Today’s installment of the EnvIowa podcast features an interview recorded Feb. 7 with Dr. Andrew Forbes, an evolutionary ecologist at in University of Iowa biology department. Forbes chats about the ecological importance of parasitic insects and shares insights about other creepy crawlies like emerald ash borers and periodical cicadas.
Listen to learn more about his work on insect diversity and speciation.
New observational research has found that people with high exposure to common “pyrethroid” insencticides were 56% more likely to die during a study period than others. Cardiovascular disease was the leading cause of death in the exposed.
CGRER member Wei Bao, assistant professor of epidemiology in the University of Iowa College of Public Health, is an author of the study, published Jan. 30 inJAMA Internal Medicine.
Pyrethroid insecticides are used in most household insecticides and some pet products and head-lice shampoos. The study followed a sample of 2,116 adults who took the United States National Health and Nutrition Examination Survey between 1999 and 2002, representative of the U.S. population as a whole. The researchers noted levels of pyrethroid-associated chemicals in their urine and found death records to determine how many had died by 2015, as well as their cause of death.
While those with higher pyrethroid exposure were more likely to die overall, the highly exposed were three times more likely to suffer cardiovascular deaths than others as well. Bao said in an Iowa Now feature that the study does not prove that the insecticides are the cause of death, only that death and exposure are correlated.
Neonicotinoids, a specific class of pesticides, have been detected for the first time ever in tap water according to a recently published study by University of Iowa scientists and the U.S. Geological Survey.
A team of researchers compared tap water samples from the University of Iowa drinking water supply to samples of Iowa City municipal tap water. Tap water from each source was tested for three primary neonicotinoid types: clothianidin, imidacloprid and thiamethoxam. The University of Iowa filtration system removed only a minute amount of each insecticide. In contrast, the City of Iowa City successfully removed 100 percent, 94 percent and 85 percent, respectively, of each primary neonicotinoid.
Researchers say this can be explained by the different filtration systems used in each facility. Neonicotinoids readily dissolve in water, they say, and therefore easily slip through the University’s sand filters. The city employs an activated carbon filter that successfully removes the chemicals. Dr. Gregory LeFevre, University of Iowa environmental engineer and one of the study’s authors, said that activated carbon filters can be a cost-effective way to tackle these insecticides in an interview with the Washington Post. In fact, the University purchased a small activated carbon filtration system shortly after the study wrapped up in July 2016.
Levels of neonicotinoids in University water were relatively small, ranging from 0.24 to 57.3 nanograms per liter. LeFevre said, “Parts per trillion is a really, really small concentration.” The U.S. Environmental Protection Agency has not set a limit for neonicotinoid levels in drinking water. The study’s authors argue that more research is called for to assess neonicotinoid exposure on a larger scale. LeFevre explained, “Without really good toxicity data it is hard to ascertain the scale of this, but whenever we have pesticides in the drinking water that is something that raises a flag no matter what type of concentration it is.”