As pollen torments millions, it might be getting worse, and it’s poorly measured in America

PHILADELPHIA – He found masses of pollen as thick as “oatmeal,” and once discovered that grains from palm trees had ridden the winds for hundreds of miles to reach his front porch. For 17 years, Timothy Craig intercepted the airborne gametes of trees, grasses, and weeds with a whirling trap, assiduously examined the captives with a microscope, and posted his inferred daily pollen counts for the benefit of science and the allergy-tormented. Not many people are going through that much trouble these days. “It’s very labor-intensive and time-intensive,” said Craig, a professor of medicine and pedi...