Community Spotlight: Dr. Cara Maesano, environmental epidemiologist and air pollution researcher

Cara is part of the C40 project through the women4climate mentorship program. C40 is an organisation of cities around the world that is committed to taking action to mitigate carbon emissions and tackle climate change, and to create resilient cities.

Here’s an interview that’ll take your breath away. Let’s welcome Dr. Cara Maesano, environmental epidemiologist and air pollution researcher, to the community spotlight. Cara talks about her upcoming participation in C40, a network of megacities worldwide committed to addressing climate change. Discover how Cara went from building a neutrino detector in a French cave as a particle physicist to wearing an air pollution sensor every day for the next year as part of a global initiative to combat the effects of climate change! We also talk about the delicate balance between science, government, and business.


Connect with Cara here and discover more about her work.

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Nia Cason: Cara – could you introduce yourself in a few words?

Cara Maesano: My name is Cara Maesano, I’m originally from California and I live in Paris. I did a PhD in particle physics at UC Davis in California in 2012, and am now a post-doc at Sorbonne University in environmental epidemiology. Most of my work is on air pollution and how it affects health; we look at how air pollution concentrations correlate with the number of hospital visits and mortalities, for example. Air pollution is related to respiratory health, cardiac health, and dermatological issues, and we’re also looking at the effect of air pollution and other environmental stressors on diabetes, obesity, and neurodevelopmental issues at the moment.

NC: What inspired the move from particle physics to air pollution?

CM: Apart from situational factors, there’s some overlaps that meant the move was possible. I originally came to France to help build a neutrino detector next to a nuclear reactor. So one overlap, and actually my first introduction to particles in the air, was cleanliness of the lab – even dust can interfere with a neutrino signal, so we needed it to be really, really clean – the added challenge was that this was in a cave! I decided to stay in France, but jobs in particle physics are of course very competitive. I began voluntarily editing papers for Dr. Isabella Annesi-Maesano, who’s a research director at INSERM/IPLESP, and analysing some data to get to grips with a statistical package I wanted to learn – that led on to a post-doc position at her lab. So, the statistics aspect is another overlap that allowed me to make the change.

NC: Could you tell me about C40? What is it?

CM: I only start next Thursday, so I’ll do my best! I’m part of the C40 project through the women4climate mentorship program. C40 is an organisation of cities around the world that is committed to taking action to mitigate carbon emissions and tackle climate change, and to create resilient cities. I think cities – where most people live – feel a particular responsibility to address climate issues, and that there’s the general feeling that national governments aren’t doing enough. So, local governments are taking it upon themselves to try and address the problem. Also, climate change is a multi-faceted problem and needs to be approached from all angles – all the C40 projects are involved in climate change, but some are finance-based, some science-based, and so on.

NC: And what’s your personal C40 project?

CM: Paris already has a network of sensors at fixed stations that continuously measure air quality, but they don’t capture personal exposure. My C40 project will be looking at personal exposure to air pollution versus average city concentrations. I’ll carry a mobile sensor with me wherever I go and so will also be taking note of my location. In that way, we can build up a picture of what air quality is like in different kinds of spaces – in a park, at home, on the street, on a bus, in the metro. Through this mentorship and the C40 women4climate program, I plan to do this for 9-12 months. Results of our pilot study this summer look promising.

NC: Why is monitoring air pollution important?

CM: Paris air quality can get bad. Usually, you compare levels against the WHO recommended annual averages. For particulate matter, we refer to PM10, PM2.5, or PM1, for example, which correspond to the different sizes – the smaller they are, the easier they are to absorb into your lungs and the blood stream. In Paris, the levels are usually double the WHO values, and much higher on bad days, and this doesn’t even cover gasses such as NO2 or Ozone. Air pollution usually comes from cars – but not just from emissions. Grinding of the brakes also produces tiny metal particles that get released into the air, resuspension disturbs previously settled pollution when you drive, and tyre particles also get released into the air. That’s why electric cars won’t solve all the problems.

NC: Can you recommend any worthy scientific events?

CM: It’s a little hard to suggest an event to the general public because scientific events aren’t always inclusive. And for researchers, there’s often a limited amount of time and money to go to events. That said, a worthy event in the field of environmental epidemiology is the ISES-ISEE joint meeting, which is held at the end of the summer. In terms of interesting public events in Paris, there’s the Fête de la Science coming up in October.

NC: Do you have any advice for PhD students or post docs?

CM: Make sure you’re really interested in your topic: that’s what carries you through. And, choose an advisor that suits you, because it’s a long program...  I also don’t want to give anyone the illusion that it’s easy to change fields between a PhD and a post-doc. I often feel like a grad student – there’s many things to learn, and I don’t always have the same intuitions I developed in physics. But it’s interesting to see science from a different perspective.

I do think networking is important, but I find the term a little weird. In business, I think people understand the importance of networking and there’s no shame attached to it, but in science, it has a twinge of opportunism that’s perhaps unnatural to a scientist. You want to talk to people, but you’re not necessarily trying to wiggle your way into something.

NC: So how do you think science is related to business, and how does a governmental organisation such as C40 fit into that equation?

CM: The goal of businesses is to turn profit, the goal of a government is to take care of its people, and the goal of science is to acquire new knowledge. I think science wouldn’t get funded if there were no commercial applications, but getting grants isn’t really the purpose of the science itself. In terms of air quality, the differences in the motivations of science and government initiatives and the motivations of businesses can have serious implications. Take the recent Volkswagon diesel scandal – they fudged their results, which is something I’d argue no real scientist would do – especially in a field where the negative impacts are high. It’s not clear what incentive companies have to improve air quality or their products, but government regulations could force them to meet certain standards, and public perception is also a factor – this is where the government comes in. A network like C40 can then promote these regulations and help cities promote local changes. An example of a local change is the the Crit’Air Program, whereby super polluting cars are no longer allowed inside Paris.

NC: What scientific personalities do you follow online?

CM: I would suggest 500 Women Scientists, which is an international organisation focused on gender issues in science. They speak out on various issues including discrimination and harassment, equal pay, etcetera. One resource is ‘request a scientist’, which is a resource for journalists and panel organisers to find female experts.