge increase in relative surface area top mass / volume, the fate of particles deposited by diffusional forces is very different. Dissolution rates can be orders of magnitude higher than for the same materials presented as larger particles and such particles have been shown to pass across the cell interstitium intact and to be collected for instance in the liver.

So, particles within the diffusion range behave very differently from those in the inertial range when they enter into the respiratory tract.  So far so good, but that is not the full story, because these differences apply just the same when we talk about filtration, so important for cleaning the air in our homes, our offices and our transport. They are just as relevant in vehicle emissions technology, clean room technology, ambient air assessments and really, across the whole gamut of aerosol science real world applications. Which makes me a little concerned when it is suggested that the aerodynamic equivalent diameter of particles much smaller than 500 nm should be of interest and that we should monitor it.  I have always been concerned by this need to manipulate date sets, say from an inertial sizing device with a concurrent data set from a diffusional mobility sizing device. One company I used to work for even had a software package that would merge two such sets of data based on the assumption that the two data sets would/ should form a continuum. Why? To me it is like assuming that the distribution of lorry sizes would form a continuum with the distribution of bicycle sizes. They are different data sets, describing different properties which have profoundly different effects on their components’ behaviour. Why should they intersect?

Don’t get me wrong; I have studied the new Aerodynamic Aerosol Classifier and it is surely a great step forward in the technology we are able to deploy as we search for a better understanding of the behaviour of airborne particles. I look forward to “having a play” with one. And this is not even the first time this overlapping of technologies has occurred; the MSP MOUDI (Micro Orifice Uniform Deposit Impactor) is a conventional impactor, of great design and worth, but then they added several low pressure stages with cut points down in the 10’s of nanometres where diffusional rather than inertial deposition must surely be of greater interest, and how were we to reconcile changes in dominant deposition factors across the different regimes into one continuous relationship?  The Dekati ELPI is another similar device that crossed the intersect between the diffusional and inertial regimes without perhaps giving sufficient consideration to the relevance and applicability of the two very different sets of processes. My issue is the conflation of inertial and aerodynamic descriptors and which terms would be of the most relevant across what regimes. Instrument developers need to more fully appreciate the requirements of their potential customer base. It isn’t what your instrument can do that will sell it in huge numbers so we can all retire to sunnier climes, but it is very much more related to what your customers want it to be able to do for them. Those of you that know me well, will recognise this as a particular and long held hobby horse of mine. Again, do not get me wrong, I am not criticising Cambustion, MSP or Dekati , in any way, but does there seem to be a lack of rigor that should be asking, “OK, but why on earth would I be interested in the aerodynamic diameter of a particle whose behaviour is dominated by its diffusional properties”, and vice versa.

Maybe we have to give far greater consideration to the “why” of aerosol monitoring as well as to the “how”? I would welcome your thoughts.

There is still such a long way to go….

The California Air Resources Board (CARB) has lead the way in understanding, monitoring, legislating and abating the toxic urban pollution that is largely a result of our love affair with the infernal combustion engine, but even in the Golden State, there is clearly still a long way to go. The Los Angeles Times today reports that Los Angeles and Bakersfield are at the top of the US list of cities with the worst air pollution, and it looks like the chief villain of the piece is still fine particles.


To quote the LA Times, “Millions of Californians live in places with dirty air, according to an annual report card issued Wednesday that ranks two major urban areas in the state as the nation’s most polluted. Bakersfield tops the list for having the most unhealthy days from airborne particles spewed by highway traffic, diesel trucks, farm equipment and fireplaces, the American Lung Assn.’s State of the Air 2016 report says. Los Angeles remains the nation’s leader in harmful ozone pollution from car tailpipes emissions, the report says.Air pollution can trigger asthma attacks and heart attacks, lead to lung cancer and cause premature death. Eight out of 10 Californians — 32 million people — live in counties with unhealthy levels of ozone or particle pollution some time during the year, says the report, using U.S. Environmental Protection Agency data for three years ending in 2014.”

California  suffers the double jeopardy of high primary emission particulate levels (directly from the tail pipe) and, because of it’s climate, topography and water usage,  also has high levels of secondary fine particles and no one is going to solve one without solving the other. Once they enter the atmosphere particles from both sources scrub out the gaseous pollutants they share the urban soup withy and become almost indistinguishable from each other without the use of prohibitively expensive particle chemistry analysers which still cannot get down to the small particle sizes causing the health problems.

This whilst only last month the Southern California Air Quality Management Board vowed a “friendlier approach to pollution from the oil refineries” down there.  Apart from the particulate issuing from refinery stacks, most importantly there are huge amounts of Volatile Organic Compounds (VOCs) that billow forth 24/7 and which are then carried by the prevailing winds up along the California coast lands to the metropolitan areas of Los Angeles and San Francisco. During this transit, atmospheric processing will transform much of this material into fine particles.

Then, on top of all this, we are still not even looking at this pollution with a still relevant set of kit and parameters. Fine particles? OK, that’s alright, we have optical particle counters that monitor PM2.5! No worries!

None of these particles gets anywhere near large enough to be effectively seen by an OPC and besides, it’s the number (maybe the surface area) not the mass of particles which is creating such an increase in ill health. In fairness, most cities can demonstrate reductions in mass concentrations, but the number of fine particles rises every year. OPC’s cannot seAQ Urbane particles smaller than, say 250 nanometer (nm), but maybe 90% of the particle number concentration is less than 200 nm. It’s like trying to carry water with a sieve – it’s just not the right tool for the job – especially when perfectly suitable buckets are available!

Devices are now available that will routinely, relevantly, effectively, and cheaply monitor fine particle number, mass and surface area concentration right down to 20 nm so they can see circa 98% of the fine particle distribution.  Only when we can see the full picture will we start to understand the full picture. We should have these devices on every street corner! We should be making use of the billions spent on smart city technologies that allow such devices to monitor, to map, to model and to warn our citizens of high pollution events.

It is going to take decades to clean up our urban air, but we cannot even start to formulate plans until we know exactly what it is we are dealing with. Our last major offensive on pollution was aimed at all that black smoke coming out of factories, power plants and automobiles, and although we can’t see the smoke any more, it is still there and maybe orders of magnitude more toxic than it used to be.

Just because we can’t see them shouldn’t stop us focusing on fine particles

According to today’s Guardian, “The number of premature deaths attributed to particulate pollution has risen, government figures show.

According to Public Health England, the percentage of premature deaths attributable to minute particles known as PM2.5s rose to 5.3% in 2013 in England from 5.1% in 2012. The death rate in London rose to 6.7% from 6.6%. The figures follow significant improvements in air quality across England in 2010 and 2011.” (But only when monitored by technologies which are unable to even detect, let alone monitor the key pollutant – ultrafine particles – IPB)

“The figures were announced as scientists at King’s College London warned of “high” or “very high” particulate pollution across much of London and south-east England for a second day. People with heart conditions or breathing problems were advised to reduce exercise and to stay at home.”

It is estimated that there are currently 40,000 early deaths every year in the UK and over 500,000 a year across Europe. Our air does look cleaner than it used to do, but sadly it may be more toxic and hazardous than ever before – we just can’t see it with the tools we have been using.

Fine particles are produced when we burn fossil fuels; wood, coal, gas, oil – they will all produce fine particles when they are burned and we don’t seem to have a very effective respiratory defence system to cope with them. Years ago everyone was sick and fed up of all that black smoke billowing out of the back of fairly basic diesel engines. The fact that it was black meant that we could see it and the fact that we could see it meant that the particles were, relatively speaking – huge! Our respiratory tract knows how to get rid of such particles; their deposition onto the surfaces of the conducting airways was optimised by the design of these airways over millions of years. Once deposited, the particles are cleared within, let’s say 24-36 hours- tops! Off they go to the gut and, as they have a relatively small surface area, not much gets absorbed before they leave the body in the approved manner! So, engine manufacturers cleaned up their act; lean burn engines, cleaner fuels, better fuel economy all helped bring down the mass of black soot that belched forth into our breathing zones. After engine treatments further reduced the mass pollution and suddenly, diesel engines looked no dirtier than petrol engines, which, once TEL had been taken out was perfectly harmless right? Well no, not really.

True, the mass concentration had been much reduced, but  all these incremental improvements had caused the fuel to be burned much more effectively and so the particles that were produced were much smaller. A single, easily visible 10µm particle has the same mass as 1,000,000 0.1 µm particles. Some, many 10µm particles were trapped before they could reach our urban air, and so the mass concentration of particulate started to drop. But some of those larger particles got broken down; they became smaller and smaller, broken down into fine particles and so the number of very fine particles began to increase – significantly.

Those charged with the assessment of our air quality hit a problem. Regulatory authorities do not like change – especially in key parameters used to define what is going on. National, International and global agencies rallied to prop up PM10 and PM2.5, despite the growing scientific evidence that observed health effects associated with poor air quality were no longer tracking mass based fractions of large particles anymore. In other words, we could have a pea souper of very large particles without a corresponding rush to A+E, but sometimes there were huge increases in admissions and referrals associated with respiratory and circulatory disease when accepted air monitoring requirements didn’t show any cause.

That’s because the particles are too small to even be seen by our conventional monitoring methods; they are too small to contribute to an upsurge in mass, but they do exist, and are highly toxic. As they have got smaller, particles’ surface area increases exponentially, by the square of the reduction in diameter, so two things happen in the respiratory tract: The particles are not effectively deposited onto the conducting airways so they pass straight through to the still air in the alveolar air sacs where gas exchange takes place. In the relatively still air they become deposited onto the surface of millions more cells than was previously the case and then they either stay around causing local effects, or because they are so small they can squeeze between cells and into the circulatory system where they can wreak havocAQ Urban just about everywhere, but mainly in the heart, the circulatory system, the liver, kidneys and brain. Even if these fine particles are made up of the same material as those huge black smoke plumes used to be, their fate  and their effects in our bodies are hugely different. Why? Because of their size – they are simply much, much smaller.

For years, we have had to resort to monitoring NOx gases (don’t ask!) which have tracked well with fine particles concentrations within urban air. But the technology to routinely, robustly, cost effectively and directly monitor fine particle number concentrations (or surface area) wasn’t available. Now it is. Pegasor, a company up in Finland has come up with a technology that can do all this and report moment by moment concentrations across cities and beyond. Here’s what the number concentration did a few days ago in Tampere:

PN Tampere 24 hours

You can see that those local hotspots and short term incidents mentioned in Dispatches last night on Channel 4 are not static, they can move around, passing through one location quite quickly depending on wind speed and direction etc, so maybe something with a little more resolution is needed for fine particles than the 15 minute time weighted average used for larger particles.

There is a growing mountain of evidence that suggests that fine particles simply are not the same as their larger counterparts; their biological fate and availability are substantially different. There is no credible evidence that suggest that they are the same. We don’t monitor “Gases”, we monitor specific gases with known hazards, so why would we monitor “particles” without taking note of their size, their morphology and their associated hazards, risks and toxicity.

You can expect a lot more in this vein during my talk at Air Quality – Science and Technology in Milan next month. Come along and find out how we finally got a handle on fine particles.


China; a country determined to deal with environmental issues

I recently spent 10 days in China developing links to a burgeoning environmental monitoring and remediation market. Intellectually, you know that China is huge, with a huge population and growth rates that the rest of the world would still kill for. But until you have experienced the scale and the energy of China, it is hard to fully grasp the enormity of the challenges and opportunities that 1.3 billion people can create.

In Beijing we met with many groups who are in the process of laying claim to the regional channels to market. Beijing city has a population of 12 million people and has huge environmental problems. But here is the most important difference that struck me; they acknowledge that there are problems and are doing real things to make things better. They are not just talking about it, they are making real improvements to urban air and by direct relationship, to indoor air. DSC_3329As well as all their energy, they have a practical focus that drives them to be quite sure they know what the problems really are, on the ground, not just theoretically, as described by scientists, so they go out there and they set up monitoring stations, networks and modelling data management processes that leave Europe and North America in the shade.

Next we visited Guangzhou in the south, a “smaller” city of only 9 million people. Here we were part of a delegation from the City of Tampere as part of their twinning with Guangzhou, so we travelled with the Deputy Mayor of Tampere and met with the Deputy Mayor of Guangzhou and his various Directors of all things Environmental. It was amazing to see how such a trip 6FO23O9bcFTeV_OG6Rt31BUF3Ajncwa_JjtHTOZcNrUHVO8IJtFilv9lXsJL0kvTuqLrFOa21NCeO_NYlXA5Pgcould get us in front of people at levels we would never hope to achieve on our own. Again, we were so impressed by their willingness and enthusiasm to accept real issues and to look for real solutions. It’s always good to meet with Finns, and this crew were no exception, so helpful and cheery. It really is the way to get things done. We visited their environmental Labs (I have never seen such a comprehensive set up anywhere in Europe or North America) as well as a monitoring station (see last brackets!) and their Vehicle Test Centre.  Later we visited their new Waste to Energy Incinerator. It was particularly frustrating for me given that any suggestion that we burn our waste to provide energy is met with howls of protest from well meaning but misinformed “tree huggers” in the UK. Everywhere we were met wit hospitality and a keenness to learn. If we spend some time learning about how China does business there are huge opportunities for western technology companies in China. But we have to realise that business is managed very differently in China, not better, not worse, just differently.

Finally we went off to Shanghai, the largest city in the world at 15million residents rising to 24 million if the entire directly controlled municipality is considered. Not only does Shanghai cover a huge area, like Beijing and Guangzhou (and over a hundred other Chinese cities larger than 1 million people) but it rise to great heights too. Monitoring and modelling in such circumstances adds a new dimension, literally! Fine particles are a huge problem for China’s cities, but their city managers have recognised the challenges and as they are judged on the standard of living they deliver for their residents, have a vested interest in resolving the issues fully and well. It is up to us in the west to make the most of these opportunities, not to criticise the Chinese for poor air quality (and water) but to congratulate them on their resolve to put things right.

Huge thanks go to Pekka Salmi, Satu Vuorinen from City of Tampere and Yanan Mi from Pegasor who mades sure I did no harm, came to no harm, translated my words and showed me her country so well.