The Iowa Department of Natural Resources currently tests state park beaches for a toxin produced by microscopic organisms that can form algae blooms. But a new analysis by the Environmental Working Group says the state should do more monitoring to protect public health.
According to the report, algae blooms can form when fertilizer and manure run off from farmland and get into bodies of water like lakes or ponds. Some blooms produce toxins, called microcystins. Exposure to microcystins can lead to nausea, a sore throat or diarrhea.
The Iowa DNR analyzes water samples from the 39 state park beaches for microcystins weekly from Memorial Day to Labor Day, and more recently, it started testing about 130 “significant publicly-owned” lakes three times a year for the toxin. But Anne Schechinger, EWG’s senior economic analyst and the report’s author, said those lakes should be tested more frequently, and ponds and reservoirs should be included too. The report says Iowa has 846 lakes, reservoirs and ponds.
“You can’t tell if a blue-green algae bloom is toxic unless you test. You can’t just look at it and tell it’s toxic,” Schechinger said. “So you really need to do testing in any body of water that people are going to recreate in or near to really keep people safe.”
Schechinger said the state should do more monitoring to keep people from getting sick from the toxin. Long-term health issues from microcystins include cancer and liver failure.
“Since they have such potentially serious public health impacts, it’s really important to monitor so we can warn people to stay away from affected water bodies,” Schechinger said.
Roger Bruner, the Iowa DNR’s supervisor of the water quality monitoring and assessment section, said the DNR is “proactive” with microcystin testing, and he doesn’t think more monitoring is needed.
“We haven’t seen a large number of blooms in our beach monitoring program in the last few years,” Bruner said. “… Our lake results don’t seem to indicate there’s a significant problem. So at this point, I don’t think additional monitoring is justified based on the data that we’ve got to date.”
Bruner said the DNR has a “finite” amount of funds it can spend, and when the cost of each test is added together, monitoring for microcystins costs thousands of dollars.
Schechinger said Iowa tests for microcystins more often than Minnesota and Wisconsin, which don’t test every year. She added climate change is making algae blooms worse.
“We’re going to see more and more frequent blooms and potentially blooms that last more days or weeks in the summer,” Schechinger said. “So that’s just more of a motivation to me to have extra testing than what we have now.”
