GHAE Blog

Dr. Micaela Martinez is an Adjunct Assistant Professor in the Heilbrunn Department of Population and Family Health at the Columbia Mailman School of Public Health. An infectious disease ecologist, she earned her Ph.D in Ecology & Evolution in 2015 at the University of Michigan, followed by two years at Princeton and four years as an Assitant Professor at Columbia. She is now a member of the faculty at Emory University in the Department of Biology. Dr. Martinez's research aims to understand how ecology, structural determinants of health, immunology, climate change, and demography intersect to shape health and disease. Her expertise includes vaccination and transmission of epidemic-prone diseases, climate change and human health, structural racism and health. During the pandemic, Dr. Martinez has been working on how environmental racism and social inequities manifest COVID-19 health disparities, with particular emphasis on Black and Latinx communities in NYC. 

Tell us about your interests and the work being done at the Martinez Lab. Are there any discoveries (or lack thereof), that have influenced your current research?

Over the last nine months or so my lab has been focused on structural racism, particularly in New York City, and trying to come up with holistic approaches and policies for dealing with structural racism across aspects of society, particularly think about climate justics, maternal and infant health, health disparities, environmental issues such as chemical pollution, air pollution and defects within homes. What we've been doing is large data collection and data integration where we can think of new analytical tools for trying to quantify structural racism and how it impacts communities with the goal of then being able to use New York City's data as a template to look at structural racism more broadly across the country. 

In addition to my work on structural racism, I have two ongoing reproductive health collaborations. The first project is using data from menstrual cycle tacking appls to look at sexual activity and fertility and how that is structured seasonally. We have been studying 500,000 women from around the world from which we have data where they record daily their sexual activity, their menstrual symptoms, birth control use etc. Second, I have a collaboration with colleagues at MIT and Dartmouth focused on the composition of breast milk. My lab's contribution is thinking about the parts of the maternal immune system that moms pass to their infants via breast feeding.

What is your current research on birth seasonality?

Birth seasonality is this phenomenon that—even though humans can give birth all year around, we are fertile all year around, and can conceive year ‘round—when we look at data from anywhere in the world, whether contemporary or historical data, you can see that births are not equally distributed throughout the calendar year. It has been argued about for 200 years, why is this happening? Is birth seasonality due to differences in sexual activity or is fertility actually changing throughout the seasons? Fertility is notoriously hard to measure, especially when it comes to female fertility, and it is hard to measure the frequency of sexual activity at a population level throughout the seasons because that is very intimate data. 

With the health tracking revolution and digital apps we decided to take a stab at addressing this more than 200-year-old question. We took the simple approach; we know that conception is a combination of fertility and sexual intercourse, in particular, unprotected sexual intercourse. If we can nail down how much sex is being had day-to-day in a country, we can account for that part of the equation and mathematically back out the fertility rate since we know how many babies are being born. We found it was very clear that there was seasonal fertility. Based on our study of US, France, Brazil and the UK, fertility is elevated around the time of winter solstice in each country. 
 

How does this compare with quantifying structural racism? How do you think about measuring and data?

One of the things that set my lab aside from other labs in public health is that myself and the people that come into my lab are trained as ecologists and my PhD is in Ecology and Evolutionary Biology. Specifically, I worked on population ecology. Other people with my kind of background would typically study things like interactions between species or how populations change over time and wildlife. Largely when it comes to studying wild organisms we rely on thinking about the population as a unit and even though you might not be able to get data on every individual you can look at patterns at the population level, either across time or across geographic locations. That’s what we do with seasonal fertility but the same holds true when we think about structural racism. We have discrimination that individuals can and do experience and we can look at how individual experiences can manifest as population-level features, such as population health disparities, that differ among populations due to their unique composition of individuals. We can see that those population differences are manifestations of what is happening to the individual in that population. 

"We have discrimination that individuals can and do experience and we can look at how individual experiences can manifest as population-level features, such as population health disparities, that differ among populations due to their unique composition of individuals. We can see that those population differences are manifestations of what is happening to the individual in that population."

What are the tools and data sets that are most interesting?

There has been quite a call in the health disparities literature to come up with mathematical tools and statistical tools for quantifying structural racism as a system. The best working definition of structural racism is that it is the way in which society fosters discrimination through a set of mutually-reinforcing systems of inequity; these systems include inequity in education, housing, healthcare, economics, etc.  The important thing is that these systems of marginalization and discrimination reinforce one another. For example, communities of color or communities in poverty being underserved by the education system, if you do not have an educational foundation for viable employment then you have more poverty, which can lead to the ratcheting-in of poverty-driven health disparities. This whole system self-perpetuates. These health disparities can then feedback on the system. 

Recently, I have been proposing the idea that we can mathematically quantify structural racism as an ecosystem. If we can get data on health disparities whether this be food security, infant mortality, air pollution, defects in the home, we can see how tightly correlated they are to each other, then construct a quantitative picture of how things are interconnected. 

You joined Mayor Eric Adams’ Social Justice Commission last fall. Tell us how your recommendations will impact the lives of Black and Latinx New Yorkers.

Before I begin, one important point about the commission is that it is independent of the mayor and has no political affiliation, but we are making recommendations to the mayor. Our hope is if every single one of our recommendations is taken up by the mayor, and tackled by the city, that we can see a just city, where we have fairness, equity, and equal opportunities for all New Yorkers regardless of the color of their skin, disability status and socio-economic status.

"Our hope is if every single one of our recommendations is taken up by the mayor, and tackled by the city, that we can see a just city, where we have fairness, equity, and equal opportunities for all New Yorkers regardless of the color of their skin, disability status and socio-economic status."

Our policy recommendations range from ensuring that we have proper maternal care across the city, buffers from climate change, green space access, protections for freedom of speech and we address the criminal legal system. It is a tragedy that NYC has really strong health disparities in communities of color. We have really strong disparities in the infant mortality rate. We have some neighborhoods with 20 times more childhood asthma hospitalizations. This is unacceptable.  

A city is only able to do so much in terms of changing overall legislation. A mayoral office does not have full, complete power, but it does have some power and a budget. As a commission, we asked ourselves, how do you go in with limited resources and limited power to attack a big problem? Last semester when we were working on those policy pieces, myself, Terry McGovern and others in the commission were thinking about big picture interventions. We needed to be able to measure the existing disparities, have a target for addressing it and a metric for measuring how well we are doing at addressing it and the downstream effects. 

In addition to New York, environmental exposures disproportionately affect Black and Brown people in states like Mississippi and Louisiana. Describe your experience as the moderator of the Scientific Evidence panel at the December RJ/EJ panel, where those states were the focus. What do you think is the most effective way for scientists and advocates to work together to address the poor reproductive outcomes for Black and Brown women?

For me it was a life changing experience, especially as a scientist because it really highlighted how so much of science is done backwards. My first long-term research project was on seals in the arctic. We had to work carefully with Indigenous populations, anything we did we had to get permission. We relied heavily on Indigenous knowledge. So being someone who had experience having research tied into community, this was very visceral. There have been so many years of activists led work. There has been too much siloing between the research community and the research agenda versus what really needs to be done on the ground and what has already been pushed forward by activists. I think that scientists need to start learning to follow the lead of the activists, have them set the agenda.

"There has been too much siloing between the research community and the research agenda versus what really needs to be done on the ground and what has already been pushed forward by activists. I think that scientists need to start learning to follow the lead of the activists, have them set the agenda."  

Following the meeting, I have now been a part of a working paper to structure science to study chemical pollutants and removing pollutants from the market. In this country the process of things is no regulation or little regulations for these chemical companies. All of the chemical manufacturing gets rolled out. It is not until there is sufficient harm that we evaluate if there was enough harm done to remove a chemical. 

What do you have planned next that has you excited?

Ongoing research that I’ve had has been looking at seasonal changes and circadian rhythms in the human body, so how our bodies not only change throughout the seasons but how they change during the day and night cycle. Right now, I am in the process, at Emory, of building a clinical facility. It is going to be what is called a Chronobiology facility. Chronobiology is the study of biological clocks. The facility is going to be equipped to do mother-infant dyad studies and adult studies where we can look at all kinds of aspects of the body thought the seasons and day and night. Individuals can stay for multiple days or a week at a time, where during that time we can take biological samples and keep them in constant conditions. 

One thing that ties into the justice work that I have been interested in doing for a number of years is trying to understand why childhood asthma exacerbations can happen in the early morning hours, in that transition period from nighttime to wake-up time. There have been proposals that it has to do with circadian rhythms. We know that childhood asthma is shaped by many environmental conditions, whether there is a gas stove burning, whether there is air pollution, whether there is mold in the home. There are all these environmental and structural racism components, and potentially there is this body clock component to it too− I want to use my new clinical facility to do this work. My new facility will allow me to design studies to understand how our environment and biology interact to shape our health. Unfortunately, our environment has a lot of negative components to it, especially for marginalized people, but if we can understand how our environment gets under our skin and impacts our health, then we may be able to policy forward that protects people. 

This interview was conducted by Ashley Williams, a Communications Officer in the Heilbrunn Department of the Population and Family Health and Clarisa Bencomo, Associate Director, Global Health Justice and Governance Program. It has been edited for length and clarity.