San Diego

People who work at businesses on 1st Avenue between Market Street and Harbor Drive and at the site of the new convention center downtown may have been exposed to ammonia gas over the past three weeks, county health officials said Thursday.

Hazardous-waste specialists who have been investigating complaints of ammonia odors in the area said they believe a local business has been dumping ammonia into a storm drain.

Officials said they have not determined the concentration of the gas. They suggested that anyone who works in the area and has been suffering from respiratory problems in recent weeks see a physician.

Pat Hoy, a specialist in hazardous-waste management, said that the county Department of Health Services’ investigation is not complete but that the case will be brought to the district attorney’s office if illegal dumping is found to have taken place.