Source: "Water Hazard. Aquatic Contamination by Neonicotinoid insecticides in the United States." CDC PDF here. Sep 2015. 40 pgs.
Neonicotinoids, or "neonics", have widespread use, but also as seed coatings. The neonics are water soluable, and so they are taken up by the plant that grows from the treated seed, making the whole plant toxic to almost all insects. But the neonics are not controlled, they are also dispersed in the land, air and water. Neonics include: acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam. They are systemic insecticides meaning the plant absorbs the pesticide, and no matter what part of a plant an insect eats, the insect dies.
Scientists across Canada, the US, and Europe keep finding neonic levels that exceed safe levels, and which harm aquatic creatures. The hundreds of neonic products approved by the EPA are supported by sparse and incomplete studies, with huge gaps in knowledge at important areas. What's more, the FDA appears to be on collusion, with employees taking bribes, and finally a lawsuit against the FDA itself.
The report of neonics in waterways considered the most comprehensive is one from October 2014 by University of Saskatchewan toxicologist Professor Christy Morrissey. The study is called "Neonicotinoid contamination of global surface waters and associated risk to aquatic invertegrates: a review." The abstract from ScienceDirect is here.
- The EPA's toxicity levels are far too lax for these chemicals and lack common scientific support, especially outside the US.
- Runoff cannot be controlled and neonics end up in streams, then in rivers, and in the lakes they dump into.
- Even bird declines correlate to neonic contamination.
- Coated seeds are exempt from pesticide polices, per EPA rules. Exemptions almost always mean a company lobbied for said exemption.
- These chemicals are very persistent. They do not go away easily on their own. Thiamethoxam can degrade in water from sunlight, but degradation is almost non-existent below 3 inches of water.
- Most toxicity studies are acute studies, and only look at how many animals die at a certain level of pesticide. There are almost no studies about the effects of repeated exposure or low exposure over time.
- Daphnia magna, a type of water flea, is used in 116% of all neonic studies, yet D. magna is known to be resistant to neonics on the level of 200-300% more than other species. D. magna is simply a very large species of daphnia. The studies that use D. magna are inappropriate for determining toxicity.
- The highest concentrations of neonics were found in the Southern High Plains states where farming is common. The highest level there was 225ppb. There is a graph in the PDF showing other states.
- A 2015 report by the USGS and Michelle Hladik and Dana Kolpin, found neonics in 63% of US waterways.
- The same report finds that neonics were found in all 79 water samples from Iowa.
- A 2011 California study report found imidacloprid in 89% of 67 samples.
- 15 million households rely on well water taken from aquifers. Some aquifers can span 2-5 states. Once neonics get into an aquifer it spreads to household wells of other counties and states.
- Van Dijk, Tessa C., Marja A. Van Staalduinen, and Jeroen P. Van der Sluijs. Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid. PLOS ONE. 2013; 8(5). e62374. Full PLOS ONE study here. Link to NIH study here.
- Morrissey, Professor Christy, et al. Neonicotinoid contamination of global surface waters and associated risk to aquatic invertegrates: a review. Environment International. 2014. Abstract here. PDF of full study here.