Researchers have found the some ingredients found in typical Halloween candy can have coal tar derivatives. Some found that one family of chemicals, PAHs (polycyclic aromatic hydrocarbons) present in all chocolate samples and the most carcinogenic compound was found in 23 of 25 samples.
Others point out that the typical yellow dye used in traditional goodies like candy corn is "known to cause allergic reactions such as asthma and urticaria...." What is "urticaria?" It is a skin condition with symptoms like a rash, raised bumps, or hives. Also of concern is the potential mutagenic or carcinogenic properties.
While none of that sounds particularly appealing, it pales in comparison to the ingestion exposure that kids can get when living with a coal tar sealed asphalt surface near the home. A joint study with the USGS and Baylor University found that the total amount of these chemicals eaten by children with dust tracked in from coal tar paved surfaces is nearly 10x the amount of a typical child's entire dietary intake! That includes grilled meats and other major sources.
"The increased cancer risk associated with coal-tar-sealed asphalt likely affects a large number of people in the U.S.," says lead study author E. Spencer Williams, PhD, assistant research scientist at Baylor University's Center for Reservoir and Aquatic Systems Research.
Obviously candy, for most kids, is a small percentage of their dietary intake.
So if you're really concerned with what your kids are eating this season, then surprisingly the first place to start is your own driveway.