A building in Long Island City was evacuated for the second time in two days yesterday morning after occupants complained of a toxic odor.

One person was hospitalized and emergency workers evaluated 35 people on the scene after workers on the seventh and eighth floors of 3300 Northern Boulevard complained of noxious fumes, fire department officials said. On Tuesday, the building was evacuated due to similar reports of an odor and 13 people were hospitalized.

Tests so far have not indicated any hazardous chemicals in the air, city officials said, but monitoring continues. Investigators have focused on a nearby rail yard as the possible origin of the fumes, but testing so far has not been able to identify the source of the odor.

Council Member Eric Gioia, who represents the district, said yesterday in an interview that he believed construction at the rail yards is behind the two evacuations.

“We’ve known for a long time that it’s polluted land filled with toxic chemicals, and whoever is excavating has an obligation to use the utmost care,” Mr. Gioia said. “It’s unacceptable that people living and working in the neighborhood would be getting sick and have to wonder about the health effects of the air they’re breathing.”