Potential Impacts of Climate Change on the Toxicity of Pesticides towards Earthworms

Abstract

This review examined one of the effects of climate change that has only recently received attention, i.e., climate change impacts on the distribution and toxicity of chemical contaminants in the environment. As ecosystem engineers, earthworms are potentially threatened by the increasing use of pesticides. Increases in temperature, precipitation regime changes, and related extreme climate events can potentially affect pesticide toxicity. This review of original research articles, reviews, and governmental and intergovernmental reports focused on the interactions between toxicants and environmental parameters. The latter included temperature, moisture, acidification, hypoxia, soil carbon cycle, and soil dynamics, as altered by climate change. Dynamic interactions between climate change and contaminants can be particularly problematic for organisms since organisms have an upper and lower physiological range, resulting in impacts on their acclimatization capacity. Climate change variables such as temperature and soil moisture also have an impact on acidification. An increase in temperature will impact precipitation which might impact soil pH. Also, an increase in precipitation can result in flooding which can reduce the population of earthworms by not giving juvenile earthworms enough time to develop into reproductive adults. As an independent stressor, hypoxia can affect soil organisms, alter bioavailability, and increase the toxicity of chemicals in some cases. Climate change variables, especially temperature and soil moisture, significantly affect the bioavailability of pesticides in the soil and the growth and reproduction of earthworm species.

Natural soils in OECD 222 testing — influence of soil water and soil properties on earthworm reproduction toxicity of carbendazim

“…Future research could compare the results generated in the laboratory with results from earthworm field studies with the same agricultural soil. Beside differences in soil properties or species specific sensitivity, the exposure scenario and toxicity is for example dependent on climatic conditions like precipitation and drought events (Kaka et al 2021 ; Owojori and Reinecke 2010 ) or changes in temperature (Velki and Ečimović 2015 ; Römbke et al 2007b ). Therefore, further research both in the laboratory under controlled conditions and under realistic field conditions is required to evaluate the effects of pesticides and the conservatism of the assessment factor under the influence of co-stressors like heat, drought and periodical flooding which are supposed to occur more frequently under human-induced climate change.…”

Dissipation Residue Behaviors and Dietary Risk Assessment of Boscalid and Pyraclostrobin in Watermelon by HPLC-MS/MS

“…In addition, higher temperatures can promote the growth of microorganisms and, to a certain extent, accelerate the degradation of pesticides by the environment [ 35 ]. In addition, acidification can be enhanced by high precipitation, and influence the degradation of pesticides [ 36 ]. Since Hunan province is in the subtropical monsoon climate zone, higher temperatures and abundant precipitation may cause the dissipation rate of fungicides to be different from that of other areas.…”

“…In addition, higher temperatures can promote the growth of microorganisms and, to a certain extent, accelerate the degradation of pesticides by the environment [35]. In addition, acidification can be enhanced by high precipitation, and influence the degradation of pesticides [36].…”

Handling the impacts of climate change on soil biodiversity

“…Primary food production is mainly associated with resource-based impacts (associated with depletion of various abiotic resources and soil use) and emission-based impacts (covering global warming, acidification, and eutrophication related to the use of chemicals, both organic and mineral) (Djekic et al, 2021). Temperature increases and changes in precipitation regimes mainly result in more extensive pesticide use, increasing pesticide toxicity (Kaka et al, 2021). In parallel, other effects may occur, such as decreased soil pesticides' bioavailability and changes in growth patterns and reproduction of earthworm species, combined with increased acidification and eutrophication potential.…”