HHIT Series Episode 11: environmental chemical exposures across the life course: Implications for inequities and intervention with Julia Varshavsky.
On the Human Health, Impact and Technology webinar series [#HHITseries] on April 23, 2024, Julia Varshavsky, Assistant Professor in Health Sciences and Civil and Environmental Engineering at Northeastern University, spoke to host Professor Patricia Maguire about her research on environmental chemical exposures across the life course: Implications for inequities and intervention.
Environmental Health in nutshell
Julia researches the interdisciplinary field of environmental health and its impact on human health. “Environmental health in a nutshell is basically how the environment impacts human health versus the other way around.” She explains that as we're exposed to a lot of different chemical and non-chemical stressors throughout our daily lives the environment can mean a lot of different things – “from the air we breathe, the water we drink, the food we eat, products we use and the social context in which we live”.
Chemical Exposures
Julia’s research focus is on chemical exposures and how chemical levels in the body impact health. She explains that since World War II synthetic chemical production has increased dramatically worldwide, and according to the US National Cancer Institute, babies are now being born effectively pre-polluted with many synthetic chemicals in their bodies at birth. “We care about that because a lot of these chemicals are biologically active compounds that at a low dose can interfere with molecular signalling that governs human reproduction, development and function”.
Her research looks at exposure sources and how those relate to chemical levels in the body, and then how those levels in the body relate to biological effects, like placental disruption and endocrine disruption. “Those effects relate to clinical and subclinical maternal and child health outcomes, including pregnancy outcomes, cognitive and behavioral outcomes, and effects on growth and metabolism”.
PROTECT and ECHO Projects at Northeastern University
The PROTECT study in Puerto Rico as well as ECHO, include a combination of multiple longitudinal pregnancy and birth cohorts across the United States looking at chemical mixtures and how they relate to maternal health complications and child development.
“We have a paper currently under review at EHP, that is showing that paraben and phenol mixtures are associated with increased risk of hypertension during pregnancy, which is a really important pregnancy complication. We're also seeing that PFAS mixtures are associated with changes to early markers of infant neurodevelopment that have been associated with reduced cognition and development later.”
How do we limit our exposure?
Her advice to limit exposure to chemicals in foods including phthalates and pesticides is to try to buy fresh and less packaged ingredients, less processed foods and organic when possible. In personal care and consumer products, try to use fragrance-free products. “Of course these options aren't easy for everybody, and not necessarily a fair burden to place on individuals, and the problem with persistent chemicals like PFAS, is even more complex because they don't break down easily in the environment and therefore they've contaminated a lot of drinking water systems worldwide.”
Societal Policy
The issue of persistent chemicals like PFAS contaminating drinking water systems worldwide is a complex problem that requires action at the source. At a societal level, a chemicals policy that regulates the emissions of chemicals and advocating for green chemistry, safer solutions and safer alternatives is vital.
There are differences between the US and European policy, mainly in the US the burden of proof has historically been placed on the EPA to prove chemicals are harmful after they've already been released onto the market. The burden is not placed on industry to demonstrate they are not toxic before letting chemicals into commerce. In the EU there is more burden placed on the industry before pre-market.
Plastic, oil and gas
“You can't really talk about plastics and chemicals from plastics without talking about oil and gas production”. Julia refers to a recent paper in the New England Journal of Medicine by Tracy Woodruff on (opens in a new window)Health Effects of Fossil Fuel–Derived Endocrine Disruptors that discusses how fossil fuel production and plastic production has increased more than 15 times since the 1950s and fossil fuels are a source of many chemical and plastic chemicals. Julia explains that although chemicals impact humans differently due to our different biologies and co-exposures, a lot of chemicals operate on a molecular level. “So things that are harmful for wildlife and harmful for the environment tend to be also harmful for us as living organisms”.
Micro Plastics and our health
New research from Italy published in (opens in a new window)The New England Journal of Medicine linked microplastics in a main artery to increased experience of heart attack and stroke. “It really resonates with people that these physical pieces of plastic are getting caught in our bodies and clogging our arteries”. Julia’s research at Northeastern has been looking at how different chemicals can impact cardiovascular disease through different molecular pathways or physiological pathways, like oxidative stress and inflammation. “Now we're seeing that the actual physical particles themselves are also increasing our risk of these things so the combination of the physical and chemical risk is really important to understand”.
We’re not all created equal
A lot of different factors influence our susceptibility and our risk such as biological factors like, how old we are and if we are developing. “There's a lot of signaling going on, hormone signalling, for example, which makes children, babies, anyone undergoing some sort of developmental process more susceptible”. There are also socioeconomic factors and social stressors that impact our susceptibility. She explains that if we are burdened by additional chemical exposures or social stressors like poverty and racism, we are more at risk of both exposure and disease.
Green Chemistry and Future Innovation
Julia says we need changes at many different levels. Individuals and consumers need to understand how they can best protect themselves with the tools and resources they have. As a society we need to push for better policies that reduce the source of these pollutants directly and we need to in the same way be pushing for industry innovation, green chemistry and safer alternatives. “Possibilities are out there and we don't necessarily have the incentives currently in place to push industry to move towards safer alternatives, and we can do a better job at all of those levels”.