Research Highlight: Infant Diet found to Exceed EPA Guidelines for Phthalate Exposure

Dr. Sheela Sathyanarayana
Center member Sheela Sathyanarayana's work on phthalate exposure is getting new attention. A recent paper in the June issue of Environmental Health was followed by articles in ASPPH, the Association of Schools & Programs of Public Health, and the Washington Post.

Read about it here:

Washington Finds Infant Diet Exceeds EPA Guidelines for Phthalate Exposure

Significant exposure to endocrine-disrupting chemicals may come from our diet, particularly from dairy products and other high-fat foods. New findings by researchers at the University of Washington School of Public Health show that adolescents and infants may be especially vulnerable to high exposures of phthalates in their diet, exceeding even the US Environmental Protection Agency’s guidelines. The study was published in the June 2014 issue of Environmental Health.

Commonly used as plasticizers in food packaging, phthalates can leach out of packaging because of their chemistry. These endocrine-disrupting chemicals have been linked to adverse health effects, particularly in prenatal and early life exposures. Increased maternal urinary concentrations of metabolites have been associated with shorter anogenital distance in male infants, signaling the exposures may have an effect on male hormones and the development of male sex characteristics.

Samantha Serrano, M.S.

Samantha Serrano, MS, and Dr. Sheela Sathyanarayana, an adjunct assistant professor in the School of Public Health, investigated how certain foods affect dietary exposure to phthalates. They analyzed data from 17 studies that measured phthalate concentrations in United States and international foods, three epidemiological association studies, and three interventions.

Cooking oils, cream-based dairy products, and meats, particularly poultry, had high phthalate concentrations.

The estimated phthalate exposure in a typical diet consumed by adolescents and women of childbearing age fell below the EPA maximum acceptable dose. However, the exposure estimate for a typical diet in infants ages 1-2 exceeded the EPA maximum dose, and a diet high in meat and dairy went over the threshold by approximately four times. For adolescents, a diet high in meat and dairy also exceeded the EPA maximum acceptable dose.

Dr. Russell Dills from the University of Washington, Dr. Joseph Braun from Brown University, and Dr. Leonardo Trasande from New York University also contributed to this study, which was funded by the National Institute for Environmental Health Sciences and the University of Washington Department of Environmental and Occupational Health Sciences.


--Elizabeth Sharpe and Marilyn Hair

Event Highlight: Lower Elwha Klallam Art Show illustrates impact of the dam removal

Blue Salmon Paddle by Darrell Charles

Lower Elwha Klallam Tribe (LEKT) member Roger Fernandes and The Legacy Gallery organized an Art Show on May 23rd at the Lower Elwha Klallam Heritage Center in Port Angeles. After visiting Port Angeles last June to see the Elwha River Restoration, (see blog), I was eager to attend.

LEKT artists Linda Wiechman, Darrell Charles, and Roger Fernandes exhibited their work, ranging from paintings to drumheads to carved canoe paddles like the one pictured above. The focus was the impact that removing the Elwha River dams has had on the tribe and the environment. Linda and Roger led a panel discussion, and among those who attended were LEKT Council chairman Francis Charles and former Tribal Council member Dennis 'Sully' Sullivan.

The Elwha and Glines Canyon dams blocked the salmon from migrating up the Elwha River to spawn. The chinook would swim 5 miles upriver and find themselves blocked by the Elwha Dam. They hung in the water beneath the dam. In the first years after the dam was built, the salmon would smash their heads against the dam until the river was bloody. Salmon runs have dwindled since the dams were built, and some have gone extinct.

In native lore, salmon are the Salmon People who live in villages under the ocean and come back to the rivers to feed the people. Roger told us, We are the salmon people. Our culture is built around salmon. Northwest tribes have many traditional stories about the salmon.

The artists reported that when they were children, their parents and elders told them the dams would come down someday. The tribe's struggle to make that happen lasted for 30 years. It wasn't a political struggle, it was spiritual, a battle for a way of life. The LEKT never gave up. Roger said, They don't call us 'The Strong People' for nothing

For the Lower Elwha Klallam Tribe, the Elwha River Restoration means recovery of the salmon and the ecosystem. 

Linda Wiechman said, The river is life. Releasing the dams brings life back to the salmon people, and salmon bring back the whole ecosystem. Salmon are good medicine. Roger Fernandes said, Removing the dams is a huge statement about environmental wellness. When the salmon return, the ecology returns. 

According to Tribal Council Chairman Francis Charles, We do this for the children, for the future. Sully Sullivan recalled that when he was a child, fishing by tribal members was illegal. He and his friends learned to hide from the game warden and families hid their smoked salmon under their beds. But the people never stopped fishing.

Elementals of Nature by Linda Wiechman

Linda's painting, Elementals of Nature, depicts the recovering ecosystem. The river runs through cedar forest and snowberries. 

Eagle stands about to feed on a salmon whose remains will enrich the riverbank. Kingfisher observes, and so does Sasquatch, a shy being who stays in the background. Can you find the Sasquatch in the trees?

Another of Linda's paintings, The Changer, shows a mythical being who has created the salmon. Releasing the salmon into the river will restore the ecosystem. 
The Changer by Linda Wiechman

Lady of the Mountain Breaks the Dam
by Roger Fernandes
Roger Fernandes' painting, Lady of the Mountain Breaks the Dam depicts the mythical woman who sleeps. She helped make creation, then went to the mountains, promising to come back if ever she was needed. Here she is, tearing down the dam so the natural world can come back. As she frees the river, a salmon swims upstream. Thunderbird overlooks the scene; in native lore, Thunderbird drives the salmon up the river.

Roger Fernandes says, The river is free, the salmon are returning. But removing the dams is not the end, it's the beginning of something. It's still a figuring-out process. We changed the world, the environment is being re-established. Now we have to figure out what to do with that. 

Roger plans to bring the art show to The Legacy Gallery in Seattle this summer.

As for the ongoing Elwha River Restoration, new beaches are forming at the mouth of the river and marine life is showing up that's been missing for decades. Dive surveys in the summer of 2013 found juvenile crabs on the floor of the strait off the river mouth. Crab pots are being set near the mouth of the river.

Oregon Sunshine (Eriophyllum lanatum) is blooming on the drained bed of former Lake Aldwell. This perennial sunflower was planted from seed as part of the restoration, 

The Elwha Water Facilities Project, Port Angeles' water treatment plant that shut down because of river sediment, is operating again. And less than 30 feet of the Glines Canyon Dam remains to be torn down. Dam removal will resume after the spring river flows slow, and after June 30th when the fish migration ends. Dam removal is scheduled to be completed in fall, 2014.

-- Marilyn Hair
Sources: 


Research Highlight: Understanding Individual Differences in Chemical and Drug Metabolism

Environmental exposures affect health. 
Exposure science is the study of chemical, physical, or biological agents that humans come in contact with in their environments. Exposure information is needed to understand health risks from chemicals and other agents.

Evaluating the amount of specific chemicals people are exposed to allows scientists to estimate the dose of the chemicals people are getting. Knowing this allows researchers to develop studies to test whether that dose may affect human health. Results from exposure science studies are critical for developing interventions to prevent or minimize health hazards.

As our Center theme is gene-environment interactions, measuring exposures and understanding the dose is needed to be able to estimate the interaction of genes with chemical exposures.

Exposure science is known for its interdisciplinary approach. The Exposure Sciences ARE draws on the expertise of Exposure Sciences Program faculty within our department, Environmental and Occupational Health Sciences, including two faculty whose main appointments are in Environmental Engineering and Biostatistics. Two more Exposure Sciences ARE faculty come from the School of Pharmacy.

The Exposure Sciences ARE members work collaboratively with colleagues in the other CEEH cores to provide state-of-the-art methods in the use of various exposure assessment tools including biomarkers, a molecule in blood or urine that indicates a physiological or a particular disease state.

Exposure Sciences ARE member Yvonne Lin, a faculty in the School of Pharmacy, led a study this year to search for a biomarker in urine that would reflect the activity of a metabolic enzyme called cytochrome P450 2D6 (CYP2D6). This enzyme plays a role in metabolizing 15% of clinical drugs, including antipsychotics, antidepressants, beta-blockers, opioid analgesics, and dextromethorphan, a cough suppressant found in many over-the-counter cough and cold medicines.

CYP2D6 has wide genetic diversity. Some healthy people have no CYP2D6 activity (these folks are called Poor Metabolizers), while others have some activity and still others have extensive activity.
Phenotyping to test a person’s level of CYP2D6 activity is done with probe drugs or drug cocktails and blood draws. A safer, less invasive method would be to identify a biomarker, for example in urine, to measure the real-time activity of the CYP2D6 enzyme. This is what Lin and her team members did.

Child participants were given cough syrup.
One hundred healthy children were given the drug dextromethorphan, a common over-the-counter medication given to adults and children. Urine samples were collected before and after participants were given the drug. Samples were analyzed to try to identify urinary metabolites, small molecule fragments of the drug that could predict the child’s CYP2D6 phenotype.

Lin and her team were able to identify a candidate biomarker molecule that indicated the metabolism of dextromethorphan. The molecule was nearly absent in the 9 poor metabolizers and present in 91 participants in proportion to their CYP2D6 phenotype.

The team searched established databases to identify the molecule, but found no matches. They identified the biomarker by its mass, 443.3026 Da, and refer to it as Unknown 1, or Unk1. A paper about the study has been submitted and is currently in review.

Next steps are to identify Unk1 and validate it as a biomarker that can be used to measure clinical drug metabolism. This discovery has the potential to improve personalized medicine in children by providing a means to measure in a urine sample an individual ‘s response to the clinical drugs metabolized by CYP2D6.

Dr. Lin’s research interests include pharmacokinetics, the process by which a drug is absorbed, distributed, metabolized, and eliminated by the body; pharmacogenetics, genetic differences in metabolism that can affect individual responses to drugs; the regulation of drug metabolizing enzymes such as CYP2D6 in children; the effect of obesity and diabetes on the metabolism and elimination of clinical drugs, and metabolomics, the study of the chemical fingerprints and metabolites left behind in metabolism, as a tool to identify biomarkers.

Research Highlight: Studying the Links between Chemical Exposures, Genetics, and Neurodegenerative Disease


Lucio Costa, NND ARE leader
As the US population ages, more and more Americans suffer from neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and Amyotrophic Lateral Sclerosis (ALS).1

Alzheimer’s disease is the 6th leading cause of death in the US. More than 5 million Americans are living with Alzheimer’s.2 In addition, over 500,000 Americans live with Parkinson’s.3

Approximately 5,600 Americans are diagnosed with ALS each year. The life expectancy of an ALS patient averages two to five years from diagnosis, and as many as 30,000 Americans have ALS at any given time. The National Institute of Neurological Disorders and Stroke (NINDS) reports that only 5–10% of ALS cases can be traced to genetics.4

Why and how these neurodegenerative diseases develop is for the most part unknown, and environmental factors such as the potential harmful effects of chemicals may play a role.
Investigators in the CEEH Neurotoxicology and Neurodegenerative Disease (NND) Area of Research Emphasis (ARE) study how certain chemicals can affect growth and development and how this might contribute to neurodegenerative diseases. They also look for genetic variations that might explain why some people are more susceptible to the harmful effects of chemicals than others, and work to understand the actual cellular, biochemical and molecular mechanisms of these neurotoxic chemicals.

Core leader Lucio Costa and Core member Clement Furlong study the gene family Paroxonase (PON), which includes PON1, PON2 and PON3. These genes provide the code that allows the body to produce enzymes to help break down certain kinds of pesticides in the body.

Recently Drs. Costa and Furlong investigated the level of one of these enzymes (confusingly named PON2 after the gene that codes for it) in mouse brain cells after the cells were treated with quercetin, a chemical compound found in fruits and vegetables. Previous research has shown that quercetin is an antioxidant that helps protect cells from the harmful effects of oxidative stress. Under normal conditions, the human body uses oxygen to fuel itself by combining the oxygen we breathe with the food we eat and digest. This process produces dangerous by-products such as “free radicals,” unstable atoms or molecules that wreak havoc in cells. Oxidative stress is a disturbance in the balance of free radicals and anti-oxidant defenses such as quercetin. Oxidative stress is associated with neurodegenerative diseases and also plays a role in age-related degeneration.5

Costa and Furlong’s team treated mouse brain cells (astrocytes) with quercetin. They found that these treated cells had higher levels of the PON2 enzyme, and that the PON2 levels increased in proportion to the concentration of quercetin. The team also measured the concentration of free radicals in the treated cells and found decreased levels of these. These findings suggest that quercetin increased the ability of the cells to destroy harmful free radicals and thus protect them from some of the damage caused by oxidative stress.

In cells taken from control mice that didn’t have the PON2 gene, and therefore didn’t produce the PON2 enzyme, quercetin was significantly less protective against oxidative stress. This suggests that the PON 2 enzyme plays an important role in helping quercetin protect us from free radicals. A next step in this research is to move from cells to animal models and study the effect of quercertin on PON2 levels in complex organisms.

Dr. Costa earned a degree in Pharmacology at the University of Milan and came to the US as a postdoctoral fellow at the University of Texas at Houston. As a post-doc, he was asked to discover why animals could become tolerant to the neurotoxic effects of organophosphorus insecticides. This research project sparked his lifelong interest in the myriad ways that chemicals can harm the nervous system.

References
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Newsflash: Dietary Study Has Unexpected Results

© 2013, JupiterImages

Center member Dr. Sheela Sathyanarayana and her colleagues have published the results of an intervention trial that attempted to reduce exposure to endocrine-disrupting phthalates and Bisphenol A (BPA) in the diet. The article was released today in the Journal of Exposure Science and Environmental Epidemiology.

Phthalates and BPA are found in a wide variety of plastic products and contaminants in food. They can harm pregnant women and young children. The researchers wanted to find out if asking families to follow written instructions would lead to reduced exposure to these chemicals, compared to providing a catered diet specially prepared without plastics.

The study took place in summer, 2011 in Seattle. Eligible participants were 2-parent families with at least two 4-8 year-old children. Ten families with a total of 40 individuals were enrolled. The families were randomly assigned, half to the dietary replacement group and half to the written materials  group. The study lasted for 16 days.

Days 1-5 were Baseline Days during which the study was explained, instructions and materials such as glass food storage contains were provided, and detailed dietary questionnaires were completed for each family member every day. The written materials group was given written guidelines to reduce phthalate and BPA exposure, including descriptions of phthalates and BPA, sources of exposure with a focus on plastics, and suggestions for how to reduce exposure in daily activities. Urine samples were collected from all family members on Day 5.

Days 6-10 were Intervention Days. The dietary replacement group was provided with catered food from a local caterer who used fresh, local and, whenever possible, organic ingredients. The food was prepared, stored and transported without using plastics. Both groups were instructed to use filtered water, consume beverages from non-plastic containers when possible, use non-plastic utensils and dishware, and store foods in the glass storage containers provided. Dietary surveys were completed every day. A urine sample was collected for each family member on Days 9 and 10.

Days 11-16 were Post-Intervention Days. Dietary surveys were completed every day and urine was collected on Day 16.

Here's what they found:  There was a significant increase in phthalate metabolites during the intervention period compared to the baseline period for the group that ate a catered diet. The average phthalate level in the dietary replacement group when they ate the catered diet (Days 9 and 10) was 25 times the level at baseline (Day 5). This was a complete surprise! In contract, they found no change in urinary phthalate metabolites in the written materials intervention group between baseline and intervention.

Since the increase in urinary phthalate concentration in the dietary replacement group was unexpected, the researchers tested the food ingredients in the dietary replacement group to see if there was phthalate contamination. They found that the dairy products milk and cream had phthalate concentrates above 440 ng/g, and that the spice mix had very high concentrations, 700 ng/g in ground cinnamon and cayenne pepper and the astounding level of 21,400 ng/g in ground coriander. All other ingredients had phthalate concentrations in the range reported in the literature.


The researchers had hoped to see reductions in urinary phthalate metabolites in both groups, but expected that providing written materials would be less effective than providing catered organic food prepared without exposure to plastics. But that was not what they found. Instead, they concluded that accepted methods to reduce dietary exposure to phthalates and BPA (e.g. minimize contact with plastics) may not actually reduce urinary concentrations of these chemicals. This study highlights how contaminated foods can contribute to excessive phthalate exposure. However, it is not known whether this was a isolated and rare contamination event or whether the food supply is systematically contaminated with high phthalate concentrations.

With no change in phthalate and BPA levels between baseline and intervention days in the group who received written materials, the trial supported the team's hypothesis that providing written recommendations to reduce dietary exposure to plastics is insufficient. This is corroborated in primary practice where it has been shown that written guidelines are ineffective to change health-related behaviors.

Families can focus on buying fresh, low-fat foods and avoiding plastic packaging and dishware. But this study demonstrates that it may take federal regulation to eliminate phthalates from the food supply.



Upcoming Event: Public Health Cafe: Nanotechnology & Nanotoxicology



presented by Terry Kavanagh & Megan Cartwright 

Tuesday, May 13th, 7-8:30 pm  

Chaco Canyon Cafe, West Seattle 

Research Highlight: Using Zebrafish As Models for Toxicology Investigations


The genome is an organism's hereditary information, encoded in DNA. Genomics is the study of the structure, function, evolution, and mapping of genomes. A xenobiotic (in Greek, xenos means “stranger” and biotic means “related to living beings”) is any substance that is foreign to the body. Drugs, pesticides, and carcinogens are examples of xenobiotics. Xenobiotic disposition, or drug metabolism, refers to the biochemical changes (biotransformation) made by enzymes in the body that break down and eliminate drugs and other foreign substances from the body.

Our Genomics of Xenobiotic Disposition Area of Research Emphasis (ARE) focuses on understanding why individuals metabolize drugs differently. Why do some people break down and eliminate a drug or toxin relatively quickly compared to others who retain it longer? People who retain a xenobiotic are exposed to it for a longer time and are thus potentially more vulnerable for harmful health effects.

Factors that influence individual differences in xenobiotic disposition include genetics, previous exposure to the xenobiotic (or other xenobiotics), nutritional status, and the individual’s stage of development.

It is known that xenobiotics such as cadmium, copper, and certain pesticides interfere with the sense of smell in fish. Fish depend on their sense of smell to find prey, sense predators, and find their way to natal streams. Salmon are particularly at risk because they rely so much on their sense of smell.

Genomics of Xenobiotic Disposition ARE core leader Evan Gallagher is working to understand what happens at the cellular, molecular, and biochemical levels to the olfactory system of fish when they are exposed to copper.

In a recent study, his team exposed adult zebrafish for 24 hours to 3 concentrations of copper, concentrations within the range of copper concentrations from urban runoff. The olfactory systems of the fish were then harvested and analyzed to discover whether genes involved in pathways in the sense of smell, the olfactory system, behaved differently when the fish were exposed to copper.

Current research suggests that copper exposure causes epigenetic changes in the genes in the olfactory pathway. Epigenetic changes are changes in the activity of genes not caused by changes in the DNA sequence. Epigenetic changes regulate whether the genes are turned on or off.

In this study, the researchers looked at epigenetic changes caused by microRNAs, or miRNAs, small molecules found in plants and animals that regulate genes. The research team identified changes in the concentrations of several miRNAs that regulate various genes in the olfactory system. Some of the dysregulated genes are involved in neurogenesis, the creation of new nerve cells needed to heal after an injury to the nervous system. The change in miRNA levels was greater as the concentration of copper increased.

These results suggest that changes in the concentration of miRNA molecules are a possible mechanism by which copper damages the olfactory system. The next step is to focus on the target genes identified in this study and explore their specific roles in the olfactory system in fish.

This study appears to be the first to look at miRNA regulation as the mechanism by which copper damages the olfactory system in fish. The results provide new information about the potential role of miRNA molecules in gene regulation when fish are exposed to copper.

Gallagher’s work on metal exposure in fish doesn’t discourage him from eating fish. An avid fly fisherman, he says, “It's my opinion that our salmon are overwhelmingly beneficial for us, especially in the Puget Sound region. They have all the things you find in over-the-counter vitamins and supplements – Vitamin E, antioxidants, omega-3 fatty acids – that protect against heart disease and age-related disorders.”

Event Highlight: CEEH Outreach at UW Science and Engineering Fest in Yakima

UW Freshman Jose Lopez helped at the Pesticides & Health table hosted by the Center's Outreach Group 
Along with other UW programs, the Center's Community Outreach and Ethics Core (COEC) hosted a table at the UW Genome Sciences Education Outreach (GSEO) annual Science and Engineering Festival in Yakima on March 25-26. The audience was junior high and high school students and the community.

The theme of our display was Pesticides and Health: Ethical Implications for Genetic Testing in the Workplace. We offered this verbal spiel, in English and Spanish:

  • Pesticides are chemicals that kill insects and weeds. Do you think something intended to kill insects are good for people? (Our visitors thought not).
  • Gene-environment interactions help explain why some people get sick from being exposed to toxic substances like pesticides, and others don't.
  • We all have a gene called PON1, for paraoxonase 1. The gene holds the recipe for an enzyme that's also called PON1. Because of small differences in the PON1 gene, different people make very different amounts of the PON1 enzyme.
  • The job of the PON1 enzyme is to break down foreign molecules in our bodies. PON1 breaks down organophosphate pesticides. 
  • People who have less PON1 enzyme have a higher risk of getting sick from being around pesticides because the pesticide stays in their body longer.
Visitors answered 4 ethical questions by dropping a colored stone in a graduated cylinder labeled Yes or No. The questions were:
  1. If you had a genetic variant that made you more likely to get sick from pesticides, would you want to know?
  2. Should genetic testing be required for employees who work with pesticides?
  3. If a worker has been tested for PON1 status, to measure if they are more likely than average to get sick from pesticides, should their employer be told the test result?
  4. Should family members who live with a farm worker, and those who live or go to school near farm fields, also be tested for PON1 status to find out if they are more likely to get sick from pesticides?
We offered our handout about PON1. We also have a fact sheet, Health Risks of Pesticides in Food.

The majority answered Yes to all questions. Nearly everyone answered Yes to Q1, wanting to know their own risk. More visitors answered No to each subsequent question. Students were more likely than adults to answer Yes, they would share genetic information with employers Adults were more hesitant, and some even debated the pros and cons out loud. Some feared workers would be discriminated against if test results were known. 

For Q4, a larger minority answered No, they didn't think family members should be tested. Some shrugged, perhaps feeling it didn't matter, or there was nothing they could do about it. One mother told of living in a home surrounded by orchards with a young child who had severe asthma. She asked the orchardist if he could let the family know when pesticide spraying would be done so they could take the child away. The orchardist was unable to tell her when the spraying would happen.

Among our visitors were farmworkers, orchardists, and student and adult community members who lived near orchards and fields. Everyone seemed to know that pesticides are dangerous. Several reported that personal protective equipment is highly regulated and used, which was good to hear.

Many visitors wanted to know how to protect themselves. We offered to stay inside during spraying; wash fruit and vegetables; eat organic produce if possible; eat green tea and blueberries--foods like these that are high in antioxidants can increase the activity of PON1.

Pesticides, health, and genetics were pertinent topics to bring to the agricultural Yakima Valley. It's valuable to go to communities with our Center research, both to share what we know and to listen and learn from them.

- Marilyn Hair