A study of air quality in New York City while it was heavily affected by Canadian wildfire smoke revealed that multi-day transport to the New York region significantly transformed the smoke, but serious health risks remained. The results are published in Environmental Science and Technology Letters. A study of air quality in New York City while it was heavily affected by Canadian wildfire smoke revealed that multi-day transport to the New York region significantly transformed the smoke, but serious health risks remained. The results are published in Environmental Science and Technology Letters. Environment Phys.org – latest science and technology news stories