A teen was arrested Monday in connection with mercury spills at three Houston businesses that led to one hospitalization, according to authorities.

Christopher Lee Melder, 19, faces charges of burglary, unlawful disposal of hazardous material and an outstanding felony drug possession warrant, according to Houston’s FBI office. Earlier, the office said a man was being questioned in connection with the spills.

A person called police at about 11:15 a.m. Sunday to report a white liquid on the ground, Houston Fire Chief Sam Pena said at a news conference Sunday night.

Less than a pint of mercury had been spilled outside a Walmart, a Sonic Drive-In and a Shell gas station, officials said.

Investigators were looking into reports that someone checked into a Houston-area hospital claiming to have been exposed to mercury on Friday, as well as reports of a possible recent warehouse break-in.

Between 30 and 60 people at the locations were hosed down, and a pregnant woman was taken to the hospital as a precaution.

Pena said dangers from exposure to the spills were “low risk” because the mercury was spilled on the ground, would evaporate and is only dangerous if ingested or inhaled.

“The threat to the public is very low because the spill occurred outdoors and the amount of chemical spilled is small,” Dr. David Persse, local health authority for the Houston Health Department, said in a statement. “The amount of chemical detected on those exposed is below the level that’s dangerous to the average individual.”

Mercury is liquid at room temperature, according to the Centers for Disease Control and Prevention.

High levels of mercury exposure can harm the brain, heart, kidneys, lungs, and immune system, and could affect the development of fetuses and young children, according to the Environmental Protection Agency. Symptoms of mercury exposure are headache, stuffy nose and nausea.

A private company was conducting cleanup at the three businesses.