Have a science question on a public policy issue? Ask us.
Q: When is the human heart fully developed, and when are heartbeats audible during pregnancy?
A: A developing heart has all of its primary structures after about nine weeks of pregnancy. Some forms of ultrasound can detect cardiac activity in an embryo in the sixth week, but a heartbeat wouldn’t be audible until about 10 weeks on a Doppler fetal monitor.
Q. Did the Environmental Protection Agency change its rules to allow companies to use asbestos in manufacturing?
A. No. Asbestos is already allowed in numerous products. A proposed EPA rule would prohibit the use of asbestos in certain products unless granted EPA approval.
Q: Did people develop cancer because of the polio vaccine?
A: There are no known cases, and it’s very unlikely. In the 1950s and 1960s, people did receive polio vaccines contaminated with a virus that causes cancer in rodents. But research suggests this virus doesn’t cause cancer in humans.
Q: Does the National Institutes of Health fund research on human-animal chimeras, or organisms that are part-human, part-other animal?
A: With some exceptions, the NIH doesn’t fund research on human-animal chimeras. But the agency has proposed a rule to widen the scope of research it funds in this area.
Q: Did climate change cause the wildfires out West?
A: Scientists say a hot and dry summer — conditions more likely in a warmer world — caused widespread wildfires in Western states. But land use changes also have played a role.
Q: Does the herbicide glyphosate cause cancer?
A: There is evidence to suggest it may cause cancer at very high doses, but not at the low doses typically found in foods.
Q: Is bacon better for you than tilapia? Does tilapia cause cancer and/or Alzheimer’s disease?
A: No. These false claims, spread by multiple websites, are not supported by solid scientific evidence.
Q: Have scientists confirmed that e-cigarettes cause an incurable respiratory disease called “popcorn lung”?
A: No. The vapor of some e-cigarettes contains a chemical associated with popcorn lung, but there’s not enough evidence to conclude they cause the disease.
Q: Are the chemicals in fracking solution protected from being made public by a law passed while Dick Cheney was vice president?
A: Yes. A 2005 law bans the federal government from requiring companies to disclose fracking chemicals. But 28 states do require disclosure of some fracking fluids.
In January 2015, we launched SciCheck — a feature devoted to fact-checking false and misleading scientific claims. Today, we introduce Ask SciCheck, which will provide answers to your questions about science and public policy.