Critical Science

SummaryIn this episode, Dr. Lyle Burgoon discusses a study published in JAMA Network Open that claims a link between prenatal exposure to certain chemicals and metabolic syndrome risk in children. He analyzes the study using the seven tips he discussed in a previous episode and highlights several flaws and limitations in the study design. Dr. Burgoon emphasizes the importance of being skeptical and checking biases when evaluating scientific studies. He criticizes the media, particularly CNN, for sensationalizing and misrepresenting the study's findings, causing unnecessary fear and confusion among the public.TakeawaysBe skeptical and evaluate scientific studies based on their scientific merits, regardless of who funded them.Consider the study design and sample size when assessing the reliability and generalizability of the findings.Recognize the limitations and uncertainties in observational studies and the inability to establish causation.Check biases and avoid confirmation bias when interpreting scientific studies.Be critical of media reporting on scientific studies and consider waiting for scientific consensus before drawing conclusions.

I get asked now and then if I have tips to help people spot poorly done science, bad science, or what I prefer to call pseudoscience. Here are 7 tips! If you want to see the infographic, visit our Critical Science website (https://critscipod.com/episode-25-7-tips-for-assessing-science/).

SummaryIn this episode, Dr. Lyle discusses benzoyl peroxide and the recent concerns raised by Valashur about the presence of benzene in benzoyl peroxide products. He explains that Valashur has a history of testing products for impurities and notifying the FDA. However, the benzene was only found in products that were exposed to high heat for extended periods, which is not how they are supposed to be stored. Dr. Lyle emphasizes that one molecule of benzene is not toxic and that there are thresholds for toxicity. He also highlights the importance of educating the public about the science and not relying on activist talking points.TakeawaysBenzene was found in benzoyl peroxide products that were exposed to high heat for extended periods, which is not how they are supposed to be stored.One molecule of benzene is not toxic, and there are thresholds for toxicity.It is important to educate the public about the science and not rely on activist talking points.Follow the manufacturer's instructions for storing and using benzoyl peroxide products.Chapters00:00 Introduction to benzoyl peroxide00:30 Valashur's testing and FDA involvement01:24 Benzene presence in benzoyl peroxide03:23 No safe level of benzene exposure04:06 Toxicity of one molecule of benzene05:05 Thresholds for toxicity06:04 Long history of benzoyl peroxide use06:29 Detection of impurities over time07:56 Educating the public about thresholds08:25 Activist talking points09:23 DNA repair mechanisms10:24 Xeroderma pigmentosa and DNA damage11:24 Homeostasis and cell signaling12:22 Dose-response curves13:20 Oncotic necrosis and cell death14:48 Relevance of Valashur's study19:00 Following manufacturer's instructions19:53 Take-home messagesReferences:https://ehp.niehs.nih.gov/doi/10.1289/EHP13984

SummaryIn this episode of the Critical Science podcast, Dr. Lyle Burgoon discusses the topic of drug testing, with a focus on methamphetamine testing. He explains the different forms of methamphetamine and how they affect the brain. Dr. Burgoon highlights the presence of levomethamphetamine in over-the-counter products and the potential for false positive methamphetamine tests. He emphasizes the importance of accurately listing all medications, including over-the-counter drugs, when undergoing drug testing. Dr. Burgoon also explores the probability of drug use based on positive test results and the challenges of interpreting drug tests. He concludes by emphasizing the need for due diligence and additional confirmatory tests in the drug testing process.TakeawaysMethamphetamine has two forms: levo and dextro, with only the dextro form having psychoactive effects on the brain.Over-the-counter products containing levomethamphetamine can lead to false positive methamphetamine tests.Positive drug tests do not necessarily indicate drug abuse, as there is a high probability of non-users testing positive.Confirmatory tests, such as enantiomer-specific tests, are necessary to accurately determine the presence of methamphetamine.Chapters00:00 Introduction to Drug Testing00:28 Different Forms of Methamphetamine01:53 How Methamphetamine Affects the Brain03:10 Levomethamphetamine in Over-the-Counter Products04:07 Ramifications of Positive Methamphetamine Tests05:59 Forgetting to List Over-the-Counter Drugs06:26 Drug Testing in Various Settings07:24 Probability of Drug Use Based on Positive Test08:20 Bayes' Rule and Prevalence of Drug Users09:46 Probability of Positive Test for Non-Users12:37 Performance Characteristics of Drug Tests13:34 Low Probability of Drug Use Given Positive Test16:37 High Probability of Non-Users Testing Positive18:10 Challenges of Drug Testing and Confirmatory Tests20:27 Enantiomer Specific Test for Methamphetamine23:21 Additional Steps in Drug Testing Process25:31 Importance of Due Diligence in Drug Testing26:01 Positive Test Does Not Indicate Drug Abuse26:58 Orthogonal Assay for More Accurate Results27:25 Conclusion and Closing Remarks

Happy New Year! New Year, New You, right? Well, it wasn't quite in the new year, but the American Academy of Pediatrics may have re-made themselves into a Merchant of Fear. In December 2023, the AAP released a statement that although GMOs themselves are fine, glyphosate (which is commonly associated with GMO crops) is not okay for children. In fact, the AAP says that glyphosate "Recent studies show that glyphosate is present in many foods, especially ultra-processed foods (more information, below). It also shows up in 80% of urine samples taken from people in the U.S.—including kids as young as 6 years. This suggests that most children and adults are consuming foods that may increase their chances of developing cancer."So this creates a confusing dynamic: do I trust the US EPA and the US FDA, or do I trust the AAP? The US Government and the AAP can't both be right. The US Government says that glyphosate does not cause cancer. Yet the AAP says glyphosate may increase the chances of children developing cancer. Who's right here?The science is clear -- the US Government is right, and the AAP is pushing a chemophobic agenda. Find out more in today's podcast!

Thanks for your patience while I was away on travel. I spent a couple of weeks in Korea presenting at 2 conferences, including 1 Keynote Address. And somehow one of my kids speaks better Korean than me!?! (It's not hard to speak better Korean than me). Anywho, big few weeks in the toxicology world. The European Commission granted another 10 year approval to glyphosate! I did not have that on my bingo card! The Biden-Harris Administration is looking to replace all of the lead service lines -- that's simply fantastic news! Now, on to more our topic of the day -- phosphatidylethanol or PETH (see why we just call it PETH; I trip over that word and I have a biochemistry background, which means I am trained to say big words like that). Anywho, today's topic is this: PETH and its use in Family Law cases. I've seen it mostly when a parent, in a co-parenting situation, has temporary custody of a child and is not allowed to drink in the presence of the child. I'm going to talk today about why PETH is not the right biomarker to use in these cases.And I want to give a shout-out to the Toxicology Education Foundation (TEF; toxedfoundation.org). Fully disclosure: I'm on the Board and I am the Secretary. Part of the TEF's mission is to educate the public about toxicology in our daily lives. We want to raise the level of scientific literacy in our country. But we can't do it without your help. Please consider donating to TEF -- small dollar donations are always welcome.