A test of plants near where Madison’s annual Independence Day fireworks are fired shows elevated concentrations of undesirable elements, according to city officials.
City officials harvested plants at Warner Park before the 2012 Rhythm & Booms display and 23 days after. A draft report showed plants harvested after the display had maximum concentrations of aluminum, barium, cobalt, iron, magnesium and sulfur.
The author of the report is James P. Bennett, a member of the city of Madison's Committee on the Environment who recently retired from UW-Madison Institute of Environmental Studies. He said the perchlorate values were either at critical levels or nearing toxicity levels for plants.
In another report, city hydrogeologist Brynn Bemis said there was an increase in perchlorate in the lagoon’s surface water after the fireworks.
Madison Ald. Anita Weier suggested the fireworks display be modified or moved away from a wetlands area.
“Perchlorate may have adverse health effects because ingestion can interfere with iodide uptake into the thyroid gland in mammals and aquatic vertebrates such as fish,” she said.
Bemis recommended that all fireworks debris be cleaned up to avoid leaching or contaminants and that it might be best to use fireworks with little or no perchlorate.
The Madison Committee on Environment will consider the reports in March.
The tests were financed by the city of Madison and nonprofit Wild Warner.