Agricultural insecticides threaten surface waters at the global scale

Abstract

Compared with nutrient levels and habitat degradation, the importance of agricultural pesticides in surface water may have been underestimated due to a lack of comprehensive quantitative analysis. Increasing pesticide contamination results in decreasing regional aquatic biodiversity, i.e., macroinvertebrate family richness is reduced by ∼30% at pesticide concentrations equaling the legally accepted regulatory threshold levels (RTLs). This study provides a comprehensive metaanalysis of 838 peer-reviewed studies (>2,500 sites in 73 countries) that evaluates, for the first time to our knowledge on a global scale, the exposure of surface waters to particularly toxic agricultural insecticides. We tested whether measured insecticide concentrations (MICs; i.e., quantified insecticide concentrations) exceed their RTLs and how risks depend on insecticide development over time and stringency of environmental regulation. Our analysis reveals that MICs occur rarely (i.e., an estimated 97.4% of analyses conducted found no MICs) and there is a complete lack of scientific monitoring data for ∼90% of global cropland. Most importantly, of the 11,300 MICs, 52.4% (5,915 cases; 68.5% of the sites) exceeded the RTL for either surface water (RTL SW ) or sediments. Thus, the biological integrity of global water resources is at a substantial risk. RTL SW exceedances depend on the catchment size, sampling regime, and sampling date; are significantly higher for newer-generation insecticides (i.e., pyrethroids); and are high even in countries with stringent environmental regulations. These results suggest the need for worldwide improvements to current pesticide regulations and agricultural pesticide application practices and for intensified research efforts on the presence and effects of pesticides under real-world conditions. global surface waters | insecticide contamination | agriculture | regulatory risk assessment | biodiversity

Evaluation of spot and passive sampling for monitoring, flux estimation and risk assessment of pesticides within the constraints of a typical regulatory monitoring scheme

“…Assessment of the potential risks of pesticides to non-target organisms (i.e. non-pest 66 species including many aquatic organisms) and human health requires improved 67 understanding of their occurrence, transport and fate in the environment [Fernandez et al,68 2014; Stehle and Schulz, 2015]. 69 In order to assess the ecological and chemical status of a water body, the WFD requires that 70 water quality is monitored at least once a month (12 sampling a year) and compared with the 71 EQS.…”

Agroecology: A Global Paradigm to Challenge Mainstream Industrial Agriculture

“…The paradigm and future prospect of modern industrialized agricultural systems is being challenged on several fronts because of its dependence on capital, external energy and agrochemical inputs, and for its adverse impact on biodiversity and on human health [2,[15][16][17][18][19][20]. According to the American Medical Association, in reference to industrial agriculture, "these methods have contributed to the development of antibiotic resistance; air and water pollution; contamination of food and water with animal waste, pesticides, hormones, and other toxins; increased dependence on nonrenewable fossil fuels (including fertilizers); and a food system that is increasingly vulnerable to accidental or intentional contamination" [4,21].…”

Estado de conservación y distribución de la biodiversidad de agua dulce en los Andes tropicales

“…El efecto de la contaminación de cuerpos de agua dulce por pesticidas usados en agricultura no había sido cuantiicado hasta ahora, pero un estudio reciente (Stehle y Schulz 2015), muestra que las concentraciones de pesticidas legalmente permitidas podrían reducir en hasta un 30% la riqueza de macroinvertebrados acuáticos. En una revisión global sobre la aplicación de pesticidas, incluyendo más de 800 publicaciones en 73 países, los autores encontraron que en más del 50% de los casos la concentración de insecticidas excedía los niveles permitidos (Stehle y Schulz 2015).…”

“…En una revisión global sobre la aplicación de pesticidas, incluyendo más de 800 publicaciones en 73 países, los autores encontraron que en más del 50% de los casos la concentración de insecticidas excedía los niveles permitidos (Stehle y Schulz 2015). Esto tiene importantes implicaciones para las regulaciones y control de la aplicación de pesticidas.…”