Spatio-temporal distribution of pyrethroids in soil in Mediterranean paddy fields

Abstract

Purpose The demand of rice by the increase in population in many countries has intensified the application of pesticides and the use of poor quality water to irrigate fields. The terrestrial environment is one compartment affected by these situations, where soil is working as a reservoir, retaining organic pollutants. Therefore, it is necessary to develop methods to determine insecticides in soil and monitor susceptible areas to be contaminated, applying adequate techniques to remediate them. Materials and methods This study investigates the occurrence of ten pyrethroid insecticides (PYs) and its spatio-temporal variance in soil at two different depths collected in two periods (before plow and during rice production), in a paddy field area located in the Mediterranean coast. Pyrethroids were quantified using gas chromatography-mass spectrometry (GC-MS) after ultrasound-assisted extraction with ethyl acetate. The results obtained were assessed statistically using non-parametric methods, and significant statistical differences (p < 0.05) in pyrethroids content with soil depth and proximity to wastewater treatment plants were evaluated. Moreover, a geographic information system (GIS) was used to monitor the occurrence of PYs in paddy fields and detect risk areas. Results and discussion Pyrethroids were detected at concentrations ≤57.0 ng g −1 before plow and ≤62.3 ng g −1 during rice production, being resmethrin and cyfluthrin the compounds found at higher concentrations in soil. Pyrethroids were detected mainly at the top soil, and a GIS program was used to depict the obtained results, showing that effluents from wastewater treatment plants (WWTPs) were the main sources of soil contamination. No toxic effects were expected to soil organisms, but it is of concern that PYs may affect aquatic organisms, which represents the worst case scenario. Conclusions A methodology to determine pyrethroids in soil was developed to monitor a paddy field area. The use of water from WWTPs to irrigate rice fields is one of the main pollution sources of pyrethroids. It is a matter of concern that PYs may present toxic effects on aquatic organisms, as they can be desorbed from soil. Phytoremediation may play an important role in this area, reducing the possible risk associated to PYs levels in soil.

New Insights into the Microbial Degradation of D-Cyphenothrin in Contaminated Water/Soil Environments

“…A B Generally, multiple SPs are used in rotation instead of repeating a single pyrethroid for a longer time. Therefore, residues of various SPs are found in terrestrial and aquatic environments [50,51]. Different SPs including tetramethrin, permethrin, bifenthrin, allethrin, and chlorempenthrin were separately added to the MSM medium at a final concentration of 50 mg·L −1 .…”

Pyrethroid residues on tropical soil of an Indonesian tea plantation: analytical method development, monitoring, and risk assessment

“…In this study, risk assessment for each pyrethroid was performed by estimating its concentration in the soil that might be washed off through leaching and runoff to surface water by calculating the ECEW max (μg L − 1 ) value using the following Eq. (2) [19]):…”

“…Typically, pesticide monitoring involves laborious analytical methods. Many analytical methods for the extraction and analysis of pyrethroids in the soil based on green analytical chemistry have been proposed [8,15,19,20]. However, the extraction of tropical soil of tea plantation was performed only once [18], and the method was time-consuming, required large volumes (up to 100 mL) of organic solvents, such as acetone and dichloromethane, and used large amount of samples, thus generated massive amounts of laboratory waste during analysis.…”

Phytotoxicity of pyrethroid pesticides and its metabolite towards Cucumis sativus

“…This study (Weston et al, 2013)reaffirms the contribution of pyrethroids to sediment toxicity even though sampling was not specifically focused on areas of high pyrethroids use. Pyrethroids were detected at maximum concentrations of 57.0 μgkg −1 before plow and 62.3 μgkg −1 during rice production in the soil in Mediterranean paddy fields, being resmethrin and cyfluthrin the compounds found at higher concentrations (Aznar et al, 2017). Pyrethroids presence was much higher in the sediments of creeks within a residential neighborhood near Roseville (Weston et al, 2005), where cyfluthrin, permethrin, bifenthrin, and cypermethrin were found at maximum concentrations of 169, 335, 437 and 736 μgkg −1 , respectively.…”