Key environmental processes affecting the fate of the insecticide chloropyrifos applied to leaves

Heterogeneous degradation of pesticides by OH radicals in the atmosphere: Influence of humidity and particle type on the kinetics

“…calculated for OH radical concentration used for the calculation was 1.5 x 10 6 molecule cm -3 and the average exposure time was 12 hours Table 1 shows that available kinetic constants of pesticides in the heterogeneous phase toward OH radicals vary from -14 cm molecule -1 s -1 (i.e., half-life greater than 1000 days) to 10 -11 cm 3 molecule -1 s -1 (i.e., half-life of 1.3 days) with the majority of them being around 10 -13 cm 3 molecule -1 s -1 . Values obtained in our study for pesticides degraded by OH radicals are of the order of between 10 -13 cm 3 molecule -1 s -1 and 10 -12 cm 3 molecule -1 s -1 which is in accordance with kinetic constants available in the literature calculated for other pesticides of the same or different chemical families on hydrophobic silica (Pflieger et al, 2013), hydrophilic silica (Liu et al, 2005;Palm et al, 2011;Zetzsch, 1991), quartz surfaces (Bouya et al, 2015;Masri et al, 2014), and leaves (Lester et al, 2017). However, our values are of one to two orders of magnitude smaller than values determined by one research team for pesticides adsorbed on silicas (Palm et al, 1997(Palm et al, , 1998(Palm et al, , 1999.…”

“…Pesticides are of great interest for both the scientific community and the general public due to their worldwide uses and potential adverse health or environmental impacts (Carvalho, 2017;Inserm, 2013). They are present in the atmosphere in concentration levels from some picogram per cubic meter (pg m −3 ) to several nanograms per cubic meter (ng m −3 ) (Coscollà et al, 2013(Coscollà et al, , 2014Désert et al, 2018;Estellano et al, 2015;Lester et al, 2017;Zivan et al, 2016Zivan et al, , 2017.…”

“…The heterogeneous degradation of some pesticides with OH radicals has already been studied (Al Rashidi et al, 2011Bouya et al, 2015;Lester et al, 2017;Liu et al, 2005;Palm et al, 1997Palm et al, , 1998Palm et al, , 1999Palm et al, , 2011Pflieger et al, 2013;Zetzsch, 1991), but conditions employed to determine kinetic constants were very diverse in terms of surface (different silica particles, quartz surface, plant leaves) and humidity (<1% RH to 70% RH). To our knowledge, no study investigated the influence of relative humidity on the degradation kinetics of pesticides with OH radicals, although this factor has an influence on the heterogeneous degradation of organic compounds by ozone (Kaiser et al, 2011;Mattei et al, 2018;Pöschl et al, 2001).…”

Commercial Formulation of Chlorpyrifos Alters Neurological Behaviors and Fertility

“…According to the results, prolonged Judo 40 exposure can cause impairment of the neurological alterations and sex hormones leading to impaired fertility. Therefore, chemical handlers should be educated on protection and risk minimization.Biology 2020, 9, 49 2 of 15 environment, chemical formulations of CPFs such as Judo 40 will undergo evaporation, hydrolysis, oxidation, photolysis, and microbial metabolism [15]. Owing to active soil absorption and the low water dissolubility of CPFs, this can result in the contamination of percolated water, runoff water, and sediments [16], leading to a high accumulation of CPF residues, thus posing acute and chronic health risks to consumers [17].It has been documented that the occupational exposure of humans to pesticides, including CPFs, are high [18].…”

“…Biology 2020, 9, 49 2 of 15 environment, chemical formulations of CPFs such as Judo 40 will undergo evaporation, hydrolysis, oxidation, photolysis, and microbial metabolism [15]. Owing to active soil absorption and the low water dissolubility of CPFs, this can result in the contamination of percolated water, runoff water, and sediments [16], leading to a high accumulation of CPF residues, thus posing acute and chronic health risks to consumers [17].…”