As mentioned above, humic acid substances have the effects of solubilizing, enhancing efficacy and reducing the decomposition rate of pesticides. What kind of impact will these effects have on the toxicity of pesticides after use? This is a question that everyone is concerned about. With this question, Jingfeng Humic Acid researchers studied the acute combined toxicity of four commonly used pesticides, omethoate, thiophanate-methyl, chlordimeform and cypermethrin, with fulvic acid. First, they determined the oral LD50 of the tested samples in mice. The order of the tested samples was omethoate, thiophanate-methyl, chlordimeform, cypermethrin and fulvic acid, and their LD50 were 17.8, 382.3, 825, 161.2 and 2000 mg/kg, respectively. The acute combined toxicity test of the four commonly used pesticides with fulvic acid was to use a dose of half the LD50 mixed and orally administered to the test mice. After one week of observation, the mortality rate was 0.
According to other reports, after humic acid is mixed with the pesticide lindane, its LD50 is 6.25 times higher than lindane and 4.58 times higher than lindane emulsifiable concentrate. This shows that the toxicity of humic acid to mammals can be greatly reduced when it is used in combination with pesticides.
