Subway air does extra damage.The hodgepodge hodge·podge
A mixture of dissimilar ingredients; a jumble.
[Alteration of Middle English hochepot, from Old French, stew; see hotchpot. of minute compounds that drifts through the air in many environments has been linked to heart and respiratory problems. But mixtures vary in composition from place to place, and it's not known which ones are most harmful.
Research now indicates that the mix of airborne particles in subterranean transit stations is more damaging to human cells in culture dishes than are particles in street-level air. Time spent underground might therefore contribute to health risks in sensitive people, suggest Hanna L. Karlsson and her colleagues at the Karolinska Institute in Stockholm.
The researchers collected particles smaller than 10 micrometers in diameter from air in a Stockholm subway station and along a busy street above it. In the lab, the scientists exposed lung cells to solutions containing various doses of particles from one location or the other.
In similar doses, particles from subway air caused about eight times as much DNA DNA: see nucleic acid.
or deoxyribonucleic acid
One of two types of nucleic acid (the other is RNA); a complex organic compound found in all living cells and many viruses. It is the chemical substance of genes. damage as did those from street air. The former particles also produced four times as much evidence of cellular injury from particularly reactive chemicals called free radicals, the scientists report in the January Chemical Research in Toxicology toxicology, study of poisons, or toxins, from the standpoint of detection, isolation, identification, and determination of their effects on the human body. Toxicology may be considered the branch of pharmacology devoted to the study of the poisonous effects of drugs. .
"Probably the particles in the underground arise from friction between the wheels and the steel rails," Karlsson says. Compared with the particles in street air, subway particles contain at least 10 times more iron, most notably in the form of magnetite magnetite (măg`nətīt), lustrous black, magnetic mineral, Fe3O4. It occurs in crystals of the cubic system, in masses, and as a loose sand. . That compound is a type of iron oxide The material used to coat the surfaces of magnetic tapes and lower-capacity disks. that's particularly good at generating free radicals. Subway air is also 5 to 10 times as thick with particulate matter particulate matter
n. Abbr. PM
Material suspended in the air in the form of minute solid particles or liquid droplets, especially when considered as an atmospheric pollutant.
Noun 1. as street level air is, enhancing its harmful potential, the researchers say.