This overview of possible adverse effects associated with rising GBH use is focused on mammalian health risks. There are also many environmental and soil-ecosystem problems associated with heavy and repeated uses of GBHs affecting other organisms (for example, fish, butterflies, earthworms, beneficial soil microorganisms) [47]. | ᅟ |
These problems arise from the large volumes of GBHs applied across vast areas in many farming areas (for example, 80% or more of the harvested cropland in many counties in the U.S., and provinces or political jurisdictions in other countries, are sprayed with GBHs). | ᅟ |
Glyphosate binds strongly to some soils, but not others. After repeated applications, it can accumulate and become a long-term source of soil and groundwater contamination [48]. The main pathways of GBH degradation are known and the principal breakdown products (AMPA, formaldehyde) could be toxic to a variety of non-target organisms. Continued long-term use of GBHs could pose a threat to soil health and fertility [47, 49], with possible adverse effects on crop productivity. | ᅟ |
Low levels (50 ppb) of glyphosate have been shown to have significant negative effects on the aquatic invertebrate Daphnia magna [50]. When measured against the U.S. EPA’s Maximum Contaminant Level of 700 ppb, or the Canadian short-term (27,000 ppb) and the long-term (800 ppb) freshwater aquatic standards [51], one quickly sees how the regulatory eco-toxicological risk levels set for glyphosate are orders of magnitude too high. | ᅟ |