Global Review Shows Alarming Impacts of Pesticides on Biodiversity and Ecosystems

By Dr. Chinta SidharthanReviewed by Lily Ramsey, LLMFeb 19 2025

Every year, nearly 4.1 million tons of pesticides are applied worldwide, helping secure food production but posing hidden dangers to nature. Could these chemicals be accelerating the biodiversity crisis?

A recent global study published in Nature Communications that synthesized data from over 1,700 research papers provides a sobering answer. It reveals that pesticides, may it be insecticides, herbicides, or fungicides, harm plants, animals, and microorganisms across ecosystems.

Even at doses considered environmentally safe, these chemicals disrupt growth, reproduction, and vital biological functions in non-target species, raising urgent concerns about the long-term sustainability of pesticide use.

Image Credit: Fotokostic/Shutterstock.com

Pesticides

Pesticides are essential tools in modern agriculture and disease control, safeguarding crop yields and public health. However, their influence extends beyond target pests.

Decades of research have revealed that pesticides harm beneficial insects like bees, reduce plant fertility, and disrupt soil microorganisms. Studies also link pesticide exposure to declining amphibian, bird, and mammal populations.

However, although individual experiments have shown species-specific impacts, broader patterns across ecosystems remain unclear. The global consequences of pesticides on biodiversity across land and water systems remain poorly understood.

Furthermore, regulatory safety assessments typically rely on laboratory tests with a few species, missing real-world complexities of ecosystems.

The Current Study

In this study, an international team of researchers conducted a large-scale meta-analysis, integrating data from 1,705 experimental studies from all over the globe. These studies assessed the effects of insecticides, herbicides, and fungicides on non-target organisms, including animals, plants, and microorganisms.

A total of 20,212 effect sizes were extracted, representing responses from 830 species and additional species groups. The data were collected from both laboratory and field experiments spanning tropical and temperate regions, as well as terrestrial and aquatic systems.

The studies evaluated four main biological responses — growth, reproduction, behavior (animals only), and biomarkers representing metabolic or physiological changes. The pesticide exposure levels in these studies included both typical agricultural application rates and environmentally relevant concentrations found in water bodies.

Additionally, the meta-analysis applied statistical models accounting for the evolutionary relationships of species to ensure robust comparisons. It also distinguished between older pesticides and newer formulations authorized under strict European Union regulations.

The researchers examined the effects of pesticides on various taxa, including invertebrates, vertebrates, seed plants, spore-producing plants, bacteria, and fungi.

They also analyzed differences based on pesticide type (insecticides, herbicides, fungicides), experimental setting (laboratory vs. field), and climatic zones (temperate vs. tropical).

Major Findings

The study revealed that pesticides negatively affected the growth, reproduction, and behavior of various non-target organisms across plants, animals, and microorganisms.

These impacts were consistent in both aquatic and terrestrial environments and persisted even when pesticide exposure was limited to real-world concentrations.

In animals, pesticides reduced growth, impaired reproduction, and altered behavior. Insecticides were especially harmful, affecting animal nervous systems and reducing longevity and fertility. Fungicides and herbicides also interfered with animal reproduction and behavior.

Additionally, pesticides disrupted metabolic biomarkers, indicating stress and damage at the cellular level.

Plants exposed to pesticides experienced reduced growth and lower reproductive success. Herbicides, as expected, had the strongest negative effect, but insecticides and fungicides also impaired plant health. Photosynthesis, respiration, and cellular processes were the processes that were commonly disrupted.

Microorganisms, which are vital for soil health and nutrient cycling, were similarly harmed. The study found that pesticides suppress microbial growth and reproduction while altering metabolic processes. Fungicides were particularly damaging to fungi, reducing spore production and root colonization.

The analysis showed that pesticide effects were stronger in temperate regions compared to tropical zones, likely due to differences in chemical breakdown rates and environmental conditions.

Laboratory experiments generally reported greater pesticide impacts than field studies, though both revealed significant harm. Surprisingly, newer pesticides showed no reduction in negative effects compared to older chemicals.

The study highlighted that regulatory risk assessments, often based on a limited set of test species, failed to capture the broad vulnerability of biodiversity. Notably, studies with declared industry funding were more likely to report neutral pesticide effects, raising concerns about bias.

The researchers presented some of the limitations of the study, including the potential underrepresentation of tropical data and the exclusion of non-English studies. Moreover, field conditions would encompass variables such as weather and soil that laboratory tests cannot replicate. Nonetheless, the study provided compelling evidence that pesticide use poses a widespread threat to non-target biodiversity.

Conclusions

In summary, the study reported that pesticides harm a wide range of non-target taxa across plants, animals, and microorganisms, impacting growth, reproduction, and biological processes. These effects were widespread across environments and persisted even with newer pesticide formulations.

The findings emphasized the need to reduce pesticide reliance and strengthen biodiversity risk assessments.

Additionally, sustainable farming practices and integrated pest management that offer pathways to protect both agricultural productivity and the health of ecosystems globally need to be promoted.