On behalf of Chemical Engineering Department Faculty of Engineering Diponegoro University successfully conducted Visiting Lecturer on November, 7th 2023 at Department of Chemical Engineering UNDIP with title of “Measuring and Mitigating Exposure to Air Pollution” and held by Prof. Greg J. Evans, B.A.Sc., M.A.Sc., Ph.D., P.Eng., FCAE, FAAAS. He is Director, Institute for Studies in Transdisciplinary Engineering Education and Practice (ISTEP), Director, Southern Ontario Centre for Atmospheric Aerosol Research (SOCAAR)
Director, Collaborative Graduate Program in Engineering Education, and Principal Investigator, Evans Research Group from Chemical Engineering & Applied Chemistry, University of Toronto. The visiting lecturer has been held by hybrid mode with number of 125 audiences, not only students as audiences but also the lecturers.
Below, the summary during the visiting lecturer.
Airborne particles
The pollution comes from different sources. Carbon is the biggest source for air pollution in the world. The particles come from anywhere, and have a lot of concentration. Sometimes we can see “them” such as steam. Although, we can see them to prevent us from seeing. Or see their influence.
2 pictures of particles that collected:
Young particle and older particle
Older particle: have layer, spiral, and theres black area in the center
Aerosol particles come from sources and atmospheric formation. Such as industry.
Also, particulate of pollution can be classified by their particle size.
Air pollution becomes the top environmental burden of health. Cause 8.8 million premature deaths per year. The chronic diseases: heart, lungs, and cancer. Actually, the exposure matter of air pollution more at key life stage (around 1-3 years old).
Particulate particles also can affect the lungs depending on their size. So when you take a deep breath, particles go onto your lungs, what happens is your body attacks, fights back, and the first line of defense is the antioxidants on your lungs. So we have ascorbic acid, which is vitamin C, and glutathione, and these are two strong antioxidants agents, so the particles will attack and they cause free radicals, they cause oxidative stress to occur, the antioxidants counter that. So one of the ways that we can measure how toxic the particles are is how they react with the antioxidants. So we take particles from all over and we mix it with synthetic lung fluid, stuff that has glutathione, ascorbate, and we see how it depletes the antioxidants. We call this the oxidative potential.
As you get a value of 1.1, that means a 10% greater chance. 1.2 means a 20% greater chance. And what it shows is that if we look at the places where the oxidative potential is low, the blue line there, we don’t see an effect. Whereas if we look at places where the oxidative potential is high, we see a much bigger effect. And so all of the data that I’ve shown you up to this point about the risks in Indonesia, in the US, in Canada, assume that all particles are the same. Whereas every particle is different. I showed you those pictures. They’re all different. They all have different oxidative potential. So around the globe, there’s a move to suggest that we should move to this metric rather than measure particulate matter just by the mass, assuming they all have the same chemistry, to something that’s more biologically relevant. And so there’s work going on around the world now to measure oxidative potential in different places. We’re part of that in Canada. If you look at the next slide, we’ve collected samples for one month, over two years, from 40 different locations in Canada to see how much the oxidative potential varies in Canada, a place where it’s relatively clean. So one of the things about research in Canada is that we have a lot of expertise in what happens at lower levels of air pollution. And so we have some of the leading people doing the epidemiology of low-level pollution. And if you go on to the next slide. So this is Canada. We’ve measured oxidative potential samples from all of these sites. And you can see it varies by about a factor of four or five. Some of the ones at the top are mining towns, where they’re extracting copper, gold. And because it’s a mining town, there’s a lot of dust. And there’s a lot of reactive chemicals, metals mostly, in that dust. And you get higher oxidative potential.
Traffic dominates near roads: (% from local traffic)
- Ba 90%
- NO 88%
- UFP 70%
- BC 60%
- NO2 40%
Discussion time
Question (Jason, student): all of us want to deplete the CO2 concentration and even minimize it. But I have, like, I think I have misunderstood in the concept that are we actually, can we actually deplete the CO2 contained in the atmosphere since we are actually just moving it from another place to maybe into another. And that, for example, that we are actually speaking about trees, yeah? We, the trees, kan, I have read about article, yeah? I have read about an article where we, when we plant trees, the trees just actually absorb the carbon dioxide, but when we cut those, the carbon dioxide will actually just going back to the atmosphere. And as we know that the population will be growing and growing, and therefore we will need more land and land. And so it’s like a contradicting concept, and so I think I need some enlightening in those concepts. Thank you.
Answer: Thank you for a wonderful question. There was many other wonderful energy sources, wind, solar, hydro. There’s many non-fossil fuel energy sources that could make up for the fossil fuels we need. So that’s the first step. The second one, which is more connected to your question, is once it’s in the atmosphere, what can we do? What will happen is we release CO2 in the atmosphere. It’s in the atmosphere for about 40 years. So the atmospheric lifetime of CO2 is 40 years. So we are experiencing effects from CO2 that wasn’t making 40 years ago. And that’s why people say that this is something not for our children, but for our grandchildren. But what we do now is going to affect two generations from now. Where does it go? It goes into the ocean. So it transfers from the air into the ocean, and that’s creating the added problem of ozone acidification. So we can’t just wait for it to go in the ocean because that would cause another problem. The main method that people are talking about is two methods, or three methods. One is carbon capture at the source. So you have a process where you use amines to scrub the CO2 from the exhaust gas. It’s a separation process. It’s something chemical engineers know a lot about. And you capture it, and then you bury it underground. A second process is we use trees. You’re absolutely right. If we just grow trees, it’s a circle. It’s a cycle. It’s going to go back into the atmosphere. However, if we grow trees and then we burn the trees to capture the CO2 and put it underground or deep in the ocean, then that creates a net flow. So it goes from the atmosphere to the trees to capture it when it’s burning. We get energy from that, and then it goes underground. So that causes a net flow back into the ocean. So that’s kind of two ways that we can do it. The third way is tougher. There’s certainly lots of people working on how to convert CO2 to fuels, to value-add processes. There we use the sunlight to cause the CO2 to react with hydrogen. We take it from CO2 to, say, methane. We put a hydrogen back onto the carbon. You convert it again to get some fuel. So that’s the third way, and people are looking at that type of storage process as well. So thank you for that question. Thank you.
Question (Rachel, student): Do you think that we can eliminate fuels and coals in the near time? How long do you think that it can take for us to eliminate those and substitute it with cleaner energy? Considering that we are not to be pessimistic or whatsoever, I think we have problems that are bigger, like poverty, starving, corruption, and all of those things. Researching trying to get cleaner energy needs a lot of money.
Answer: Climate change is so linked to energy, so linked to chemistry, it’s a place that we can make a difference and create the options for people. And then it’s the government, it’s the population that decides which is the priorities. So, in terms of the timeline, Canada has an ambitious timeline. We’re trying to decarbonize by 2030 to have reduced by 45%. I don’t know if we’re going to make it. That’s a big challenge. Indonesia has an even bigger challenge. The goal here is 2060. And because of the dependence upon coal at the moment, Indonesia has a big production of coal as well. That’s going to be challenging, but our job as chemical engineers is to provide people with the options that may allow it. One of the nice things about energy sources is that the research can be done both locally and globally. So, development of solar cells, development of wind, that’s going on across the globe. Development of nuclear, I saw plans for some small modular nuclear reactors. Perhaps, at one point, Indonesia was very looking at nuclear. That phased away. Perhaps that will come back as well. But try to come up with the options for it. So, it’s up to a country to decide its path. But it’s up to engineers to come up with the technologies that can allow this path.
The bigger the vehicle used, the greater the emission gas produced, for example, trucks used to transport large loads will produce more emission gas than general vehicles. The blue sides come from the trucks, and the orange over there, which is the line, is the black carbon that comes from the trucks. And what it shows is that these pollutants, which are related to the trucks, it’s not how busy a road is, it’s what number of trucks it has on it. So this is typical for Canada, it may not be applicable for Indonesia, where there’s other types of vehicles as well. In Canada we have a problem in that trucks last a long time, so we have a lot of them that have old emission treatment technologies, and we also have a number of drivers that disconnect the emission treatment technologies to save a bit of money. Based upon these data, our government changed the way we monitor vehicle emissions. So based upon this, we used to have to take our car in once every three years to get the emissions tested, and now they’ve moved it to trucks. So this is a way that the evidence we provided changed the policy, so now there’s a focus on trucks instead.
Question (Ibnu, student): So the question is about how do we come up with effective sensors to measure air pollution?
Answer: That’s a great question, and that is sort of where we ended up as well. And in fact, I will share some, so I’m trying to decide what to present as we go through. I’ll include the stuff on the work we’re doing with sensors. In fact, I think I’ll already be able to answer some of that question, so I’ll make sure to include it. So thank you for that as well. So just to go back, the idea of sensors is a way that we can do the research much more widely, much less expensive, much more accessible, bring citizens in, bring the population in, and that’s kind of what’s occurring around the globe at the moment. So your question is exactly what others are thinking.
Divergent and convergent thinking
Research: Inductive (specific to general) and Deductive (general to specific).
I decide I want to study traffic-related air pollution. That’s the entrance here. I read everything I can about other people’s work, do a literature survey, everything that’s been done on traffic pollution, and the project grows. It’s bigger and bigger and bigger. That’s the divergent thinking. It gets to the point where I can’t bring in any more ideas, and I start to focus it down and say, what’s really important? What is unknown at the moment? Where is the area I can make a difference? And that’s the convergent thinking. I then do some execution of the study, I do some experiments, I get some findings, and then at the end I go to the so what, who cares about this, why is it important, and I then go back again to the divergent thinking, to how is the specifics that I came up relevant to the bigger picture, to other people in the world. So here we’re switching back and forth between convergent thinking and divergent thinking. Two things that I want to do to think about and get familiar with is the inductive and deductive thinking, and convergent and divergent thinking. So just to introduce those. When I try to come up with research questions, those are the two ways that I approach it.
Measurement of PM on filters: The air filter that will be checked for 24 hours and then tested for what substances are contained in the air. so in the case of Jakarta, they’ll measure filters, they’ll analyze organics on those filters, metals on the filters, and then you find out on different days which pollutants, which metals, I’m showing aluminum and calcium here, vary in time in the same way, and if they show the same time variation, it means they likely come from the same source.
NO emissions will increase at low temperatures, in the winter season NO gas emissions will generally increase and will decrease as the temperature increases.
You may have seen that when you take a piece of wood and it’s burning, it’s on fire, and you put it out. You dip it in some water or something like that. Then you see the smoke coming from it. You see the particles. So, you get a lot more particles when it’s smoldering, but we have to put out the fire. It’s a wildfire. And so, even after the fire is out, we still get lots and lots of particles. So, we’re doing a study in terms of how much did these wildfires impact air quality across Canada. And we’ll probably have results for that for next year. What did it look like? I’ll show you on the next graph. Here are concentrations for Toronto, our population of 5 million people. There was a fire burning 1,000 kilometers away up in Quebec. Typically, we have concentrations of about 6 or 8. Here is what I’ve experienced in Jakarta, 50 or 60. We were hitting 150, 200 for many days in a row. And so, this is some really bad air quality. Not quite as bad as what they have in Delhi at the moment. Sort of way worse than what I’ve seen in Indonesia so far. And that was very good for Canada. And it’s been a real light up there. And there’s no reason not to think it’s not going to happen again next summer. So, this is an impact of climate change that we’re seeing now.
Question (Prof Herman, moderator): Most air pollution is caused by vehicles. Recently, many people have said that electric vehicles are a very good solution. What is your opinion about it?
Answer: In my opinion, using an electric vehicle is one of the best solutions, but what needs to be considered is the ability to cover long distances, so you still need to think about it.
So, this comes to the end of our little journey together. Hopefully, you can now describe to someone, to your family, to a friend, how air pollution is impacting you.