INDIANAPOLIS -- Results from the latest test on algae-produced toxins at Geist Reservoir are pending, but people using the water for recreational activities probably still should take precautions, an environmental expert told residents Friday.

Geist-area residents met with health officials and politicians at the Indy Yacht Club on Friday morning to discuss the toxin, which officials warned earlier this month was in the water.

In August's first half, officials said people could get sick from swallowing large amounts of untreated Geist water because blue-green algae were creating the toxin, and they recommended that people not swim there.

On Friday, Lenore Tedesco, director of the center for earth and environmental sciences at Indiana University-Purdue University Indianapolis, said a risk for illness still exists.

"If I had a 2-year-old child that I know is going to be swallowing a lot of water, I probably would not have them in the reservoir," Tedesco said.

Indianapolis' drinking water supply comes from Geist, but water company officials have said that the toxin is removed through treatment before the water gets to the tap, 6News' Julie Pursley reported.

Swallowing untreated water at Geist can cause abdominal cramps, nausea and diarrhea, health officials said. In rare cases, drinking the algae toxin can cause liver damage.

The toxin can also cause skin rashes, possibly affecting even those who boat or ski in the reservoir, officials said.

Tedesco said it is OK to ski or boat there as long as one rinses off afterward.

Steve King, who lives near the reservoir, said he'll let his teenage daughters go boating at Geist this weekend.

"We're going to say, 'Please, if you're skiing, if you're tubing or whatever, keep your mouth closed. And then when (you) do get out of the water, make sure you're showing off as soon as possible,'" King said.

A test revealed the toxin this month. Health officials said results of a second test, ordered this week, could be known Friday evening.

Experts told residents Friday that they could help cut toxin production by not using fertilizer with phosphates, which can run to the reservoir and help algae grow.

Tedesco and lawmakers said the area needs long-term solutions like watershed and runoff management.

"It's not just a Geist Reservoir problem," said state Sen. Beverly Gard, R-Greenfield. "We're depending on (Environmental Protection Agency) research. There's a lot that the state needs to be involved with. It's a very long-term issue."

Tedesco said she advises against treating the water to kill the algae, because that could drop the reservoir's oxygen content quickly and significantly, causing a fish kill and a fast release of more toxin.

The Indiana Department of Natural Resources said the toxin does not adversely affect the fish supply and that fish caught at Geist can still be eaten.