
A study published in the American Journal of Psychiatry Thursday found that mothers exposed to the banned pesticide DDT were nearly one-third more likely to have children who developed autism, Environmental Health News reported.
The study, led by Columbia University's Mailman School of Public Health with the participation of researchers at the University of Turku and the National Institute of Health and Welfare in Finland, was the first to use biomarkers of maternal pesticide exposure to link pesticide exposure to increased autism risk, according to materials provided to ScienceDaily by Columbia University.
"This adds another piece to the puzzle in terms of the possible risk factors for autism," lead author and Columbia University Medical Center professor Dr. Alan Brown told ABC News. "Although we can't prove that it is a cause, we are working towards learning more about how such environmental risks may be altering brain development and possibly increasing autism risk."
Autism is a disorder that impacts communication ability and is associated with repetitive movements and behaviors. Incidence in the U.S. has increased from one in 150 children in 2000 to around one in 59 today, according to Environment Health News.
In Thursday's study, Researchers looked at 778 cases of autism in Finland between 1987 and 2005 and matched the mothers in these cases to a control group whose children did not develop autism. They then analyzed maternal blood samples for DDE, a metabolite of DDT, and polychlorinated biphenyls (PCBs), another dangerous pollutant, according to ScienceDaily.
They found that mothers with high levels of DDE in their bloodstream were 32 percent more likely to have a child with autism and more than two times more likely to have a child with autism and an intellectual disability, ABC News reported. They found no effect linked to high PCB levels in the mothers' blood.
DDT was widely banned more than 30 years ago, but it takes such a long time to break down that people can still be exposed to it.
"We think of these chemicals in the past tense, relegated to a long-gone era of dangerous 20th Century toxins," Brown said, according to ScienceDaily. "Unfortunately, they are still present in the environment and are in our blood and tissues. In pregnant women, they are passed along to the developing fetus."
Professor Kristen Lyall of the Drexel Autism Institute at Drexel University, who was not involved in the study, told Environmental Health News that people are most often exposed to DDT by eating contaminated food, especially fish.
The U.S. Food and Drug Administration (FDA) told ABC News they were aware of the results.
"We are aware of the study and will carefully consider its findings," they wrote in a statement. "The Federal Drug Administration has action levels for DDT, and this pesticide is included in our monitoring program. The most recent report summarizes the results of FDA's pesticide monitoring program and shows that the levels of pesticide chemical residues measured by FDA in the U.S. food supply are generally in compliance with the U.S. Environmental Protection Agency's pesticide tolerances."
Researchers don't yet know why DDT exposure would cause autism, but they have two hypotheses, Environmental Health News reported.
First, DDT exposure is linked to premature birth and smaller babies, both risk factors for autism.
Second, DDT exposure impacts the ability of androgens, male sex organs, to bind to receptors. This is an important step in neurodevelopment, according to ScienceDaily.
However, the study needs to be repeated to be confirmed and does not prove that DDT exposure causes autism.
A 2017 study by Lyall also assessing the impact of DDT and PCB exposure on autism risk found opposite results: PCB exposure increased risk and DDT exposure did not, Environmental Health News reported.
Lyall's study was based in California and drew from a smaller population.
"It tells us about the importance about studying different populations, and then to home in on what might be different about this population to tell us even more about autism," Brown told Environmental Health News.
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By Aaron W Hunter
A chance discovery of a beautifully preserved fossil in the desert landscape of Morocco has solved one of the great mysteries of biology and paleontology: how starfish evolved their arms.
The Pompeii of palaeontology. Aaron Hunter, Author provided
<h2></h2><p>Although starfish might appear very robust animals, they are typically made up of lots of hard parts attached by ligaments and soft tissue which, upon death, quickly degrade. This means we rely on places like the Fezouata formations to provide snapshots of their evolution.</p><p>The starfish fossil record is patchy, especially at the critical time when many of these animal groups first appeared. Sorting out how each of the various types of ancient starfish relate to each other is like putting a puzzle together when many of the parts are missing.</p><h2>The Oldest Starfish</h2><p><em><a href="https://www.biorxiv.org/content/10.1101/216101v1.full.pdf" target="_blank" rel="noopener noreferrer">Cantabrigiaster</a></em> is the most primitive starfish-like animal to be discovered in the fossil record. It was discovered in 2003, but it has taken over 17 years to work out its true significance.</p><p>What makes <em>Cantabrigiaster</em> unique is that it lacks almost all the characteristics we find in brittle stars and starfish.</p><p>Starfish and brittle stars belong to the family Asterozoa. Their ancestors, the Somasteroids were especially fragile - before <em>Cantabrigiaster</em> we only had a handful of specimens. The celebrated Moroccan paleontologist Mohamed <a href="https://doi.org/10.1016/j.palaeo.2016.06.041" target="_blank" rel="noopener noreferrer">Ben Moula</a> and his local team was instrumental in discovering <a href="https://www.sciencedirect.com/science/article/abs/pii/S0031018216302334?via%3Dihub" target="_blank" rel="noopener noreferrer">these amazing fossils</a> near the town of Zagora, in Morocco.</p><h2>The Breakthrough</h2><p>Our breakthrough moment came when I compared the arms of <em>Cantabrigiaster</em> with those of modern sea lilles, filter feeders with long feathery arms that tend to be attached to the sea floor by a stem or stalk.</p><p>The striking similarity between these modern filter feeders and the ancient starfish led our team from the University of Cambridge and Harvard University to create a new analysis. We applied a biological model to the features of all the current early Asterozoa fossils in existence, along with a sample of their closest relatives.</p>Cantabrigiaster is the most primitive starfish-like animal to be discovered in the fossil record. Aaron Hunter, Author provided
<p>Our results demonstrate <em>Cantabrigiaster</em> is the most primitive of all the Asterozoa, and most likely evolved from ancient animals called crinoids that lived 250 million years before dinosaurs. The five arms of starfish are a relic left over from these ancestors. In the case of <em>Cantabrigiaster</em>, and its starfish descendants, it evolved by flipping upside-down so its arms are face down on the sediment to feed.</p><p>Although we sampled a relatively small numbers of those ancestors, one of the unexpected outcomes was it provided an idea of how they could be related to each other. Paleontologists studying echinoderms are often lost in detail as all the different groups are so radically different from each other, so it is hard to tell which evolved first.</p>President Joe Biden officially took office Wednesday, and immediately set to work reversing some of former President Donald Trump's environmental policies.
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