Pesticides increasingly threatening to biodiversity

Is the world really reducing the chemical threat to nature? The results of the study, published in the journal Science, show that reality does not match declarations. Despite the adoption of the UN’s global goal to reduce pesticide risks by 50 percent by 2030, the total toxicity of pesticides used in most regions of the world has been increasing in recent years.

Researchers from the University of Kaiserslautern-Landau in Germany analyzed data from 201 countries, covering 511 active substances and 8 key groups of organisms – from invertebrates and aquatic plants, to fish, to pollinators and soil organisms. The conclusions are clear: chemical pressure on biodiversity is intensifying, and aquatic organisms and invertebrates, which are the foundation for the functioning of entire ecosystems, are particularly vulnerable.

Rising pesticide toxicity vs. UN global goal

In 2022. The United Nations Global Biodiversity Framework has adopted a goal of reducing pesticide risks by 50 percent. By 2030. relative to the 2010-2020 level. The problem, however, was the lack of an indicator to measure both the starting point and the progress of change. In 2025. Optionally, the aggregate total applied toxicity (ATAT) index was adopted, based on the concept of total applied toxicity (TAT).

TAT is an indicator used to assess the actual environmental burden of pesticides. It does not measure the amount of pesticides used per se, but combines the amount of active substances used with their toxicity to non-target organisms (such as pollinators, aquatic organisms or birds).

The study was carried out on data from 2013-2019, and 15,041 threshold toxicity levels (RTLs) from 7 regulatory regimes (including the EU, US, Japan, China) were used for calculations. The amount of pesticides applied was evaluated in terms of their toxicity to specific groups of organisms. What did it turn out to be?

Six of eight groups of organisms under increasing pressure

Between 2013 and 2019, global weighted toxicity (nTAT), or pesticide harm per unit area, increased in 6 of the 8 groups of organisms analyzed. The largest increase was in terrestrial arthropods, up 6.4 percent per year, followed by soil organisms (4.6 percent per year) and fish (4.4 percent per year). There was an increase of 2.9 percent per year for aquatic invertebrates, and 2.3 percent for pollinators. Toxicity declined only for aquatic plants (by -1.7 percent) and terrestrial vertebrates (by -0.5 percent).

The authors found the trends observed in aquatic organisms – fish and invertebrates – crucial to the functioning of trophic networks, water quality and fish production to be particularly worrisome. Increasing toxicity to these groups means a growing risk of disruption to entire freshwater ecosystems.

Agricultural intensification and toxicity hotspots

The highest values of toxic effects of pesticides on plants and animals were recorded in regions of intensive agriculture: in North and South America, Western Europe, South Asia and East Asia. In terms of time, the maximum nTAT increased globally during the 2013-2019 period, and this increase was observed in 54-80 percent of the spatial units analyzed.

Particularly rapid rates of nTAT growth have been recorded in sub-Saharan Africa, Central Asia, parts of the Indian subcontinent and southern Australia. Although levels of pesticide toxicity there are sometimes lower than in Europe or the Americas, the dynamics of its growth indicate the risk of perpetuating negative trends with the development of industrialized agriculture.

A few substances account for most of the risk

Pesticides do not act uniformly. In many countries, an average of 20.3 ± 14.3 substances (out of 511 analyzed) account for more than 90 percent of the national TAT. The toxicity of tested compounds varies by more than seven orders of magnitude even within the same chemical class.

Aquatic organisms are particularly negatively affected by pyrethroids and organophosphate insecticides – responsible for more than 80 percent of the TAT of aquatic invertebrates and fish. For pollinators, more than 80 percent of TAT was generated by neonicotinoids, organophosphorus compounds and lactones. Aquatic plants were heavily affected by acetamide and bipyridyl herbicides.

The analysis shows that assessing only the weight of the agents used is misleading – small amounts of highly toxic substances can generate disproportionately high risks to aquatic and terrestrial organisms.

Countries and crops – where is the pressure greatest?

The highest nTAT intensity (per unit area) was recorded in Brazil, China, Argentina, the US and Ukraine. India – despite having the largest acreage under cultivation – is characterized by moderate intensity, due to its dispersion over a large area.

Among crops, potatoes (including mancozeb, paraquat), sugarcane (λ-cyhalothrin, diuron), cotton (acetochlor, imidacloprid), soybeans and corn (glyphosate, chlorpyrifos) showed the highest nTAT intensity. Cereals (excluding corn and rice), fruits and vegetables had relatively lower toxicity intensity, although they sometimes receive multiple insecticide treatments.

Of the 65 countries providing 79.4 percent of the world’s cropland, only one – Chile – is moving toward the goal of a 50 percent reduction by 2030. China, Japan and Venezuela are recording declines, but still not enough. Unfortunately, in many countries at least one indicator has doubled in 15 years.

However, rapid change is possible – in the US, significant shifts in trends for aquatic plants, aquatic invertebrates and pollinators were observed in just 3 years. The huge potential is also evidenced by the example of France, where, according to the researchers, neonicotinoids could be replaced by non-chemical methods in 78 percent of the cases analyzed.

Pesticides continue to threaten aquatic ecosystems and global biodiversity

The study shows unequivocally: between 2013 and 2019, the global toxicity of pesticides used has been increasing, covering most groups of organisms – including key aquatic organisms. The increase is a clear indication of inadequate implementation of UN goals and increasing pressure on freshwater ecosystems.

While there are examples of effective measures (such as China’s zero growth pesticide policy or Denmark’s pesticide tax, introduced in 2013), without a broad transformation of agricultural systems – reducing the most toxic substances and developing non-chemical alternatives – achieving the goal of a 50 percent reduction by 2030 seems unlikely.

Reducing pesticide use will require broad systemic changes – from transforming crop patterns and reducing food waste to dietary changes and developing organic or pesticide-free agriculture. The transition to such systems could mean a decrease in yields by as much as 19-25 percent (depending on the crop and bioclimatic conditions), but will promote an increase in biodiversity and improvements in soil and water quality.

---

Source:

Jakob Wolfram et al, Increasing applied pesticide toxicity trends counteract the global reduction target to safeguard biodiversity.Science 391,616-621(2026).DOI:10.1126/science.aea8602