The Bronx is surging.

The borough, which lost one in five residents during the 1970s when it was afflicted by high crime and arson fires, has not only recouped its population loss but also appears to have surpassed its historic peak, according to new census projections.

An influx of immigrants helped boost the borough’s population to 1.455 million as of July 1, 2015, according to the United States Census Bureau. At the annual rate the Bronx has been growing since 2010, about 1 percent, the highest of any county in the state, that would place the current total ahead of the high of 1.472 million in 1970, demographers agree.

And Queens, already a polyglot mix of residents from every corner of the globe, is growing ever more diverse. Nearly half, or about 48 percent, of the population of Queens is foreign-born, ranking the borough second only to Miami-Dade in Florida (with nearly 53 percent) among larger American counties in the share of residents from abroad. One-fourth of Queens residents come from Asia.

The latest figures from the bureau’s American Community Survey and other estimates also confirm that New York City’s total population has exceeded 8.5 million, the highest it has ever been.