"This was a nonunion job using unskilled labor," said Richard Weiss, a spokesman for the Mason Tenders District Council of New York, which represents masonry workers.
Most of the 20 masonry workers on the job that day were undocumented immigrants who were either paid in cash or were going to be paid in cash, at the rate of $7 per hour, the district attorney's office said.
Within occupations, the prevalence of elevated airborne silica exposure levels ≥ 0.10 mg/m among workers with the job title "masonry worker" in the stonework masonry industry was twice as high (6.9%) as the prevalence among workers with the job title "bricklayer" in the same industry (3.1%).
The city ordered the masonry repaired and workers to finish erecting the scaffolding.
But even then, health experts thought the standard was too lax, allowing masonry and construction workers to breathe unhealthy amounts of silica.
"Everything is changing in the city, but still, generation after generation, it continues," said Mahmoud Qais al-Arousi, a 65-year-old builder, as he stood watching his workers mix masonry outside Mr. Othaim's home.
For the past three years, as workers repointed the masonry and made other repairs costing about $7 million, the scaffolding and dark netting kept sunlight from reaching the chancellor's office and other rooms in the mazelike headquarters.
In addition surface workers in carpentry, masonry, garage, foundry, welding, machine workshop and surveying were excluded due to other types of dust exposure.
The long years of renovation allowed workers to patch up masonry, replace fallen stones and install staircases, lighting and electricity.
"We hear reports of people gentrifying these old buildings: 'Oh gosh, I was pregnant and remodeling, and I just didn't think lead was a problem around here.' " Ms. Lewis-Fontanez, who suspects that the high concentration of lead in her apartment is a result of workers exposing the original masonry when they installed new windows, tends to agree.
Workers mixed the moist chocolate-brown masonry known as teen while a master builder supervised, a dagger hanging from his belt.
