When a yellowish haze of toxic smoke blanketed the sky during the deadly Camp Fire in Northern California this past November, John Balmes, a medical professor, was alarmed to find a man in a paper mask jogging in Sacramento.
“Now that’s misuse,” said Balmes, who is an expert on the respiratory effects of air pollutants at the University of California in both Berkeley and San Francisco.
While experts recommend the simple over-the-counter masks, known as N95s, to help filter out particles of smoke if people have no choice but to step outdoors, they are nowhere close to a good ...