Why did researchers take a knife to a cute little plastic gingerbread man? To make him give up the source of his toxic fumes. Or so explained Bill Doucette, this morning, in a particularly entertaining session at the Society for Toxicology and Environmental Chemistry’s annual meeting. But the underlying message that this Utah State University scientist brought home to his audience was anything but funny. He graphically illustrated that hidden dangers may lurk in surprising places.

No one would choose to eat polychlorinated biphenyls, or PCBs — yet we unwittingly do. And a new study finds that the cost of their pervasive contamination of our food supply can be elevated blood pressure, a major risk factor for heart disease.

Weather-monitoring stations in the Lower 48 have been logging record daily highs in temperature at twice the pace of record lows. Yet more evidence of climate warming. Many people have pointed to colder than normal winters — or summers — as evidence that global warming is a myth. Climatologists have countered that weather, the meteorological features that we experience at any given hour or day, may show anomalies even as Earth’s overall climate warms. So weather can locally mask the planet’s overall slowly rising fever. Except that any such mask appears to be disappearing throughout most of the United States, according to a new study.

Negotiators representing 181 nations completed their final prep work in Barcelona, Spain, last Friday, on a new climate treaty — one that they hope to build a month from now at a major conference in Copenhagen, Denmark. But at least one scientist worries that what comes out of the Copenhagen deliberations may not have sufficient coordination and strength to meet the challenges that Earth’s climate has begun throwing at us.