Seasonal distribution of herbicide and insecticide residues in the water resources of the vineyard region of La Rioja (Spain)

Abstract

Pesticides are needed to maintain high production in the vineyard area of La Rioja (Spain), and monitoring their spatial distribution is a priority for preserving the quality of natural resources. Accordingly, the purpose of this work was to conduct a study to evaluate the presence and seasonal distribution of herbicide and insecticide residues in ground and surface waters in this region. The monitoring network comprised 12 surface waters and 78 groundwaters, covering the three subareas (63,593ha) into which the vineyard region is divided. The quality of natural waters was examined through the analysis of twenty-two herbicides, eight of their main degradation products, and eight insecticides. Pesticides were extracted by solid-phase extraction, and analysed by gas chromatography-mass spectrometry or by liquid-chromatography-mass spectrometry. The results reveal the presence of most of the herbicides and insecticides included in the study in one or more of the samples collected during the four campaigns. The herbicide terbuthylazine and its metabolite desethylterbuthylazine were the compounds more frequently detected (present in >65% of the samples across all the campaigns). Other compounds detected in >50% of the samples in one sampling campaign were the herbicides fluometuron, metolachlor, alachlor and ethofumesate. Insecticides were present in a small number of samples, with only pirimicarb being detected in >25% of the samples in March and June campaigns. The results reveal that the sum of compounds detected (mainly herbicides) was higher than 0.5μgL in >50% of the samples, especially in the campaigns with the highest application of these compounds. A possible recovery of the quality of the waters was detected outside the periods of crop cultivation, although more monitoring programmes are needed to confirm this trend with a view to preventing and/or maintaining the sustainability of natural resources.

Pesticides from the EU First and Second Watch Lists in the Water Environment

“…The presence of neonicotinoids has been detected in various types of water reservoirs, including ditches, pools, ponds, mountain streams, rivers, periodic marshes, meltwater, and groundwater, effluents from WWTPs, and drinking water . The monitoring data were mainly available for four or less EU countries although neonicotinoids are widely used in Europe as Plant Protection Products (PPPs) and biocides.…”

“…Water pollution owing to the use of pesticides in agriculture is a priority issue that is currently of global concern . Surface water contamination by pesticides is usually linked to the farming season, and its effect could be more temporal than contamination of groundwater.…”

“…Surface water contamination by pesticides is usually linked to the farming season, and its effect could be more temporal than contamination of groundwater. Groundwater contamination by pesticides is more persistent because its biodegradation is slower . The uncontrolled discharge of pesticides into the environment, even at trace concentrations, may contribute to their accumulation in the aquatic compartments, with potentially detrimental toxicological effects to both aquatic ecosystems and human health when water is used for public consumption or food production …”

Determination of Pesticides in River Surface Waters of Central Chile Using Spe-Gc-MS Multi-Residue Method

“…In spite of this limitation, studies have documented the presence of organochlorine, carbamate and organophosphate insecticides in Mediterranean bodies of water, noting that these compounds are generally found in low concentrations (ng L -1 ) or detected infrequently [8,31]. Finally, it is important to stress that the presence of insecticides in bodies of water constitutes a high risk to the biodiversity of these ecosystems, given that it has been demonstrated that elevated toxicity can have adverse effects on aquatic invertebrates in a short time period [32][33].…”

“…Studies carried out in Asia [6], Europe [7][8] and the USA [9] show that pesticides and their degradation products are often detected in surface water, in some cases at levels exceeding the maximum individual limit (0.1 µg L -1 ) established by the European Commission (EC) for drinking water [10]. Therefore, various countries around the world have developed monitoring programs to evaluate the level of pesticide contamination in bodies of water, taking the measures necessary to minimize the impact of these substances on the environment and protect the quality of water resources [11].…”