On today’s episode of The Confluence:Norfolk Southern has hired a company to conduct testing of air in residents’ homes near the derailment of the company’s train in East Palestine, Ohio. A ProPublica investigation finds the testing may not be capturing the whole picture of the health and environmental impact from the derailment. Reporter Sharon Lerner tells us what concerns experts and residents still have. (0:00-8:20)The historians at Rivers of Steel, which supports heritage and tourism at the Carrie Blast Furnaces National Historic Landmark, have long known the furnaces’ namesake was likely a family member, but it wasn’t until recently they confirmed Carrie’s identity. Ron Baraff, director of historic resources and facilities at Rivers of Steel, gives us the backstory. (8:20-17:28)As part of our Good Question, Kid! Series, we answer the question: Where do primary colors come from? Clayton Merrell, a professor of art at Carnegie Mellon University tells us about red, yellow and blue, or as he clarifies, “magenta, yellow and cyan.” (17:28-22:30)