For some semivolatiles such as phthalates, dermal uptake can at least match entry via lungs
For some toxic air pollutants, more can get into the body through the skin than via breathing, new human data indicate.
The natural assumption is that inhalation is the primary route by which air pollutants invade the body. Each breath delivers those chemicals to the blood, which courses through the lungs’ tiniest airways. But the body’s biggest organ is the skin, and recent studies show “that we’re big sponges for these chemicals,” says John Kissel of the University of Washington in Seattle.
Earlier research had suggested that semivolatile compounds — those that move through air in both the gas and condensed phases — tend to pass through skin relatively slowly. “But,” Kissel says, “if the whole body is exposed, then even low rates of exposure can deliver what turns out to be nontrivial amounts of these chemicals.”