Hello. Welcome to All Things Air.

My name is Kieran Sheth, and I'm a science communication and environmental justice intern for the US Forest Service.

In this podcast, we dive into air quality, air control, and basically all things air. From talking to different podcast episode, I am talking to David Gay, the coordinator of the National Atmospheric Deposition Program at the University of Wisconsin Madison.

Awesome. So let's just get started.

So Okay.

What, is your role exactly, as a researcher? I think I saw in your bio that you were the coordinator of National Atmospheric Deposition Program at University of Wisconsin. So what do you find most interesting about that role that you currently have?

Well, it's an interesting role. I mean, it's they call me the coordinator, but I'm basically the manager of the network. So my job is to keep all the monitoring running from a physical standpoint.

Samples in the bucket, samples to the lab, and then the analytical data and the QA that follows it up so that all researchers have the data that we provide.

And it's a challenge with three hundred and fifty monitoring locations across North America. It's a challenge sometimes.

But the network's been running forever, and I personally am a researcher more in the mercury end of things.

We have one network that just does mercury deposition. And so and I'm a lover of statistics, one of those strange people that love statistics, and I like to run long term trends. And so from that standpoint, the NAEP provides me the perfect dataset to work on in the kinds of research that I like to do or the conditions of deposition getting better or worse with time.

Are they lining up with policies that come in and restrict emissions, which should lead to lower deposition before we actually seeing that in the real world. So sort of tying the the regulation to actual changes in the environment. So it's kind of fun to do that. Yeah.

So that's pretty much the kind of thing that I do.

Yeah.

I run the network and then a little bit of research on the side when I get a chance.

Yep. Definitely. And I think I also saw, in your bio that you did sort of like consulting also, in a sense for a firm. So what kind of has been your takeaway from, you know, doing that kind of business aspect also with, you know, kind of the science and environmental aspect, of, your research?

Well, the consulting world, was a long time ago.

I've been in the app I've been in the academic side of things for quite a while, but, two very different worlds.

In the consulting end, it's very much tied to doing or completing exactly what the customer wants on the customer's time scale.

And that's funny because you get to see a lot of different things. I got to I did a lot of particulate monitoring, back then, a lot of CO monitoring back when people were worried about carbon monoxide.

A lot of field work, a lot of meteorological setups. I don't really do any of that anymore.

I'm more of pushing a lot of paper around up for my job now.

So I don't actually get out in the field, any at all. But there is no research on the private side, at least not my position. And I really like that part of it, You know, keeping your hands tied to the latest science and, you know, we're bringing on new or we're trying to bring on new constituents to monitor within the network, and that's fun and exciting.

Bringing more data to more people, more useful data, hopefully.

Like black carbon, we're talking about we're going to do a test run of a black carbon network soon.

I've gotten involved a lot with, fluorinated compounds, polyfluorinated compounds, PFAS, as most people refer to it.

Something I never really worked with at all in graduate school or until this point. So it pays better on the on the private side, but, the research is much more fun on the academic side.

So Definitely. And when you say that But in very different worlds.

Yeah.

I I'm sure. Definitely.

And when you say that you kind of want to or use this data for people, have you been able to actually communicate your findings and your research with the general public itself so they kinda know the importance of your research?

But most of the talks I do are to more general public, and I actually like it. It's I used to teach college. It's a lot like, you know, teaching introductory, freshman level classes. You know, they're they're fairly well educated or they tend to be.

They know a little bit about science, but so it's nice to come in and say, you know, this is what we've been doing with your tax money. This is why it's valuable. This is why we continue to do it. These are the kinds of things we've been able to determine, detect, conclude with the data that that would the money we're spending.

And most people don't have, most people are unaware of an ADP and I'm on the public side. And, you know, they're all usually pretty happy to hear what we do and why we do it and glad that the US is supporting this kind of role and all the agencies that go in this.

So it's quite fun. I like talking to general audiences. I always have.

Yeah. And then for those of you or those of people that are listening to this podcast that don't know, what specifically does the NADP, the National Accessory Deposition Program, do for the public, just for people that might not know?

Yeah. Well, we have five, monitoring networks, and we monitor over North America. So it's not just the US, it's Canada and Mexico too.

The the main focus or the biggest network, perhaps, I should say, that we have we monitor the rate at which pollution moves out air pollution moves down of the atmosphere and moves into the biosphere and down to the surface of the Earth. So we are measuring the pH of rainfall, so called acid rain, which was a much larger problem before you were born, and how the network got its start. But we measure how much sulfur and nitrogen and calcium and magnesium is moving out of the atmosphere and down to the ground. And we do that in a very we do that for precipitation. So when it rains, the precip washes the atmosphere clean of pollutants. And we measure that precipitation to save it for that.

So scientists, this much nitrogen came out during this particular week at this particular location and we stitch all those measurements together and then we can provide maps over the North America and say during this particular year, this much nitrogen came in from one end of the continent to the other. And then we make all that map our maps and all of that data available to anybody here for an advanced user.

So Wow.

That's amazing. And how long have you been with the NADP?

I've been with NADP since two thousand and three.

Okay.

But NADP has been running since nineteen seventy eight. Wow. So it's one of the oldest monitoring networks in the world. Yeah. We have probably six hundred thousand precipitation samples analyzed and categorized and available on the web. So we have, you know, forty five year record of the movement of pollution out of the atmosphere and rainfall in North America. It's, it's an astounding feat just to keep it all going Wow.

Honestly. And, you know, concerning that tremendous amount of data that you have, and the fact that you've been with them since two thousand and three, how have you seen kind of, you know, the acidic nature of precipitation change over time, or what trends have you seen, as a researcher over time?

Yeah. The specific to pH, which is how the network are going and this whole acid rain idea, the pH of rainfall has gotten much higher over the time. So pH going lower is more acidic, going higher is less acidic. And so it's not back to where it should be.

We would forecast with no pollution, but it's much closer, much, much closer for all regions of the country. So we've seen that problem get, you know, ninety percent better than it was when I was in school.

And, we've seen most of that decrease is due to the loss of sulfuric acid in the atmosphere. So when you have sulfur in a fuel, primarily coal, when you combust that coal, that sulfur gets converted to sulfur dioxide.

And in the presence of water, it gets converted to sulfuric acid in the atmosphere, which made the overall majority of the acid rain. And we've gotten rid of sulfur in the coal combustion stream, and so we've seen pH come up drastically.

And so it's become much less acidic, and the sulfur has become much less important. But now the much of the focus is on nitrogen.

Because nitrogen in the atmosphere goes through the same oxidizing process and produces atmosphere or atmospheric acids and other pollutants in the atmosphere. So the the focus has shifted, but we're still seeing issues with air pollution and the atmosphere coming out of rainfall.

Yeah. And, you know, with our current trajectory of, you know, our climate plans and everything else like that, what do you see kind of as the future of precipitation and its some subsequent impact sort of, you know, as we try to kind of mitigate more pollutants entering the atmosphere Mhmm. Which is nitrogen and things like that.

Yeah. The the nitrogen situation is even changing.

The a huge focus has been on oxidized nitrogen, in the past, but a lot of the focus is now more on reduced forms of nitrogen, ammonia, organic nitrogens. And so the import many of the important sources of that pollutant are changing.

But the one of the interests I've always had in where things are beginning to move is more towards organic pollutants, You know, organic compounds, that are made in our industrial society and lost through evaporation or several different things that have been in the atmosphere. And we're seeing a lot of those pollutants come down now. PFAS is a good example of that.

Polyfluoridated compounds, basically, a lot of different kinds. I've spent a lot of time studying metals in the atmosphere, mercury.

And so I I think a lot more people are beginning to look at more exotic things rather than the basic pollutants that we were interested in in the seventies and the eighties.

So there's a lot of pollutant in it, a lot of pushing in the atmosphere. A lot of it's showing up in rainfall and a lot of science still yet to be done for sure.

Definitely.

And, you know, you're just talking about kind of this a lot of researchers focusing on these, like, new exotic pollutants, so to say. Do you think that it's still, worth focusing on the original ones that you saw in, like, the seventies and the eighties? Do you think that's still around today?

What?

Yeah. I mean, there's a sense that we could should continue monitoring for those balloons that have become much less of a problem. So if they become a problem again, we'll know about it. But we've still got a lot of those basic components.

The situation may be a little bit better, but they're still causing problems. Nitrogen is a good example of that.

The forest service and the park service in particular are interested in nitrogen wet deposition and dry deposition because it adds nitrogen to the forest and parks. And in nitrogen limited areas, that allows for plant growth. And a lot of times that plant growth is our species that they are not natural, and it's changing the park essentially or the forest. At least has potential to do that. So, yes, there's always good reasons to keep going with the same things, that we've been studying for a while.

Yeah. Definitely. And, you know, from my time as an intern for the AIR program, I've kind of been able to talk to a lot of different researchers in the air program also and kinda see, you know, the different aspects that they do. I know I've talked to some people that are in smoke and fire management and things like that. Right. And so I was just wondering, like, have you been able to, you know, coordinate with the air program in any sense for any research that you've done historically in the past?

Most sure that yeah. I mean, over the last few years with the very large wildfire outbreaks, that has been a huge issue, at least in the air quality community.

What kind of pollutants are coming off of the these fires? Where are they going? What impacts are they having? And that's a lot of the connection, between the forest service and EPA looking at wildfires and this idea of of, like, carbon network.

We have not traditionally measured carbon deposition or at least, you know, so called black carbon deposition. And this is a very timely thing because it would feed into the kinds of information that they need to study wildfires and their their effects on the environment.

Outside of the fire, obviously.

Yeah.

Yeah. Because the the the smoke and everything that is in in that smoke or all the different compounds in that smoke can go quite a long ways and so have an effect over a large area, much larger area than the forest fire itself.

Definitely.

Yeah. No. Because so no. Go ahead. Yeah.

I was just gonna say that that one tailors perfectly to the kinds of things that the forest service is interested in and the air quality people in the forest service in particular.

Right. Definitely. Because my last podcast was with Janice Peterson who recently retired this week. She spent four decades in the air program, you know, researching smoke and fire management you know, your research and your expertise kinda, like, coincides with that in the in the sense.

Definitely. Yeah. Yeah. Yeah. It's it's a very interesting topic because it, you know, air quality doesn't really notice political boundaries. You know, a fire in Canada can affect the environment here, and it can go between continents and states. And, yeah, it's a it's a very interesting topic and a lot of different compounds.

I mean, my background is mercury. And when you have a forest fire going, most people are interested in the particulate coming off that black smoke that you see, in black carbon. That's where most people interests lie, but they're also a huge source of mercury in the atmosphere. And, you know, it's gonna have an effect on our mercury record too, and that's sort of more how I plug into that idea. But, you know, basic monitoring of the environment provides a lot of very valuable data to a lot of different scientists.

So that's why a lot of people like Forresters come to NADP and support sites because we're giving them the kind of data that can help them pursue the research ends that they have. And we all do it collectively, essentially, we're monitoring the market really.

Right. Definitely. And, you know, based on your expertise, I know you've had a long history in researching, and you have so many different, qualifications, but based on your expertise, if you had to choose one thing that people should know about precipitation or air quality in this day and age, what would you say?

Well, some of the basic lessons I usually say in my talks, I usually start out by saying, given, you know, four years or almost forty years in the business and having, you know, spent my original time doing a lot of work in LA and where air quality was really bad.

I mean, we have problems in the US, but the air quality in the US is pretty good worldwide.

The age of probably fifteen or sixteen times over the last ten years. And the air quality here is far superior. So our problems are different than the rest of the world. You know, we've cleaned up a lot of our basic problems, but we still have a lot of problem. There are still a lot of pollutants in the atmosphere, and there's a lot of focus particularly now on particulate matter and black carbon, and all of those need to be studied.

So, you know, further monitoring and further modeling mathematical modeling with our data is always a valuable thing. A lot of countries follow our lead.

And so, you know, we we can always day aboard, but we've done a very good job in this country of a lot of basic problems. We still have a few more to go, though.

Absolutely.

There we are quality people after me for sure.

Well, you know, that's why, you know, a reoccurring theme in these podcasts have every single researcher, or specialist that I've talked to has stressed the importance of educating the younger generation because they are the ones doing the continuation of the research and tracking air quality and making sure that data actually gets implemented and used in Yeah. Concrete and tangible ways. So Yeah.

That's always important. Very, very true.

You know, you don't get air pollution because people wanna make air pollution. You get air pollution because of our lifestyle.

And so it's always a choice. You know? It's we we have all these electrical devices that we all are tied to now, you know, in our homes, in our hands, in our automobiles.

And with the coming of electric automobiles, you gotta produce electricity, and there's an environmental cost to do with that. And it's it's a trade off. You know what I mean? So we just need to be smart about how we do it, and education is a big part of that.

Definitely. Definitely. I completely one hundred percent agree.

Well, those are all the questions that I have for you today. But is there anything that I haven't asked that you would like to share that you think might be important to our listeners?

Well, I think you ought to show we have some animations on our website, and they show the particulate pollutant deposition or flux of that pollutant over time. And I encourage people to take a look at those, particularly the sulfur and the pH flux animations. They will show that, you know, regulation and being smart about the emissions we put in the atmosphere and restricting those as well as we can have a very important impact and things get better. You know, it's spending a little money to take out the pollutants in a smart way can have good, you know, impacts in the long run.

You know, we're we're we're making good decisions. We can always be more efficient and all that sort of things, but things are getting better. We're finding other problems, and we will get beyond those two. Definitely.

Just gotta be smart about it.

For sure.

Well, thank you so much for taking up the time to speak with me today. I really appreciate it, and I'm very excited for our listeners to hear this podcast.

That concludes the fifth podcast in this series. Thank you so much to all who listened. And thank you to David for taking out the time to speak with me. We will see you next time on all things air.