Joseph Braun, MSPH, Ph.D. Associate Professor of Epidemiology
Linking environmental exposures and children’s health.
You have degrees in biochemistry and nursing. How did you become interested in public health, and the link between environmental pollutants and children’s health?
My undergraduate studies were in biochemistry. I really enjoyed the science and the molecular biology of the human body. After working in several different labs, I wanted more clinical experience so I went back to nursing school to learn more about the direct application of health. In nursing school I did a research assistantship with a professor who really got me interested child health, and gave me the unique opportunity to play with data. She said, “Here’s some data, now go answer some questions about learning disabilities in children.” I looked at the relationship between tobacco smoke exposure, lead, and some other environmental chemicals and learning disabilities. It was interesting to me that chemicals are things that we are involuntary exposed to, and largely have no control over. The only way to reduce exposure is to regulate chemicals—how they enter into the marketplace, and ultimately, how they enter into our environment. Doing work to reduce chemical exposure is what really drove my passion to be an epidemiologist and to seek advanced training in environmental health.
A lot of parents have concerns about toxic environments and health outcomes, but sometimes this leads to misunderstandings. When the word “toxic” is often mis-used, how do you differentiate your fact-based work from the noise?
For the advanced consumer of research, differentiating “fact” from “noise” is easy to do. However, for the lay public, it is difficult to find unbiased information that isn’t funded by special interest groups. With chemicals, there are people who firmly believe that a certain chemical is toxic no matter what and likewise, there are people on the other side, who firmly believe that same chemical is not toxic, and nothing will change their mind.
Unfortunately, some of the confusion is because there has been erosion in the public trust of science. We have to get out there and talk to people. Translating science becomes very important. It boils down, really, to us engaging.
Chemicals is a broad term of course. What specific chemicals do you focus on in your research and how prevalent are these in our everyday lives?
When I started out, I was focused on lead and tobacco smoke, particularly on the effects of second-hand tobacco smoke on children. Soon, I decided it was important to start studying other chemicals that were out there. I’ve spent a lot of time studying bisphenol A, which is a compound used to make polycarbonate plastics and some resins, which are used in things like food can linings and some medical equipment. I’ve also studied phthalates, which are a large multifunctional class of chemicals used in everything from personal care products to pharmaceuticals. More recently I studied triclosan, which is an anti-microbial compound used in some toothpastes, and used in hand soaps and hand washes until recently in the US. I’ve also been studying perfluoroalkyl substances—a large class of chemicals of which thousands are used to manufacture water- and stain-repellent fabrics.
The traditional paradigm has been to study these chemicals one at a time—let’s study the association between BPA and ADHD, for example. But we know that exposure doesn’t occur one at a time like in a study. We are exposed to lots of things at once. So we’ve been studying chemical mixtures; what’s the effect of the “toxic soup” in our environment? Is there an effect of being exposed to all of these things at once? There’s a lot of excitement about that right now, so that’s one of the directions in which our work is headed.
What can new parents do to mitigate the potential effects of these chemicals?
In my opinion, there are three important recommendations. Although the evidence is still being developed, these are reasonable and shouldn’t hurt you.
- A water filter for your drinking water with ongoing maintenance. It’s not enough to buy the water filter, you have to use it and replace the cartridge when needed; this can protect you from water pollutants.
- If you vacuum, use a HEPA filter vacuum. Most traditional vacuums blow a lot of hot air out and particles—some of which are semi-volatile—spread all over your house again. A HEPA filter can prevent this.
- Eat a balanced diet. We know that chemicals are found in food. For example, with fish, there are different concentrations of mercury. But if you eat a balanced diet, you’re spreading your risk around evenly. A balanced diet has multiple benefits in addition to being the best way to reduce all of your chemical exposures.
By following these basic recommendations, you can reduce your exposure to lots of things all at once. After the basics, you can ask yourself, “What can I do to reduce my exposure to BPA?” Stop eating canned foods. If you don’t want pesticide exposures, you can eat organic. But for some chemicals, like the perfluoroalkyl substances (PFSA), there’s not a lot you can do—the primary driver is diet, which is why regulation is so important.
In your own home, are there any products that you try to stay away from?
Outside of the recommendations I gave, we don’t microwave in plastic, we don’t buy a lot of smelly colognes or perfumes that might have phthalates or parabens in them, and we try to buy organic when we can. It’s substantially more expensive to buy organic, but there are certain foods where organics matters more. Bananas, for instance, have a peel on them so the fruit doesn’t have many pesticides in it; whereas something like strawberries or peppers are directly exposed to pesticides. There are lists of pesticide prone fruits and vegetables that can help you decide about buying organic.
Public health students come from all different backgrounds. I’ve met students with history degrees, backgrounds in Russian Literature, and veterinarians. As a public health researcher with a variety of experiences, what advice do you give new public health students, especially those who may be coming from different fields?
I think learning some basic biology is really important. You’re studying public health, and a lot of the basis of health is biological, in addition to being psychosocial and behavioural. If you haven’t taken a lot of biology, take some biology. It doesn’t hurt to understand a variety of physiological and psychological impacts on health and be conversant in them.
I also tell students that they should be willing to learn new things because public health is always going to be changing. We’re responding to the changing regulatory landscape right now, and there are new developments coming. So be ready to learn new things, and be passionate about learning and doing.