Perspective is important. It's an extrapolated figure, based on trace-element factors for Cd, Cr, Mn, Ni, but not lead. That seems incredibly dishonest.
What's more, they report 0.86–1.70 ng/m ambient lead level... which upon brief examination, is about 1/4th the average urban ambient lead level, and from what I'm able to determine, about 20% of the EPA 2022–2024 non-source Pb-TSP daily mean. In other words, it's significantly lower than sources with known lead. (Similarly, it's about ~20% of historic ambient national levels - couldn't find date later than 2019 for this.)
Looks like they played very Orwellian with their data interpretation. "The use of wood as an energy source is a relic of the past, one that should not be relived if given a choice." is... well. This is "let them eat cake" level hubris. Whoever said this either has a disdain for the people they're's studying, or have zero economic understanding.... and based on the actual study findings, I can't say it appears to be truthful, either.
The people who burn wood are not doing it out of personal preference. They're doing because they can afford it: they have no other choice. Chopping, splitting, drying, and burning wood is a labor intensive activity. It's done out of fiscal/economic necessity: fuel prices for heating are extremely high, and in the area they sampled, they rely primarily on heating oil (basically: diesel fuel). Even last winter, the average household heating cost was about $1800/month, about twice what it was in 2015. With fuel prices surging? You can effectively expect twice that cost (or more) this coming winter due to the conflict with Iran.
Musing: Were the lead actually higher in the area (from what I can tell, it's not), I wonder if the "high" lead in the air would be representative of "carbon sequestration" of the trees over the past 70 odd years: as they grew, they absorbed the lead in the air?