SALT LAKE CITY — Water from some canals is once again flowing to crops in Salt Lake and Utah counties while toxicologists and scientists from multiple agencies scramble to determine the scope of risks from using water tainted with cyanobacteria on crops.

At least one canal company was able to find an alternative source of water — the Provo River — an option that is being strongly urged by the state water quality and agriculture officials in light of algal blooms that have contaminated Utah Lake, the Jordan River and Big Cottonwood Creek.

Salt Lake County, in the meantime, has set up a hotline at 801-743-7045 for livestock owners who may need an alternative source of water.

Donna Kemp Spangler, communications director for the Utah Department of Environmental Quality, said the agency is investigating to determine if there is chemical analysis that can be done on fruit and vegetables to assess if they have unsafe levels of cyanotoxins.

The potential for produce to develop the toxins depends on multiple factors, including their concentration in the water, the specific type of toxins, how long the crops are irrigated, the time between harvest and consumption, the type of plant and whether flood or spray irrigation is used.

Both DEQ and the Utah Department of Agriculture and Food are urging farmers, gardeners and ranchers to use "caution" when irrigating vegetation with the contaminated water.

"It is too early for us to make a statement about the safety of consuming produce," said Utah's agriculture commissioner LuAnn Adams. "After the toxicity reports come back and we have had an opportunity to analyze the results and compare them to the limited research that is available on this subject, we may be able to make a statement. We wish to communicate reliable science-based information to consumers and expect to do so in the coming days."

Nathan LaCross, an epidemiologist with the Utah Department of Health, said there's been no clear answers revealed on the level of toxins that exist in the water, the type, and if they are a danger.

"It is a lot of ifs, and we'd love to be able to be certain one way or the other," he said. "The main problem is what little research there is it shows that certain plants grown for people to eat can uptake these toxins and potentially present them at levels that could be a health risk."

What research has been done has focused on a particular group of toxins, and within that group there are dozens upon dozens of different strains, he added.

"It is one of the common ones encountered so it gets a fair amount of research."

Test results from water affected by blue-green algae were "non-detect" for three of four strains of toxins produced by cyanobacteria, according to an analysis done by the U.S. Environmental Protection Agency. The samples, however, were only estimated because the water was at room temperature, said DEQ.

The agency says it expects to have more conclusive results by late Wednesday.

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Effects of algal blooms continue to spread throughout Wasatch Front

Concern over contaminated water from a toxic algal bloom persists among multiple agencies, with worry that harmful levels of cyanobacteria may have infected farmers crops.

The EPA lab, however, does not have the ability to test for one strain called saxitoxin, so samples are being sent to a private lab.

The Salt Lake County Health Department is advising residents to avoid any produce that has been watered with secondary water since July 15 and for residents to make direct inquiries of vendors at area farmers markets about their watering practices.

"What we need to know is if the strain we are experiencing has the ability to produce toxins and if it does, is it producing those toxins at a level that concerns us," LaCross said. "It is almost impossible for us to predict if they are producing toxins."

Chris Bittner, a DEQ toxicologist, said the issue is made more complicated because there is no federal standard for measuring these kind of toxins in plants.

While test results may show the absence of toxins one day, those results could be different in another round of sampling, he added.

"We don't understand what turns the toxin production on and off," he said. "This particular species has four potential toxins. Two are neurotoxins and two are liver toxins, and they are all pretty different. The threat could go on for weeks."

One particular toxin, for example, has 70 varieties, and Bittner said there are analytical methods developed for just two of them.

The Utah Poison Control Center has received 463 calls since the bloom was first observed July 13, with 388 documented cases of exposure to cyanobacteria. Of those, 20 people reported adverse effects that included nausea, vomiting, headaches and diarrhea.

Bittner stressed that there has no been no toxin information collected that provides an answer as to why people exposed to Utah Lake water have become ill.

"We cannot tell what is causing that yet," he said. "The number of bacteria tells us that clearly there is potential of health effects if people come in contact with the water."

Agal blooms are caused by excess levels of nitrogen and phosphorus, which naturally occur in the environment but also make their way into water from human activity such as stormwater runoff, agriculture, and discharge from sewer treatment plants.

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