Pesticide Exposure Linked to Alzheimer’s Disease
By Robin Lally
Scientists have known for more than 40 years that the synthetic pesticide DDT is harmful to bird habitats and a threat to the environment.
Now researchers at Rutgers University say exposure to DDT—banned in the U.S. since 1972 but still used as a pesticide in other countries—may also increase the risk and severity of Alzheimer’s disease in some people, particularly those over the age of 60.
In a study published online Tuesday in JAMA Neurology, Rutgers scientists discuss their findings in which levels of DDE—the chemical compound left when DDT breaks down—were higher in the blood of late-onset Alzheimer’s disease patients compared to those without the disease.
DDT was used in the U.S. for insect control in crops and livestock and to combat insect-borne diseases like malaria. It was introduced as a pesticide during WWII. Rutgers scientists (the first to link a specific chemical compound to Alzheimer's disease) believe that research into how DDT and DDE may trigger neurodegenerative diseases, like Alzheimer's, is crucial.
“I think these results demonstrate that more attention should be focused on potential environmental contributors and their interaction with genetic susceptibility,” said Jason R. Richardson, associate professor in the Department of Environmental and Occupational Medicine at Robert Wood Johnson Medical School and a member of the Environmental and Occupational Health Sciences Institute. “Our data may help identify those that are at risk for Alzheimer’s disease and could potentially lead to earlier diagnosis and an improved outcome.”
Although the levels of DDT and DDE have decreased significantly in the U.S. over the last three decades, the toxic pesticide is still found in 75 to 80 percent of the blood samples collected from the Centers for Disease Control and Prevention for a national health and nutrition survey. This occurs, scientists say, because the chemical can take decades to breakdown in the environment. In addition, people may be exposed to the pesticide by consuming imported fruits, vegetables and grains where DDT is still being used or eating fish from contaminated waterways.
In the Rutgers study, conducted in coordination with Emory University Alzheimer’s Disease Research Center and the University of Texas Southwestern Medical School’s Alzheimer’s Disease Center, 74 out of the 86 Alzheimer’s patients involved (whose average age was 74) had DDE blood levels almost four times higher than the 79 people in the control group who did not have Alzheimer’s disease.
Patients with a version of ApoE gene (ApoE4), which greatly increases the risk of developing Alzheimer’s, and high blood levels of DDE exhibited even more severe cognitive impairment than the patients without the risk gene. Brain cell studies also found that DDT and DDE increased the amount of a protein associated with plaques believed to be a hallmark of Alzheimer's disease.
These sticky amyloid proteins—which may form in regions of the brain involved in memory, learning and thinking—break off and clump together in the brain and increase as the disease progresses. This new research is important, Richardson says, because it suggests that DDT and DDE may directly contribute to the process of plaque development.
“We need to conduct further research to determine whether this occurs and how the chemical compound interacts with the ApoE4 gene,” Richardson said.
Although the exact cause of Alzheimer’s disease, with which five million Americans are now suffering and millions more expected to fall prey with the graying of the Baby Boom Generation, is not known, scientists believe that late-onset Alzheimer’s may be linked to a combination of genetic, environmental and lifestyle factors. Much of the research into Alzheimer’s and other neurodegenerative diseases has mostly been centered on finding genetic connections, Richardson explained.
“This study demonstrates that there are additional contributors to Alzheimer’s disease that must be examined and that may help identify those at risk of developing Alzheimer’s,” Richardson said. “It is important because when it comes to diagnosing and treating this and other neurodegenerative diseases, the earlier someone is diagnosed, the more options there may be available.”
Scientists Ananya Roy, Stuart Shalat and Brian Buckley at the Environmental and Occupational Health Sciences Institute at Rutgers, Allan Levey and Maria Gearing at Emory University School of Medicine, and Dwight German at the University of Texas Southwestern Medical Center contributed to the research.
Britain's Prince William interviewed famed broadcaster David Attenborough on Tuesday at the World Economic Forum's annual meeting in Switzerland.
During the sit-down, the 92-year-old naturalist advised the world leaders and business elite gathered in Davos this week that we must respect and protect the natural world, adding that the future of its survival—as well as humanity's survival—is in our hands.
What's more, the accounting firm predicts that another 21 million electric cars will be on the road globally over the next decade due to growing market demand for clean transportation, government subsidies, as well as bans on fossil fuel cars.
By Matthew Savoca
Plastic pollution in the world's oceans has become a global environmental crisis. Many people have seen images that seem to capture it, such as beaches carpeted with plastic trash or a seahorse gripping a cotton swab with its tail.
Greenland is melting about four times faster than it was in 2003, a new study published Monday in the Proceedings of the National Academy of Sciences found, a discovery with frightening implications for the pace and extent of future sea level rise.
"We're going to see faster and faster sea level rise for the foreseeable future," study lead author and Ohio State University geodynamics professor Dr. Michael Bevis said in a press release. "Once you hit that tipping point, the only question is: How severe does it get?"
Finally, some good news about the otherwise terrible partial government shutdown. A federal judge ruled that the Trump administration cannot issue permits to conduct seismic testing during the government impasse.
The Justice Department sought to delay—or stay—a motion filed by a range of coastal cities, businesses and conservation organizations that are suing the Trump administration over offshore oil drilling, Reuters reported. The department argued that it did not have the resources it needed to work on the case due to the shutdown.
Most people have heard of the Amazon, South America's famed rainforest and hub of biological diversity. Less well known, though no less critical, is the Pantanal, the world's largest tropical wetland.
Like the Amazon, the Pantanal is ecologically important and imperiled. Located primarily in Brazil, it also stretches into neighboring Bolivia and Paraguay. Covering an area larger than England at more than 70,000 square miles, the massive wetland provides irreplaceable ecosystem services that include the regulation of floodwaters, nutrient renewal, river flow for navigability, groundwater recharge and carbon sequestration. The wetland also supports the economies of the four South American states it covers.
By Andrea Germanos
Organizers said 35,000 people marched through the streets of the German capital on Saturday to say they're "fed up" with industrial agriculture and call for a transformation to a system that instead supports the welfare of the environment, animals and rural farmers.
By Patrick Rogers
If you have ever considered making the switch to an environmentally friendly electric vehicle, don't drag your feet. Though EV prices are falling, and states are unveiling more and more public charging stations and plug-in-ready parking spots, the federal government is doing everything it can to slam the brakes on our progress away from gas-burning internal combustion engines. President Trump, likely pressured by his allies in the fossil fuel industry, has threatened to end the federal tax credits that have already helped put hundreds of thousands of EVs on the road—a move bound to harm not only our environment but our economy, too. After all, the manufacturing and sale of EVs, hybrids, and plug-in hybrids supported 197,000 jobs in 2017, according to the most recent U.S. Energy and Employment Report.