Researchers look to toxins in the environment for answers to Alzheimer’s

November 26, 2019

Can insecticides, industrial and commercial pollutants, antimicrobials, heavy metals and air pollutants contribute to the onset of Alzheimer’s?

As our population ages at a breakneck pace, visions of a society overwhelmed by the sorrows of the “silver tsunami’ strike fear and concern, but answers remain elusive. Researchers across the world continue to search valiantly for answers for Alzheimer’s. Alzheimer's ASU scientists are studying environmental factors in the onset of Alzheimer's disease. Download Full Image

With no clear answers, people are asking, should I take vitamins or supplements? Are there foods I should avoid? Are chemicals in the environment a threat? Do I need to exercise more? Do crossword puzzles? Brush my teeth more often? Does it all come down to genes from my mother or father?

Scientists believe that Alzheimer's is caused by specific genetic changes that virtually guarantee a person will develop the disease less than 1% of the time. The other 99% of cases? Scientists are beginning to believe there may be as many causes and types of Alzheimer’s as there are types of cancer. And the causes may be a combination of genetic, lifestyle and environmental factors.

The incidence of Alzheimer’s is growing along with our aging population. Alzheimer's disease is now a leading cause of mortality in the developed world. Billions of dollars are being spent to try to unravel this puzzle, with the federal government recently increasing funding by $400 million, bringing the research budget up to $1.4 billion.

In addition to genetics, scientists at Arizona State University are looking to inflammation, viruses, lack of nutrients and even air pollution as possible factors in the disease. And with the latest study, the researchers at the Biodesign Center for Environmental Health Engineering are scoping out what they call “Alzheimerogens.” In the same vein as carcinogens, Alzheimerogens are any environmental substance suspected to induce Alzheimer’s or other dementias.

Scientists believe that some man-made environmental compounds can be associated directly or indirectly with Alzheimer’s disease, including various insecticides, industrial and commercial pollutants, antimicrobials, heavy metals and air pollutants. These chemicals, often used for industrial, medical, agricultural and military purposes can persist in the environment long after initial use, causing toxicity to flora and fauna.

“What we know is that genes load the gun; the environment pulls the trigger,” said lead researcher Rolf Halden, director of the Center for Environmental Health Engineering at the Biodesign Institute and senior sustainability scientist in the Julie Ann Wrigley Global Institute of Sustainability.

“With this study, we looked for a smoking gun, but we raised more questions — good questions — than we could answer,” he said. The fact that Alzheimer’s begins long before its symptoms appears also makes it challenging to draw a direct correlation between exposure to toxins and the disease itself. Halden and his team are eager to build on this study.

Some researchers and scientists are shifting attention from genes to the environment, searching for the missing pieces to explain what causes late-onset Alzheimer’s. Research publications have provided convincing evidence indicating the role of environmental contaminants in the development of neurodegenerative disorders. However, there are very few reports that compare the prevalence of Alzheimer’s among genetically similar populations living in completely different environments. The future of Alzheimer’s research relies in part on identifying the environmental risk factors and understanding how to reduce the impact of these risk factors.

Halden’s study, “Assessment of persistent bioaccumulative and toxic organic environmental pollutants in liver and adipose tissue of Alzheimer’s disease patients and age-matched controls” appears in the journal Current Alzheimer’s ResearchHalden collaborated with Thomas Beach, senior scientist at the Civin Laboratory for Neuropathology, Banner Sun Health Research Institute; molecular biologists Bhagyashree Manivannan and Manivannan Yegambaram from the University of Arizona; and Samuel Supowit, senior environmental engineer with the U.S. Department of Health and Human Services. Samples were provided by the Banner Sun Health Research Institute Brain and Body Donation Program at the Banner Sun Health Research Institute in Sun City.

Using liquid and gas chromatography in tandem with mass spectrometry, the study measured the concentrations of 11 environmental contaminants in postmortem liver and adipose tissues of Alzheimer’s patients — and in patients without evidence of Alzheimer’s. Toxins included antimicrobial agents, industrial and commercial pollutants and insecticides.

“Our most important finding is that we were able to identify the presence of seven toxins with only one gram of tissue,” Halden said. “It’s exciting to know that it becomes possible to get a pretty solid understanding of exposure on small human tissue samples.”

The study used both liver and adipose tissues from 12 patients with Alzheimer’s disease and 12 without. Researchers found a concentration of the pesticide fipronil (a weed control chemical) in both the liver and the adipose tissue. This is the first study to find high amounts of the flame retardant, TBBPA, in the liver.

Liver and adipose tissue, as opposed to brain tissue, were selected for study because many toxins do not cross the blood-brain barrier. Researchers agree it is important to study it further in nonbrain tissue to gain a better understanding of its role in Alzheimer’s.

“Our study demonstrated the detection of multiple persistent, bioaccumulative and toxic organic environmental pollutants in small sample volumes of human liver and adipose tissue of Alzheimer’s patients and healthy people,” Halden said. “This is the first data we have on how parabens (MPB), insecticides (fipronil) and plasticizers (TBBPA) find their way into human tissue.”

The plasticizer, BPA, found in some sports water bottles, canned foods and plastic food storage containers was identified at higher levels in the liver tissue of Alzheimer’s patients than in previous studies using fetal tissue, indicating the need for additional research.

The toxins examined include plastics like BPA (bisphenol A), pesticides like DDE (a metabolite of DDT) and dieldrin, used for termite control and still found in basements of homes, largely in the Southeast. Other chemicals — a number of parabens found in makeup, moisturizers, and hair care and shaving products — were also identified, along with antimicrobials, triclosan and triclocarbans. Triclosan has been found in brain tissue. In 2016, Halden led a successful movement to ban the use of triclosan and triclocarbans in the U.S.

Regardless of the bans, many of these chemicals — used for industrial, medical, agricultural and military purposes — persist in the environment today. Past studies have drawn a direct correlation between occupational exposure to pesticides and the development of Alzheimer’s and Parkinson’s disease. This new study builds on a 2015 study, Role of environmental contaminants in the etiology of Alzheimer's disease: a review, in which Halden and his team provided an overview of in vitro, animal and epidemiological studies on the cause of Alzheimer’s, highlighting available data supportive of the long hypothesized link between toxic environmental exposures and development of Alzheimer’s disease.

Written by Dianne Price

Student teams make EPIC impacts through pitch competition

November 26, 2019

The Engineering Projects in Community Service, or EPICS, program in the Ira A. Fulton Schools of Engineering at Arizona State University provides student teams the opportunity to work on projects focused on developing solutions to real-world problems in communities across the globe. 

This year at the Fulton Schools’ second annual EPICS Elite Pitch Competition, the top eight teams working on EPICS projects presented five-minute pitches of their solutions to a panel of judges. man speaking in front of a screen At the second EPICS Elite Pitch Competition, eight student teams working on projects to solve real-world problems pitched their solutions to a panel of judges to earn additional funding. Photo by Erika Gronek/ASU Download Full Image

“The EPICS Elite Pitch Competition is an opportunity for our top teams to compete for additional funding to allow them to construct larger prototypes as well as to fully deliver their system to the community,” said Fulton Schools lecturer Jared Schoepf, EPICS program’s director of operations.

“It’s also an opportunity for students in other classes to get an idea of what some of these elite teams are working on and provides additional opportunities for them to start working on real-world projects and help the community,” Schoepf said.

The first-place team, the Puerto Rico Water Contamination Project, won $1,500. The Phoenix Zoo Elephant Engagement Project, which placed second in the competition, won $1,000. The third-place team, Headcount, won $500. Each of the eight teams that competed won an additional $1,000 in funding for their project from an eSeed grant.

“It is fantastic to see some of our top EPICS teams realize the power of turning their lab-based projects into marketplace-based ventures,” said Brent Sebold, who organized the eSeed funding for the teams. “Luckily for our students at ASU, we have myriad opportunities for them to advance their entrepreneurial pursuits. Specifically, the winners of the EPICS Elite Pitch Competition have all won funding from the eSeed challenge funding track within our ASU Venture Devils Program.”

Puerto Rico Water Contamination

The Puerto Rico Water Contamination team is working to clean grey water, or household wastewater, from washing machines in Mariana, Puerto Rico, and use it to supply local crops.

“Mariana and Puerto Rico as a whole have been going through quite a bit since they were hit by Hurricane Maria in 2017,” said Blake Stephens, a junior in mechanical engineering and the team lead on the Puerto Rico Water Contamination Project. “It’s definitely important to us that people know about it and help out.”

Drawing inspiration from industrial systems in large water-treatment plants, the team settled on a dual-tank system of removing chemical contaminants from water. 

In the first stage, water is run through a pump into the distillation tank system. It enters the first tank where it is heated to 100 degrees Celsius. The steam produced goes to a condenser to return the water back to its liquid state. The water then goes into a storage container.

The team found that in this stage there was still bleach present in the water and a lot of the nutrients necessary for plants to thrive had been removed. 

To remedy this, in the second stage of filtration the water passes through an activated carbon filter that removes the bleach and adds nutrients back in.

The Puerto Rico Water Contamination Project is designed to help the people of Puerto Rico help themselves by teaching them how to use the system, and the team is looking forward to the next steps in its efforts.

With the additional funding the team plans to design a microcontroller to modulate the flow of water, run tests on the carbon filter and increase the size of their system.

“We realized that our small-scale model was pretty effective, so if they want to have a garden at their own home, they can hook the system up to their own personal washing machine,” Stephens said. “We’re also going to be making an assembly guide and as well as a troubleshooting guide so if any break happens, we can tell them how to fix it.”

Phoenix Zoo Elephant Engagement

The Phoenix Zoo Elephant Engagement team aspires to use engineering to provide safe mental and physical stimuli to elephants at the Phoenix Zoo to keep them happy and physically fit. 

“In the short term, we hope to be able to engage the elephants and see them moving around the enclosure,” said Taylor Benning, a third-year student studying mechanical engineering and the team lead for project. “We are looking at ways to automate the process of measuring the activity of the elephants. In the long term, we hope to see a decrease in the elephants’ weight because they are currently overweight.”

The team is designing a motion sensor game using steel frames and motion detecting buttons. When a light or sound goes off, the game begins, triggering a series that requires button inputs from elephants at every stage of the game. The zookeepers can interface with the game using an iPad and can vary the time between intervals, as well as the number of button pushes needed in the series, for the elephants to receive a treat at the end.

“The most challenging aspect so far has been trying to get the programming done,” Benning said. “For a while, nobody on my team had any experience with any programming language, so it was a lot of trial and error. Now, we have a couple of members with experience with Python, and have made substantial progress in getting the game working. We should have a fully functional prototype by the end of this semester.”

With the additional funding from the EPICS Elite competition, the team has made a fully functional prototype of its design using acrylics, and are planning to use the rest of the funding to create a metal version.

“The project has the potential to be used for cognitive studies on elephants, which previously could not be done,” Benning said. “It provides the most interaction between elephants and humans without physically touching. Seeing it work and having people and elephants use something we built is amazing.”


The Headcount team is working on a solution that impacts students on campus. They are developing a better way to count the number of people who move in and out of rooms at the Fulton Schools' career fairs. 

“The current method they have uses clickers, and they have to communicate from one doorway to another, and it’s not very accurate,” said Nicholas Iwanski, a third-year student studying electrical engineering and the new team lead for the Headcount project.

“If they exceed capacity, and the fire marshal is called and they don’t have an accurate count of the number of people in the room,” Iwanski said. “The entire event is shut down and everybody loses out on opportunities to get jobs and internships. So, we’re planning on automating the whole process.”

The team’s current prototype involves a thermal camera and artificial intelligence technology that can track people as they enter and leave a room and achieve a much more accurate count of how many people are at the attendance.

Since the team formed in fall 2018, the members have explored a few different prototypes and overcome a number of unique challenges, including trying to find a way for the device to communicate between rooms without using Wi-Fi, so it would adhere to ASU policies. 

“It’s really cool seeing how the project started with just three of us, and now there are nine people who are all very passionate about the project and plan to come back in the next semester,” Iwanski said. “Knowing that at the end of it we’re going to have something that we can see here at ASU and everyone in the Fulton Schools is going to be able to use, that’s really cool to be able to give back to the community around us.” 

Once the team finishes its first prototype, they plan to use the money from the competition to purchase multiple units of the counters.

They hope to test two fully-built prototypes by the spring 2020 career fair. Once they’ve fixed all the bugs, the team plans to install the device in every room at the career fair next fall. 

Karishma Albal

Student Science/Technology Writer, Ira A. Fulton Schools of Engineering