The biotechnology industry has been using CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) gene-editing technology to manipulate the genetic material of organisms and crops, resulting in altered taste profiles, extended shelf life, and increased resistance to certain pathogens, but the health consequences are unknown.1
So far, such genetic modifications have been carried out within the confines of controlled laboratory environments. But a disturbing new development is on the horizon: a new pesticide designed to edit genes could soon be on the market, and it is being touted as being “greener” than chemical pesticides.2
A team of scientists recently expressed concern about the potential consequences of releasing this product into the open, where it could affect not only the intended target but also a wide range of non-target organisms, causing widespread ecological damage. And leading the list of potential collateral damage are we humans.3
How does CRISPR gene editing work?
The principle of CRISPR gene editing technology, which is called a revolutionary tool in biotechnology, comes from nature itself. At its core, CRISPR is a defense mechanism found in bacteria and archaea, which helps protect these microorganisms from viral pathogens. Scientists have adapted it for use in other organisms and turned it into a gene editing tool.4
The CRISPR system relies on two main components: the Cas9 protein and a guide RNA (gRNA). The Cas9 protein acts like a pair of molecular scissors that can cut DNA at specific locations, while the gRNA is designed to match and bind to a specific DNA sequence, guiding the Cas9 protein to the exact location where the cut is needed.5
When the Cas9 protein reaches the target site, a double-stranded break occurs in the DNA. The cell’s natural repair mechanisms then kick in to repair the break. This repair process can be used to perform edits, such as introducing new genetic material, inserting new genes, deleting existing genes, or modifying genes to achieve desired traits or correct genetic defects. However, several studies have shown that this technology carries a number of potential risks.6
Recent study reveals unintended side effects of CRISPR-edited pesticides
A group of scientists who have raised alarms about gene-edited pesticides have published their findings in the journal Ecotoxicology and Environmental Safety.7 They combined computational tools and in silico modeling to simulate the potential impacts of CRISPR-edited pesticides on a variety of non-target organisms (NTOs).
“CRISPR/Cas9 is a powerful genetic engineering tool that has been widely adopted in agriculture, allowing the introduction of novel traits into plants at large scale and without the need for conventional breeding methods… Our goal was to evaluate the potential activity of organisms that could be exposed to genome editing in an uncontrolled environment.” The author wrote:
They started by simulating three plausible scenarios for the application of these pesticides: irrigation, pesticides, and fertilizers. To identify potential unintended consequences, they focused on gRNAs designed to target specific genes in pests. They also investigated whether they could interact with unintended genes in nontarget species.
The study included 18 species commonly found in agricultural settings, including crops such as corn and soybeans, livestock such as cattle and chickens, pollinators such as bees, and soil organisms such as earthworms and fungi. They also identified three pests that could potentially be targets for these new pesticides: the western corn rootworm, the red flour beetle, and the fungus Sclerotinia sclerotium. According to their findings:8
“It is not important whether NTOs are desirable or not. The consequences of modifying NTOs are unpredictable, as many unintended modifications occur. Of the 18 NTOs investigated in this study, gRNA activity was observed in 12.
These hybridization sites revealed genes that function in a variety of annotated metabolic pathways, ranging from central nervous system morphogenesis in honeybees to several pathways involved in human cancer and hormone metabolism. In total, 155 metabolic pathways were enriched for 12 different gRNA scenarios, with most hits occurring in the human genome.”
Unknown consequences may affect the environment and human health.
In short, the researchers found that the gRNA of the gene-editing pesticide affected 12 of the 18 NTOs, causing unintended genetic changes that could potentially cause unpredictable health effects. These off-target effects were observed in human genes involved in metabolic processes, including cancer and hormone regulation. A total of 155 metabolic pathways were disrupted in these 12 species, with the majority of these effects occurring in human genes.9
Beyond the potential risks to human health, the authors warn that even small changes in the behavior of key ecosystem species caused by gene-edited pesticides could have major ramifications for the environment.
For example, earthworms play an important role in pastures by helping to cycle nutrients, improve soil structure, and regulate water. Even a small decrease in earthworm activity due to repeated exposure to gene-editing chemicals could have a significant impact on soil health and, consequently, on land productivity.
The authors argue that these technologies should be considered potential emerging environmental contaminants given their potential to affect a wide range of organisms when released into the environment. They also call for a more comprehensive risk assessment of gene editing technologies used outside of isolated, controlled laboratory settings.10
Unexpected effects in CRISPR-edited organisms are not new
Genetically engineered (GE) crops have often shown unexpected toxic or allergenic properties that are not present in conventional crops. The reality is that researchers have limited understanding of the potential side effects that DNA modification can cause, because the results can be highly unpredictable.
Even CRISPR, despite being touted as more precise than other genetic engineering techniques, causes off-target effects, as shown in the featured study, published in The CRISPR Journal11 Supporting these concerns, it has been shown that when CRISPR tools cause double-stranded breaks in DNA at the target site, a variety of genetic outcomes can occur, including small insertions or deletions of DNA bases and large-scale rearrangements of the genome.
CRISPR technology has also been explored to modify T cells in adaptive T lymphocyte therapy. However, according to a study published in Nucleic Acids Research12 Although they aim to target specific genes, they note that they inadvertently cause structural variations (SVs) in the genome, including chromosomal translocations, in which parts of a chromosome are rearranged, and large deletions. The authors conclude:
“Our findings raise concerns about the safety of CRISPR/Cas9-edited T cell-mediated immunotherapy. Persistent SVs could be problematic for CRISPR/Cas9-edited TCR (T cell receptor) T cells or similar CAR (chimeric antigen receptor) T cells, as cells containing these SVs could acquire further mutations during further clonal expansion.”13
Moreover, researchers at Boston Children’s Hospital found that using CRISPR in human cell lines can cause significant DNA rearrangements that may increase cancer risk. These disruptions were observed in up to 6% of cases.14
In a previous article, I also discussed the implications of CRISPR-edited salad greens.15 insect16 Even babies.17 I encourage you to delve deeper into this topic and understand the serious and dangerous consequences this technology has for our environment and future.
What does the future hold for gene-edited pesticides?
As if conventional pesticides weren’t already a major problem for human health and the environment, we may soon be faced with the challenges posed by gene-edited pesticides. While the technology promises benefits such as reduced environmental impact, the reality presented in the featured study is far more worrying.
We may be looking at a future in which the genetic makeup of our ecosystems, from soil microbes and pollinators to crops, livestock, and humans, can be inadvertently altered. The rapid advances in this technology are outpacing our understanding of the long-term impacts, essentially turning our environment and food supply into a vast, uncontrolled experiment.
The future of agriculture does not have to be a choice between harmful chemical pesticides and unpredictable gene editing technologies. Instead, we must invest in truly sustainable and regenerative agricultural practices that work with nature, not against it.
Regenerative agriculture focuses on soil health and biodiversity, eliminating the use of pesticides. Using techniques such as crop rotation and integrated pest management, it creates a balanced ecosystem where natural predators naturally control pests. Incorporating animals into the system further enhances this approach.
Grazing animals not only control weeds and pests by consuming them, but also enrich the soil with manure. This in turn creates healthy soil, producing stronger, pest-resistant plants, eliminating the need for chemical intervention and naturally improving crop yields and quality.
