EHP : The Researcher's Perspective

Several studies have reported links between asthma in children and the presence of phthalates in dust from the children’s homes. But the presence of a chemical is not the same thing as exposure, so Norway’s Environment and Childhood Asthma Study has taken the research a step farther by measuring phthalates in the urine of children with and without asthma. In this podcast Randi Bertelsen discusses her recently published findings.

Your bulges are busier than you may think . . . Many people see adipose tissue—fat—as nothing more than lumpy extra baggage. But fat serves several important functions in the body. It helps us store energy and endocrine hormones that can affect behavior, energy regulation, immune and vascular function—to name a few. It also protects against toxic effects of persistent organic pollutants, or POPs. In this podcast, Michele La Merrill talks with host Ashley Ahearn about the diverse ways that fat interacts with these chemicals as both a modulator and a target of POP toxicity.

Despite dramatic decreases in atmospheric lead levels over the past few decades, lead exposure remains a problem, especially for children. In this podcast, Marie Lynn Miranda discusses one remaining, albeit relatively minor, source of lead exposure: leaded aviation gasoline.

Arsenic is a problem in communities around the world, from Bangladesh to New Hampshire. It’s one of the environmental chemicals the National Toxicology Program explored at a recent workshop as possibly contributing to the worldwide rise in diabetes. In this podcast, Ana Navas-Acien talks about a new review by investigators at that workshop, who summarize the evidence for a link between arsenic exposure and diabetes.

New Orleans is already known as a hot, moist place—ideal growing conditions for mold. Now factor in Hurricane Katrina, which hit the city in August of 2005, leaving behind even more indoor mold and other asthma-causing allergens. Host Ashley Ahearn talks with Patricia Chulada about research to study and improve post-Katrina asthma symptoms in the children of New Orleans.

Children whose mothers smoked during pregnancy are more likely to have problems like low birth weight, asthma, and possibly obesity, cancer, and high blood pressure. For clues into the mechanism behind these effects, scientists are looking to the epigenome, the personalized set of directions that tells our cells how and when to produce proteins, which is one of the ways gene activity is controlled. In this podcast Stephanie London and Bonnie Joubert discuss the results of their recent study in which they identified a set of genes with methylation changes present at birth in children whose mothers smoked during pregnancy.

Over the past million years humans have migrated in response to food shortages, droughts, ice ages, and many other reasons, but in the coming decades, migrations related to climate change are expected to increase, perhaps dramatically. Different circumstances—be it forced displacement, a planned resettlement, or migration into a city—can present different humanitarian and health adversities, but population movements also can offer benefits for migrants themselves, the communities they left, and the communities where they land. In this podcast, Celia McMichael and Jon Barnett tell host Ashley Ahearn about research and policy steps needed in advance of the rising tide of climate change–related migration.

Human beings, as a species, are putting on weight. Obesity rates are rising in rich and poor countries alike for a variety of reasons, from changing dietary habits and activity levels to exposure to artificial nighttime light. Mounting evidence from over the past decade suggests that certain chemicals may be playing a role as well. For some people, so-called obesogens may be altering their metabolism and fat cell development, making it harder to maintain a healthy weight. In this podcast, host Ashley Ahearn talks with Bruce Blumberg about the state of our understanding of obesogens.

Reproduction, growth, behavior, and sleep patterns are just a few of the bodily functions controlled by hormones. Endocrine disruptors are chemicals that interrupt or imitate natural hormonal messages, and even at very low doses, endocrine disruptors may have very real effects that are not seen at higher doses. In this podcast, host Ashley Ahearn talks with Laura Vandenberg about her recent review of the evidence on health effects of low-dose exposures to endocrine disruptors.

Many organic foods and high-energy products are sweetened with brown rice syrup as an alternative to high-fructose corn syrup. Consumers who eat these products may be avoiding high-fructose corn syrup, but they also may be exposed to arsenic that’s been absorbed by the rice plants from which the syrup is made. In this podcast, Kathryn Cottingham talks with host Ashley Ahearn about her recent market-basket study of products containing brown rice syrup and other rice-based ingredients. Arsenic was detected in all the products tested, although Cottingham cautions it’s too soon to say what this means in terms of potential health effects.

Burning forests, grasslands, and fields have been part of the landscape probably for as long as humans have been on the planet. But it’s only in recent years that we’ve begun to explore the health effects of exposure to landscape fire smoke, which is now known to exacerbate preexisting disease and induce new disease. In some parts of the world, people are chronically exposed to smoke from landscape fires that burn for a large portion of the year. In other areas, exposure is sporadic and short-term. In this podcast, host Ashley Ahearn talks to Fay Johnston and Sarah Henderson about their study in which they estimate the number of deaths worldwide attributable to smoke from landscape fires.

Americans are widely exposed to phthalates in soft plastic products from toys to medical equipment. A perhaps lesser-known potential source of exposure is the timed-release coatings on certain pharmaceuticals and dietary supplements, which enable active ingredients to reach the correct part of the gastrointestinal tract for working properly. In this podcast, host Ashley Ahearn talks to Katherine Kelley about her new study on the extent to which phthalates are used in medicinal products.

Hydraulic fracturing ("fracking") is a controversial practice used in natural-gas drilling. Fracking makes it much more feasible to free the vast reserves of natural gas locked underground, but the practice comes with concerns that the natural gas boom is proceeding too fast, before we understand the human health impacts. Discussions about fracking and community health typically involve questions about methane contamination of drinking water wells around drill sites. In this podcast, host Ashley Ahearn talks with Robert B. Jackson about another fracking-related water concern: the millions of gallons of contaminated wastewater generated by the process.

In our daily lives we're rarely exposed to just one chemical at a time. Metals, for example, are ubiquitous in the environment, and most of us are exposed to different combinations of metals each day through air, water, and food. Simultaneous exposures to different metals may have synergistic effects in children, whose developing brains are particularly vulnerable to adverse effects from these potentially neurotoxic agents. In this podcast host Ashley Ahearn discusses the neurodevelopmental effects of metals mixtures with researcher Robert O. Wright.

With more than 1 billion people estimated to not have enough to eat, food security is a pervasive problem. An estimated one-third of the global burden of disease afflicting children under the age of 5 is caused by undernutrition. Climate change is anticipated to reduce cereal yields, further threatening food security and potentially increasing child undernutrition. In this podcast, host Ashley Ahearn discusses the connection between climate change and undernutrition with researcher Sari Kovats.