Pesticides in a case study on no-tillage farming systems and surrounding forest patches in Brazil

Abstract

With the growing global concern on pesticide management, the relationship between its environmental recalcitrance, food security and human health has never been more relevant. Pesticides residues are known to cause significant environmental contamination. Here, we present a case study on long-term no-tillage farming systems in Brazil, where Glyphosate (GLY) has been applied for more than 35 years. GLY and its main breakdown product, aminomethylphosphonic acid (AMPA) were determined in topsoil (0–10 cm) samples from no-tillage fields and nearby subtropical secondary forests by high-performance liquid chromatography coupled with a fluorescence detector. In addition, the presence of carbamates, organochlorines, organophosphates and triazines were also screened for. GLY and AMPA were present in all soil samples, reaching values higher than those described for soils so far in the literature. A significant decrease for AMPA was observed only between the secondary forest and the farm's middle slope for site B. GLY and AMPA were observed respectively at peak concentrations of 66.38 and 26.03 mg/kg soil. GLY was strongly associated with forest soil properties, while AMPA associated more with no-tillage soil properties. Soil texture was a significant factor contributing to discrimination of the results as clay and sand contents affect GLY and AMPA retention in soils. This was the first study to report DDT and metabolites in consolidated no-tillage soils in Brazil (a pesticide fully banned since 2009). Based on human risk assessment conducted herein and the potential risk of GLY to local soil communities, this study offers a baseline for future studies on potential adverse effects on soil biota, and mechanistic studies.

Indirect Effects of the Herbicide Glyphosate on Plant, Animal and Human Health Through its Effects on Microbial Communities

“…Soil particles with glyphosate and AMPA can also be transported by runoff or wind erosion to surface waters (Geng et al, 2021;Hofman, 2020;Silva et al, 2018;Yang et al, 2015), where they can remain in the particulate phase, be dissolved in water or adsorbed onto the bottom sediment (Maqueda et al, 2017). Glyphosate and AMPA are now widespread in soil and a variety of natural waters and sediments (Battaglin et al, 2014;Bento et al, 2019;Carles et al, 2019;Daouk et al, 2013;da Silva et al, 2021;Geng et al, 2021;Maqueda et al, 2017;Peruzzo et al, 2008;Poiger et al, 2017;Silva et al, 2018;Tauchnitz et al, 2020). It has also been detected in air and falling rain (Battaglin et al, 2014;Chang et al, 2011), irrigation water (Gomes et al, 2020), and in outlets from wastewater treatment plants (Poiger et al, 2017).…”

“…AMPA has a similar toxicity spectrum as glyphosate (Daouk et al, 2013;Gomes et al, 2016;Katholm, 2016;Kwiatkowska et al, 2014;Woźniak et al, 2018). Current soil residues of glyphosate and AMPA (with maxima ranging from 2.1 to 1.9 mg/kg in Europe to 39.1 and 14.6 mg/kg in Brazil), enhanced by applying contaminated manure, may delay germination, root growth and yield of subsequent crops (Bento et al, 2019;da Silva et al, 2021;Fernandes et al, 2020;Helander et al, 2019;Muola et al, 2021;Silva et al, 2018;Weng et al, 2019;Zhang et al, 2015).…”

Glyphosate as a Food Contaminant: Main Sources, Detection Levels, and Implications for Human and Public Health

“…Glyphosate and AMPA were found in all soil samples at maximum concentrations of 66.38 mg/kg and 26.03 mg/kg, respectively. Another discovery was the presence of dichlorodiphenyltrichloroethane (DDT) and its metabolites in the soil, despite the insecticide being banned in Brazil since 2009 [ 103 ].…”

Effects of glyphosate exposure on intestinal microbiota, metabolism and microstructure: a systematic review

“…6,7 Among the most diverse types of pesticides on the market, glyphosate (GLY), a non-selective, synthetic, post-emergent and broad-spectrum herbicide, 8 is the most commercialized, accounting for around 25% and 52% of total pesticide applications, in terms of volume, in the world and in Brazil, respectively. 9 However, this scenario has proved to be quite worrying, since the herbicide, currently marketed by the Bayer company, despite having long been considered harmless to human health, in 2015 was classified as potentially carcinogenic by the World Health Organization (WHO). 10 This new scenario has opened room for numerous debates about the safe use of GLY in relation to the health of non-target species, such as humans.…”